Science of Food & Nutrients

1. Science of Food & Nutrients Dr Asna Urooj Associate Professor Dept of Food Science & Nutrition University of Mysore Mysore

2. What is nutrition?? Nutrition – science of food, the nutrients & other subs.. Their action, interaction & balance in relation to health & disease. Process by which organisms.. Ingest, digest, absorb, transport, utilize & excrete. Health - state of complete physical, mental & social well being . Not merely the absence of disease / infirmity.

3. Nutritional Status condition of health of the individual as influenced by utilization of nutrients. determined → medical, dietary history, physical examination laboratory tests Malnutrition pathological state .. Relative or absolute deficiency or x’s of one or more essential nutrients – 4 forms • Under nutrition 2. Over nutrition 3. Imbalance 4. Specific deficiency

4. Science of Food and Nutrients Science of food – study of chemistry, physics, biology & economics of food & its production. - Involves agricultural & veterinary science. Amount & type of food – Environmental factors Differences in food – storage, preparation distribution, Differences between people – sensory, personal, cultural, social and medical.

5. Nutrients - chemicals in food needed to maintain life. Substances - may include nonessential nutrients, additives, toxicants contaminants. Essential nutrients - 46. Provided by the food we eat. Carbohydrates Proteins Fats/lipids Vitamins Minerals

7. NUTRIENT SUPPLY FOOD Amount Energy Protein CHO Fat g/ml Kcals g g g • Cereals 100 350 6-12 60-70 1-2 • Pulses 100 340 18-25 60 1-5 • Milk 100 65 3-5 8 4-6 • Vegetables 100 35- 55 1-2 8-15 - • Oils / fats 20 180 - - 20 • Fruits 100 30-55 1-1.5 10-15 - • Sugar 20 80 - 20 - • Meat 100 80-140 12-22 - 3-13

8. Three types of fats SATURATED FATS ------- BAD Carbon chains with hydrogen bonds Meat, Butter, coconut, milk chocolate, creams, Ghee UNSATURATED FATS ------- GOOD carbon chains with one or more double bonds Monounsaturated : olive oil, nut oils Polyunsaturated : corn oil, vegetable oils, soy etc. TRANS FATS -------- BAD Manufactured fats. Liquid  Solid (hydrogenation)

9. Facts about fats Source of energy, 1g = 9kcal, Source of Essential Fatty Acids. Carrier for fat sol vit A, D,E, K Palatability Satiety value Invisible & visible fat Cholesterol – only foods of animal origin

10. Carbohydrates: more than sugar Starches, sugars and fiber. Simple sugars – fructose, glucose, lactose Sweetness varies Complex carbohydrates – starch, glycogen, cellulose, pectins. Most carbs in our diet come from Plant foods Starches & sugars – 4 kcal per gram

11. Carbohydrates - importance Provide energy. Stored as glycogen in the body. Protein sparing Antiketogenic action Bulk – by fiber in diet specialized functions- structural “scaffolding” of cells, signal transduction, ribose – DNA & RNA,

12. Food sources of carbohydrates • Sugars honey, fruits, berries, cane sugar, jaggery, jams, soft drinks, milk, confectionary etc. • Starches cereals, pulses, potatoes, vegetables, animal food (liver, oysters, crab) • Fiber whole grams, Unrefined cereals, pulses,vegetables, fruits, nuts

13. Research information • Similar content – cereals, pulses • Differ in digestibility – food source- cereal, pulse etc • Food form – influences digestibility • Method of cooking- steaming, pr cooking, boiling, baking Processing influences digestibility & glycemic response

14. Facts About Proteins • Needed for survival, growth, maintenance, enzymes, hormones • Building blocks amino acids – e.a.a & n.e.a.a • “ 2 Q’s ” - Quantity & quality matters – nutritional value of protein foods • Food processing – insignificant effect • Digestibility (%) varies among sources Egg > soy, milk, corn * > wheat>milk> rice> corn,beans, milk *> corn > corn, beans ( *taken together)

15. Proteins – facts • Protein-rich foods are often high in fat • Expensive eg., dairy foods, meat • Foods differ in amino acid composition • Differ in biological value • Protein needs differ in different groups • Extra needs – growth, pregnancy, lactation, surgery, injury, burns, recovery from mal-nutrition

16. Knowledge of foods with High BV • People on veg diets, starvation ( ltd food sources) Fruitarians Vegans Lactovegetarians Lacto-ovogetarians Semi- vegetarians • People on wt-reducing diets • Poor quality protein improved – combined with right foods. Eg: cereals + legumes, bread+ cheese

17. Proteins • Nitrogen balance- +, -, equilibrium. Protein status of a person • Heat no harmful effect • High protein diets – health consequences High fat intake – body fat Calcium loss Dehydration, fluid imbalance Gout

18. Balanced Diet Contains different types of foods in such quantities & proportions so that the need for various nutrients is adequately met - provision for extra nutrients – to withstand short duration of low intake - to calculate – know Recommended Dietary Allowances [ RDA] – ICMR - Tables of Food Composition

19. RDA – influenced by • AGE, GENDER • PHYSIOLOGICAL STATE • ACTIVITY • DIETARY FACTORS – Bioavailability _ Inter relationship b/w nutrients

20. Who are likely to have nutrition problems • Elderly • Poor • Large size families • Pregnant women • Children • People in isolated communities

21. Deficiencies seen • Malnutrition – prot-energy in children • Anemia – children, preg &lact women, elderly • Vitamin A – children • Iodine [ IDD] – newborn, cren, Adults

22. Dietary guidelines • Nutritionally adequate diet – variety • Addnl food – pregnancy & lactation • Breast feeding – must - 4-6 months • Supplements – infants by 4-6 months • GLV, other veg, fruits – eat in plenty • Cooking oils – moderation • Avoid over-eating • Salt & sugar use - to limit.