COMMON TERMS ASSOCIATED WITH MILK
We often come across puzzling terms like pasteurized, homogenized, standardized etc. in relation to milk. These terms are explained below for you.
Bactofugation: Process designed for removal of bacteria from milk by means of centrifugation. It is simply physical separation and does not involve any chemical treatment of milk.
Butter oil: Butter oil refers to the fat concentrate obtained mainly from butter or cream by removal of practically all the water and solids not fat content. It is similar to ghee but is bland, that is, it does not have distinct ghee flavour. It is useful for preparing recombined milk and for standardization of fat in milk.
Colostrum: Milk produced by mammals during first few days after parturition (child birth). It is a valuable source of antibodies to protect the new born from infections.
Double toned milk: Milk that has been standardized to contain a minimum of 1.5% fat and 9.0% solids not fat.
Full cream milk: Milk that has been standardized to contain a minimum of 6.0% fat and 9.0% solids not fat.
Homogenization: Homogenization is the process of breaking down the fat globules in milk from their original size of 0.1 to 15 µm to a more uniform and smaller size of 2 µm or less. This ensures that milk fat does not separate and form a creamy layer on top. However, one does not get ‘malai’ in homogenized milk even if it may contain the same amount of fat as in unhomogenized milk. Homogenized milk is whiter, feels richer in mouth and is better for making tea but is not useful if you are looking for a creamy layer on the top surface of milk in a container.
Lactose hydrolysed milk: Milk in which lactose is hydrolysed as glucose and galactose by giving treatment with the enzyme ‘lactase’. It is useful specifically for those who cannot digest lactose, a condition called ‘lactose intolerance’.
Mineralized milk or mineral enriched milk or mineral fortified milk: Milk in which one or more minerals have been externally added.
Pasteurization: It is a process involving heating of milk (temperature/time = 630C/30 minutes or 720C/15 seconds or equivalent) followed with rapid cooling to 100C or less. Heating destroyed all disease causing microorganisms making milk safe for consumption. But some microorganisms are still left after heating which cannot cause disease, but can grow/multiply and spoil milk by souring/curdling. Rapid cooling slows down growth/multiplication of microorganisms. Hence, pasteurization makes the milk safe for consumption and also prevents its spoilage till the date declared on pack of milk when kept cool under refrigeration.
Recombined milk: Means homogenized product prepared by mixing of milk fat, non-fat milk solids and water.
Reconstituted milk: Mean a product prepared by mixing whole or skim milk powder and water.
Separation or skimming: It is the process of fractionation of whole milk into skim milk and cream. It is very useful process for standardization of milk.
Shelf life or Keeping quality: It refers to the time for which a product retains its edible qualities and is acceptable for consumption.
Skimmed milk: Milk from which almost all the milk fat has been removed by the process of separation. It has negligible fat content (0.5%) and is good for people who want to avoid consuming fat.
SNF (Solids Not Fat): It refers to the solids, excluding milk fat, in milk. That is, it refers to protein, carbohydrate and salt/ash in milk.
Spray drying: It is a process wherein milk is sprayed as a fine mist into a hot-air chamber leading to almost complete evaporation of water from milk instantaneously. The resultant product is called milk powder. It is useful for making reconstituted or recombined milk and standardization of solids in milk.
Standardization: Standardization of milk refers to the adjustment (raising or lowering) of the milk fat and solids not fat content of milk to prepare different varieties of milk, e.g. double-toned, toned, standardized milk, etc.
Standardized milk: Milk that has been standardized to contain a minimum of 4.5% fat and 8.5% solids not fat.
Sterilization: The term sterilization, when used in association with milk, means heating milk in a sealed container continuously to a temperature of either 1150C for 15 minutes or equivalent. It frees the milk of all microorganisms and, hence, sterilized milk can be stored at room temperature (no refrigeration) for prolonged periods (e.g. six months) in an unopened original pack.
Toned Milk: Milk that has been standardized to contain a minimum of 3.0% fat and 8.5% solids not fat.
UHT (Ultra High Temperature) Sterililizaion: It is the process of heating of milk to 1350C to 1500C for 1 to 6 seconds followed by cooling to a suitable temperature and aseptic packaging. It frees the milk of all microorganisms and, hence, UHT sterilized milk can be stored at room temperature (no refrigeration) for prolonged periods (e.g. six months) in an unopened original pack. Owing to a very short time of exposure to heat, the original properties (colour, flavour, nutrients etc.) of milk are better retained in UHT sterilized milk as compared to in conventionally sterilized (1150C/15 minutes) milk.
Vitaminized milk or vitamin enriched milk or vitamin fortified milk: Milk in which one or more vitamins have been externally added.
(Disclaimer: The information compiled here is taken from various sources freely available and is intended for larger purpose of public information only. There is no commercial interest associated and no intention to infringe upon any rights whatsoever.)