Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download CHEMICAL COMPOSITION OF SOME LESSER
Document related concepts
Transcript
i CHEMICAL COMPOSITION OF SOME LESSER-KNOWN WILD FRUITS AND VEGETABLES CONSUMED IN AYAMELUM LOCAL GOVERNMENT AREA OF ANAMBRA STATE BY ONUEKWE MONICA EKWUTOSI REG. NO: PG/M.Sc /03/34109 DEPARTMENT OF HOME SCIENCE, NUTRITION AND DIETETICS FACULTY OF AGRICULTURE, UNIVERSITY OF NIGERIA, NSUKKA. MARCH, 2012 i APPROVAL PAGE THIS PROJECT REPORT HAD BEEN APPROVED FOR THE DEGREE OF MASTERS OF SCIENCE IN HUMAN NUTRITION OF THE UNIVERSITY OF NIGERIA, NSUKKA BY __________________________ Professor N.M. Nnam Supervisor ________________________ Date _________________________ Professor N.M. Nnam Head of Department ________________________ Date __________________________ External Examiner _______________________ Date ii CERTIFICATION Onuekwe Monica Ekwutosi a post graduate student of Home Science, Nutrition and Dietetics, Faculty of Agriculture, University of Nigeria, Nsukka, with registration number PG/M.Sc/03/34109 has satisfactorily completed the project report for the award of Master of Science (M.Sc) degree in Human Nutrition. The work embodied in this project is original and has not been submitted in part or in full to any other institution in part or in full to a degree or diploma. ___________________________ Professor N. M. Nnam (Supervisor) ___________________________ Professor N. M. Nnam (Head of Department) Date_______________________ Date_______________________ iii DEDICATION This work is dedicated to my husband and children and to God to whom alone belong all praise and glory. iv ACKNOWLEDGEMENTS The researcher wishes to acknowledge with humility and profound gratitude of her supervisor, Professor N. M. Nnam for her invaluable guidance, patience, useful criticism, encouragement for the success and completion of this research. Her thanks and gratitude also go to all the lecturers in the Department of Home Science, Nutrition and Dietetics, especially Prof. (Mrs.) E. C Okeke, Prof. Obizoba and Miss Udenta E. A. for their encouragement and concern in her research. Her appreciation also goes to her lovely husband Mr. Ignatius Onuekwe, her brother, Mr. Paul Nwunonye and her sister and her husband Mr. and Mrs. Obodoeze for their unending love, moral. Spiritual, and financial support without which her education and stay in the University of Nigeria and the pursuit of her dream would have been impossible. Her appreciation also goes to her brother-in-laws, Mr. Stephen Onuekwe and Benchuks Onuekwe, they have been a source of encouragement. She also wishes to appreciate the wonderful encouragement of her friends Mrs. E. N. Chukwuemeka and Mrs. B. N. Obi-Agunwa. You are the best anyone can have. Above all she gives thanks to Almighty God for giving her life, strength, grace, mercy to pursue her education. v ABSTRACT The study identified some edible fresh wild green leafy vegetables and fruits and determined their nutrients, antinutrients and food toxicants content. The proximate, micronutrients, antinutrients and food toxicants contents of these fruits (Olax viridis (“Osenga”), Gongronema species (“Aado”), Ficus carpensis (“Akankolo”), Napoleona/imperialis (“Ukpodikili”), Afromonum species) (“Okwocha”) and vegetables Vitex doniana (“Uchkulu”) and Ficus carpensis) were determined using standard methods. The moisture content of the fruits ranged from 59.83 to 75.40% in Olax viridis (“Osenga”) and Gongronema species, (“Aado”) respectively. Olax viridis (“Osenga”) fruits had high levels of protein (6.52%),ash (12.52%),and fibre (13.58%).Fiscus crapensis (“Akankolo”) fruit contained appreciable quantities of ascorbate (36.mg).Gongronema species fruit is rich in iron (23.50mg), phosphorus (44.66mg), copper (14.06mg) and zinc(12.43mg). The fruits equally contained high levels of phytate (12.60-108mg) in Gongronema species (“Aado”) and Olax viridis (“Osenga”). Afromonum species (“Okwocha”) had high oxalate (127.22mg). Tannins and saponins levels of the fruits were low (0.05-0.12mg and 0.02-0.30mg), respectively. Ficus carpensis (“Akankolo”) leaf had high moisture (60.44%) and low protein (2.18%), fat (3.42%), ash (10.5%),fibre(8.91%) .Vitex doniana (“Uchakulu”) had less than 50% carbohydrate (35.74%) and high fibre(11.45%). Vitex doniana (“Uchakulu”) leaf contained appreciable amounts of β-carotene (67.83mg), and Fiscus carpensis (“Akankolo”) leaf had lower B-carotene (27.94mg) relative to that of Vitex doniana (“uchakulu”) .07.83mg. The ascorbate level (67.83mg) was high in Vitex doniana. Vitex doniana leaf had appreciable quantities of phosphorus (28.63mg) and high oxalate level (128.56mg). Saponins (0.02mg) and tannins (0.12mg) were low in the two vegetables. The edible lesser-known wild fruits and vegetables can contribute much more nutrients especially micro nutrients to the diet of families in Ayamelum Local Government Area of Anambra State. The antinutrients phytate, oxalate, tannin and saponin levels of the fruits and vegetables were at safe levels. Increased consumption of these foods is advocated. vi TABLE OF CONTENTS Title page -- -- -- -- -- -- -- -- -- -- i Approval page -- -- -- -- -- -- -- -- -- -- ii Certification -- -- -- -- -- -- -- -- -- -- iii Dedication -- -- -- -- -- -- -- -- -- iv Acknowledgement -- -- -- -- -- -- -- -- -- v ABSTRACT -- -- -- -- -- -- -- -- -- -- vi Table of contents -- -- -- -- -- -- -- -- -- vii List of Tables -- -- -- -- -- -- -- -- -- -- xi -- -- -- -- -- -- -- -- --1 1.1 Background of the study -- -- -- -- -- -- -- -- 1 1.2 Statement of the problem -- -- -- -- -- -- -- -- 2 1.3 Objectives of the study -- -- -- -- -- -- -- -- 3 1.4 Significance of the study -- -- -- -- -- -- -- -- 3 2.0 LITERATURE REVIEW -- -- -- -- -- -- -- -- --4 2.1 Micronutrients -- -- -- -- -- -- -- 4 2.2 Importance of fruits and vegetables in diet -- -- -- -- -- 5 2.3 Mineralizing effect -- -- -- -- -- -- -- -- 7 2.4 Laxative effect -- -- -- -- -- -- -- -- -- 7 2.5 Vegetables -- -- -- -- -- -- -- -- -- -- 8 2.5.1 Leaves of the annuals and shrubs -- -- -- -- -- -- 9 2.5.2 Leaves of trees -- -- -- -- -- -- -- -- -- 9 2.6 Green leafy vegetables -- -- -- -- -- -- -- -- 9 2.7 Nutrient composition of green leafy vegetables -- -- -- -- -- 10 2.8 Composition and nutritional quality of vegetables -- -- -- -- 10 2.8.1 Carbohydrate -- -- -- -- -- -- -- -- -- 11 2.8.2 Moisture -- -- -- -- -- -- -- -- -- -- 11 2.8.3 Energy -- -- -- -- -- -- -- -- -- -- 11 2.8.4 Protein -- -- -- -- -- -- -- -- -- -- 11 2.8.5 Ether extract -- -- -- -- -- -- -- -- -- 12 2.8.6 Mineral composition -- -- -- -- -- -- -- -- 12 2.9 Vitamins in vegetables -- -- -- -- -- -- -- -- 12 -- CHAPTER ONE 1.0 INTRODUCTION CHAPTER ONE -- -- vii 2.10 Antinutrient content of green leafy vegetable -- -- -- -- -- 13 2.10.1 Phytate -- -- -- -- -- -- -- -- -- -- 13 2.10.2 Oxalate -- -- -- -- -- -- -- -- -- -- 13 2.10.3 Tannins -- -- -- -- -- - -- -- -- -- 14 2.10.4 Saponins -- -- -- -- -- -- -- -- -- 14 2.11 Some commonly consumed vegetables in Nigeria -- -- -- -- 15 2.11.1 Fluted pumpkin: (Telferia occidentails) -- -- -- -- -- 15 2.11.2 Water leave -- -- -- -- -- -- -- -- -- 15 2.12 Fruits -- -- -- -- -- -- -- -- -- 17 2.13 Nutrient composition of fruits -- -- -- -- -- -- -- 17 2.13.1 Protein -- -- -- -- -- -- -- -- -- -- 18 2.13.2 Moisture -- -- -- -- -- - -- -- -- 18 2.13.3 Fats -- -- -- -- -- -- -- -- -- -- 18 2.13.4 Fibre -- -- -- -- -- -- -- -- -- -- 18 -- -- -- -- -- -- -- - -- 18 2.14 Vitamins in fruits -- -- -- -- -- -- -- -- 18 2.15 Commonly used fruits -- -- -- -- -- -- -- -- 19 2.15.1 Guava -- -- -- -- -- -- -- -- -- -- 19 2.15.2 Pineapple -- -- -- -- -- -- -- -- -- 21 2.15.3 Mangoes -- -- -- -- -- -- -- -- -- 25 2.15.4 Pawpaw -- -- -- -- -- -- -- -- -- 28 2.15.5 Orange -- -- -- -- -- -- -- -- -- -- 28 2.15.6 Avocado -- -- -- -- -- -- -- -- -- 30 2.15.7 Apple -- -- -- -- -- -- -- -- -- -- 33 2.15.8 Banana -- -- -- -- -- -- -- -- -- -- 34 3.1 MATERIALS AND METHODS-- -- -- -- -- -- -- -39 3.2 Pilot Study-- -- -- -- -- -- -- -- 39 3.2.1 Identification of samples -- -- -- -- -- -- -- 39 3.2.2 Preparation of materials -- -- -- -- -- -- -- 45 3.3 -- -- -- -- -- -- - -- 45 -- 2.13.5 Minerals CHAPTER THREE -- Chemical analysis -- 3.3.1 Fat determination -- -- -- -- -- -- -- -- 45 3.3.2 Moisture determination -- -- -- -- -- -- -- 46 -- -- -- - -- -- -- 46 3.3.3 Ash determination -- viii 3.4 Crude fibre determination -- -- -- -- -- -- -- 47 -- -- -- -- -- -- -- 47 3.5 Crude protein determination -- -- -- -- -- -- -- 47 3.5.1 3.4.1 Method -- -- -- Digestion -- -- -- -- -- -- -- -- -- 48 3.5.2 Distillation -- -- -- -- -- -- -- -- -- 48 3.5.3 Titration -- -- -- -- -- -- -- -- -- 48 -- -- -- -- -- - -- 48 -- 49 3.6 Carbohydrate determination 3.7 Determination of iodine, iron, copper, calcium and zinc, phosphorus -- 3.8 Pro-vitamin A (RE) determination -- -- -- -- -- -- 49 3.8.1 Principle -- -- -- -- -- -- -- -- -- 49 3.8.2 -- -- -- -- -- -- -- -- -- 50 -- -- -- -- -- -- -- -- -- 50 -- -- -- -- -- -- -- 50 3.10 Determination of antinutrients -- -- -- -- -- -- -- 51 3.10.1 Method 3.8.3 Calculation 3.9 Ascorbic acid determination Phytate -- -- -- -- -- -- -- -- -- 51 3.10.2 Tannins -- -- -- -- -- -- -- -- -- 51 3.10.3 Saponins -- -- -- -- -- -- -- -- -- 51 3.10.4 Oxalate determination -- -- -- -- -- -- -- 51 3.11 Statistical analysis -- -- -- -- -- -- -- 52 -- -- -- -- -- -- -- 53 4.1 Proximate composition of fresh wild fruits -- - -- -- -- 53 4.2 Vitamin composition of fresh wild fruits -- -- -- -- -- -- 54 4.3 Mineral composition of wild fruits -- -- -- -- -- 54 -- -- -- -- -- 55 -- -- -- -- -- -- 59 5.1 Proximate composition of wild fresh fruits -- -- -- -- -- 59 5.2 Vitamin composition of wild fresh fruits -- -- -- -- -- -- 60 5.3 Mineral composition of wild fresh fruits -- -- -- -- -- -- 61 5.4 Ant nutrient composition of wild fresh fruits -- -- -- -- -- 62 5.5 Vitamin composition of lesser-known fresh wild green leafy vegetables -- 64 5.6 Mineral composition of fresh wild green leafy vegetables CHAPTER FOUR 4.0 RESULTS -- -- -- -- 4.4 Antinutrient composition of fresh wild fruits CHAPTER FIVE 5.0 DISCUSSION-- -- -- -- -- -- -- 64 5.7 Antinutrient composition of fresh wild green leafy vegetables -- -- -- 65 ix Conclusion -- Recommendations REFERENCES -- -- -- -- -- -- -- -- -- 65 -- -- -- -- -- -- -- -- -- 65 x LIST OF TABLES Table 1: Some wild fruits and indentified for use in Ayamelum local government area Table 2: Nutrients composition of commonly used fresh green vegetables in Nigeria, (per 100g) -- -- -- -- -- -- -- -- -- -- -- 16 Table 2: 2: vitamin composition of commonly used green leafy vegetables (mg/100g) 17 Table 3: Proximate composition of guava, raw: Psidium guajava -- -- -- 20 Table 4: Mineral composition of guava -- -- -- -- -- -- 21 Table 5: Vitamin composition of guava -- -- -- -- -- -- 21 Table 6: Nutrients composition of pineapple, raw: Ananus comosus -- -- -- 23 Table 7: Mineral content of pineapple -- -- -- -- -- -- -- 24 Table 8: Vitamin content of pineapple -- -- -- -- -- -- 25 Table 9: Proximate composition of mangoes, raw Mangifera idica -- -- -- 26 Table 10: Mineral composition of mangoes -- -- -- -- -- -- 27 Table 13: Vitamin content of mangoes -- -- -- -- -- 27 Table 14: Proximate composition of orange, raw, Citrus sinersis -- -- -- 29 Table 15: Mineral content of orange -- -- -- -- -- -- -- 30 Table 16: vitamin content of orange -- -- -- -- -- -- -- 30 Table 17: Avocado, raw, Persea american -- -- -- -- -- -- 31 Table 18: Mineral content of avocadoes -- -- -- -- -- -- 32 Table 19: Vitamin content of avocados -- -- -- -- -- -- 33 Table 20: Proximate composition of banana, raw: Musa paradisiacal -- -- 34 Table 21: Mineral content of banana -- -- -- -- -- -- -- 35 Table 22: Vitamin content of banana -- -- -- -- -- -- -- 35 -- -- -- 36 -- -- -- 36 Table 25: vitamin composition of commonly used fruits in Nigeria (mg/100g) -- 37 Table 26: Proximate composition of commonly used fruits in Nigeria (%) -- -- 37 Table 27: Mineral composition of commonly used fruits in Nigeria (mg/100g) -- 38 -- Table 23: Proximate content of pears, raw; Pyrus communis Table 24: Mineral content of peers -- -- -- -- Table 1: Some wild fruits and vegetables in Ayamelum local government area identified for use. -- -- -- -- -- -- -- -- -- -- 39 -- -- -- -- 53 Table 2: Vitamin composition of fresh wild fruits (mg /100g) -- -- -- 54 Table 3: Mineral composition of wild fruits (mg/100g) -- -- -- 55 Table 4: Antinutrient composition of fresh wild fruits (mg/100mg) -- -- -- 56 Table 1: Proximate composition of fresh wild fruits (%) -- xi Table 5: Proximate composition of fresh wild green leafy vegetables -- -- 56 Table 6: Vitamin composition of fresh wild green leafy vegetables (mg/100g) -- 57 Table 7: Mineral composition of fresh wild green leafy vegetables (mg/100g) -- 57 Table 8 Antinutrient composition of fresh wild green leafy vegetables (mg/100g) -- 58 1 CHAPTER ONE 1.0 INTRODUCTION 1.1 Background of the study Micronutrient deficiency is still a public health problem in Nigeria despite the effort that has been made to eliminate it. World Health Organization (WHO) (2002) reported that about 30% of the population in developing countries suffer currently from one or more of the multiple forms of nutritional deficiencies, especially that of micronutrient. Nnanyelugo (1983) stated that incidence of malnutrition is higher in the rural areas than urban slums, particularly protein and micronutrient deficiencies. Onyezili et al., (2005) observed that in most developing countries three micronutrient deficiencies are common. These are vitamin A deficiency (VAD); iron deficiency anemia (IDA) and iodine deficiency disease (IDD). Nnanyelugo (1983) observed that deficiency diseases were caused partly because of the food gap seasonality in which people experience food abundance, especially vegetables during the rainy season and severe scarcity during the dry season. Fruits and vegetables provide people with a range of compounds, many of which have more than one role, being involved both with immediate good health and with protection against disease that can develop over a long period of time, such as cancer, heart conditions, stroke, hypertention, birth defects, cataracts and diabetes.(Tenny and Barrett, 1997). Fruits and vegetables are generally acceptable as good sources of nutrient and supplement for food in a world faced with scarcity .They are known to be excellent source of nutrients such as minerals and vitamins (Nhar et al., 1990) The high incidence of malnutrition, especially in children has been seen as the core cause of major forms of anemia in children and pregnant /nursing mothers (that is nutritional deficiency and haemolytic anemia) (Trumb and Yates, 2001). Pamploma-Rogres (2004) stated that fruits and vegetables have been linked to the management of anemia because of 2 they are rich in vitamins and minerals. Some of these vitamins are not directly involved in red blood cell production but they promote the absorption of other important minerals, example ascorbic acid promotes the absorption of iron from the small intestine. In Anambra State, most staple foods are consumed without vegetables especially during the dry season. There are many wild vegetables and fruits wasting in forest. Uzo (1989) reported that such vegetables as Geotum Africana (“Okazi”), Pterocarpas milbreadi (“ora”), Pterocarp sp (“Uturukpa”) grow wild. There are many fruits and tender leaves of the wild vegetables that are readily available in the forest and farmlands during the dry season. They could be utilized to provide protein and micronutrient needs of the populace. In Ayamelum local government area of Anambra State, many leafy vegetables and fruits are grown wildly and there has been little or no work on their nutrient composition. Documentation of the nutrient potentials of these wild fresh fruits and vegetables would be valuable in the food-based approach to eliminating micronutrient deficiencies. 1.2 Statement of the problem There are many wild fruits and vegetables in Ayamelum local government area of Anambra State which were popular in the past but are no longer popular in the present time. The fruits and vegetables are not owned by a particular individual, they could be collected freely and consumed by the populace to increase nutrient intake. Some of the wild vegetables are available during dry season when many domestic fruits and vegetables are scare and very expensive. Thus, they could fill the gap experienced in vegetable consumption in rural community during dry season. Despite the abundance of these fruits and vegetables, there is still problem of micronutrient deficiency in Nigeria. There is need to identify and evaluate the nutrient, antinutrients and food toxicant levels of some of the wild vegetables and fruits. The fruits and vegetables could be integrated in the food-based approach for fighting micronutrient deficiency in Nigeria. 3 1.3 Objectives of the study The general objective of the study is to determine the nutrient, antinutrients and toxicant levels of lesser-known wild fruits and vegetables consumed in Ayamelum local government area. The specific objectives were to, (i) identify some wild fruits and vegetables consumed in Ayamelum local government area; (ii) determine the proximate, minerals and vitamins levels of the wild fruits and vegetables identified; and. (iii) determine the antinutrients and food toxicant (phytate, oxalate, tannins and saponins) levels of the wild fruits and vegetables identified. 1.4 Significance of the study The study will directly benefit the inhabitants of Ayamelum local government. This is because fruits and vegetables to be identified and analyzed are already available in their locality. They could be sensitized to the availability of the fruits and vegetables for integration in their dietary plan. The study will provide base-line information on the nutrient and antinutrient composition of the wild fruits and vegetables found in Ayamelum local government area. The information will be of use to Dieticians, Nutritionists and Home Economic Extension Staff in their nutrition Education programme to popularize the fruits and vegetables. The study will assist help in the estimation of dietary requirement of the fruits and vegetables. The accurate information on the nutrient and antinutrients composition of these fruits and vegetables will also help to integrate them in the food based approach for fighting micronutrients deficiency. 4 CHAPTER TWO 2.0 LITERATURE REVIEW 2.1 Micronutrients Calcium: Calcium is one of most minerals found in the human body. The teeth and bones contain most of calcium (about 99%). Nerve cells, body tissues, blood and other body fluids contain the remaining calcium.(Hamrick and Count, 2002). Calcium helps in maintaining healthy bone and teeth. Proper levels of calcium over a lifetime can prevent osteoporosis. Calcium assists in blood clotting, nerve signaling, muscle contraction and relaxation, and the release of certain hormones. It is also needed for normal heart beat. Calcium is one of the minerals believed to be an important factor governing fruit storage quality (Lech et al., 2005). It has been reported to delay ripening senescence and reduce storage disorder in fruits (Fergusan, 1984). Institute of Medicine (IOM) (1997) reported the following to be daily dietary intake of calcium, 210mg-270mg for infants, 500mg-1,300mg for children, 1,300mg for male and female adolescents (14-18years), 1000mg for adults males and females 19 to 50 years. Phosphorus: Phosphorus is a mineral that makes up 1% of a person‟s total body weight, (IOM, 1997). It is present in every cell of the body but most of the phosphorus in the body is found in bone and teeth. Phosphorus is needed in the formation of bone and teeth. It plays a vital role in the body in the utilization of carbohydrates and fats and in the synthesis of protein or the growth, maintenance and repair of tissue. It is crucial for the production of ATP, a mode to store energy in the body. Phosphorus works with vitamin D, assists in the contraction of muscles, in the functioning of kidneys, in maintaining the regularity of the heat beat, and in nerve conduction (IOM, 1997).They reported the recommended dietary intakes of phosphorus to be 700mg/day for adults, 1,250mg per day for pregnant and lactating women who are younger than 18 years, 5 500mg per day for children who are between four to five years, 275mg per day for children who are 7 to 12 months, 100mg per day for children birth to 6 months old. Iron: Iron is an essential nutrient. Iron occurs in two forms in foods, heme („organic‟) and non-heme („inorganic‟).The body require iron for the oxygen synthesis, transport of proteins heamoglobin and myoglobin, and other iron containing enzymes which participate in electron transfer oxidation –reduction reactions (IOM, 2000).They recommended the following daily dietary intake of iron, 10mg for adults males, 18mg for adolescents 11years and above, 610mg for infants, 15mg for six months to three years old, Zinc: Zinc is needed for the body‟s defensive system (immune) to work properly. It plays a role in cell division, cell growth, wound healing and break down of carbohydrates. Zinc is also needed for senses of smell and taste (IOM, 2000). The following recommended daily dietary intake were given by (IOM, 200), 2mg for infants 0-6 months, 3mg for infants 7-12 months, 3mg for children 1-3 years, 5mg for children 4-8 years, 8mg for children 9- 13 years, 11mg for male adolescents and adults 14 years and over, 9mg for female adolescents and adults 14- 18 years, 8mg for female adolescents and adults 19 years and over. Iodine: Iodine is a trace mineral and an essential nutrient found naturally in the body. Iodine is needed for normal metabolism of cells. Human needs iodine for production of thyroid hormones. Vitamin A: Vitamin A occur in forms. The first is retinol, vitamin A from animal sources, another one is carotenes, a yellow pigment found in fruits and vegetables (Leslie and Lendal, 1989). They stated that carotene is not absorbed or utilized as efficiently as retinol, but it is an important source. Vitamin A is essential for maintaining healthy eyes and preventing nightblidness. Vitamin A is involved in bone and teeth development. Vitamin A keeps the 6 tissue linings of the respiratory, digestive and urogenital tracts healthy. Vitamin A is also necessary for healthy skin. 2.2 Importance of fruits and vegetables in diet Fruits and vegetables are highly beneficial in human diet. The main physiological action of fruits and vegetables are as follows: (i)Hydrating effect Fruits and fruit juice, vegetables and vegetable juice are the most pleasant way of hydrating the organism (Getahum, 1994). The water absorbed by sick person in this manner has added advantage of supplying sugar and minerals at the same time. (ii)Diuretic effect Clinical observations have showed that potassium, magnesium and sodium contents of fruits and vegetables act as diuretic. The diuretic frequency of the urination is considerably increased when fruits and vegetable juice are taken (MacGee and Harold, 2004). They lower the urine density and thereby accelerate the elimination of nitrogenous waste and chloride. The diuretic effect of vegetables like potatoes, beans, spinach, radish, turnip are specially important in cases of edema or swellings, kidney and heart conditions (Getahum, 1974). (iii)Alkalinizing effect The organic acids of the salts in fruits and vegetables provide alkaline carbonates when transformed within the organism, which alkalize the fluids. All the fruits and leafy vegetables promote intestinal elimination. This keep the body free from toxic wastes, which creep into blood system from an overloaded, sluggish intestinal tract. Fibre in vegetables act as mechanical intestinal expanders, draws more water and protein in them. Carbohydrates of vegetables are chiefly in the form of sugar, dextrin and acids, which are easily digestible and are completely absorbed. On account of this, they are very useful for sick and invalids for quick energy and heat. Fibres inform of cellulose help, elimination of cholesterol. Fibre 7 lowers serum cholesterol by reducing the absorption of dietary cholesterol. Fibre complex with bile acids, which are compounds manufactured by the liver from cholesterol that are necessary for the proper digestion of fat. After complexing with bile acids, the components are removed from circulation and do not make it back to the liver as a result the liver must use additional cholesterol to make new bile. Bile acids are necessary for normal digestion of fat, American Dietetic Association (ADA, 1997). 2.3 Mineralizing effect Fruit furnish minerals to the body. Some are rich in calcium and iron. These minerals are essentials for strong bone and teeth, respectively (Adam and Wiles, 2004). Two important minerals, calcium and iron, found in vegetables are specially useful, calcium is for strong bone and teeth, iron is needed for blood formation and an essential constituent of hemoglobin (Okigbo, 1990). 2.4 Laxative effect Cellulose, the fibrous matter in fruit and vegetables, aids in the smooth passage of food in the digestive tract and easy bowel action. The sugar and organic acids contained in fruits also increase their laxative effect. Hence, regular use of fruits and vegetables prevent and cure constipation (Jannic, 1990). He stated that certain types of fibre are referred to as fermentable because they are fermented by the “friendly” bacteria that live in the large intestine. The fermented dietary fibre in the large intestine produces a short-chain fatty acid called butyric acid which serves as the primary fuel for the cells in the large intestine and help in maintaining the health and integrity of the colon. Fibre that are not fermentable in the large intestine help maintain bowel regularity by increasing the bulk of the faeces and decreasing the transit time of faecal matter through the intestine. Bowel regularity is associated with a decreased risk for colon cancer and hemorrhoids when the hemorrhoids are related to screening and constipation. 8 Tonic action: Fruit and vegetables are dependable sources of vitamins, exert a tonic effect in the body (Farrell, 1999).Guava, apples and citrus fruits, like lemons and oranges, are particularly valuable sources of vitamin C. These fruits are usually eaten raw and fresh, thus making the vitamins fully available to the body. Several fruits contain good amounts of carotene which gets converted to vitamin A in the body. He further stated that a mediumsized mango can provide as much as 15,000 international units of vitamin A which is sufficient for full one week and this vitamin can be stored in the body, Common papaya is an excellent source of vitamin A and carotene. Fruit cure: Fruits are highly beneficial in maintaining acid-alkaline balance in the body. They neutralize the toxic condition of the body resulting from excessive intake of acidforming foods and restore its alkalinity (Farrell, 1999). They clear the system of morbid waste and cater to the body‟s requirement of natural sugar, vitamins and minerals. Vitamins, minerals, enzymes and trace elements contained in fresh fruits juices are extremely beneficial in normalizing all the body processes. They supply needed elements for the body‟s own healing activity and cell regeneration and speed up the recovery. 2.5 Vegetables Vegetables are edible parts of plants, which are usually cooked or salted prior to consumption. Vegetables are important protective food for the maintenance of health and prevention of diseases they contain valuable food nutrients which can be successfully utilized and repair the body (Enwere, 1998). There are different kinds of vegetables. They may be edible leafy vegetables for examples lettuce, stem vegetables (asparagus), root vegetables (carrot), flower vegetables (broccoli) and bulbs (garlic). There are botanical fruits such as cucumbers and pumpkins as well as legumes such as green, beans and fleshy immature seeds such as those of peas or beans. They may be cultivated or wild, may be trees, herbs, shrubs or 9 erect plants that cut across the plant kingdom. Certain fruits such as tomatoes and beans are used as vegetables (Enwere, 1998). 2.5.1 Leaves of the annual and shrubs Although accurate statistics on the production these leaves are unavailable, data from several food intake studies (Oguntona et al., 1989; Addo and Eka, 1982) indicate that leaves of annuals and shrubs constitute the bulk of green leafy vegetables consumed in Nigeria. In general, however, these are cultivated plants that grow fairly rapidly and are harvested within weeks of cultivation. 2.5.2 Leaves of trees If the statistics on production and utilization of leaves of annuals and shrubs are scarce, those on use of tree leaves as vegetables are much more scarce (Oguntona, 1998). This is because trees are generally considered important only as source of fruits rather than leaves for human consumption. Several communities in Nigeria utilize the leaves of many shrubs and trees. They constitute the group usually referred to as „„lesser- known‟‟ (Temple, 1998). 2.6 Green leafy vegetables Green leafy vegetables constitute an indispensible constituent of human diet in Africa, generally and West Africa in particular (Oguntona, 1986). Generally they are consumed as cooked complements of major staples like cassava, cocoyam, guinea corn, yam, maize, millet, rice, unripe plantain and banana. Indeed, most of the meals based on these staples are considered incomplete without a generous serving of cooked vegetables. The variety of green leafy vegetables utilized are as diverse as both the staples, they are used in Nigeria alone (Okoli et al., 1988). These range from leaves of annual and shrubs of the consumed within the localities. There are over sixty species of green leafy vegetables that are (Amaranthecea, Composite, Portulaceae and Solanacea) to leaves of trees. Many of 10 these leafy vegetables (eg Amaranth) are common in all parts of Nigeria. However, some are restricted to their natural distribution and mostly found in northern Nigeria. The seasonal variation affects the availability of these green leafy vegetables. These vegetables grow abundantly in rainy season when they are much more readily available than in the dry season. This is particularly true of the annual. Seasonal variation in production and availability naturally decide the quantities to be consumed by the local consumers. 2.7 Nutrient composition of green leafy vegetables Green leafy vegetables are good sources of micronutrients (Rajyalashms, 2001; FAO, 1997). There are a lot of green leafy vegetables in Nigeria ecosystem. These could provide adequate quantities of micronutrient in the diet. In spite of these, Nigerians still suffer from micronutrient deficiencies (OMNI and USAID, 1993; NDHS, 1990). Green leafy vegetables consumed in Nigeria have been the subject of many analytical studies, especially during the 1970‟s (Oke, 1967; Oke, 1968; Fafunso and Bassir, 1977; Ifon and Bassir, 1979). The nutrient composition of tropical green leafy vegetables and other groups of tropical foods are available, an excellent compilation (West et al., 1988) exists for food commonly consumed in East Africa, However, information on green leafy vegetables is not extensive. Oguntona (1998) reported that the wide variation in nutrient content of green leafy vegetables are due to (a) a problem of taxonomy or proper identification of samples, especially given the ever increasing range of strains and hybrids available, (b) variation in the nutrient and fertilizer status of the soil in which the crop is grown, sample preparation procedures prior to analysis cause considerable problem and (c) analytical procedures vary in techniques and quality (Oguntona, 1998). 2.8 Composition and nutritional quality of vegetables Vegetables contain non-volatile acids, organic acids, mineral salts, volatile sulphur compounds and tannin, which impart flavour in diets. The colours of vegetables depend on 11 the pigments they contain. Arthocyanin imparts purple and red to vegetables such as reddish and red cabbage Chlorophyll colours vegetables green, especially leafy ones, green beans and cucumber while carotenoids are responsible for the yellow colour of ripe tomatoes, carrots, sweet potatoes and maize (Uwaegbute, 1989). 2.8.1 Carbohydrate: The carbohydrates in vegetables consist mainly of indigestible fibrous materials such as cellulose, hemicelluloses and lignin. These are in addition to small quantities of sugars such as glucose, fructose and sucrose. However, the proportion of fibre in vegetables depends on stages of maturity. (Ifon and Bassir 1989 Uwegbute, 1989). Carbohydrates are the main component of fruits and vegetables and represent more than 90% of their dry matter. From an energy point, carbohydrate represents the most valuable of the food components. Daily adult intake should contain about 500g carbohydrate (Kurczek, 2005). Carbohydrate plays a major role in biological system and in foods, 2.8.2 Moisture: Green leafy vegetables are high in moisture that ranges from 72% in cassava leaves to 92.93% in India spinach and waterleaf. The turgidity or rigidity of vegetables depends on the water content. The amount of individual sample depends on several factors including (a) age (b) agronomic practices prevailing during cultivation and (c) freshness (Oguntana, 1988). Freshness is a function of time between harvest and analysis as well as the condition under which the samples are kept during time lag. 2.8.3 Energy: Green leafy vegetables are not good sources of dietary energy. This is a reflection of low dry matter (DM) content of many of these leaves (Oguntana, 1998) 2.8.4 Protein: Fresh green leafy vegetables have crude protein content ranging from 1.5 to 1.7%. However, Aletor and Adeogun, (1995) however, reported that a mean of 4.2% for seventeen of such vegetables, when dried samples were used , crude protein range from 15.0 to 30%. Shmidt, (1971) indicated that 75% of total nitrogen in most vegetables were protein. 12 Many reports indicated that leafy vegetable protein is low in sulphur amino acids (Oguntona, 1998). 2.8.5 Ether extract: Leafy vegetables are low in fat and none contain cholesterol (Okigbo, 1977). Among the proximate component, fat content is lowest. The level of ether extract scarcely exceeds 1.0% in fresh leafy vegetables.(Oguntona, 1998) 2.8.6 Mineral composition: The amount of minerals contained in fruits and vegetables depend on variety, climate, cultivation and soil type (Teny, Pawn, Mathew and Barrett,1997). This is the reason for the reported wide variation in some of the published data for green leafy vegetables in the study of twelve Nigerian vegetables(Oguntona, 1998). Latande and Dada (1990) reported that the total iron content differed significantly. It ranged from 29.4 to 92mg|kg. Most of the earlier studies (Oke, 1968: Oyenuga, 1968) showed that Nigerian green leafy vegetables contain appreciable amount of minerals. This was confirmed by more recent studies (Ifon and Bassir, 1979; Faboya, 1983; Aletor and Adegun, 1995) 2.9 Vitamins in vegetables As with other nutrients many factors influence the composition of vitamins in green leafy vegetables. Cultivars and maturity are important factors as well as light. It is known that crops mature during autumn contain high pro-vitamin A precursor than those that mature in poorer light of winter (Selman, 1994). Many vegetables contain a substance known as carotene, which is converted to vitamin A. Green leafy vegetables are good sources of ascorbate (Oguntona, 1998). Plants contain its vitaminA precursor, beta-carotene. Beta-carotene is found in orange and yellow vegetables as well as green leafy vegetables. Vitamin C is contained in good amounts in several vegetables such as tomatoes and leafy vegetables such as spinach, cabbage. Fresh 13 vegetables are better sources of vitamin C. Green leafy vegetables are good sources of micronutrients (Raiylakshims, 2001 and F.A.O., 1997).There are a lot of leafy vegetables in Nigeria. These could provide adequate micronutrients in the diet when properly processed and utilized. 2.10 Antinutrient content of green leafy vegetable The major antinutrients commonly found in green leafy vegetables are phytic and oxalic acids. These are important because of their significant adverse effect on nutritional value of these vegetables (Oguntona 1998). High levels of either phytate and oxalate inhibit the absorption and utilization of minerals in animal and man (Osagie,1998). 2.10.1 Phytate: Phytate is an important storage form of phosphorus in plants. It is insoluble and cannot be absorbed in the intestine (Osagie, 1998). Phytate has 12 replaceable hydrogen atoms which it could form insoluble salts with metals such as calcium, iron, zinc, and magnesium. The formation of these insoluble salts renders the metals unavailable for absorption. Phytate can also affect availability by chelating with calcium or by binding with substrate or protolytic enzymes. Heaney, Weaver, Fitzsimmons, (1991) reported that calcium absorption increases with low phytate (3.01mg/g). 2.10.2 Oxalate: These are naturally occurring substance found in plants, and in humans. In chemical terms oxalate belong to a group of molecules called organic acids and are routinely made by plants and humans. Our bodies always contain oxalate, and our cells routinely convert other substances into oxalates. For example, vitamin is one of the substances that our cells convert into oxalates. In addition to the oxalates that are made inside the body, oxalates can enter at our body from the outside from certain foods that contain them (Sienera, 2006). 14 Parivar, Low, and Stoller (1991) observed that low oxalate content foods have less than 2mg per serving and moderate oxalate food has from 2-10mg per serving and should be limited to 2-3 serving per day. 2.10.3 Tannins: Tannins are astringent, bitter plant polyphenols that either binds and precipitate shrink proteins and various other organic compounds. The astringency from the tannins is what cause the puckrey feeling in the mouth following the consumption of unripened fruits or red wine (MacGee, 2004). Tannins have traditionally been considered antinutritional but it is now known that their beneficial or antinutritional properties depend upon their chemical structure or dosage. Studies have demonstrated that products containing chestnut tannins included at low dosage in diet (0.15-0.2%) can be beneficial (Schiavone, et al., 2008) If ingested in excessive quantities, tannins inhibit the absorption of minerals such as iron which may if prolonged, lead to anemia (Brien, Rossander, Hallberg, 1989).This because tannins are metal ion chelators, and tannins chelated metal ions are not bioavailable. Tannins have been shown to precipitate protein (Bate-Smith and Swain, 1962). Tannins do not affect absorption of either trace minerals such as zinc, copper, and manganese in rats (Afsanak, Shiga, Ishizka, Hara, 2003).Large quantity of tannins may cause bowel irritation, kidney irritation, liver damage, irritation of the stomach and gastrointestinal pain. 2.10.4 Saponins: Saponins are steroid or treerperoid glycosides which are characterized by their bitter or astringent tastes, foaming properties and their hemolyptic effect on red blood cells They are widely distributed in the plant kingdom being found in over 500 genera (Nandy,1991; Birk and Peri, 1980). Saponins have been shown to posses beneficial (cholesteole lowering, and deleterious (cytotoxic, permeabilization of the intestine) properties and to exhibit structure dependent biological activities (Peri et al., 1987; Oarkenful and Sidhum 1989). 15 There are suggestions that the consumption of saponins should be encouraged because of their nutritional importance. Forage saponins have been reported by Ceake et al., (1978) to cause toxic and anorexic effects in rats and swine thereby limiting the feeding value of high animals‟ feeds such as alfalfa. Cassidy and Dalaise, (2003) reported 146mg of saponin to be safe level, this implies that saponin levels above 146mg is toxic. 2.11 Some commonly consumed vegetables in Nigeria. 2.11.1 Fluted pumpkin: (Telferia occidentails) The leaves of this crop are important food vegetables for many people, especially in the mid-western parts of Nigeria. The local names include “Ugu‟‟ (Igbo and “Iroko‟‟ Yoruba).The crop is a member of Cucubitaceae family. It is a perennial vine its stem is as long as 10 meters. The male plant produces leaves that are similar to the female plants. It has been estimated that approximately 0.5 kg leaves and hoots are obtained from one plant per harvest (Tindall, 1983) and up to 15 harvests are obtained between 3-4 months. The leaves are highly cherished as cooked vegetables and the seeds are used in soups.etc. The leaf was found to contain in (g/100) 30.5% dry weight, 2.5% crude protein, 3.0 ± 0.15% crude lipid, 8.3 ± 0.50% crude fiber and 8.4 ± 0.50% total ash. The potassium, calcium, magnesium and iron contents of ash were 594,144, 100 and 120mg/100g dry net respectively. The leaf was found to contain high level of tannic acid but the levels of phytic acid and oxalate were within the normal range (Food chemistry, 1985). 2.11.2 Water leave: Water leaf vegetables are rich sources of vitamins A, C and minerals such as iron, calcium, phosphorus, sodium, potassium and many other carotene content of water leaf vegetables varied from ponnanganni greens to water convolvulus, vitamin C from 17 ponnanganni green) to 247mg (checkurmanis) and iron from 0.9 (water leaf) to 34.8mg (water convolvulus) per 100g edible portion phytochemicals were oxalate, saponin, tannin and phytate and alkaloid. 16 Water leaves have great nutritional value. They contain very high amount of zinc, important in many enzyme functions and keeping the skin fresh. They also contain saponins and tannin (glycosides), as well as alkaloids. At least 13 other new compounds or vital ingredients have been found in these leaves after a 40 years of study, and have the following benefits, anti-malaria, anti-bacteria, anti-parasites, anti-cancer, scurvy sciatica and reheumatism. Bitter leaf has high protein (33.3%) fat (2.1%), crude fiber (29.2%), ash (11.7%), minerals (sodium, calcium, magnesium, zinc and iron, phytate (10.54mg/100g) and tannin (0.6%) content, and it contains low cyanide (1.1mg/kg).(Food chemistry, 1995) Table2: Nutrients composition of commonly used fresh green vegetables in Nigeria (per 100g) Vegetables Moisture Carbohydrate Protein Fat Fibre Ash Amaranth 84 7.0 4.6 0.2 1.8 2.9 64.4 22.2 2.7 10.9 10.00 2.9 1.6 0.3 0.6 11.00 4.4 2.4 0.4 1.4 2.00 Trace 4.3 0.8 2.3 6.00 Aramanthus hybridus Bitter leaf 21.6 mygdaluina Indian spinach 93.4 Basella alba Water leaf 90.8 Trangulane Fluted 86.0 pumpkin Telfera occidentalis Source: Oguntona (1988) 17 Table 2: 2: vitamin composition of commonly used green leafy vegetables (mg/100g) Vegetables Ascorbate Amaranth 40.5(a) Bitter leaf, Vernonia amygdalina 34.5(a) Indian spinach, Basella alba 62(a) Water leaf ,Talinum triangulane 280(a) Fluted pumpkin Telfere occidentalis 340(a) B-carotene 672, (b) Sources: (a) Oguntona (1988), (b) Pamploma -Rogers (2006) 2.12 Fruits The term fruits have different meaning. Botanically, a fruit is the ripened ovary together with seeds of a flowering plant. In many species, the fruit incorporates the ripened ovary and surrounding tissues. Fruit are the means by which flowering plant disseminate seeds (Lewis ,2002), in cuisine fruits that are sweet and fleshy, examples of which include apple and orange (MacGee, and Harold, 2004). However a great many common fruits as well as nuts and grins are the fruit of the plant species they come from (MacGee and Harold,2004). Majority of the fruit are fleshly or juicy (Umoh, 1995). 2.13 Nutrient composition of fruits Fruits are found to be rich in vitamins, especially vitamin C, minerals, sugar (Achinewu, 1983; Oguntona, 1991). However, higher values for carbohydrate have been reported in various fruits (Ose, 1971). The main sugar in fruits are glucose and fructose and sucrose. Some fruit are low in carbohydrate and consequently low in calorie. 2.13.1 Protein: The protein constituents of fruits are low. They serve as components of nuclear and cytoplasmic structures that take part in determining and maintaining cellular organization, including the full components of enzymes involved in the metabolism during 18 growth and maturation of the fruit (Umoh, 1998). He further reported that fruits are low in nitrogenous components as compared to seeds, leaves and some other plant parts and tissues. 2.13.2 Moisture: The moisture content of fresh fruits at maturity is generally high (Umoh, 1998). Moisture content of fruits determines how fresh the fruits were at harvest, or for how long they have been stored before analysis ( Sheila,1978). 2.13.3 Fats: Fruits are not good sources of fat and are usually recommended as part of weight reduction diet (Sheil, 1978; Platt, Umoh and Oke, 1978), reported on the nutritional value and chemical composition of fruits such as lesser-known fruit and seeds. Their reports showed that oil fruit and seeds contain oils and fats. 2.13.4 Fiber: Fruits and vegetables as sources of dietary fibre normalizes blood glucose levels. Fibre slows the rate at which food leaves the stomach and by delaying the absorption of glucose following a meal. Fibres also increase insulin sensitivity. As a result, high intake of fiber plays a role in the prevention and treatment of type 2 diabetes. In addition, by slowing the rate at which food leaves the stomach, fibres promotes a sense of satiety, or fullness, after a meal, which prevents overeating and weight gain (Lom, 2001). 2.13.5 Minerals: Fruits contain mineral elements in low quantities. Gibson, (1997) reported that plants tend to concentrate calcium in their leaves and phosphors in the seeds. Fruits, like dried fruits are rich in calcium and iron (Mauseth and James, 2003). 2.14 Vitamins in fruits Umoh (1998) stated that the main contribution of fruits and their products to nutrition is their supply of vitamins most, especially the antiascorbic vitamins (Mopson, 1970). Fruits and vegetables are the main sources from which primates derive their vitamins. Ascorbic 19 acid alongside with other vitamins performs useful functions in the body. Drugs such as asprin and the contraceptive pills affect the plasma levels of ascorbic acid (Kilgour, 1987). Ascorbic acid in the body aids in iron absorption from the intestines. It is required for connective tissue metabolism especially the scar tissue, bones and teeth. It is also necessary as an anti-stress and protector against cold, chills and damp. It prevents muscle fatigue and scurvy. It is thought to be necessary for metabolism of cholesterol, reduces the degree of formation of carcinogenic nitrosamsin from their preculsors and is required in the hydrocylation of proline to hydroxyperoline of the collagen in the body. 2.15 Commonly used fruits 2.15.1 Guava: Guava is a rich source of vitamin c. It contains a far higher amount of vitamin C than most of the imported and local fruits. It contains three to six time more than vitamin C than in orange, 10-30 times more than bananas and about 10 times more than papaya (USDA, 2001). Most of the vitamins C is concentrated in skin and outer mesocarp, reaching a maximum green fully mature fruit and declining as the fruit ripens. Guava is very good source of vitamins, fibres as well as minerals. Being rich in vitamin c, guava is effective in treating male infertility caused by sperm duping, adhension and other abnormalities. Guava has been associated with treating of wounds, when applied externally. Guava has general haemostatic properties and can be used for treating bleeding nose, gums and minor internal hemorrhaging. Guava helps cures dysentery by inhibiting microbial growth and removing extra mucus from the intestines. Guava helps the body in combating free radicals produced during metabolism and aids in preventing age-related chronic diseases such as alchenimers cataractoid and arthritis. Guava is one of the richest sources of dietary fibre and thus good for those suffering from constipation. Guava strengthens bones up the digestive system and even disinfect the same. Guava having high content roughage no cholesterol and less digestible carbohydrate 20 is good for those trying to lose weight. Guava can improve the texture of skin and helps avoid skin problems. For this purposes guava can either be eaten raw or wash skin with decoction of guava leaves is known to bring relief in cough and cold. Research has shown that guava is pretty effective in preventing cancer and even heart diseases in people. The present complex carbohydrates and dietary fibres in guava make it effective in lowering cholesterol and blood sugar levels. The presence of vitamin c and phytoutire carotenoids, isoffavonoids and polyphenols, in guava has led to it being an effective antioxidant. Guava has been found to be beneficial to people suffering from the following ailments: (1) Acidosis, (2) Asthma, (3) Bacterial infections (4) Catarrh (5) Convulsion (6) Congestion of lungs (7) Epilepsy (8) High blood pressure and (9) Obesity, (10) Oral ulcers (11) Poor circulation (12) prolonged menstruation (13) scurvy (14) swollen gums and (15) toothache. Table 3: Proximate composition of Guava, raw: Psidium guajava Nutrients Units Value per 100g of edible Sample count portion Proximate Units Water G 86.10 2 Energy Kcal 51 0 Energy Kj 213 0 Protein G 0.82 1 Total lipid (fat) G 0.60 0 Carbohydrate G 11.88 0 Fiber G 5.4 0 Ash G 0.60 0 Source: USDA (2006) Std error 21 Table 4: Mineral composition of Guava Minerals Units Value per 100g of sample count Std error edible portion Calcium Mg 20 32 1.971 Iron Mg 0.31 12 0.022 Magnesium Mg 10 12 0.216 Phosphorus Mg 25 33 1.465 Potassium Mg 284 16 16.710 Sodium Mg 3 15 0.417 Zinc Mg 0.23 12 0.047 Copper Mg 0.103 12 0.020 Sample count Std error Source: USDA (2006) Table 5: Vitamin composition of Guava Vitamins Units Value per 100g of edible portion Vitamin C Mg 183.5 112 15.120 Vitamin, A, RE Mcg RE 792 25 285.960 Vitamin I U. IU 79 25 28.596 Source: USDA (2006) 2.15.2 Pineapple: Pineapples nutrients include calcium, potassium, fibre, vitamin. It is low in fat and cholesterol. It is also a good source of vitamins B1, B6, and fiber. Pineapple is a digestive and a natural anti-inflammatory fruits. A group of sulfur containing protolytic enzyme in pineapple aid digestion. Fresh pineapples are rich in bromelain. Bromelain has demonstrated significant anti-inflammatory conditions such as acute smusitis, sorethroat 22 arthritis and gut and speeding recovery from injuries and surgery. Pineapple should be eaten alone between meals (USDA, 2001).Pineapple enzymes have been used with success to treat rheumatoid arthritis and to speed tissue repair as a result of injuries diabetic ulcers and general surgery. Pineapple reduces blood clotting and helps remove plague from arterial walls. Studies request that pineapple enzymes may improve circulation in those with narrowed arthritis such as argina sufferers. Pineapple are used to help cure bronchitis and throat infections. It is efficient in the treatment of arteriosclerosis and anemia. Pineapple is an excellent cerebral toner, it combats loss of memory, sadness and melancholy have exceptional juice and exceptional health benefits. It is rich in manganese and just one cup of pineapple provide 73% of the daily recommended amount of manganese. This aids the growth of bones in young people and the strengthening of bones in older people. Due to its high vitamin c content, pineapples are good for oral health. Vitamin c can reduce risk of gingivitis and paridental disease. Vitamin c also increases the body‟s ability to fight invading bacteria and other toxins that contribute to gum disease. Pineapple has been thought good for the heart conditions and indeed should not be used by people with haemophillia or by those with disease of the kidneys and liver. This is because it seems to reduce the time taken to coagulate the blood – which is why it can be useful for heart patients. Pineapple could be useful for women suffering from painful periods. Ripe fruits of good colour should be chosen. Pineapple are not sweeter on storage if they are picked unripe. This is because the starch in the stem is taken up into the fruit and converted to sugar only at the final stage of ripening. Pineapple has been shown to be important in maintaining good eye health and helping to protect against age-related eye problems. There are even some beneficial molecules hidden in the stems of pineapple. These molecules haven been seen to 23 act as a defence against certain types of cancer. Aside from fiber, there are many other essential nutrients. Vitamins that can be found in pineapple are vitamin and nutrients that can be found in pineapple include vitamin C, vitamin A, calcium and potassium. It is believed that the best source for these nutrients is fresh pineapple. Pineapple contains bromelain, which is known to help relieve or even stop coughs altogether. The main reason is because it is anti-inflammatory and ultimately, it is known to help with the loosening of mucus. Table 6: Nutrients composition of Pineapple, raw: (Ananus comosus) Nutrients Units Value per 100g of edible Sample count Std error 86.50 37 0.300 portion Proximate Water g 49 0 Energy kcal 205 0 Energy kj 0.39 17 0.012 Protein g 0.43 15 0.148 Total lipid (fat) g 12.39 0 Fibre, total dietary g 12 0 Ash g 0.29 32 Source: USDA (2006) 0.010 24 Table 7: Mineral content of Pineapple Minerals Units Value per 100g of Sample count Std error edible portion Calcium Mg 7 10 0.778 Iron Mg 0.37 15 0.025 Magnesium Mg 14 11 0.529 Phosphorus Mg 7 10 0.365 Potassium Mg 113 12 5.626 Sodium Mg 1 11 0.074 Zinc Mg 0.08 15 0.007 Copper Mg 0.110 15 0.009 Sample count Std error Source: USDA (2006) Table 8: Vitamin content of Pineapple Vitamins Units Value per 100g of edible portion Vitamin C Mg 15.4 11 0.550 Vitamin, A, RE Mcg RE 23 22 5.188 Vitamin I U. IU 2 22 0.519 Source: USDA. Nutrition database for standard reference, release (14 July, 2006) 2.15.3 Mangoes: Mangoes contain several important phytochemicals including cryptoxanthin, lutein, galic acid and anacardic acid. Mangoes are an incredibly healthy snack. The entire fruit can be eaten for just over hundred calories. High in fibre, virtually fat free and mangoes contain numerous vitamins. Mangoes contain, B – carotene which may slow the aging process, reduce the risk of certain forms of cancers, improve lung function, and reduce complications associated with diabetes. Mangoes are rich in antioxidants such as beta carotene (44.5g/100g fruit) and 25 vitamin C (27.79/100g fruit). Mangoes contain vitamin A (equivalent 38g/100g fruit), vitamin E. Mangoes also contain vitamin B6, (0.134mg/100g fruit), other vitamins B1and B12. Mangoes supply nutrients such as potassium (15.6mg/100g fruit), calcium (10mg/100g fruit), Magnesium (10g), iron (0.12mg) and zinc (0.04mg/100g) and fibre and are low in calories. Mango peels and pulp also contain carotenoids, polyphenols, and antioxidant. The edible peel of the mango is a good source of fibre (USDA, 2001). Mango is considered as an energizer in Ayurved as 100g mango fruit provides about 17.0g carbohydrates. The fruit is rich in pre-biotic dietary fibre, vitamins, minerals and polyphenol and flavonoids and antioxidant compounds. Mango is a very good sources of vitamin A and flavornoid like beta carotene, alphacarotene and beta cryptoxanthin. These compounds are known to have antioxidant properties and are essential for vision. Vitamin A is also required for maintaining healthy mucus membranes and skin. Consumption of natural fruits rich in carotene are known to protect from lung and oral cavity cancers. Fresh mango is a very rich source of potassium. Potassium is an important component of cells and body fluids that helps in controls heart rate and blood pressures. It is also a very good source of vitamin B6 (pyridoxine), vitamin C and copper. Consumption of food rich in vitamin c helps body develop resistance against infectious agent and scavenge harmful oxygen free radicals. Copper is a co-factor for many vital enzymes including cytochrome c-oxidase and superoxide dimutaser. Copper is also required for the production of red blood cells. Mango peels are also rich in phytonutrient such as the pigment antioxidants like carotenenoids and polyphenols (USDA, 2001). 26 Table 9: Proximate composition of Mangoes, raw( Mangifera idica) Nutrients Units Value per 100g` of edible sample count Std error 0.323 portion Proximate Water g 81.71 108 Energy kcal 65 0 Energy kj 272 0 Protein g -0.51 79 0.025 Total lipid (fat) g 0.27 47 0.039 Carbohydrate g 17.00 0 Fiber g 1.8 0 Ash g 0.50 66 0.033 Source: USDA (2006) Table 10: Mineral composition of Mangoes Minerals Units Value per 100g of Sample count Std error edible portion Calcium Mg 10 27 0.850 Iron Mg 0.13 21 0.021 Magnesium Mg 9 20 0.580 Phosphorus Mg 11 41 0.746 Potassium Mg 156 24 8.441 Sodium Mg 2 24 0.624 Zinc Mg 0.04 1 Copper Mg 0.110 17 Source: USDA (2006) 0.009 27 Table 13: Vitamin content of mangoes Vitamins Units Value per 100g of Sample count Std error edible portion Vitamin C Mg 27.7 162 1.740 Vitamin, A, RE Mcg RE 389 91 24.817 Vitamin I U. IU 3894 91 24.417 Source: USDA (2006) 2.15.4 Pawpaw: Pawpaw is very nutritious fruits. They are high in vitamin C, magnesium, iron, copper and manganese. They are good sources of potassium and several essential amino acids .They also contain significant amount of riboflavin, niacin, calcium, phosphorus, and zinc. Pawpaw contain these nutrients in amounts that are generally about the source or greater than those found in bananas, apples, or oranges (USDA, 2001) Pawpaw has a higher protein and fat content. Banana exceeds pawpaw in food energy and Carbohydrate content in pawpaw is most similar in overal composition. Pawpaw has three times as much vitamin C as apple, twice as orange. Pawpaw has six times as much as riboflavin as apple, and twice as much as orange. Niacin content of pawpaw is twice as high as bananas, fourteen times as high as apple and four times as high as orange. Pawpaw and banana are both high in potassium having about twice as orange and three times as much as apple. Pawpaw has one and half times as much calcium as orange and about ten times as much phosphorus, four to twenty times as much iron, five to twenty times as much zinc five to twelve times as copper, and sixteen to one hundred times as much as manganese, as do banana, apple or orange. Protein in pawpaw contains all of the essential amino acids and it exceeds apple in all amino acids. It exceeds or equals banana and orange in most of them. 28 2.15.5 Orange: Orange like other citrus fruits is known for vitamin C content. Due to this high amount of vitamin C, orange helps in absorbing calcium into the body and maintaining the health of teeth and bones. It also contains vitamin A and vitamin B. 100g of orange contains about 60 calories. This energy is available in form of sugar which can be absorbed by the body easily. Hence orange juice is often fed to people who have become weak due to some illness. Orange juice is also a good refresher after a long exhaustive day. The nutritional value of orange makes good for indigestion constipation, bowel disorder, dyspeosia, dental care, pyorrhea, bone health, heart diseases, respiratory problems, cold, cough influenza, skin care, pimples, acne, fever measles, typhoid and tuberculosis (USDA, 2001). Table 14: Proximate composition of Orange, raw,( Citrus sinesis) Nutrients Units Value per 100g of edible Sample count Std error 0.121 portion Proximate Water g 86.75 88 Energy kcal 47 0 Energy kj 197 0 Protein g 094 69 0.014 Total lipid (fat) g 0.12 4 0.010 Carbohydrate g 11.75 0 Fiber g 2.4 0 Ash g 0.44 79 Source: USDA (2001) 0.006 29 Table 15: Mineral content of Orange Minerals Units Sample count Mg Value per 100gm of edible portion 40 Calcium Std error Iron Mg 0.10 64 0.004 Magnesium Mg 10 212 0.171 Phosphorus Mg 14 68 0.439 Potassium Mg 181 180 1.408 Sodium Mg 0 72 0.029 Zinc Mg 0.07 3 Copper Mg 0.045 64 0.003 Sample count Std error 0 Source: USDA (2006) Table 16: Vitamin content of Orange Vitamins Units Value per 100g of edible portion Vitamin C Mg 53.2 148 5.890 Vitamin, A, RE Mcg RE 205 148 0.890 Vitamin I U. IU 21 Source: USDA (2006) 2.15.6 Avocado: Avocado is a fat-rich fruit, its fat content is about 23%. It contains dietary fibre. It is rich in minerals such as copper magnesium, manganese and moderate in iron, calcium, iodine, selenium, zinc and phosphorus. Avocado is well known for its high vitamins K and A content. It also contains small amount of vitamins B C, vitamin E, thiamin, riboflavin, niacin, vitamin B6, biotin and folate. Fruits are normally not rich in calories and are eaten for their ability to provide vitamins, minerals and digestive fibre content. However, 30 avocado owing to its high fat content provides good quantity of calories. A -100g of edible portion of the fruit provides about 215 calories.The nutritional value of avocado makes it good for indigestion, hair care, heart health, skin care, psoriasis and bad breath (USDA, 2001). Table 17: Avocado, raw,( Persea American) Nutrients Units Value per 100g of edible Scruple count Std error portion Proximate 0.817 Water G 74.27 58 Energy kcal 161 0 Energy Kj 674 0 Protein G 1.98 58 Total lipid (fat) G 15.32 54 Carbohydrate g 7.39 0 Fiber g 5.0 0 Ash g 1.04 57 Source: USDA (2006) 0.042 0.093 31 Table 18: Mineral content of Avocadoes Minerals Units Value per 100g of Sample count Std error edible portion Calcium Mg 11 6 1.610 Iron Mg 1.02 54 0.122 Magnesium Mg 39 54 3.062 Phosphorus Mg 41 54 2.996 Potassium Mg 599 30 57.306 Sodium Mg 10 30 1.146 Zinc Mg 0.42 1 Copper Mg 0.262 54 0.020 Sample count Std error Source: USDA (2006) Table 19: Vitamin content of Avocados Vitamins Units Value per 100g of edible portion Vitamin C Mg 7.9 6 1.528 Vitamin, A, RE Mcg RE 612 6 70.839 Vitamin I U. IU 61 6 7.084 Source: USDA.(2006) 32 2.15.7 Apple: The health benefits of apple are enormous. These makes it one of the most valuable and savored fruits throughout the world. Apple contains minerals such as magnesium, copper, manganese, calcium, iron, potassium and phosphorus in small quantities. Apple also contains dietary fibre, which helps in reducing the bad cholesterol level. Apple is rich in vitamin A and C. Vitamin A concentration is higher in the outer skin than the flesh. Like potatoes, vitamin C concentration is higher just below the skin in apples also. Based on this the skin should not be discarded. Other vitamins present in apple include vitamin K, thiamin, riboflavin and B6. Apple does not have calories as high as avocado or olives. It is an excellent source of energy. The calorie content varies as per the type of apple. Apple contains sugar which is easily absorbed by the body. The weak and ill are often advised to eat apples for gaining weight and fast recovery. The nutritional value of apple makes it useful for digestion, stomach disorders, anemia, weakness, dental care, dysentery, heart disease, reheumatism, eye disorders, cancers, gouts, and skin care (USDA, 2001). 2.15.8 Banana: Banana is rich in potassium, it also contains other minerals such as calcium, iron, magnesium and phosphorus in large quantities. It is rich in fibRE making it useful laxative and good for easing constipation. Bananas contains about 90 to 93 calorie per 100g. This energy is easily absorbed by the body. Consumption 3-4 bananas daily, especially with milk, is often recommended to gain weight, banana is useful for 100mg, weight because it has only 90 calories per 100g (USDA, 2001). The nutritional value of banana makes it useful for weight gain as well as weight loss, constipation, bowel problems, anemia, blood pressure, heart problems, ulcers, brain stimulation, depression, nervous disorders, stress and morning sickness. 33 Table 20: Proximate composition of Banana, raw (Musa paradisiacal) Nutrients Units Value per 100g of edible portion Sample count Std error Water G 74.26 116 0.381 Energy Kcal 92 0 Energy Kj 385 0 Protein G 1.03 111 0.026 Total lipid (fat) G 0.48 11 0.135 Carbohydrate G 23.43 0 Fiber G 2.4 0 Ash G 0.80 110 Proximate 0.016 Source: USDA (2006) Table 21: Mineral content of Banana Minerals Units Sample count Std error Mg Value per 100gm of edible portion 6 Calcium 5 0.374 Iron Mg 0.31 108 0.015 Magnesium Mg 29 103 1.265 Phosphorus Mg 20 102 Potassium Mg 396 55 6.356 Sodium Mg 1 61 0.141 Zinc Mg 0.16 13 0.008 Copper Mg 1.104 109 0.009 Source: USDA (2006) 34 Table 22: Vitamin content of Banana Vitamins Units Value per 100g of Sample count Std error edible portion Vitamin C Mg 9.1 14 0.339 Vitamin, A, RE Mcg RE 81 5 10.050 Vitamin I U. IU 8 5 1.005 Source: USDA (2006) Table 23: Proximate content of Pears, raw;( Pyrus communis) Nutrients Units Value per 100g of edible portion Sample count Std error Water G 8381 44 Energy Kcal 59 0 Energy Kj 247 0 Protein G 0.39 40 0.021 Total lipid (fat) G 0.40 5 0.121 Carbohydrate G 15.11 0 Fiber G 2.4 0 Ash G 0.28 44 Proximate Source: USDA (2006) 0.008 35 Table 24: Mineral content of Pears Minerals Units Sample count Mg Value per 100g of edible portion 11 Calcium Std error Iron Mg 0.25 42 0.014 Magnesium Mg 6 38 0.287 Phosphorus Mg 11 38 0.269 Potassium Mg 125 22 3.920 Sodium Mg 0 21 0.043 Zinc Mg 0.12 5 0.026 Copper Mg 0.113 45 0.006 6 Source: USDA (2006) Table 25: Vitamins A & C composition of commonly used fruits in Nigeria (mg/100g) Fruits Ascorbate B-carotene 7.90 61.0 Guava Psidum guajava 180 79.0 Orange citrus species 53.2 21.0 Mango, Magnifera indica 27.7 38.9 765 IU Pineapple Ananas comosus 15.4 1.20 Pawpaw, Carica papapya 61.8 17.5 Source Pamploma-Roger (2006) 36 Table 26: Proximate composition of commonly used fruits in Nigeria (%) Fruits Moisture Carbohydrate Protein Fat Avocado peer 2.39(a) 1.98(a) 5(a) Guava 6.07(a) 0.82(a) 5.40(a) Orange, Citrus 91(c) 9(a) 0.42(a) 94(c) 11.20(a) 0.39(a) 87(c) 8.01(a) 0.6(a) 0.12(a) Ash 0.08(c) Fiber 2.40(a) species Pineapple 1.20(a) Ananas cosmosus Pawpaw Carica papaya Sources: a = Pumploma – Roger (2006) b = Umoh (1998) c = Muncro and Bassir (1969) 4.83(c) 1.80 37 Table 27: Mineral composition of commonly used fruits in Nigeria (mg/100g) Fruits Calcium Phosphorus Iron Zinc Avocado peer 11.0 41.0 1.02 0.42 Guava 20.0 25.0 0.31 0.23 Orange 40.00 46.0 0.10 0.07 Magrifera 10.0 11.0 0.13 0.04 Ananas 7.00 7.00 0.37 0.08 Carica 24.00 5.0 0.10 0.07 Mango Copper 0.04 indica Pineapple, cosmosus Pawpaw papaya Sources: Pamploma – Roger (2006) 0.5 38 CHAPTER THREE 3.1 MATERIALS AND METHODS The fruits and vegetables used in this study were identified and collected from forests in Ayamelum local government area. Ayamelum local government comprises eight communities (Omor,Umumbo, Omasi, Ifite-Ogwari, Umueje, Umerum, Igbakwu, and Anaku) 3.2 Pilot study 3.2.1 Identification of samples Three men and two women (Ayamelum indigenes) assisted the researcher to collect and identify some of the wild fruits and vegetables are consumed in the locality. The fruits and vegetables were collected from forests in two communities (Omor and Umumbo) in Ayamelum local government area of Anambra State. They identified the wild fruits and vegetables with their local names. Subsequently the researcher took samples of the fruits and vegetables to the Department of Botany, University of Nigeria, Nsukka, for characterization and identification with their botanical names. The result is shown in Table 1. Table 1: Some wild fruits and vegetables identified for use in Ayamelum local government area. Local names Botanical names Common names Parts of the plant 1 “Osenga” Olax viridis - Fruits 2 “Uchakulu” Vitex deniana black plum Leafy vegetable 3 “Akankolo” Ficus carpensis Fig trees in Fruits & vegetable general 4 “Aado” Gongronema Sp - Fruits 5 “Ukpodikili” Napoleona imperialis Tree species Fruits 6 “Okwocha” Afromomum Sp Monk‟s malaqueta pepper or Fruits 39 All the fruits and vegetables collected were analyzed fresh for various nutrients and anti nutrients Vitex doniana 40 Napoleona imperalis 41 Afromonum specie 42 Ficus carpensis 43 Gongronema sp 44 3.2.2 Preparation of materials Polyethylene bags were used for collecting and storing of samples to avoid contamination. The leaves were picked to remove unwanted materials. The leaves and fruits were washed with iodized water and excessive water was dripped off. Edible portions of the vegetables and fruits were cut into pieces and homogenized using a blender. The homogenized samples were transferred into an air tight container. The leaves and fruits were analyzed fresh. 3.3 Chemical analysis The samples were weighed to the nearest gram and transferred to the laboratory for analysis. Each sample was homogenized separately and aliquots were taken from each sample for moisture analysis. All analysis were done in triplicate. Proximate, mineral, vitamin, antinutrient and food toxicant composition of the samples were determined using AOAC (1995) methods. 3.3.1 Fat determination Fat was estimated by the Soxhlet extraction (AOAC, 1995) procedure 1. Two (2y) grammes of samples were weighed into dry Soxhlet thimbles 2. The thimbles were suspended in a beaker and dried to a constant weight in an oven and then placed in a soxhlet condenser containing ether. 3. A reflux condenser was attached to the contracted tube and heated, the ether was returned to the flask with fat when the thimble was full. 4. The extraction was continued for about 6 hours at 120.c 5. The flask and fat were drained in air to vaporiate the ether and weighed to a constant weight. 6. Fat was washed off with a fat solvent , dried and weighed again. 45 %fat = Where X1 = initial weight of flask X2 = final weight of flask W = weight of samples 3.3.2 Moisture determination This was done by hot air oven method of Pearson (1976). 1. Two (2a) grammes of samples were weighed into an empty aluminum dish with a known weight. 2. The dish and samples were dried in an air oven at 1000C for 24 hours and cooled in dessicator and re-weighed. 3. This process was repeated until weight is obtained. % Moisture = Where X = weight of empty dish Y = initial weight of dish + weight of sample 3.3.3 Ash determination 1. One (1g) of sample was placed in a clean crucible of known weight. The crucible was placed in a muffle furnace (6000C) over night or 24 hours. 2. The crucible and content were cooled in a dessicator and weighed again %Ash = Where X = weight of crucible Z= weight of crucible and ash 46 3.4 Crude fibre determination The crude fibre content of the samples were determined by using (AOAC) (1995).method 3.4.1 Method 1. Two (2g) grammes of the sample was placed in a 250ml beaker, boiled for 30 minutes with a 100ml 0.12 MH2SO4 and filtered through a funnel. 2. The filtrate was washed with boiling water until the washing was no longer acidic. 3. The solution was boiled for another 30 minutes with 100ml of 0.12m sodium hydroxide solution filtered three times with hot water and methylated spirit. 4. The residue was transferred into a crucible and dried in an oven for 1 hour. The crucible and its content were cooled in a dessicator, and re-weighed (w2). The crucible and its contents were taken to a furnace for ashing for 1 hour. 5. The ash sample was removed from the furnace after temperature had cooled and put into a dessicator and later re weighed (w3). The crude fibre content was obtained between the weight before and after incineration. The percent of the crude fibre was calculated thus. %Crude fibre = Where W1 = weight of crucible W2 = initial weight of sample and crucible W3 = final weight of sample and crucible 100 = percentage 3.5 Crude protein determination The micro-kjedahl method (AOAC,) (1995) involve digestion, distillation and titration was used to obtain the crude protein content of the samples. 47 3.5.1 Digestion 1. One (1g) gramms of each sample was weighed into a 100ml Kjeldahl flask. 2. Twenty five (25) grammes of anhydrous sodium sulphate, 05g copper sulphate (catalyst) and 5ml of concentrated sulphuric acid was added. 3. The flask was placed in fume chamber and heated gently until the solution turns black, then the heat was cooled, washed and transferred into a 250 volumetric flask and rinsed down with distilled water. 3.5.2 Distillation 1. A combination of boric acid and methyl red indicator was poured into conical flask and placed under a condenser in such a way that the condenser tip was under the liquid. 2. About 5ml of the digest plus 10ml of 60% concentrated sodium hydroxide was placed in a Markham distillation apparatus. 3. Steam was let down through the distillation apparatus for 5 minutes. Ammonia was evolved, which changed the color of the indicator from purple to green characteristics of alkaline gas. 3.5.3 Titration 1. The distillate was titrated with 0.1 hydrochloric acid (HCl) until a neutral point was reached (faint purple) 2. Titre value (T) = final biuret reading-initial biuret reading. %Crude protein = 3.6 Carbohydrate determination This was determined by difference ie. % carbohydrate = 100- (%protein + % fat + fibre + % ash + % moisture). 48 3.7 Determination of iodine, iron, copper, calcium, zinc and phosphorus AOAC (1995) wet digestion procedure was used in estimating iron (Fe), iodine, (12), copper, calcium, zinc and phosphorus. 1. Five millitres (5ml) of perchloric acid and 10ml of neuric acid were heated under fume chamber until the solution turned colourless and free of nitrogen. One (1g) gramme of the sample was weighed into a 100ml round bottom flask and diluted into a known volume before used for absorption spectrophotometer. 2. A spectrometric atomic absorption spectrophotometer was used on a general principle that minerals are absorbed at different wavelength, Fe (248.30), 12(353.0, Cu(324.70), Zn(213.90) , Ca(230.0) and P(470) 3. Readings were obtained against standard for each mineral and distilled water was used to zero the spectrophotometer after each reading. Calibration curve was constructed for each mineral and used to calculate its concentration. 3.8 Pro-vitamin A (RE) determination Provitamin A was determined using the method adopted from IVACG (1982). The vitamin A activity, as retinol equivalent (RE) was calculated based on the vivo concentration factor (WHO, 1982). Caratenoids (RS) (U-V-spectrophotometric method Reagents Cyclohexane Carotenoids (RS) 3.8.1 Principle The principle was based on the use of U-V- spectrophotometric method as ashing with cyclohexane. 49 3.8.2 Method The samples or prepared portions were dissolved in cyclohexane such that it contains 9-15 units per ml and obtained the wavelength of maximum absorption. The extinctions at the wavelength were measured and calculated as fractions relative to that at 328nm. The Eicm figure was calculated at 328nm if the wavelength of maximum absorption is 326 – 329nm and observed relative extinction was within 0.02. 3.8.3 Calculation Potency (units 1g) = 1900x E328nm. The following correction was applied if the maximum lies in the same range, but the relative extinction are not within 0.02 E238 (corrected 3.52(2E328 – E328 – E316 – E340). 3.9 Ascorbic acid determination AOAC (2005) official methods of analysis was used. Ascorbic acid was determined by using a dye solution of 2.6 dichophenol, indophenol (4 tablets of dye were dissolved in little water and transferred to stopered measuring cylinder making volume to 100cm3 and mixing well and labeled 1cm3 = 0.4mg AA. The quantity of samples was weighed, mashed and liquidized with 50cm3 dilute acetic acid and transferred to stopered measuring cylinder and made to 100cm3 .with water. The sample was homogenized, allowed to settle and the supermatant liquid was decanted off. This was filtered with a muslin cloth and labeled 10cm3. An aliquot was transferred to a small conical flask using a pipette and titrated against the dye solution to pale pink that pointed persisting for 15 seconds. Ascorbic acid content was calculated in mg per 100g of sample. If average titration result = Vcm3dye (0.4mg Aacm3). 100 extract contains V x 0.4 x 100 x100/wmg- AA =40v/wmg AA. 50 3.10 Determination of antinutrients 3.10.1 Phytate The method described by Latta and Eskin (1980) was adopted. About 0.5g of each sample was extracted with 100ml of 24% of hydrochloric acid. The diluted extract was passed through the amberite resin. Inorganic phosphate was eluted with 0.1ml of sodium chloride and 0.7m sodium chloride. Colour was developed with 1ml of modified Wade reagent, 0.03% Fecl,6 Hz 0 and 0.3% sulphur salicylic acid. The absorbance was read at 500m in a CE 2343. Digital grading spectrophotometer was made up to mark 25ml 30% HCL. 3.10.2 Tannins Tannins was determined by using the spectrophotometric method described by Price and Butter (1977). About 0.5g of each sample was extracted with 3ml methanol. The extract was mixed with 5.0ml water 3ml of 1.0ml (Fecl2 in 0.1N and 0.8 ml2 Fe (w2) was added to 0.1ml of the solution. The extract was read at 720nm on a spectrophotometer. 3.10.3 Saponins About 0.1g of the sample was boiled and filtered with Whatman No.1. Five (5)ml of the titrate was pipetted into a test tube and 2ml of olive oil was added. The solution was shaken vigorously for 30 seconds and read at 620 against a blank. Saponins = reading from convex dilution. Factor x 100 (mg/100g) Weight of sample x 10 3.10.4 Oxalate determination Two (2g) grammes of the sample were prepared into 300ml flask. Twenty (20)ml of 30% HCL was added and allowed to stand for 20 minutes. Four (4) grammes of ammonium sulphate was added and solution was filtered into 200ml volumetric flask and made up to 51 25ml 30% HCL. Ten mililitres (10) ml of the filtrate was transferred in 100ml centrifuge and adjusted to 7.0 with ether NH40H (ammonium hydroxide) or CH3C00H (acetic acid). It was centrifuged at 10000rpm for 15minutes. The supernatant was deducted with 0.10 potassium tetraoxomanganate (Kmn04) and volume was recorded. Calculation Oxalate= Fibre x molk. Mno4 x dilution factor x 10 Weight of the sample 3.11 Statistical analysis Mean and standard deviation were calculated for triplicate determination using the computer software Statistical Package for Social Sciences (SPSS) version 10. 52 CHAPTER FOUR 4.0 RESULTS 4.1 Proximate composition of fresh wild fruits Table 1 presents the proximate composition of fresh fruits. Olax viridis had 59.83% moisture, 5.30% carbohydrate, 6.52% protein, 2.25% fat, 12.52% ash and 13.58% fibre. Ficus carpensis contained 63.39% moisture, 19.45% carbohydrate, 6.5% protein, 0.46% fat, 6.56% ash and 3.49% fibre. Napoleona imperalis contained 61.15% moisture, 15.64% carbohydrate, 3.09% protein, 0.46% fat, 10.84% ash and 8.91% fibre,. Afromonum species contained 60.46% moisture, 14.41% carbohydrate, 2.08% protein, 2.52% fat, 11.05% ash, and 9.48% fibre Gongronema species contained 75.40% moisture, 20.04% carbohydrate, 2.60% protein, traces of fat, 0.66% ash and 1.38% fibre. Table 1: Proximate composition of fresh wild fruits (%) Olax Fiscus Napoleana Nutrient viridis carpensis imperialis Moisture 59.83±0.14 63.39±±0.02 61.15±0.04 Afromonun Gongronema sp 60.46±0.02 75.40±0.04 Carbohydrate 5.30±0.03 19.45±0.05 15.64±0.01 14.41±0.01 20.04 Crude 6.52±0.01 6.53±0.01 3.00±0.01 2.08±0.02 2.60±0.02 Fat 2.25±0.02 0.46±0.01 0.46±0.01 2.52±0.04 Trace Ash 12.52±0.02 6.56+0.01 10.84±0.03 11.05±0.08 0.66±0.01 Fibre 13.58±0.25 3.49±0.04 8.91±0.10 94±0.04 1.38±8.02 protein Mean±5D of three determinations 53 4.2 Vitamin composition of fresh wild fruits Table 4.2 presents vitamin composition of fresh wild fruits. Olax viridis contained 40.22mg ascorbate and 3.99mg β-carotene. Ficus carpensis had 13.68mg ascorbate and βcarotene. Napoleonu imperialis had 48.82mg ascorbate and 11.99mg B-carotene. Afromonum species contained 17.40mg ascorbate and 0.79mg β-carotene. Gongronema species had .14.84mg ascorbate and 0.25mg β-carotene. Table 2: Vitamin composition of fresh wild fruits (mg /100g) Fruits Ascorbate β-carotene Olax viridis 40.22±0.02 3.99±0.020.00 Ficus carpensis 13.68±0.02 36.00±0.020.00 Napoleona imperialis 48.87±±0.02 11.99±0.020.00 Afromonum sp 17.40±.05 0.29±0.020.00 Gongronema sp 14.84±0.02 0.25±0.02 Mean ± 5D of three determinations . 4.3 Mineral composition of wild fruits Table 4.3 presents mineral composition of wild fruits. Olax viridis contained 3.26mg calcium, 4.5mg iodine,, 1.43mg iron, 39.42mg phosphorus, 0.02mg copper and 1.29mg zinc. Fiscus carpensis had 18.03mg calcium, 1.04mg iodine, 1.04mg iron, 0.03mg phosphorus, traces of copper, and 0.42mg zinc, Napoleona imperialis had 4.63mg calcium, 4.97mg iodine,1.29mg iron, 11.46mg phosphorus, 0.02mg copper and 1.45mg zinc. Gongronema species had 16.63mg calcium, 0.10mg iodine, 23.50mg iron, 44.66mg phosphorus, 14.06mg copper and 12.48mg zinc. Afromgromum species contained 3.02mg calcium, 3.38mg iodine,1.48mg iron, 3.85mg phosphorus, 0.03mg copper and 0.02mg zinc. 54 Table 3: Mineral composition of wild fruits (mg/100g) Nutrient Olax viridis Fiscus Napoleama carpensis Imperialis Gongronema sp Afromonum sp Calcium 3.25±0.03 18.03±0.03 4.60±0.01 16.63+0.03 3.02+0.02 Iodine 4.53±0.07 1.04±0.01 4.76±0.01 0.10+0.02 3.85+0.01 Iron 1.43±0.05 1.04±0.01 1.29±0.04 23.50+0.03 1.48+0.09 Phosphorus 39.42±0.03 20.13±0.03 11.46±0.03 44.66+0.03 3.85+0.10 Copper 0.02±0.00 Traces 0.02±0.02 14.06+0.01 0.03+0.00 Zinc 1.29±0.02 0.42±0.02 1.42±0.01 12.43+0.06 0.02+0.00 Mean ± SD of three determination 4.4 Antinutrient composition of fresh wild fruits Table 4.4 presents the antinutrient composition of wild fruits. Olax viridis had 108.18mg phytate, 112.02mg oxalate, 0.12mg tannins and 0.05mg saponins. Fiscus carpensis contained 45.15mg phytate, 60.16mg oxatate, 0.05mg tannins, 0.14mg saponins, Napoleona imperialis had 41.02mg phyate, 120.08mg oxalate, 0.11mg tannins and 0.30mg saponins. Afromonum species contained 81.02mg phytate, 127.22mg oxalate, 0.12mg tannins,and 0.02mg saponins. Gongronema species had 12.06mg phytate, 122.38mg axolate, 03.40mg tannins, and 0.27mg saponins. 55 Table 4: Antinutrient composition of fresh wild fruits (mg/100mg) Fruits Phytate Oxalate Tannins Saponins Olax viridis 108.18±0.03 112.02±0.10 0.12±0.00 0.05±0.00 Fiscus carpensis 45.15±0.03 60.16±0.03 0.05±0.00 0.14±0.00 0.11±0.00 0.30±0.00 Napoleona imperialis 41.02±0.02 Afromonum species 81.20±0.07 Gongronema species 12.60±0.02 120.08±0.03 127.22±0.02 122.38±0.26 0.12±0.00 3.40±0.26 0.02±0.00 0.27±0.00 Mean ± SD of three determinants Table 5: Proximate composition of fresh wild green leafy vegetables Nutrient Fiscus carpensis Vitex doniana Moisture 60.44±0.03 34.44±0.03 Protein 2.18±0.03 4.44±0.00 Fat 3.42±0.02 1.88±0.02 Ash 10.57±0.04 2.05±0.03 Fibre 8.91±0.09 11.45±0.07 Carbohydrate 14.48±0.16 35.74±0.10 Mean ± SD of three determinants Table 4.5 presents proximate composition of fresh wild green leafy vegetables. Fiscus carpensis had 60.44% moisture, 2.18% protein,3,42% fat, 10.57% ash and 14.48% carbohydrate Vitex domiana had 34.18% moisture, 4.44% protein, 1.88% fat, 2.05% ash, 11.45% fibre and 35.74% carbohydrate. 56 Table 6: Vitamin composition of fresh wild green leafy vegetables (mg/100g) Nutrients Fiscus carpensis vitex doniana Ascorbate 8.52±0.02 27.45±0.03 Β-carotene 27.94±0.04 67.83±0.03 Mean ±SD of three determinants Table 6 presents vitamin content of two wild green leafy vegetables. Fiscus carpensis had 8.52mg ascorbate, 27.94mg β-carotene, Vitex doniana had 27.45mg ascorbate and 67.83mg β-carotene. Table 7: Mineral composition of fresh wild green leafy vegetables (mg/100g) Nutrients Fiscus carpensis Vitex doniana Calcium 2.26±0.15 1.45±0.90 Iodine 3.68±0.01 2.21±0.03 Iron 1.70±0.52 1.38±0.06 Phosphorus 1.42±0.01 28.63±0.02 Copper 0.07±0.00 1.65±0.01 Zinc 0.42±0.01 1.65±0.01 Mean ± SD of three determinants Table 7 presents mineral composition of fresh wild green leafy vegetables. Fiscus carpensis had 2.65mg calcium, 3.68mg iodine, 1.7mg iron, 1.42mg phosphorus, 0.07mg copper and 0.42mg zinc. Vitex doniana had 1.48mg calcium,2.21mg iodine,1.38mg iron, 28.63mg phosphorus,0.02mg copper and 1.65mg zinc. 57 Table 8 Antinutrient composition of fresh wild green leafy vegetables (mg/100g) Nutrients Fiscus carpensis Vitex doniana Phytate 127.00±0.09 100.18±0.02 Oxalate 124.47±0.28 128.56±0.03 Tannins 0.14±0.00 0.12±0.00 Saponins 0.02±0.00 0.04±0.01 Mean ± SD of three determinants Table 4.8 presents the antinutrient composition of two fresh wild green leafy vegetables. Fiscus carpensis had 127mg phytate, 124.47mg oxalate, 0.14mg tannins and 0.02mg saponins. Vitex doniana had 100mg phytate, 128.56mg oxalate, 0.12mg tannins and 0.04mg saponins. 58 CHAPTER FIVE 5.0 DISCUSSION 5.1 Proximate composition of wild fresh fruits Moisture: The high moisture content for Gongronema specie (75.40%) was not a surprise. Fresh fruits and vegetables are known to contain higher moisture relative to sun or shade dried samples (Mefoh, 2005). Location, maturity and seasonal variation affect moisture content of plants and their products (Umoh, 1998). The low moisture for wild fresh fruits might be attributed to seasonality. This is because Gongronema that had high moisture thrives during rainy season and other fruits thrive during dry season. Carbohydrate: The carbohydrate levels of the fruits ranged from 5.30% in Olax viridis to 20.04% in Gongronema specie. The carbohydrate level is high compared to carbohydrate level of 11.20 in pineapple (Pumploma-Roger, 2006). This indicates that the wild fruits can act as better food supplement in providing carbohydrate than commonly consumed fruits. Protein: The relatively high protein content of Ficus carpensis and Olax viridis (6.53, 6.52%) might be attributed to their low moisture conent. It is known that the lower the moisture content of a given food the higher is the protein. Oguntona (1998) reported that moisture affects nutrient content of fruits. Gongronema specie is a rainy season fruit that contains high moisture and low protein (75%, & 2.60%) respectively. Generally, all the wild fresh fruits are low in protein, because they contain much more moisture and less when they are dried. Fat: The low fat for Ficus carpensis (0.46%), Napoleona imperalis (0.46%) and Gongronema specie is expected. Fresh fruits and vegetables contain less than 0.50% fat. The low fat content of the fresh wild fruits studied in the present work is comparable to the observations of many workers (Sheila, 1978; Ihekoronye and Ngoddy; 1985), who reported that fruits are not good sources of fat. 59 Ash: The high ash for Olax viridis(12:52%) is an indicative of high minerals. This observation appeared to suggest that fresh Olax viridis is a better source of mineral than pawpaw (4.83%) a. commonly available and commonly consumed fresh fruit. It is a known fact that foods that have high ash invariably would have higher mineral composition. Fibre. The high fibre for Olax viridis (13.58%) was not a surprise. Fruits and vegetables contain high fibre whether fresh or dried. The highest moisture for Gongronema specie (75.40%) precipitated its least fibre value (1.30%). The high fibre for the wild fruits observed in this present work related to those of commonly consumed fruits, example, guava demonstrated their superiority as source of fibre (Roger, 2006). 5.2 Vitamin composition of wild fresh fruits Ascorbate. The high ascorbate content of the fresh wild fruits was not a surprise. Ascorbate is a water soluble vitamin which is easily lost upon exposure to drying treatment. The high ascorbate for Napoleona imperialis (48.37mg) strongly suggest that it could be good cheap source of the nutrient to address ascrobate deficiency. Ascrobate is very important in human nutrition. It prevents scurvy. As little as 5 to 10mg ascorbate daily intake prevents scurvy. Ascorbate is an antioxidant, that destroys free radicals in the cells Ascorbate activates folic acid and converts iron in food into the form the body utilizes it. Provitamin A (Beta-carotene): The high provitamin A in Ficus capensis (36mg) had many nutrition implications, it showed that wild fresh fruits could be good sources of porvitamin A as those of cultivated fruits. This implies that provitamin content of wild fresh fruits could maintain integrity of cell membranes in our body, especially the eyes. Vitamin A is necessary for healthy skin as well as the manufacture of glycogen and metabolism. Vitamin A is involved in bone and tooth development and keeps the tissue lining of the respiratory, digestive and urogenital tracts healthy (Leslie and Landal, 1989). 60 5.3 Mineral composition of wild fresh fruits Calcium: The fairly high calcium for ficus carpensis (18.03mg) and Gongronema specie (16.30mg) appeared to suggest that these fruits could supply adequate daily calcium requirement of the populace. The current daily requirement of calcium for children 4-8 years is (210mg) based on this, 200g portion of the fruits could supply adequate calcium need of this age group. The low levels of calcium for other fresh wild fruits might be associated with (a) soil concentration of the nutrient (b) the types of fruits and (c) deference in laboratory analysis – a commonly observed phenomenon. Iodine: The high iodine for Olax Viridia (4.53mg), Napoleona specie (4.76mg) and Afromonum specie (3.85mg) suggests that these fresh wild fruits could supply slightly higher iodine than required for good health. The daily requirement for iodine for adult males and females is 150mcg. This means that 100g portion of the fresh wild fruits could supply more of the daily requirements for this group. Iron. The iron value for Gongronema specie, (23.50mg) was higher than that of orange (1.48mg). This indicates that the fruit could supply adequate iron intake of the subjects that need weight reduction. The recommended daily requirement for iron is 10mg, as such 100g portion of Gongronema specie could supply more iron than is required. Phosphorus: The high phosphorus (39.42mg) for wild fresh Olax virides fruit demonstrated that it contained phosphorus comparable to those of most commonly used fresh fruit such as orange that contains 4.6mg/100g sample. The phosphorus content 20.13mg and 44.66mg for fresh Ficus carpensis and Gongronema specie, respectively, relative to those of Napoleona imperialis 1.46mg showed that Ficus capensis and Gongronema specie could supply one third of phosphorus than Napoleona imperialis and Afromonum specie, Olax vridis, Vicuss 61 carpensis and Gongronema specie, respectively, could supply one third of daily requirement of phosphorus. Copper: The higher copper value for these fresh fruits has some nutrition implications. The high Gongronema specie copper content (14.06mg) showed that the fruit could supply more than five times the daily requirement for copper (3mg). Zinc: The lower to trace of zinc for Olax viridis (0.02mg), Ficus carpensis (trace), Napoleona (1.42mg) and Afromonium specie (0.02mg) showed that these fresh wild fruits are poor sources of zinc as earlier observed (Leslie and Landal, 1989). However Gongronema species was an exception. It contains 12.43mg zinc. This value is more than eleven times those of the other fruits. Gongronema specie had high zinc that was more than the recommended daily requirement for zinc (9mg). One hundred grammes (100g) portion of Gongronema fruit could supply one third of the daily requirement of the nutrient. 5.4 Anti nutrient composition of wild fresh fruits Phytate: The traces or lower phyrate values for the wild fresh fruits have two implications (1) the value was so low that it could not chelate divalent minerals, (calcium, phosphorus and zinc) to cause their non-bio availability (2) it could increase much more free phosphorus. The low phytate observed was due to phytase that hydrolyzed phytate to phytin, free phosphorus and protein. Heaney, Weaver and Filzsimmons (1991) reported that calcium absorption increases with low phytate (3.01mg/g). Oxalate: The low oxalate values for all the fruits were low except that of Afromoum specie. It has the highest value (127-22mg). The higher oxalate content of Afromonum specie might have adverse effect on calcium nutriture. It is known that oxalate chelates calcium to precipitate its deficiency due to its unavailability to the body. Tannin: The low tannins for the wild fresh fruits indicates that it could not chelate iron to cause its deficiency and make it non-bioavailable. Scheiabome et al (2008) reported that 0.15 62 – 0.2%) of tannins could be beneficial. On the other hand, Cheng, Cahng, Bailey, and Remakinsing (2006), reported that tannins safe level is skill unclear. Saponins: Cassidy and Dalaise (2003) established that 146mg/g of saponins is the safe level. The saponins for the wild fresh fruits was comparable to that of Cassidy and Dalaise (2003). Afromonum had 0.02mg saponins as its highest concentration. This level of saponin was much lower than the established safe level of 146mg. This further confirms that Afromonum posses no threats to the consumers. Proximate composition of fresh wild green leafy vegetables (%) Protein: The low protein levels for the wild fresh green leafy vegetables (2.1mg and 4.44 mg each was a not a surprise. The high moisture content of the vegetables was the major causs of low protein. This observation in the present study agreed with those of many workers (Osagie, 1992 FAO, 1997, Oguntona, 1998; Roel, 2001; Udofia, 2005). They reported that fresh green leafy vegetables contain lower protein than dry vegetables because of the high moisture content of the fresh green leafy vegetables. Seasonality also affects the moisture content (Umoh, 1998). The two vegetables were dry season vegetables. The vegetable that had low protein had high moisture. Ficus carpensis had 2,18% protein. Vitex domiana vegetable protein was low (4.44%) or relative to those of commonly consumed fresh vegetables such as bitter leaf that has 22.20% (Umeh, 1998). Fat: The low fat for wild fresh green leafy vegetables 1.88% and 3.42% for Ficus carpensis and Vitex doniana was not a surprise because vegetables have very low fat to maintain cell wall integrity. The low fat value for these vegetables has nutrition implication. Besides being good sources of fibre, they could be used as a component of low diet for many patients who are placed on low fat diets. 63 Ash: The high ash for wild fresh leafy green vegetables strongly implies that the vegetables would be a very good source of minerals. Fibre: The differences in fibre content among the vegetables might be associated with differences in moisture and varietal differences. On the other hand, the high fibre for all the vegetables was not a surprised. Vegetables are known to be better sources of fibre than other plant foods. Both vitex domiana and Ficus carpensis had highest fibre and lowest moisture. The importance of fibre in human diet is well established. Body and Leelamma, (2003) reported that vegetables are good sources of dietary fibre that play an important function in digestive system. Carbohydrate: The high carbohydrate for Vitex doniana (35.77%) may be attributed to its low moisture. The low carbohydrate value for Ficus carpensis may be attributed to its high moisture that lowered its dry matter of which carbohydrate is one of them. This observation is in line with those of some workers (Eka, 1989) who reported that high moisture of a given food, affects its dry matter adversely of which carbohydrate is among. 5.5 Vitamin composition of lesser-known fresh wild green leafy vegetables The higher level of both ascorbate and beta-carotene (27.45 and 67.83mg) for Vitex doniana relative to those of Ficus carpensis (8.52 and 27.94mg) were attributed to vegetable type as well as nutrient content of the soil. Regardless of the differences in their nutrients, these two vegetables appear to be fairly good sources of the nutrients (Table 4.6). 5.6 Mineral composition of fresh wild green leafy vegetables When the individual minerals content calcium, iodine, iron, phosphorus, copper and zinc were summed up, Vitex d. had an edge (35.34mg) over Ficus c. (9..94mg) (Table 4.I). This wide variation (35.34, 9.94mg) might be associated with soil, nutrient content and type of green leafy vegetables (Table 4.7). 64 Many earlier workers (Udofia, 2005; Umoh, 2006; Ezeife, 2010; Onuora, 2010) who worked on many types of vegetables produced from various soil types had made similar observation as the present study. 5.7 Antinutrient composition of fresh wild green leafy vegetables When the individual antinutrients content of the two vegetables (Table 4.8) were summoned up, Ficus carpensis had higher value (251.63mg) relative to that of Vitex doniana (228.90mg)( Table 4.8). The reasons for the differences in antinutrients are similar to those of minerals (Table 4.7). Conclusion This study disclosed existence of many edible wild fruits and vegetables in forests and farmlands in Ayamelum Local Government Area of Anambra State, Nigeria. Many households are not aware of their existence, preparation and utilization when popular edible cultivated fruits and vegetables are less available in dry season.These fruits and vegetables contain nutrients, especially micronutrients comparable to those of commonly consumed in the communities. Wild fruits and vegetables have nutrients similar to those of accessible and cultivated alternatives. These foods are much more available in dry season when cultivated and commonly consumed fruits and vegetables are scarce and costly. Families will maintain regular fruits and vegetables consumption all year round by consumption of wild ones that contribute substantial amounts of micronutrients in diets in Ayamelum Local Government Area of Anambra State, Nigeria. The rich micronutrient potential of wild fruits and vegetables are promising among indigenous people 65 Recommendations Identification of more wild fruits and vegetables is imperative for regular consumption because of their rich nutrient potentials. Studies on the bioavailability of nutrients in these fruits and vegetables are needed. Deforestation must be discouraged to maintain constant availability of wild fruits and vegetables. Nutrient content of many wild fruits and vegetables in local food composition Tables would be an important tool for nutritionists and dieticians nationwide. 66 REFERENCES Achnewu, S.C.(1983).Chemical and nutrient composition of fermented products from plant foods. Nigeria Food Sciences Journal, 1;115-116 Aletor, M. V. A. and Adegun O. A. (1995).Nutrient and anti-nutrient components of some `tropical leafy vegetables. Food Chemistry ,5, 375-379. AOAC, (1995). Official Methods Analysis. Association of Official Analytical Chemist. Washington, D. C. U.S. A. American Dietics Association.(1997).Health implication of dietary fibre, Journal of the America. Dietetics Association. 7 (6), 26-54. Afscana, K,, Shiga, K,, Ishizuka, S,, & Hara, H.(2003).Ingestion of an indigestible saccharide, difructose anhydride3, particularly prevents the tannic acid-induced suppression of iron absorption in rats. Journal of Nutrition society, 133(11), 53-60 Brune, M. Rossnder, L, &, Hauberg, L. (1989) Iron absorption and phenolic compounds: Enwere, N. J. (1998). Foods of plant origin. Nigeria Afro-Orbis Public Ltd p. 293 Faboya, O. O. P. (1983). Mineral content of some green leafy vegetables commonly foods in the western part of Nigeria. Food Chemistry, 12,216-230. FAO (1997). Preventing micronutrient malnutrition. A guide to food-based approaches. A manual for policy makers and programme planners. Food and Agricultural Organization of United Nations and International Life Science Institute. Washington D. C. p19. Farrel, K. T. (1999). Species, condiments and seasonings, Spinger, Pp 17-19. ISBN 08034213370. Hamrick, I., & Counts, S. H. (2008). Vitamin and mineral supplements wellness and prevention. Hurrel, R. F., Readdy, M.,& Cook, J. D. (1999). Inhibition of non-haemiron absorption in man by polyhenolic-containing beverages” Br. Journal of Nutrition society. Getahum, A. A. (1974). The role of wild plants in the native diets in Ethiopia. AgroEcosystem, 1,45-56. Heaney, R. P., Weaver, C. N.& Fitzsimmons, L. M.(1991). Soy bean phytate content; Effects on calcium absorption. American Journal of Clinical Nutrition, 53,745-755 Ifon, E. T. & Bassir, O. (1979). The nutritive value of some Nigeria leafy vegetables. Part 1 vitamin and mineral contents. Food Chemistry, 4, 267- 286. Institute of Medicine,(IOM) (1997). Recommended dietary intakes of phosphorus. Washington: National Academy Press. 67 Institute of Medicine, (2000). Dietary Reference Intakes: Vitamin C, vitamin E, selenium and carotenoids. Washington. National Academy Press. Institute of Medicine, (2001). Dietary reference intakes, proposed definition of dietary fibre, Washington. National Academy Pres. Janick, J. & Simon, J. E. (1990). The new crop era. 2nd Edition. U.S.A., Timber press, Leslie, E. G. & Landal, H. K. (1989). Nutrition Management for foodservices. America; Delmar Publishers. Lewis, R. A. (2002). CRC Dictionary of Agriculture Sciences, CRC Press. Pp 375-376. MacGee, R. A. (2004). On Food and Cooking: The science and love of the kitchen. Mauseth, J. D. (2003). Botany: An Introduction to plant biology. Pp 271-272. Nnanyelugo, D. O. (1983). Seasonal variation and contribution of cowpea and other legumes to nutrient intakes in Anambra state, Nigeria, Ecol. Food. Nutri. 17:271-287. Oguntona, T. & Oguntona, C. R. B. (1986). Proximate composition of three leafy vegetables commonly consumed in Northeasthern Nigeria. Paper presented at 1st National workshop of food composition.-- Universit of Ibadan, Nigeria. Oguntona, C. E. (1991). Functional characteristics and chemical composition of indigenous wild herbs species, fruits and leafy vegetables used as food. M. Phil. Thesis, Rivers state university of Science and Technology, Port Harcourt, Nigeria. Oguntona, T. (1998). . In: Osagie, A. U. & Eka, O. U. (Eds). Nutritional quality of plant food. Nigeria Post Harvest Research Unit. 133. Oke, O.L. (1967). The ascorbic content of Nigeria vegetables. Journal of Food Sci. 32:86. Okigbo, B. N. (1977). Neglected plants of horticulture and nutritional importance in traditional farming systems of tropical Africa. Acta Horticulture. Okoli, E.C.; Nmorka, O.O. & Unaegbu, A. (1988). Blanching and Storage of Some Nigerian Vegetables. Int. Journal of Food. Sci. Tech. 23: 641. Pamplama-Roger G. D. (2006). Healthy foods, Canada, Spain, Editorial Safeliz. Pariva, F., Low, R. K., & Stoller, M. L., (1996) The influence of diet on urinary stone disease. Journal of Urolgy l. 55(2), 432-40 Pearson, D. (1976). Chemical analysis of foods. Journal of Science, Food and Agriculture, 26: 207. 68 Rajyalakshmi, K. et al., (2006). Oxalate contents of species of the polygonaceae, Amaranthaceae and chemopodiaceae. Ruel, M. T. (2001). Can food based strategies help reduce vitamin A and iron deficiency. A review of recent evidence. Washington D. C. IFPRI Suneeth, V. (2001). Total carotenoid and beta-carotene contents of forest green leafy vegetables consumed by tribes of South India. Food and Human nutrition. Schiavone, A. et al., (2007). Effects of a natural extract of chestnut wood on digestibility, performance traits and nitrogen balance of broiler chicks. Poultry Science, 87, 521-527. Selman, J. D.(1994). Vitamin retention during blanching of vegetables. Food Chem. 49;147. Schmidt, D. T. (1971). Comparative yield and composition of eight tropical leafy vegetables grown at two different fertility levels. Agronomy Journal, 63, 550-570. Sheila, B. (1978). In better health through good eating. Golgi Books, 151. Smith, I. F. (1983). Use of Nigerian leafy vegetables for diets modified in sodium and potassium. Nigerian Journal of Nutrition Science. 26; 207-220. Temple, V. J, (1998). Lesser known plant foods, in Osagie, A. U. (eds). Nutritional quality of plant foods. Post Harvest Research Unit 274. Taylor, T. G. (1975). Perspective in mineral nutrition. Proceeding of Nutritional science., 34, 41-46 Tindall, H.D.(1983). Vegetables in the tropics. London. McMilian Press, 86. Umoh, I. B. (1998). Commonly used fruits in Nigeria. In Osagie, A. U. and Eka, O. U. (eds). Nutritional quality of plants foods. Post harvest research unit, Nigeria. University of Benin, 119. Uwegbute, A. C. (1989). Vegetables, nutrition and utilization. In Mba, B. N. and Nnanyelugo (eds). Food crops production, utilization, and nutrition. Ibadan: Dotan Public Ltd. p175. WHO (2000). Iron improve life. The micronutrient initiatives, World Health Organization. Geneva.15.
