COMPOSITION OF MILK
Milk is nearly complete natural food on the earth. It contains water, fat, protein, lactose and minerals as major constituents. The proportions of these constituents vary with species of the animal. For example, Mare’s milk contains only about 1.6% fat, while Reindeer’s milk contain 22.5% fat. Apart from this, the composition also varies with several other factors, viz., the breed of animal, the feeding pattern, season, lactation period, age of animal, environment, etc..
Total solids in a milk is the Sum of milk fat and solid-not-fat (TS= fat + SNF)
Milk also contains several minor constituents like salts (Ca, PO4 , Cl, Na Mg, K, S, and citrate) and trace elements that are very important from physiological and nutritional point of view. Several enzymes, non-protein nitrogenous …show more content…
It is a blend of the individual effects produced by the colloidal casein particles and dispersed fat globules, both of which scatter light and ii) the carotene which imparts a yellowish tint. The skim milk has a bluish and whey has a greenish yellow colour.
Acidity and pH of Milk
Freshly drawn milk is amphoteric in nature. The acidity of milk is determined by titration method using alkali and phenolphthalein. It is also called natural acidity and is caused by the presence of casein, citrate, acid phosphate etc., in milk. Developed or real acidity of milk is due to the production of lactic acid as a result of bacterial action on lactose. The titratable acidity is usually expresses as a percent of lactic acid. The acidity of cow milk varies from 0.13 to 0.14% lactic acid and buffalo milk from 0.15 to 0.17 % lactic acid. The pH of normal milk usually varies from 6.4 to 6.6 for cow milk and 6.7 to 6.8 for buffalo milk. Higher pH values for fresh milk indicate that the animal suffered from udder infection (mastitis) and lower values indicate bacterial action.
Milk is nearly complete natural food on the earth. It contains water, fat, protein, lactose and minerals as major constituents. The proportions of these constituents vary with species of the animal. For example, Mare’s milk contains only about 1.6% fat, while Reindeer’s milk contain 22.5% fat. Apart from this, the composition also varies with several other factors, viz., the breed of animal, the feeding pattern, season, lactation period, age of animal, environment, etc..
Total solids in a milk is the Sum of milk fat and solid-not-fat (TS= fat + SNF)
Milk also contains several minor constituents like salts (Ca, PO4 , Cl, Na Mg, K, S, and citrate) and trace elements that are very important from physiological and nutritional point of view. Several enzymes, non-protein nitrogenous …show more content…
It is a blend of the individual effects produced by the colloidal casein particles and dispersed fat globules, both of which scatter light and ii) the carotene which imparts a yellowish tint. The skim milk has a bluish and whey has a greenish yellow colour.
Acidity and pH of Milk
Freshly drawn milk is amphoteric in nature. The acidity of milk is determined by titration method using alkali and phenolphthalein. It is also called natural acidity and is caused by the presence of casein, citrate, acid phosphate etc., in milk. Developed or real acidity of milk is due to the production of lactic acid as a result of bacterial action on lactose. The titratable acidity is usually expresses as a percent of lactic acid. The acidity of cow milk varies from 0.13 to 0.14% lactic acid and buffalo milk from 0.15 to 0.17 % lactic acid. The pH of normal milk usually varies from 6.4 to 6.6 for cow milk and 6.7 to 6.8 for buffalo milk. Higher pH values for fresh milk indicate that the animal suffered from udder infection (mastitis) and lower values indicate bacterial action.