Nutrition for Foodservice and Culinary Professionals Chapter 3 Carbohydrates

Introduction to Carbohydrates Carbohydrates are a large class of nutrients including: sugars starch and fibers that provide most of the energy for your body. Most carbohydrates are found in plants.

Photosynthesis Most carbohydrate foods are plant foods. Photosynthesis is a process in which plants use energy from the sunlight to convert carbon dioxide and water to carbohydrate.

Types of Carbohydrates Simple carbohydrates = Sugars Examples: Fructose in fruit (natural) Table sugar (processed) Complex carbohydrates = Starch = Fiber Complex carbs contain chains of many sugars.

Simple Carbohydrate (Sugars) Simple carbohydrates include: Monosaccharides = single sugar Examples Glucose Fructose Galactose Disaccharides = two sugars bonded together

Simple Carbohydrates Glucose The most abundant sugar found in nature Most important source of energy for us and for plants Blood glucose level—vital to health and having energy Found in fruits and honey (and many plant foods) Fructose The sweetest natural sugar Found in fruits and also in honey Found in high fructose corn syrup used in sodas, candy, and other foods Galactose Found in milk linked to glucose The sugar in milk is not very sweet

Disaccharides = Double Sugars Sucrose = table sugar Lactose = milk sugar

Sucrose = White Sugar Raw sugar is made from sugar cane and sugar beets. This raw sugar must be further refined for human consumption. White sugar provides virtually no nutrients for its 16 kcalories/teaspoon.

Relative Sweetness of Sugars and Artificial Sweeteners

Added Sugars and How They Affect Your Health You find added sugars in: Beverages: soda, fruit drinks, sweetened teas and lemonade, and many sports drinks, vitamin waters, and energy drink Desserts and snacks: cookies, cake, ice cream, baked goods Sweet pickles, ketchup Sugar and high-fructose corn syrup are equally harmful in excess.

Examples of Added Sugars Confectioner’s sugar Molasses White and brown sugar Maple and turbinado sugar Fructose Corn syrup High-fructose corn syrup Honey Maple syrup Brown rice syrup Agave nectar/syrup

Functions of Sugar in Cooking/Baking Sugar helps balance the acidity of ingredients such as tomatoes and vinegar. Sugar browns the crust in baking. Sugar helps retain moisture in baked goods so they stay fresh. Sugar affects texture, tenderizing in baked goods. Sugar acts as a food for yeast in breads.

One teaspoon sugar = 4 grams “Sugars” on the Nutrition Facts panel includes natural and added sugars. If the label says “40 grams” under sugar, then: 40 grams of sugar = 10 teaspoons sugar 4 grams sugar/1 teaspoon

Complex Carbohydrates Includes starch and fiber Facts about starch: Plants store glucose in the form of starch. Starch is a chain of hundreds to thousands of glucose molecules linked together. Starch is only found in plant foods.

Which foods contain starch? Grains: wheat, corn, rice, rye, barley, oats Root and tuber vegetables: beets, carrots, potatoes, sweet potatoes Dried beans, peas, and lentils: navy beans, split peas

Starches as Thickeners When heated in liquid, starch gelatinizes. Gelatinization is a process unique to starches, and so you find starches frequently used as thickeners in soups, sauces, gravies, puddings, and other foods.

Fibers Like starches, fibers are long chains of glucose units bonded together. Unlike starches, fiber can’t be broken down by human digestive enzymes. Some fiber (called soluble fiber) is digested by bacteria in the large intestine.

Which foods contain fiber? Dried beans, peas, and lentils Fruits and vegetables Whole grains Nuts and seeds Fiber is not found in meat, poultry, fish, dairy products, or eggs.

Total fiber = Dietary fiber (naturally in foods) + Functional fibers Functional fibers: fibers extracted from plants and then added to foods such as bread, cereal, yogurt, and juices. Examples: Oat fiber, wheat bran, vegetable gums, cellulose, maltodextrin, resistant starch

Whole Grains

Whole Grains (cont’d) Whole grains contain the fiber-rich bran and the vitamin-rich germ: Whole wheat Brown rice Whole wheat bread Wheaties Oatmeal If the bran and germ are removed, the grain is a refined or milled grain: White flour White rice White bread Corn flakes Most baked goods

Whole Grains (cont’d)

Whole grains have more nutrients! Whole wheat flour has more… Fiber Vitamin E Vitamin B6 Magnesium Zinc Potassium Copper Phytochemicals ...than white flour.

Refined grains are enriched. By federal law, refined grain are enriched with five nutrients that are lost in processing: Thiamin Riboflavin Niacin Folate Iron

Functions of Carbohydrates #1 source of energy for body (glucose)—brain and nerve cells almost completely rely on glucose for energy. Burning glucose for energy spares protein. Burning fat for energy without carbohydrates can be harmful to the body. You need at least 130 grams of carbohydrates daily to prevent protein and fat from being burned for fuel. You normally eat half your kcalories as carbohydrates.

Functions of Carbohydrate (cont’d) Carbohydrates are found in parts of the body including connective tissues, some hormones and enzymes, and genetic material. If you eat a lot of fiber, it helps Lower blood cholesterol Reduce blood pressure Decrease the risk of developing diabetes Keep blood sugar normal Promote regularity Lower body weights

Glycogen Glycogen: The storage form of glucose in the body; stored in the liver and muscles. Muscle glycogen is only used to supply energy for muscles.

Digestion, Absorption, and Glycemic Response During digestion, enzymes break down starch and disaccharides into sugar units that are then absorbed. Fiber is not broken down by enzymes. Some bacteria in the large intestine can digest soluble fiber. Soluble fiber slows the emptying of the stomach.

Glycemic Response How quickly, how high, and how long your blood sugar level rises after eating A low glycemic response (meaning your blood sugar rises slowly and not too high) is preferable to a high glycemic response BECAUSE it may decrease your risk factors for heart disease and diabetes.

Glycemic Response (cont’d) Several factors influence: Amount of carbohydrate eaten Type of sugar or starch Presence of fat, protein, fiber (all these slow down the emptying of the stomach)

The higher a food’s glycemic load, the higher your blood glucose goes up. High Glycemic Load: Chocolate cake with frosting, white rice, spaghetti, French fries, cola, jelly beans Medium Glycemic Load Raisin Bran cereal, brown rice, banana, apple juice, white bread, pretzels Low Glycemic Load Whole wheat bread, All-Bran cereal, apple/orange/peach/grapes, peas/carrots, legumes

Dietary Recommendations for Carbohydrates Americans get enough carbohydrate: 45 to 65 percent of total kcalories. But we eat too many: Added sugars in beverages, desserts, and candy Refined grains such as white flour in bread or white rice And we eat too little: Vegetables and fruits Whole grains such as whole wheat Milk and milk products Beans, peas, and lentils

Milk, fruit, and grains, are healthy carbohydrates, along with vegetables and beans.

Carbohydrate Recommendations (cont’d) Adequate Intake for total fiber is: 25 grams/day for women (21 g after 50) 38 grams/day for men (30 g after 50) Eat 14 grams of fiber for every 1,000 kcalories.

To Increase Fiber in Your Diet: Instead of: White bread… Rice Krispies… White pasta… Baked goods with white flour… Fruit juices… White rice… Meat/cheese sandwich… Choose: Whole-grain bread Whole-grain cereals Whole-wheat pasta Baked goods with whole-wheat flour Fresh/canned fruits Brown rice Sandwich with vegetables/peanut butter

Lactose Intolerance Lactase (enzyme) is deficient so lactose (milk sugar) is not split into its components in the small intestines. Instead it travels to the colon (large intestine), where it attracts water and causes bloating and diarrhea. In addition, intestinal bacteria ferment lactose and produce gas. Symptoms usually occur within 30 minutes to 2 hours and clear up within 2 to 5 hours.

Who is more likely to suffer from lactose intolerance? Asians Native Americans African Americans Latinos

Treatment for Lactose Intolerance Use lactose-free milk and milk products. Or use lactase as a liquid or tablet. Consume small portions of dairy with a meal containing fat and protein. Choose dairy products naturally lower in lactose, such as yogurt and hard cheeses such as Cheddar. Soymilk and rice milk are fine. Don’t forget that milk is the leading source of calcium & vit. D in the diet.

Hot Topic: Alternative Sweeteners Nonnutritive or artificial sweeteners (provide virtually no kcal) Saccharin (Sweet N’Low, Sweet Twin) Aspartame (NutraSweet, Equal) Acesulfame potassium (Sunett, Sweet One) Sucralose (Splenda) Neotame Stevia

Sugar Replacers A group of carbohydrates that are sweet and occur naturally in plants. Examples: Sorbitol and xylitol found in sugar- free gums and candy

Benefits of Sugar Replacers Don’t provide as many kcalories as sugar—only about 2 kcal/gram. Don’t promote tooth decay. Taste sweet—though not as sweet as sugar. Add bulk and texture to foods. Cause smaller increases in blood sugar and insulin than sugar. Large amounts of sugar replacers can have a laxative effect.

Sugar Replacers in Foods Chewing gums Chocolate Candies Frozen desserts such as ice cream Baked goods Salad dressings Beverages Other foods designed to be lower in kcalories, carbohydrates, and/or fat