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Download Week 6 - Minerals
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MINERALS Chapter 7 Learning Objectives • Describe the functions of minerals • Identify food sources of minerals • List minerals lacking in American diets • List foods that are the best sources of these minerals Learning Objectives • • Give tips to ensure mineral intakes are sufficient Identify cooking techniques that • promote retention of nutrients • cause nutrient loss from foods Minerals • Essential for life and health • Must be obtained from food • Do not provide energy Minerals • Needs are small measured in milligrams (1/1000 of a gram) or micrograms (1/1000 of a milligram) Minerals • 15 are essential and must be from food • Many minerals occur in nature • All are inorganic elements • no carbon in structure • All are single elements Shortfall Nutrients – or Nutrients of Concern Many people do not get adequate amounts of: Vitamins • • • • • • Minerals Vitamin A • Calcium* Vitamin C • Magnesium Vitamin D* • Potassium * Vitamin E • Sodium* Vitamin K * Biggest nutrient gaps Most diets also lacking dietary fiber Choline Most children and adults get too much sodium Minerals • Found in water and foods • Remain intact during digestion • Stable, not easily destroyed by heat, light, oxygen Two Groups of Minerals Major Minerals (100 mg or more a day) Calcium Chloride Magnesium Phosphorus Potassium Sodium Sulfate Biotin Trace Minerals (less than 20 mg/day) Iodine Iron Zinc Selenium Fluoride Chromium Copper Manganese Molybdenum General Functions of Minerals • Maintain the body’s fluid and acid/base balance • Provide structural components for blood, bone, tooth cells • Sustain immune system General Functions of Minerals • Co-factors in metabolic systems to repair cells and protect from oxidative damage • Participate in energy production, muscle contraction, transmission of nerve impulses Food Label for Nutrients % daily value Goal 100% Good Source- 10-19% of daily value Excellent Source- 20% or more of daily value Calcium • Most abundant mineral in the body • 99% used to form and maintain teeth and bones at all ages • Calcium necessary throughout life for bone mass and bone strength Calcium • Plays key role in blood clotting • Aids muscle and nerve function • Necessary for regular heartbeat, muscle contraction Calcium DRI 12-18 yo- 1300 mg/day 19- 50 yo- 1000 mg/day Over 50- 1200 mg/day Older adults, 70+- 1500 mg/day Calcium • Higher absorption in children and during pregnancy • Not all calcium absorbed • Deficiencies lead to poor bones, teeth and increased fractures Calcium - Sources • • • • • • Milk, milk alternatives Yogurt Cheese Yogurt Canned fish with bones Calcium fortified orange juice Calcium - Sources • Tofu set with calcium • Greens • Rhubarb • Legumes Food Issues with Calcium • Dairy products optimal source because protein, vitamin D and lactose boost absorption • Tofu often processed with calcium to set. Little calcium in other soy products. • Foods fortified with calcium, calcium citrate, well absorbed form Food Issues with Calcium • Full-fat dairy products high in cholesterol and saturated fat • Using a non-fat dried milk, evaporated milk and yogurt in cooking boosts calcium intake • Canned salmon with bones, sardines are rich sources of calcium Osteoporosis Calcium deficiency “brittle bones” Hip, spine, wrist Peak bone formation- first 3 decades Weight bearing exercise, calcium, vitamin D, K, magnesium intake Risk- alcohol, smoking, high sodium Osteoporosis and Calcium Age and bone calcium Maximizing bone mass Potassium • Less than 5% of Americans get optimal potassium intake • Major role in Maintaining fluid balance Works opposite sodium Acid/base balance Healthy blood pressure Heart beat Bone health Potassium • DRI- 4700 mg/day • Found in fruits, vegetables, milk, legumes • Deficiencies linked to hypertension • Low intake related to dehydration, confusion, weakness Sodium • Daily Value – 2400 mg • Dietary Guidelines for Americans, 2010 2300 mg 1500 mg for ages 51+, African Americans. hypertension, kidney disease, diabetes What Sodium Does in the Body • Regulates body fluids • Regulates acid-base balance • Helps nerves and muscles function properly • Helps glucose and amino acids move from blood into cells Problem with Excess Sodium • Can contribute to fluid retention • May contribute to hypertension Sodium sensitive Elderly People with diabetes or kidney disease African Americans Sodium • Filtered out of the blood by the kidneys • Excreted in urine • Lost through the skin via sweating Sodium and Athletes Sodium lost through sweat Replace fluids with water, but not sodium Hyponatremia Muscle cramps Clear sports drinks Exercise 1 hour or longer Consume plenty of sodium Where is Sodium Found? Table salt • • • • Salt (NaCl) is 40% sodium 1 gram of salt is 400 mg sodium 1 teaspoon of salt is 5.6 grams 1 teaspoon of salt adds about 2300 mg of sodium to a dish Where is Sodium Found? • Flaked salts weighs less than 5.6 grams per teaspoon • Less sodium per teaspoon Where is Sodium Found • 75% salt from manufacturers • 15% from salt added in cooking or at the table • 10% comes from natural content Where is Sodium Found? Common ingredients • Table salt • Baking soda • Baking powder Where is Sodium Found? • • • • • • Monosodium glutamate (flavor enhancer) Sodium benzoate (preservative) Sodium caseinate (thicken, bind) Sodium citrate (control acidity) Sodium nitrite (Curing agent) Sodium phosphate (emulsifer, stabilizer) Where is Sodium Found? Common condiments • • • • Fish sauce Soy sauce Soy sauce, low-sodium Tamari sauce Where is Sodium Found? • • • • • Mustard Capers Catsup Anchovies Hoisin sauce Where is Sodium Found Processed foods • Canned soups • Pre-prepared sauces • Cured, smoked and deli meats • Frozen foods, pizza • • • • Cheeses Cereal, ready-to-eat Breads Snack foods Sodium Issues in Food • Salt biologically preferred flavor • Sodium compounds perform many food functions in processed foods • Chefs should try to lower sodium sources as much as possible. READ LABELS Sodium Magnesium • Works with potassium to reduce blood pressure • In chlorophyll of green leafy vegetables Magnesium • Best food sources: Bran Seafood Green leafy vegetables Legumes Nuts Iron • Hemoglobin and Myoglobin • in blood cells that carrys oxygen to cells of body muscles • Heme iron (from animal sources) better absorbed than iron from plant foods • Vitamin C- helps iron absorption from plant foods; so does some heme iron Iron • Best food sources: Shellfish Liver Meats (especially red meats) Fortified cereals, meatless protein sources Legumes Molasses • Cooking in cast iron pans adds iron to acidic foods. Useful for vegetarians Iron Deficiency Anemia Low hemoglobin Most common Breastfed infants, kids growth spurts Pre-menopausal or pregnant women, female athletes Chronic bleeding conditions Poor diet Symptoms Poor growth Tired Cold Poor performance Iron RDA’s Infants > 6 months: 11 mg/day Teens: 11-15 mg/day Adult males, post menopause: 8 mg/day Women 19-50 yo: 18 mg/day Pregnancy: 27 mg/day Iodine • Necessary to make the hormone thyroxin, that regulates metabolic rate and body temperature • Food sources: Iodized salt Fish Shellfish Foods grown in iodine rich soil Iodine • Residues of cleaning compounds on foodservice equipment add to intake • ? Increased need • ? Inadequate intake Disinfectants • Dough conditioners • Dairy industry • Designer salts • Fluoride • For formation of teeth and bones and to keep them strong, anti-bacterial • Food sources: Fluoridated water Toothpaste Canned seafood Tea Fluoride • Most community water is fluoridated at 1 part fluoride to 1 million parts water. This level recommended by the dental society and US government • Excess can mottle teeth • Controversy…. Adding Vitamins and Minerals Fortification • Vitamins and minerals are added • Fortification common in breakfast cereals, milk and dairy alternatives, fruit juices Adding Vitamins and Minerals Enrichment • Vitamins and minerals are added to replace nutrients lost in processing • Enrichment is common in breads breakfast cereals, and other grain products Dangers of Excess Vitamins and Minerals • Amounts found in foods are safe • Regular intake of high-dose supplements can be dangerous, stressing liver and kidney Bioavailability • Bioavailability is the degree to which a nutrient from foods is absorbed and used by the body. Mineral Bioavailability Influenced By: • Nutrients in high dose supplements not used as well as nutrients in foods • Binders such as oxylates and phytates decrease absorption • Cooking can increase absorption breaks bonds between minerals and binders Oxalic and Phytic Acids Oxalic Acid Binds some minerals (calcium) so they are partially absorbed Found in: Spinach Oranges Rhubarb Tea Coffee Bananas Ginger Almonds Phytic Acid Binds some minerals (iron and zinc) so they are partially absorbed Found in: Cereals Nuts Sesame seeds Soybeans Wheat Pumpkin Beans Nutrient Bioavailability is Enhanced By: • Enzymes and bacteria in digestive tract can increase amount of nutrients absorbed • Vitamin C boosts absorption of iron present in plant foods • Protein and vitamin D boost calcium utilization • Fermentation processes, such as those used to make miso and tempeh, may improve iron bioavailability Nutrient Bioavailability is Reduced By: • Too much of one mineral can reduce the absorption of another • Polyphenols in regular and herbal teas, coffee and red wine bind some iron • Cooking softens cell walls of food so more nutrients released Raw Food Pros Vitamins and minerals aren’t lost from heat or leaching into water No damage to enzymes in vegetables and fruits Cons Cooking destroys salmonella and E.coli Cooked vegetables may have more bioavailable nutrients More palatable Softens food for easier digestion Nutrient Retention • Minerals are more stable than vitamins • Minerals cannot be destroyed by: • Heat • Light • Oxygen • Minerals can be destroyed by: • Leaching into water that is discarded
