On safe milk consumption

Country's food safety situation has reached a worrying stage due to widespread adulteration caused by toxins, pesticide residues, microbiological contamination, veterinary drug residues and heavy metals. Of late, the revelation that around 77 per cent of pasteurised milk available in the market contain high levels of bacteria has come as a terrible shock.  

Experts quoting a study, conducted by icddr,b with support from CARE Bangladesh, said the milk samples assessed during the research were found to be contaminated with disease-causing organisms. The study revealed that the level of bacteria found was beyond the standards set by the country's only national standards body BSTI (Bangladesh Standards and Testing Institution). An investigator associated with the study said consuming such milk directly can cause various diseases like diarrhoea, dysentery and typhoid.

The research, according to a leading newspaper report, was conducted after scientists collected 438 raw milk samples from milk producers, collectors, chilling plants and restaurants in 18 upazilas of seven milk-producing northern districts to assess the microbiological quality of milk at different stages of the dairy value chain. Besides, 95 other samples were collected from commercially-processed milk found on the shelves of retail stores in different areas.

Scientists, however, revealed that 72 per cent milk samples at the primary producers' level were contaminated with coliform, 57 per cent were contaminated with faecal coliform bacteria and 11 per cent of samples had high levels of E.coli. In fact, the presence of faecal coliform bacteria in milk indicates that milk was contaminated with pathogens or disease-producing bacteria or viruses although national and international standards have zero tolerance for the faecal coliform bacteria in pasteurised milk.

According to the study, chilling-plant samples were found to be contaminated even at a higher rate than those taken from collection points. Samples collected from all 15 chilling plants in five districts were contaminated with coliform as well as faecal coliform. Presence of some other bacteria such as B.cereus and staphylococci were also found in the samples-however within the normal limit. Experts think the dairy farmers' poor hygiene practices, environment and delay in getting the milk to the chilling points from the farmers could be the factors behind milk contamination.

The fact that milk contains some bacteria is scientifically acceptable, but what is notable here is that it multiplies exponentially when milk is kept in temperature ranging from 30-40 degrees celsius. The bacteria can also multiply at the retail level if the milk is not in the refrigerator. Experts say although most people boil milk before consuming it, that doesn't bear any guarantee that all the harmful bacteria like coliform and E.coli will be killed completely.

Milk is known to be pasteurised mainly to kill pathogenic bacteria. But people get panicked and raise eyebrows when such high level of bacteria is found in milk despite pasteurisation, which is a process in which packaged and non-packaged milk is treated with mild heat (<100 °C) to destroy certain pathogens aiming at reducing spoilage organisms and eliminating vegetative bacteria while making the product safe for consumption without radically altering taste or quality. It also comes before the public as a matter of serious concern when such high level of contamination prevails in processed milk.

The latest findings suggested that Bangladesh's dairy companies ensure end-to-end compliance. Indeed, maintenance of seamless cold chain throughout the distribution channel of processed milk from factory to consumer's table is critical for ensuring safe milk for public consumption. Creating awareness among consumers and farmers in general about refrigeration facilities for milk can be very much effective. Especially, farmers involved in milk production should be educated on proper hygiene practices.

Since the milk producers usually take a long time transporting the milk to chilling plants, installing proper refrigeration facilities close to the milk production centres could be a good idea. The government, side by side the corporates purchasing milk from the farmers, should also invest in infrastructure and distribution channels. It must be kept in mind that ensuring refrigeration at every single stage of milk supply chain is crucial in making milk consumption safe.

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