Nutrition for Foodservice and Culinary Professionals Chapter 6 Vitamins © 2013 John Wiley & Sons, Inc. All rights reserved. Learning Objectives State four general characteristics of vitamins, and explain how water-soluble and fat-soluble vitamins are different. Identify which vitamin is deficient in the American diet and two vitamins that are toxic when taken in excess. Identify functions and food sources of each vitamin presented. List benefits of eating fruits and vegetables. Discuss the use of fruits and vegetables on the menu, and describe ways to conserve vitamins when handling and cooking fruits and vegetables. Define phytochemicals and give examples of foods in which they are found. © 2013 John Wiley & Sons, Inc. All rights reserved. Basics of Vitamins Vitamins = organic substances that carry out processes in the body that are vital to health ◦ Very small amounts are needed—and only small amounts are in foods. ◦ Most vitamins are obtained by eating foods— some are made by intestinal bacteria and one is made in the skin in sunlight. ◦ There is no perfect food with all the vitamins you need in just the right amounts. ◦ Vitamins do contain kcalories. ◦ Some vitamins in foods are precursors. © 2013 John Wiley & Sons, Inc. All rights reserved. Two Categories of Vitamins Fat-soluble ◦ Occur in foods containing fats ◦ Stored in the body ◦ Include vitamins A, D, E, and K ◦ Excessive intake of A or D may lead to undesirable symptoms such as weak bones Water-soluble ◦ Includes vitamin C and B-complex vitamins ◦ B vitamins work in every cell where they function as part of coenzymes ◦ A coenzyme combines with an enzyme to allow the enzyme to do its job ◦ Must take daily because excess is excreted (except B6 and B12) © 2013 John Wiley & Sons, Inc. All rights reserved. Water-Soluble Vitamins ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ Vitamin C Thiamin Riboflavin Niacin Vitamin B6 Folate Vitamin B12 Pantothenic acid Biotin © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamins: Too little and too much What is the vitamin most likely to be deficient in United States? Vitamin D In addition, some elderly are deficient in vitamin B12 and women capable of becoming pregnant are often deficient in folate. What vitamins are most likely to be toxic in excess? Vitamin D, also vitamins C and B6 © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin A Functions: Food Sources: ◦ Fat-soluble vitamin; ◦ Milk and eggs maintains the health of ◦ Many red, orange, or the eye and vision yellow fruits and (prevents night vegetables contain blindness) carotenoids—pigments ◦ Promote healthy skin —some of which can be and surface linings of converted to vitamin A the lungs, GI tract, etc. (such as beta carotene, which is also an ◦ Supports reproduction, antioxidant) growth, and development © 2013 John Wiley & Sons, Inc. All rights reserved. Sources of Vitamin A Many red, orange, or yellow fruits and vegetables contain carotenoids and are therefore sources of vitamin A. Some green vegetables, such as spinach and romaine, also contain vitamin A. © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin D Functions: ◦ Maintains normal blood levels of calcium and phosphorus by enhancing their absorption into the body. ◦ Normal blood levels of calcium and phosphorus are needed to make and maintain strong bones. When ultraviolet rays shine on your skin, you make a precursor of vitamin D. © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin D Very few foods contain vitamin D except for fatty fish. All milk is fortified with vitamin D. Most cereals are fortified. Several months of D can be stored in the body, so it is helpful during winter months when sun is not as strong. All milk in the United States is fortified with vitamin D. Vitamin D is also often added to breakfast cereals, butter, and margarine. Some orange juice is also vitamin D-fortified. © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin D (cont’d) A majority of adults and many children in the United States do not meet the RDA. As you get older, the amount of vitamin D your body makes from sun exposure decreases by more than 50 percent. Vitamin D deficiency in children can cause rickets; in adults can cause osteomalacia. Vitamin D deficiency can contribute to osteoporosis (fragile bones likely to break)—typically seen in older women. Vitamin D is toxic when taken in excess of the RDA. © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin E Functions: ◦ Antioxidants ◦ Protects against free radicals, which can damage cells © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin C Functions: ◦ Important to form collagen—a protein substance that provides strength to bones, teeth, skin, etc. and helps heal wounds. Collagen is like cement, holding cells and tissues together. ◦ Makes some hormones. ◦ Strengthens resistance to infection. ◦ Antioxidant. Vitamin C content of food is reduced by prolonged storage and cooking— because it is water-soluble and can be destroyed by heat. Certain people need more vitamin C: smokers, pregnant and breastfeeding women, children, and anyone with fever or infection. © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin C Food Sources © 2013 John Wiley & Sons, Inc. All rights reserved. Thiamin, Riboflavin, and Niacin Functions: ◦ All are part of coenzymes needed to get energy from carbohydrate, fats, and protein. ◦ Needed for normal growth. Food Sources: Thiamin: pork, beans, watermelon, acorn squash Riboflavin: milk and milk products, eggs Niacin: meat, poultry fish, peanut butter, milk, and eggs © 2013 John Wiley & Sons, Inc. All rights reserved. Thiamin, Riboflavin, and Niacin (cont’d) © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin B6 Functions: ◦ Part of a coenzyme involved in carbohydrate, fat, and protein metabolism —especially crucial to protein metabolism. ◦ Makes hemoglobin in red blood cells—carries oxygen to cells. ◦ Helps immune system. © 2013 John Wiley & Sons, Inc. All rights reserved. Folate Functions: ◦ Folate is part of coenzymes required to make DNA so it is needed to make all new cells. Pregnant women are at risk of folate deficiency, which may cause neural tube defects (malformed brain or spine) during first few months of pregnancy. All women capable of becoming pregnant should take 400 mcg of synthetic folic acid daily from fortified foods (breads) or supplements in addition to natural folate in foods. © 2013 John Wiley & Sons, Inc. All rights reserved. Folate © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin B12 Functions: ◦ Part of a coenzyme needed to make new cells and DNA. ◦ Activates the folate coenzyme. ◦ Ensures normal functioning of the nervous system. Found only in animal foods so could be problem for vegans. Vitamin B12 is harder to absorb for elderly, who may need foods fortified with B12 or supplements that use crystalline vitamin B12 (easier to absorb). B12 deficiency affects nervous system. © 2013 John Wiley & Sons, Inc. All rights reserved. Vitamin B12 © 2013 John Wiley & Sons, Inc. All rights reserved. Culinary Focus: Fruits and Veggies Three reasons to eat more fruits and vegetables: ◦ Most fruits and vegetables are major contributors of a number of nutrients that are underconsumed—vitamins A and C, folate, dietary fiber, etc. ◦ Consuming them is associated with less risk of many chronic diseases such as heart disease. ◦ Most fruits and vegetables, when prepared without added fats or sugars, are relatively low in kcalories. © 2013 John Wiley & Sons, Inc. All rights reserved. Tips To get a healthy variety of fruits and vegetables, think color. Store fruits and vegetables properly and use at optimum time for freshness, color, flavor, and nutrition. Keep most fruits and veggies cold and moist. Consider cooking methods such as blanching, stewing, steaming, grilling, sautéing, baking, boiling, and braising. © 2013 John Wiley & Sons, Inc. All rights reserved. Tips (cont’d) When cooking, consider texture and flavor change. Keep cover off the pot of vegetables such as cabbage, cauliflower, Brussels sprouts. Do not overcook! © 2013 John Wiley & Sons, Inc. All rights reserved. To Prevent Nutrient Loss in Fruits and Vegetables Buy fresh, high-quality produce, and check closely when receiving. Store properly (close up the wrapping tightly to decrease exposure to the air, which pulls out water) and use product when it is still fresh. When cooking: Avoid peeling, prepare small amounts at a time, cook quickly using appropriate methods such as steaming, cook just until tender. © 2013 John Wiley & Sons, Inc. All rights reserved. Menuing and Presentation © 2013 John Wiley & Sons, Inc. All rights reserved. Menuing and Presentation (cont’d) Fruits are a natural in salads, such as pineapple and raisins with carrots. Roasted fruits with shallots are a wonderful base on which to place proteins. Place chicken on a bed of roasted peaches and mango with jicama or sautéed bok choy. Fruits are a natural for dessert—fresh, roasted, or baked into a cobbler with a oatmeal almond crust. Berries are great when you want vibrant colors in sauces, purées, toppings, and garnishes. © 2013 John Wiley & Sons, Inc. All rights reserved. Menuing and Presentation (cont’d) Vegetables allow you to serve what looks like a big portion with reduced kcalories and no fat or cholesterol. When using vegetables, be mindful of the season for maximum flavor, visual appeal, and value. Also think variety. Olives add exquisite flavor—there are many great varieties, such as Manzanilla or Gaeta. © 2013 John Wiley & Sons, Inc. All rights reserved. © 2013 John Wiley & Sons, Inc. All rights reserved. © 2013 John Wiley & Sons, Inc. All rights reserved. Hot Topic: Functional Foods and Phytochemicals Functional foods are foods that contain an ingredient that provides health benefits beyond the nutrients in the food. For example, bottled drinks are enhanced with herbs and taurine. Many of the healthpromoting ingredients in functional foods are phytochemicals— bioactive compounds found in plants that are linked to decreased risk of chronic diseases. For example, cocoa is a rich source of antioxidants that may help protect your blood vessels and heart. © 2013 John Wiley & Sons, Inc. All rights reserved. Functional Foods Like dietary supplements, functional foods will not compensate for a poor diet. Whole foods still contain the right amount and balance of nutrients and phytochemicals to promote health. © 2013 John Wiley & Sons, Inc. All rights reserved.