Nutrition and Biochemistry(Lecture No. 5)

NUTRITIVE VALUE OF MILK No other single food has as many nutritive value as that of milk. It is

an ideal food for infant, but it must be supplement with other foods as child grows. However it not perfect food, since it lacks Fe, Cu, and Vita. CCHEMISTRY: PROTEINS: Chief Proteins arei) Caseinogenii) Lact-albumin iii) Lactoglobulin

Caseinogen: is a phosphoprotein (0.7% p) and carries Ca bound to it, is more in an amount in cow’s milk (2.8%) than human milk (0.5%). Caseinogens is insoluble at its Iso-elective pH(4.6)

Lact-albumin + Lact globulin: have also very ↑biological value and both are good proteins, highly digestible and heat-co-agulant.

LIPIDS: Milk fats are the most palatable and digestible and fats known. These are in the form of very fine and stable condition. It differs from other fats in containing all saturated as well as variety of unsaturated.

CARBOHYDRATES: Principal carbohydrate present is disaccharide LACTOSE (Sugar Milk) Human milk contains 7.0gm% is compared cow’s milk, 5.0gm%.

MINERALS: Milk is rich in minerals elements especially Ca, P, K, Na Cl + Zn, milk is poor in Fe + Cu (Hypochromic + micro cystic anemia in fed only on milk.Calcium and Phosphorus: 120 mg Ca + 90mg p am present in 100ml of cow’s milk higher in buffalo’s but much lower in human milk.

VITAMINS: Milk is good source of Vit-A, but very little Vit-D, Vit-C content of milk is very low, milk has rather low Conce. of Vit-B but rich in Riboflavin (B) and good in thiamine.

HUMANIZATION OF COW’S MILK: Cow’s milk fed to newborn babies has to be diluted with water to lower its protein content to that of human milk and lactose glucose, maltose or sucrose has to add to it – to raise its sugar content to the level of human milk. This process is known as humanization of cow’s milk.

NUTRITIVE VALUE OF EGG Egg is a delicious, palatable food item liked by adult as well

children it is highly nutritive. It stands with dairy production and meet.

COMPOSITION OF HEN’S EGG: It consist of approx. 30% yolk, 59% white, 11% Shell In edible part there is 15% proteins 10.5% fats

Water% Proteins % Lipids% Carbohy…% Calories100gm

Whole egg 73 12.5 12 1.6 162

Yolk 51 16 33 2.1 381

White 85 11.5 Trace 0.1 1.4 51

• WHITE PART: A solution of proteins (11.5) &Salts., H2O(85) Proteins of eggs high quality protein and used as reference standard for assessing other proteins. Proteins in white Ovalbumin: Typical albuminCon albumin : anotherOva globulin : GlobulinOva mucoid : Glycoprotein

YOLK: 51% H2o Chief Constituent are proteins (16%)& fats (33%) and1% minerals & vitamins.

Proteins: (a) Vitellin:Phosphoprotein (caseinogens milk) (b) Livetin: a globulin

Fats:30 – 33% Phospholipids cephalin & lecithin, yolk is rich in cholesterol, an average egg weighs 2 oz – contain 250 mg cholesterol.

Minerals: yolk is supplied with minerals, Ca, Fe, and PO4. It is very good source of Fe which is easily assimable.

Vitamin: Yolk is rich of vita A, D, E also B-Vita, thiamine riboVit also present but not vitamin C.

LUTEIN AND ZEAXANTHIN: Two carotenoids in eggs yolk that protect against

degeneration of the retina. Carotenoid in eggs are better absorbed than these from plant source.

BALANCE DIET A diet which contains all the nutrients (both macro & micro nutrients) in right

proportion and quantity (according to their RDA) to meet energy and other body nutritional requirements.

IN BALANCE DIET: ACCORDING TO AMDR ACCEPTABLE MACRO-NUTRIENT RANGES CALORIC

REQUIREMENT ARE AS Roll of thumb is 30-40 Kcal/kg per day =2100-2800 Kcal/day AVE = 2400-2600 K cal/day

Protein %10 – 35% Fats 20 – 35%CHO 54 – 65%

CHARACTERISTICS OF BALANCED DIET1) LOCALLY AVAILABLE 2) BE ECONOMICAL 3) FIT WITH LOCAL FOOD HABITS 4) EASILY DIGESTIBLE AND PALATABLE 5) CONTAINS ENOUGH ROUGHAGE MATERIAL.

 MUST BE CHOSEN FROM BASIC FOOD GROUP:

Milk group : ,, include dairy products Meat Group : ,, Fish, meat, eggBread & cereal group: ,, Bread, Rice, Wheat, Barley, Grains Fruits group : ,, Mango, Apple, Banana, Apricot, Peach etcVegetable, green leafy : Green leafy vegetable

Balanced diet is an intelligent assortment of items (from basic food groups) rich in different nutrients which can contribute to the total nutrients value of diet advised. 

HOW TO PLAN A BALANCED DIET:DIFFERENT CONDITIONS OF CALORIES REQUIREMENTS:Age, sex, physical exercise, disease, health, Pregnancy & Lactation. While planning Balanced diet far individual his/her age sex weight height Physical exertion, disease, health pregnant & lactation all must be taken in account in determining & calculating their total daily nutrition.SELECTION OF NUTRIENTS FROM BASIC FOOD GROUPS:Selection of nutrients should be in such a way that their total nutrients value, must satisfy the estimated calories requirements.

ECONOMIC STATUS OF INDIVIDUAL: In formulating (Calories) balanced diet, it is imperative and necessary that economic status must be taken in account so that balanced diet is within purchasing power of an individual.HIGH COST & LOW COST DIET: For rich person a balanced diet does not pose any problem as he can easily afford it, but for a low income person it poses a great problem as he cannot afford it easily. So it must be economical / low price items, nutrients, taken in account that nutrients should also fulfill the nutritional & caloric requirement.

HIGH COST DIET LOW COST DIET

Food Item Quantity g/ day Food Item Quantity g/ day

Cereal 475 Cereal 285

Pulses 65 Pulses 100

Green leafy veg. 125 Green leafy veg 200

Other 75 Potato’s 200

Roots & tubers 100 Celosia 100

Fruits 30 Ground nut 50

Milk 100 G. Bengal grain 50

Meat & fish 30 Oils 35

Fats/oils 40 Sugar 40

Egg 30

sugar 40

2800 Calories / day 2700 calories / day

DIET IN PREGNANCY & LACTATIONPREGNANCY & LACTATION are normal physiological processes. There is considerable increase in nutrition requirement due to nausea; vomiting & loss appetite in early months of pregnancy as food intake is generally reduced.

FURTHER ADDITIONAL NUTRIENTS: Are required for growth of fetus. A baby weighing 3.2 kg at birth contains 500gm proteins. 30gm calcium, 0.4gm Fe and variety of vitamins, this all has to be supplied by mother in pregnancy.

INCREASE NUTRITIONAL REQUIREMENT DURING LACTATION: Due to milk secreted by mother for baby feeding.

OTHER NUTRIENTS REQUIREMENT DURING PREGNANCY:

CALORIC REQUIREMENT: there increase greater part of extra calories are required during 2nd, 3rdtrimester of pregnancy. For growth and development of fetus, placenta and maternal reproductive organs, recommended extra calories are 300 Kcal/day

PROTEINS REQUIREMENT: About 5gm weight increase daily during last six months of pregnancy, for synthesis of fetus and maternal Hb, plasma proteins and other proteins. So extra 25-30 g/day extra proteins are recommended.

 

Fe REQUIREMENT: about 10 – 15mg/day iron rich diet required to prevent iron deficiency during pregnancy.

Ca+ P, vita D: Ca 500 – 600g addition P & 400 IU Vita-D are needed in later half of pregnancy.

Vita-A, K Thiamine 0.2mg/day Riboflavin 0.1mg/day Nicitinic acid 2mg/day Vitamina 1200 ug/day. For VitaminK dark green leafy vegetable in last trimester should be taken to prevent excessive bleeding during delivery.

LACTATION WHO experts assume that a women secrete 850ml milk/day. But an Indian women secrete about 600ml/day. So extra addition 700Cal/day are recommended during period of lactation.Protein: extra 20 -30gm/day

Calcium: 500 – 600mg/day B1 = 0.3/day

Fe: 3 – 6mg/day B2 = 0.4/day

Vita-A: 1000ug/day Nicotinic = 5mg/day