Carbohydrate (I) 2022 PDF - International Medical University

DN & NT 122 Principles of Human Nutrition Carbohydrate I Dr Sharmela Sahathevan Division of Nutrition and Dietetics [email protected]  Lesson Outcome At the end of lecture, students are able to...

DN & NT 122 Principles of Human Nutrition Carbohydrate I Dr Sharmela Sahathevan Division of Nutrition and Dietetics [email protected]  Lesson Outcome At the end of lecture, students are able to: Discuss functions of carbohydrates for human health State food sources high in carbohydrates Differentiate types of dietary carbohydrates  What are carbohydrates (CHO)? Carbohydrates: most abundant biological molecules organic compounds composed of carbon, hydrogen, and oxygen in a ration of 1:2:1; general formula C(H2O)n where n ≥ 3 Derived from process of photosynthesis Functions of Carbohydrates An Important Source of Energy Carbohydrates contain sugars that are broken down into glucose to provide the body with energy. Functions of Carbohydrates Healthy Function of the Central Nervous System Adequate consumption of carbohydrates ensures that this function remains normal when body is low on carbohydrates/ low-blood sugar levels  unable to concentrate Functions of Carbohydrates Provide Energy to Muscles CHO provide energy to muscles for their function CHO is stored as glycogen in muscle Muscle glycogen is only for local use Functions of Carbohydrates Allows Proteins to Perform its Function Adequate carbohydrates preserve other nutrients (ie protein) for other essential functions eg tissue building and development and maintenance of muscle mass.  Functions of Carbohydrates Provide Dietary Fiber Dietary fiber, a non-digestible polysaccharide provides bulk to stool which promotes regular elimination of waste from the digestive track Certain types of fiber also provide a food source for gut bacteria which in term produce beneficial and protective short chain fatty acids (SCFAs)  Functions of Carbohydrates Structural support and cell signalling As components glycolipids, glycoprotein As component of nucleic acids eg pentose sugars ribose and deoxyribose  Functions of Carbohydrates Sensory and culinary use Provide desirable flavour in food products As sweeteners in food items Provides texture in food products Aid in fermentation process in food products Sources of carbohydrate in diet Food balance sheet data (FAOSTAT 2013): Major sources of carbohydrates in the human diet are cereals, root crops, sugar crops, pulses, vegetables, fruits and milk products. In the Malaysian diet: Starch is naturally abundant in grains, vegetables and root vegetables Sugars from in fruits and juices (natural); added sugars from sugar sweetened beverages, confectionaries etc Sources of carbohydrate in diet Cereals: All grains and cereal products including wheat, rice, maize Tubers: Potatoes, sweet potatoes, cassava etc Legumes: Most legumes except peas Fruits: apple, watermelon, melon etc Additive Flavouring: table sugar, honey, molasses, high fructose syrup Texture: corn starch Types of carbohydrate in diet Simple sugars Complex carbohydrates Three to ten sugar molecules Simple sugars-monosaccharides in diet Glucose: fruits, honey Fructose: fruit, honey, corn syrup Galactose: from digestion of milk sugar Disaccharides Simple sugars-disaccharides in food in diet Sucrose (glu+fruc): table sugar, sugar beets Maltose (glu+glu): malt sugar (from germination of barley) Lactose (glu+galac): milk Oligosaccharides in food Raffinose: Brussels sprouts, broccoli, cabbage, asparagus, cauliflower, sweet potatoes and whole grains Stachyose: peas, soya beans, lima beans, green beans Fructo-oligosaccharides (FOS): banana, onions, asparagus, wheat, barley, artichoke and yacón Galacto-oligosaccharides (GOS):lentils, chickpeas, peas, kidney beans Inulin: artichoke, rye, leek Polysaccharides in diet: Starch Storage carbohydrate of plant Dietary sources Grain: wheat, rice, corn, oat, barley Tuber: yam, potatoes, sweet potato Legumes: beans, lentils Polysaccharides in diet: Dietary Fiber CHO cannot be digested by human enzymes Polysaccharides in diet: Fiber Soluble fiber Gum Dietary sources: oats, legumes, guar, barley, carrageen Pectin Dietary sources: apple, dragon fruit, papaya, prunes Mucilages Dietary sources: oat, psyllium husk Polysaccharides in diet: Fiber Insoluble fiber Cellulose Dietary sources: whole wheat, bran, vegetables Hemicellulose Dietary sources: bran, whole grains Lignin Dietary sources: mature vegetables, whole wheat Polysaccharides in diet: Chitin Structural component of insects and crustaceans Which of the following are examples of oligosaccharides in diet? Raffinose Sucrose Fructo-oligosaccharides (FOS) Galacto-oligosaccharides (GOS) Starch Pectin Which of the following are examples of oligosaccharides in diet? Raffinose Sucrose Fructo-oligosaccharides (FOS) Galacto-oligosaccharides (GOS) Starch Pectin  Recommended intake for CHO RNI (2017) recommendations: Total CHO to be 50-65% of total energy intake Sugar (added and free)