Milk-Definition – clean milk production-methods of milking – hand and machine
milking. Preservatives and common adulterants of milk.
Milk is the lacteal secretion of the mammary glands of animals. It is obtained generally
from the cow or the buffalo during the period following at least 72 hours after calving or until the milk is colostrum free. Milk is a white opaque fluid in which fat is present as an emulsion, protein and some mineral matters in colloidal suspension, and lactose together with some minerals and soluble proteins in true solution.
Clean Milk production :
Both pre-and post-secretory management of milk at the farm level should be focussed
upon for controlling the quality of milk. The post-secretory changes in milk are of paramount importance. Some of the vital factors responsible for good milk production that deserve immediate attention are type of farming, type of milk, impact on environment, farm waste disposal facilities, milking practices, procurement systems and inconsistent price policy and farmers’ education/training programmes.
Milk once secreted becomes the target for transformation by a variety of host organisms
at the farm itself. Hence, proper care must be taken regarding preservation of milk, protection of milk constituents, protection against high temperatures and natural calamity. Strict protocols are to be observed and implemented both in hand and machine milking. The microbiological quality deserves special attention for stringent export requirements for milk products in global market.
The custodian of milk should never compromise on quality.
Rural milk collection
In India, milk production is a subsidiary activity to agriculture in contrast with organized
dairy in western countries. Farmers and landless labourers mostly maintain 1-5 milch animals.
As a result, small quantities of milk are produced in a scattered manner. Milk procurement
models from western countries, such as bulk cooling, bulk transportation etc. are not applicable due to this reason, under Indian conditions. Collection of small amounts of milk scattered over long distances, therefore, posses a formidable challenge in maintaining the quality attributes and keeping costs down.
A systematic approach to rural milk collection suitable for tropical climatic and technoeconomic conditions prevailing under in India has been developed based on the indigenous experience gained over past few decades. In the first phase, extensive surveys are undertaken in the milk shed areas, where milk plant is to be established. The second phase involves “route planning” taking into account availability of quantities of milk, access to roads for plying vehicles and distance from the site of dairy plant. Then zones are identified, representing equal costs of collection and transportation. In the third phase, planning is done for locating the primary collection centres as well as chilling centres, where, milk can be cooled to 4oC before transporting to the milk plant. Milk may be collected from individual procedures either by the contractor or by forming village level cooperative societies.
At the village level, milk brought by the individual farmers is first tested for quality. As
soon as the milk supply reaches collection centres, it is weighed and a representative sample is
drawn for quality grading. The common tests carried out at the point of milk collection are taste
and smell, sediment, fat and SNF contents and acidity test. These quick tests generally form the
basis for acceptance or rejection of milk supplied. In India it is common to pay the producer on
the basis of the quantity of fat, while the minimum standard for SNF is set for accepting milk.
All the milk so collected is generally filled in cans to enable transportation to the chilling centre
or directly to the milk plant. Care should be exercised to bring the milk for chilling/processing
within 3 hours of milking otherwise serious deterioration of milk takes place, which affects the
quality of products.
In the Indian context, most of the milk is transported from rural collection centres to the
dairy plant depending upon the volumes of milk handled.
- Cans for handling up to 2,000 litre of milk per day.
- Tankers for handling between 2,000 and 5,000 litre per day.
- Rail tankers for handling 10,000 litre or more for ling distance transportation as in the
National milk grid.