Though we have made rapid strides in the modern technology, maintaining and providing safe food still remains a global problem. Contamination of food remains a major risk and serves as source of disease and death in many of the developing countries. The food contaminants may generally be classified into two groups viz. chemical and biological. The reporting system for the food borne disease is not well organized and most of the problems are of biological in nature.

Pathogenic microorganisms in milk and dairy products

The milk as drawn from a healthy dairy cow still contains a lot of microorganisms because of the complex biological nature of the udder. The legal limit for the number of microorganisms varies from few thousands in developed dairying countries to few hundred thousands in developing nations. Milk being highly nutritious is also susceptible for to microbial spoilage and pathogenic contamination. Major contaminants include gram negative, rod shaped bacteria, coliforms, spore formers (mainly aerobic in fluid milk and anaerobic in dairy products), lactic acid bacteria, yeasts and molds (mainly in dairy products).

The major pathogenic bacteria are Salmonella, Campylobacter sp, Yersinia, Vibrio, Staphylococcus aureus, Listeria sp. etc. These are the important organisms from the milk safety point of view. The reporting system is more skewed in developing countries, where less than 1% cases are reported and hence no investigation is carried out most of the time regarding the epidemiology of the outbreak. Industrially advanced countries report more than 10% cases. Despite this, incidence of food borne diseases is increasing all over the world stressing the need to take preventive control measures vigorously.

The following points may be considered as the drawbacks to meet the quality and safety of the dairy products.

Despite the best efforts taken by the government and voluntary agencies, there are incidences of food poisoning.
The existing quality control procedures involve larger expenditure in terms of manpower and energy.
The pathogenic organisms often are not uniformly distributed throughout the product and hence may be concentrated in a small portion of the batch and this make the traditional sampling of the product less effective to identify its presence.

Hence we have to lay more emphasis on prevention of the defects rather than evaluate the defects and this is more important given the increased consumer awareness on the quality and safety of the dairy food.

Prevention and control

The health problems associated with the consumption of contaminated dairy products differ depending on the environmental conditions, type of product etc. However, the prevention and control of food related illnesses may be broadly divided into the following four categories.

Safety procedures to be followed

At the farm level
At the processing dairy
During post processing
During transportation, subsequent storage and sales