Milk defination, properties and nutrition

About milk with Indian data
Reference: Sukumar Dey

1. MILK Definition, Composition, Physio-chemical and Nutritional properties

2. WHAT IS MILK? A white liquid extracted from the mammary gland of mammals. The first food and nutrition for the young. Produced after the gestation period A complete food. In India, milk is usually from cow or buffalo

3. MILK COMPOSITON

4. SPECIES WATER FAT PROTEIN LACTOSE ASH BUFFALO 84.2 6.6 3.9 5.2 0.8 COW 86.6 3.8 9.1 4.9 0.6 GOAT 86.5 4.5 3.5 4.7 0.8 HUMAN 87.7 3.6 1.8 6.8 0.1

5. FACTORS THAT AFFECT COMPOSITION Species Breed Individuality Interval of milking Completeness of milking Frequency of milking Irregularity of milking Disease Portion of milk Stage of lactation Yield Feeding Season Age Condition of cow Excitement Drugs and other

6. Properties of milk State of milk Continuous phase Acidity Amphoteric to litmus (red to blue; blue to red) Titratable acidity due to casein, citrates directly proportional to SNF Cow has 0.13 to 0.14 % (of lactic acid) Buffalo has 0.14 to 0.15% pH Cow 6.4 to 6.6 Buffalo 6.7 to 6.8

7. Density and Specific gravity Cow milk SG 1.028 to 1.030 Buffalo milk 1.030 to 1.032 Skimmed milk 1.035 to 1.037 Freezing point of milk Cow as 0.547 ◦C Buffalo as 0.549 ◦C Colour of milk Milk can be white or has yellowish tint Produced by colloidal dispersion of casein and fat Carotene gives yellow colour Cattle feeds can deepen the colour

8. Flavour Odour and taste Lactose and salty minerals Proteins damps the flavour Sulfydryl compounds responsible for the taste of heated milk Added flavours

9. PHYSIOCHEMICAL PROPERTIES Water Dissolved of suspended Most free others bound to milk proteins Milk fat In small globules Has fat globule membrane Membrane contains phospholipds and protein complex Rise up to surface when undisturbed Forms a cream layer

10. Proteins Essential and non essential Casein, B- lactoglobulin , A- lactalbumin Casein is 8% of total protein Has A,B and gama A has two sub parts calcium sensitive and non sensitive B lactoglobulin is known as whey and A lactalbumin known as serum proteins Sugar or lactose Lactose fermented to form lactic acid It as two forms A and B occur as hydrate or anhydride Responsible or sandiness in ice-cream

11. Phospholipids Lecithin, cephalin , spingomylin Provide richness in flavour , sensitive to oxidation Excellent emulsifying agent Cholesterol Part of fat globule Pigments Carotenes, xanthophyll , riboflavanins , For colour , antioxident , precursor of vitamin A Enzymes Analase for starch Lipase for fat Peroxidase for decomposition Phosphate for phosphoric acid

12. Vitamins Fat soluble K,A,D,E B complex Vitamin C

13. NUTRITIVE VALUE OF MILK Proteins Minerals Vitamins Fat Lactose Energy value

14. CONCLUSION Milk is necessary for growth and health Milk is a complete food An important factor for a balanced diet