The milk scandal in China has once again exposed the irresponsible behaviour of some trade towards food safety. China had experienced an explosive growth in its market for dairy products with annual sales doubling to $18 billion over the last five years. But the recent case of milk contamination causing death of at least four babies, sickening 53,000 people and hospitalising some 13,000 has brought to light government laxity in enforcing food safety regulations.
According to reports, food contamination has become such a routine affair in China that no company operating directly or through a joint venture can claim its final product to be safe unless the entire chain from the farm level to the market is carefully monitored for any possible contamination.
After a number of fatal incidents and ban imposed on Chinese milk food products by several importing countries, the Chinese authorities, however, of late began cracking down and insisted upon recalling of all the contaminated products.
Food safety standards are in vogue in almost most every country and as a matter of fact, global food norms are formulated by Codex. The issue is of its strict implementation at all levels of the food chain.
An attempt has been made in India to consolidate the multiple laws governing the food industry under the Food Safety and Standards Act 2006. The Act is significant in the sense of having a provision for the first time for recall of contaminated and adulterated food products from the market. We had cases of production of synthetic milk in India. A lesson that India should learn from Chinese incident is to effectively implement food safety norms and initiate the process of recall of contaminated and adulterated products whenever such a situation arises.
The milk contamination in China is the case of adulteration with melamine with a view to raise the protein content. Melamine is a toxic chemical used in production of plastics, fertilisers, fire retardants, ink and other products. According to medical data, high content of melamine can cause acute kidney failure when consumed.
Milk is a biological fluid selected by evolution to provide the best nutritional and immunological food source for the mammalian new born. According to deputy director general for animal sciences in the Indian Council of Agricultural Research (ICAR), KM Bujarbaruah, protein content in milk may vary according to the genetic make-up but cannot be as high as detected in the contaminated milk in China. It is estimated that one glass of milk contains 8 gm of proteins with caseins contributing to 78% to 80%. Together with fat, caseins are responsible for the characteristic white property of the milk.
Altogether there are six major milk proteins that contribute to the milk constituents, flow rate and milk yield. There are six casein proteins in cow?s milk?alpha s1 casein, beta casein, alpha s2 casein and kappa casein that form part of the milk solids. The percentage of caseins in milk determines many of the properties of milk including the cheese yield.
The other major milk proteins are beta lacto globulin, alpha lactalbumin and lactoferrin that are part the whey proteins and are known to influence milk constitution and yield in many ways. Variations in these proteins are known to influence the milk composition and yield and hence are projected as best molecular markers for economic traits in dairy cattle. Hence, information about gene coding for milk protein genes, especially their variability is of paramount significance in dairy improvement programme.
