Milk and Milk Products Technology

FOOD AND NUTRITIVE VALUE OF MILK

• Milk is a balanced established basic food because of its nutrients and biological value in human nutrition. It is a good source of high quality protein, calcium, phosphorus apart from riboflavin and other B-vitamins. The calcium and phosphorus of milk are well utilized by the body. Milk protein has a biological value of 90 per cent. Lysine is one of the essential amino acids, which is abundant in milk proteins. Cheese, khoa, and milk powders are in concentrated forms hence containing high amount of nutrients per unit.
• The unique milk sugar lactose, which is made up of glucose and galactose. Galactose is which is essential for the synthesis of myelin sheath. Lactose, not being easily digestible in the stomach favours the growth of lactic acid bacilli in the intestine, which decreases the pH. This drop in pH favour calcium absorption and non survival of pathogenic micro organisms. Lactose also increases the permeability of the small intestine for calcium ions.
• The milk fat adds specific odour and palatability to milk and is easily digestible. It contains important fatty acids like linoleic acid (2.1%), linolenicacid (0.5%) and arachidonic acid(0.14%). By using cream separator , cream and skim milk can be collected. Skim milk contains only less than 0.5 % fat. Buffalo milk contains high amount of fat.
• Dairy foods are a major source of calcium because of the significant amount of the mineral present. The calcium phosphorus ratio (1:2) in milk is regarded as most favorable for bone development. In addition, dairy products contain other nutrients such as vitamin C and lactose, which favor calcium absorption. The calcium requirement cannot be met easily without taking milk. Milk is a poor source of iron.
• Thiamine occurs in only fair concentration in milk, but is relatively constant in amount. Riboflavin is present in a higher concentration in milk than the other B-vitamins and its stability to heat makes milk a dependable source of this vitamin. In cheese making, riboflavin is present in whey. Because of its sensitivity to light, exposure to sunlight results in 50% reduction in riboflavin. Milk is not a good source of niacin but it is an excellent source of tryptophan. Milk is a very poor source of vitamin C. The fat soluble vitamin A and D in milk depends on their availability in the feed.

Energy value

• Milk fat 9.3 kc/g
• Milk protein 4.1 kc/g
• Milk sugar 4.1 kc/g