Dairy processing occurs world-wide. The basic dairy processes haven't changed much. Although, specialised processes such as ultrafiltration (UF), and modern drying processes that were formerly discharged have increased the opportunity for the recovery of milk solids. Moreover, all processes have become much more energy efficient. The use of electronic control systems have reduced the cost and led to improved processing effectiveness.

Milk production:

The processes taking place at a typical milk plant include:

• Receipt and filtration/clarification of the raw milk
• Separation of all or part of the milk fat (for standardisation of market milk, production of cream and butter and other fat-based products, and production of milk powders)
• Pasteurisation
• Homogenisation (if required)
• Deodorisation (if required)
• Further product-specific processing
• Packaging and storage, including cold storage for perishable products
• Distribution of final products

Butter production:

The butter-making process, whether by batch or continuous methods, consists of the following steps:

• Preparation of the cream
• Destabilisation and breakdown of the fat and water emulsion
• Aggregation and concentration of the fat particles
• Formation of a stable emulsion
• Packaging and storage
• Distribution.

Cheese production:

Virtually all cheese is made by coagulating milk protein (casein) in a manner that traps milk solids and milk fat into a curd matrix. This curd matrix is then consolidated to extract the liquid fraction, cheese whey. Cheese whey contains those milk solids which are not held in the curd mass. It is most of the milk sugar (lactose) and a number of soluble proteins.

Milk powder production:

Milk used for making milk powder, whether it is whole or skim milk, is not pasteurised before use. The milk is preheated in tubular heat exchangers before being dried. The preheating temperature depends on the season (which affects the stability of the protein in the milk) and on the characteristics desired for the final powder product.

The preheated milk is fed to an evaporator to increase the concentration of total solids. The solids concentration that can be reached depends on the efficiency of the equipment and the amount of heat that can be applied without unduly degrading the milk protein.

The milk concentrate is then pumped to the atomiser of a drying chamber. In the drying chamber the milk is dispersed as a fine fog-like mist into a rapidly moving hot air stream, which causes the individual mist droplets to instantly evaporate. Milk powder falls to the bottom of the chamber, from where it is removed. Finer milk powder particles are carried out of the chamber along with the hot air stream and collected in cyclone separators.

Milk powders are normally packed and distributed in bulk containers or in 25 kg paper packaging systems. Products sold to the consumer market are normally packaged in cans under nitrogen. This packaging system improves the keeping quality, especially for products with high fat content.

Indigenous Milk Products

Indian Dairy Products are milk products which originated India.

CULTURED

Srikhand: Srikhand is a semi-soft, sweetish sour whole milk product prepared form lactic fermented curd. The basic ingredient of Srikhand is Chakka.

Ghee: Ghee is a clarified butter fat prepaired from cow or buffalo milk. The largest ghee producing states are U.P, A.P, Punjab, Rajasthan, M.P, Bihar, Hariyana etc. The production of ghee is higher in winter and lower in summer.

Lassi: Lassi, also called chhas or matha, refers to local buttermilk. It is the by-product obtained from churning curdled whole milk with crude indigenous devices for the production of local butter. 50-60kg of lassi are produced for every kg of ghee. Lassi contains milk proteins and phospholipids.

Cheese: Cheese has high protein content in a very digestible form. It is rich in calcium and phosphorous and is an excellent source of fat-soluble and water-soluble vitamin. Cheese is a bio-enriched food the enrichment being brought about by vitamins and micronutrients being produced as metabolites of the starter bacteria.

CONDENSED

Rabri: It is concentrated and sweetened product comprising of several layers of clotted cream. It is prepared by adding sugar to the milk when it is reduced to 1/3 of the original volume.

Khoa: It is a partially dehydrated whole milk product. Products of khoa- Peda, Kalakand, Gulabjamun, Burfi

Kheer: Kheer is also known as Basundi. It is prepared by concentrating the milk to half of its original volume by open pan concentration and adding sugar and other condiments.

ACID PREPARATION

Panir: Panir refers to the indigenous variety of rennet-coagulated, small-sized, soft cheese.

Chhana: Chhana, also called panir in certain parts of the country, constitutes one of the two chief bases (the other being khoa) for the preparation of indigenous sweetmeats. Chhana refers to the milk-solids obtained by the acid coagulation of boiled hot whole milk and subsequent drainage of whey. The acids commonly used are lactic or citric, in both natural and chemical forms. It should not contain more than 70% moisture, and the milk fat content should not be less than 50.0 per cent of the dry matter.

Products of chhana: Sandesh, Rossogolla