NUTR 202 1nd Edition Lecture 7 Ch 4 Carbohydrates Sugars Starches and Fibers Carbohydrates primary functions Energy 4 kcal g AMDR 45 65 of kcal 8g carbs 2g fiber 32 kcal Fiber does not provide calories Sources include Whole grains Refined grains Fruit Milk Vegetables Refined grains milling removes bran and germ some nutrients are lost during the refining examples are wheat or white bread white rice These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Bran rich in fiber and some vitamins and minerals At base is the germ seed contains heart healthy oils Endosperm is the main starch component Refined grains such as corn flakes or puffed rice are made largely from the endosperm and are mostly starch Replace some of the nutrients removed during refining of grain This is known as Enrichment add only some of the nutrients Replaced nutrients include folic acid thiamin niacin riboflavin and iron Different from fortification nutrients added are not originally in the food Vitamin D added is not originally from the milk is to help deficiencies Not replaced Includes fiber magnesium phytochemicals and healthy fats More about nutrient balance than whole wheat if label says 100 whole grain all components are there without added Remember MyPlate wants at least half your grains whole grains Added Refined Sugar contain calories but lack fiber and other nutrients Americans typically contains 16 of calories from added sugars Empty calories Sugars from whole natural foods such as fruits vegetables and milk are more nutrient dense Recommended maximum of empty calories should be no more than 10 teaspoons of sugar 150 calories Carbohydrates made up of sugar units containing carbon hydrogen oxygen monosaccharide is made up of 1 molecule of sugar Disaccharides are made of 2 molecules of sugar BOTH are known as simple sugars Monosaccharides three types only these can be absorbed into intestine Glucose blood sugar Most important for energy Part of every disaccharide Fructose fruit sugar Sweetest of the sugars Part of fruits vegetables Galactose Only in a few foods part of milk sugar Disaccharides Maltose two glucose units bread or grain products Sucrose glucose fructose Lactose galactose glucose Types of complex carbohydrates Polysaccharides Storage form of carbohydrates in animals Glycogen Liver and muscles Storage form of carbohydrates in plants Starch Complex carbohydrate that are not capable of being broken down by human digestive enzymes Fiber 2 types Soluble vs insoluble fiber 1 Insoluble fiber Does not dissolve in water Bran skin of produce brown rice Provides bulk in the intestine to ease elimination Prevent constipation may prevent colon cancer 2 Soluble fiber Dissolves in water Oat pulp of apples beans bananas Combines with bile to eliminate some fat and prevents elevated blood cholesterol Decreases cholesterol absorption and synthesis Carbohydrate digestion Ultimate goal Glucose for absorption and use 1 Mouth some digestion Enzyme Amylase 2 Stomach none Amylase is inactivated Role of fiber 3 Small Intestine Digestive Enzymes from pancreas Complete digestion of CHO at the SI villi monosaccharides 4 Large Intestine Elimination of undigested starch fiber Modification of intestinal flora Digestion first occurs in mouth via salivary amylase and breaks down polysaccharides into shorter chains Then in the stomach salivary amylase is inactivated and no CHO digestion occurs In the SI break down disaccharides pancreatic amylases complete break down job Brush border completes break down to monosaccharides In LI fiber and other indigestible CHOs are partially broken down excreted Lactose milk sugar Low levels of lactase activity in the Small Intestine Highest immediately after birth Declines with age Lactose intolerance lactose mal digestion leads to the following symptoms nausea cramps bloating diarrhea flatulence DUE TO INACTIVITY OF ENZYME LACTASE Remember this is in the small intestine Small Intestine Absorption of monosaccharides through SI villi Active absorption Glucose and Galactose Facilitated diffusion fructose From lumen of small intestine monosaccharides Enter circulatory system to liver which has Fructose galactose converted to glucose Glucose used for energy Glucose stored as glycogen Sent to rest of body via circulatory system Blood glucose levels rise