Unprocessed milk - Health Hazard

India ranks first in milk production in the world but the quantity of milk being processed in the organized sector is hardly 10 per cent of the total production. The rest of the milk is either retained by milk producers or is sold through middle men. In villages and big cities, a large volume of milk is being supplied by middlemen and vendors for human consumption. This raw milk has a high bacterial count, which is a health hazard for consumers. Some of the effects of high bacterial count in raw milk are as under. Bacterial inhibitors naturally available in raw milk such as immunoglobalins and lactoperroxidase systems are inactivated and consequently, the growth of harmful bacteria is stimulated. Denaturation of whey proteins takes place, which reduces the available oxygen potential in milk, thereby promoting lactic acid bacterial growth, which contributes towards the spoilage of milk, Protein decomposition of products, such as peptides and amino acids are formed, which promote bacterial growth. Generally, a majority of the consumers have the impression that once the milk is boiled, the milk becomes safe for consumption. But this presumption is not correct: during heating of milk, the bacteria are only killed but are not removed from the milk. The dead bacteria remain in the milk as scum. Some bacteria such as bacillus species and clostridium species from their spores. Most of these survive pasteurization temperature. High the initial count in raw milk, more will be the spores in milk. These spores subsequently germinate, grow and spoil milk and pose health risk too. Some bacteria produce toxins. More toxins will be produced if milk has large bacterial count. Some bacteria also produce enzymes namely proteases and lipases. The proteases attack proteins and lipases attack fat, thus causing putrid and rancid off-flavours in the milk.

It is, therefore, clear that higher bacterial count in raw milk results in higher bacterial count in product, poor quality of product (higher acidity, higher toxins, off flavours, lower shelf-life, more bacterial dead cells), less safe product and higher processing cost. Thus, unprocessed milk is full of spoilage pathogens and is hazardous for human consumption.

Source : AIBA, Beverage & Food World, February 2002