Milk is an almost ideal food. It has high nutritive value. It supplies bodybuilding proteins, bone-forming minerals and health-giving vitamins and furnishes energy-giving lactose and milk fat. Besides supplying certain essential fatty acids, it contains the above nutrients in an easily digestible form. All these properties make milk an important food for pregnant mothers, growing children, adolescents, adults, invalids, convalescents and patients alike.
1: Proteins: Milk proteins are complete proteins of high quality, i.e. they contain all the essential amino acids in fairly large quantities.
2: Minerals: Practically all the mineral elements found in milk are essential for nutrition. Milk is an excellent source of calcium and phosphorus, both of which, together with vitamin D, are essential for bone formation.
3: Vitamins: These are accessory food factors which are essential for normal growth, health and the reproduction of living organisms. Milk is a good source of vitamin A, vitamin D, thiamine, riboflavin, etc.
4: Fat: Milk fat (lipid) plays a significant role in the nutritive value, flavour and physical properties of milk and milk products. Besides serving as a rich source of energy, fat contains significant amounts of so-called essential fatty acid (linoleic and arachidonic). The most distinctive role which milk fat plays in dairy products concerns flavour. The rich pleasing flavour of milk lipids is not duplicated by any other type of fat. Milk fat imparts a soft body, smooth texture and rich taste to dairy products. Lastly, milk lipids undoubtedly enhance the consumer acceptability of foods; they also serve the best interests of human nutrition through the incentive of eating what tastes good.
5: Lactose: The principal function of lactose (carbohydrate) is to supply energy. However, lactose also helps to establish a mildly acidic reaction in the intestine (which checks the growth of proteolytic bacteria) and facilitates assimilation.
| Factor | Value |
|---|---|
| Fat | 9.3 C/g |
| Protein | 4.1 Calorie/g |
| Sugar | 4.1 C/g |
Where 1 C (Food Calorie)=1000 c (small calorie)
Note: The energy value of milk will vary with its composition. On average, cow milk furnishes 75 C/100 g and buffalo milk 100 C/100 g.
Raw Milk: The sanitary quality of raw milk on the receiving dock in the society/ dairy depends on its background on the farm, viz healthy cows, clean milk production, clean utensils, freedom from colostrums, prompt cooling and refrigerated transport. Therefore raw milk can be a potential carries of disease producing organisms, which may transmit to human beings if raw milk is consumed as such. The bacteriological quality of raw milk is such that it may contain more than 50 lakhs bacteria per ml depending upon the way it is handled.
Pasteurized milk: Pasteurization is the process of heating each and every particle of milk to a temperature of 72oC (161oF) for 15 seconds in a pasteurizer and then it is immediately cooled to 5oC or below. By pasteurization, milk is rendered safe for human consumption by destruction of 100% of pathogenic micro organisms. It also helps to improve the keeping quality of milk by destruction of upto 99% of all spoilage bacteria. Pasteurization brings down the SPC/ml to below 30000. Pasteurization carried out with reasonable care has no effect on vitamin A, carotene, riboflavin and a number of remaining vitamins B, and vitamin D.
| S No: | Constituents | Milk [weight/litre] |
Carbonated Drinks [weight per litre] | Tea [per cup] | Coffee [per cup] |
|---|---|---|---|---|---|
| 1 | Fat | 30-50 g | 0 g | 0 g | 0 g |
| 2 | Vitamins | 0.10 g | 0.0009 g | 0 g | 0.0075 mg |
| 3 | Proteins | 29 g | 0 g | 0.3 g | 0.3 g |
| 4 | Carbohydrate | 45-50 g | 1 g | 0.7 g | 0 g |
| 5 | Calcium | 1.25 g | 0 g | 0 g | 0.0047 g |
| 6 | Phosphate | 2.10 g | 0 g | 0.0024 mg | 0.007 g |
| 7 | Sodium | 0.043 g | 0.004 g | 0.007 g | 0.005 g |
| 8 | Energy (kcal) | 600 | 10 | 2 | 2 |
Homogenization is the process by which milk is passed through an homogenizer at a pressure of 2000-2500 PSI to break up the fat globule in the milk so that even after 48 hours storage there is no visible cream separation. The fat globules are broken into less than 2 micron in size.The advantages of homogenization are as follows
1: There is no formation of cream layer at the top.
2: Fat in milk does not churn even on excessive agitation/rough handling.
3: Milk becomes more palatable, gets a brighter appearance besides a heavier body and rich flavour.
4: Produces soft curd and is therefore better digested and is therefore recommended for infant feeding.
5: It is less susceptible to oxidized flavour development.