Whey is the liquid that remains after milk has been curdled and strained. It is a by-product in the manufacture of cheese or casein. Whey is classified as Sweet whey and Acid Whey. Sweet Whey means the fluid separated from the curd after the coagulation of milk, cream, skimmed milk or buttermilk in the manufacture of cheese, casein or similar products, principally with non-animal rennet type enzymes. Acid Whey is obtained after coagulation of milk, cream, skimmed milk or buttermilk, principally with acids of the types used for manufacture of edible acid casein, chhana, paneer, or fresh cheese. It should be of uniform colour with pleasant taste and flavour free from off flavour and rancidity.
Whey Powder is the product obtained by spray or roller drying sweet whey or acid whey from which major portion of milk fat has been removed.
Table 1: Composition of whey powder and acid whey powder
|Requirements||Whey Powder||Acid Whey Powder|
|Moisture||Not more than 5%||Not more than 4.5%|
|Milk fat||Not more than 2% m/m||Not more than 2% m/m|
|Milk protein (N x 6.38)||Not less than 10% m/m||Not less than 7% m/m|
|Total ash||Not more than 9.5% m/m||Not more than 15% m/m|
|pH (in 10% solution)||Not less than 5.1||Not more than 5.1|
|Lactose content expressed as anhydrous lactose||Not less than 61% m/m||Not less than 61% m/m|
- Although the powders may contain both anhydrous lactose and lactose monohydrates, the lactose content is expressed as anhydrous lactose.
- 100 parts of lactose monohydrate contain 95 parts of anhydrous lactose.
Source: Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011.
The Whey Protein to Casein Ratio is Important
The whey protein to casein ratio is very important in many dairy products, and care should be taken so as not to alter this ratio. This should be observed in products such as cream powder, evaporated / condensed milk & milk products, sweetened condensed milk, and milk powder. In products like cheese, the whey protein to casein ratio should not exceed that of milk. In premature / low birth weight infant milk substitutes, the whey: casein ratio should be kept at 60:40. In hypoallergenic infant milk substitutes, the protein should be hydrolysed whey or casein or 100% free amino acids.
The Food Safety and Standards Authority of India (FSSAI), the apex body on food safety and standards in India has identified a number of food products / components in which whey is an essential component. These can be found in the Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011, and have been briefly highlighted below.
- Edible non-animal rennet casein: This is the product obtained after washing and drying the coagulum remaining after separating the whey from the skimmed milk which has been coagulated by non-animal rennet or by other coagulating enzymes.
- Thermally processed vegetable juices: These juices of vegetable parts like roots & tubers (e.g. carrots, garlic), stems & shoots (e.g. asparagus), leaves & flowers (e.g. spinach, cauliflower) and legumes (e.g. peas) is permitted to contain whey.
- Bread: This is available as white bread or wheat bread or fancy or fruity bread or bun or masala bread or milk bread etc. It is prepared from a mixture of wheat atta, maida, water, salt, yeast or other fermentative medium. Besides these ingredients, it can also contain whey.
- Canned luncheon meat: This is prepared from edible portion of meat of mammalian animal, slaughtered in an abattoir, which have been subjected to ante-mortem and post-mortem inspection and / or edible meat of poultry birds, including chickens, turkeys, ducks, geese, guinea fowl or pigeon slaughtered in an abattoir. The product should be uniformly cured with edible common salt and sodium and / or potassium nitrite. The product may be with or without binders, including whey.
- Chakka: This is a white to pale yellow semi-solid product of good texture and uniform consistency obtained by draining off the whey from the yoghurt obtained by the lactic fermentation of cow’s milk, buffalo’s milk, skimmed milk and recombined or standardised milk, which has been subjected to heat treatment, equivalent to pasteurisation.
- Yoghurt: This is a coagulated product obtained from pasteurised or boiled milk or concentrated milk, pasteurised skimmed milk and / or pasteurised cream or a mixture of two or more of these products by lactic acid fermentation through the action of Lactobacillus bulgaricus and Steptococcus thermophilus. It may also contain cultures of Bifidobacterium bifidus and Lactobacillus acidophilus and other cultures of suitable lactic acid producing harmless bacteria. Among the various other ingredients, the product may also contain concentrated whey, whey powder, whey protein, or whey protein concentrate.
The Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011 also incorporates the microbiological parameters for whey, which are tabulated below.
Table 2: Microbiological parameters for whey
|Total plate count||40,000 / g|
|Coliform count||10 / g|
|E. coli||Absent / g|
|Salmonella||Absent / 25g|
|Staphylococcus aureus (coagulase positive)||–|
|Yeast and mould count||–|
|Aerobic spore count (B. cereus)|
|100 / g|
|Anaerobic spore count (Clostridium perfringens)||10 / g|
|Listeria monocytogenes||Absent / g|