An article published in Times of India English daily on 1 Nov 2011
PUNE: Did you know that boiling and re-boiling milk on high frame for an extended period of time affects the nutritional content of the milk? Did you know that consumption of fresh milk is always better, and just one boil is enough to retain the nutrients?
A recent study reveals that Puneities do not follow the correct practices of boiling milk. A large number of people heat and re-heat the same milk again and again, and that too at a high temperature for a long time, thus, killing the nutrients. According to experts, milk subjected to less heating retains its nutrient value. Experts say milk should ideally be boiled not more than twice and not for more than 2-3 minutes.
These are some of the findings of the study – Milk Boiling Habits Study – conducted by the Indian Medical Academy, a forum of healthcare professionals based in New Delhi. The study, conducted recently, involved 300 women between 25 and 40 years of age across Pune.
“There are doubts among people about boiling milk. If milk is subjected to less heating, it retains the nutrient values. Consumption of fresh milk is always better. Just one boil is enough. Reheating milk only reduces the protein percentage.”
– Ambika Nair, consultant nutritionist and general secretary of the Indian Dietetic Association, Pune chapter
The study has found that 39% of Puneites boil milk more than three times before consumption, 62% boil it for more than five minutes and 72% do not stir it while boiling.
Pawan Gupta, endocrinologist, and project associate of the Indian Medical Academy, said, “Boiling and re-boiling milk at high temperature for a long time affects the nutritional content of the milk, particularly the B group (B1, B2, B12) of vitamins. These vitamins evaporate as heat increases. Milk should ideally be boiled not more than twice and not for more than 2-3 minutes.”
“Observations from the study show that Puneites do not boil milk the way it should be. There are chances that they might, therefore, not be consuming quality milk,” Gupta added.
According to Gupta, two reasons to this casual approach of boiling milk could be that either people are not aware of the right practices of boiling milk, or they might find it difficult to observe these practices.
There are doubts among people about boiling milk, said Ambika Nair, consultant nutritionist and general secretary of the Indian Dietetic Association, Pune chapter. “If milk is subjected to less heating, it retains the nutrient values. Consumption of fresh milk is always better. Just one boil is enough. Reheating milk only reduces the protein percentage.
“If you buy milk directly from the milkman, you should heat it at 100 degree Celsius for less than 8 to 10 minutes. In case of milk packets, the content is already pasteurised and there is no need to boil it at high temperature and heat it for less than for 6 to 8 minutes at 100 degree Celsius. This will retain the nutrients,” Nair said.
Under the circumstances, what is the ideal solution? According to Noorul Anwar, medical expert and consultant, IMA, the solution may lie in choosing UHT (ultra high temperature) milk that come in tetra packs. It guarantees both nutrition and convenience. The UHT is a type of milk that is germ-free and does not need boiling. It is a product of standardised processes.
Nair said tetra pack milk retains nutrient level. It is already heated to around 137.8 degree Celsius for two seconds before packing is done. One can consume the milk directly without heating it. One can also warm it, but not heat it, before consumption. Once, the tetra pack is open, it has to be refrigerated and consumed within two days.
The study states that milk is boiled mainly to kill germs. The milk generally consume in the households – loose milk (sourced directly from the milkman) or poly pack High Temperature Short Time (HTST) treated pasteurised milk (procured from milk booths) – contains a fair amount of disease-causing microbes. Boiling kills them. But, it does not necessarily mean the same milk can be consumed second time without boiling. Microbes might have regenerated by then due to inappropriate storage and handling.
Dr Nair said milk can get contaminated from source itself, such as milking operation, udder of the cow and the handling practices. This can lead to formation of spores of bacteria in milk. Thus, milk has to be treated to particular temperature. Otherwise, bacteria multiply.
So, according to experts, one should boil the milk correctly, or else opt for milk that does not require boiling.
What Majority Does
- 43% people boil and re-boil milk two-three times and 39% boil it more than three times
- 46% people boil milk on high flame
- 62% people boil milk for more than five minutes
- 72% people do not stir milk while boiling
The Right Way
- Do not boil milk for extended period of time
- Do not leave your milk out in the open after boiling; refrigerate it immediately
- Do not heat milk repeatedly
- Stir the milk while boiling
- Do not use microwave-ovens to heat and re-heat milk
- Use ultra high temperature milk that come in tetra packs. It guarantees both nutrition and convenience
84% people find boiling milk a tedious exercise. 75% people are even looking out for an alternative – milk that need not be boiled and can be readily consumed.
Types of milk consumed in the city
- Sourced from milkman 45%
- Poly pack 73%
- Tetra pack 2%
What They Do In Mumbai
A similar study was conducted by the Indian Medical Academy in Mumbai, which involved 300 women between 25 and 40 years of age from across the city. The study observed that 41% of Mumbaikars boil milk more than three times before consumption, 56% boil it for more than five minutes and 77% do not stir it while boiling. The study also found that 68% people find boiling milk a tedious exercise while 64% people are looking for an alternative – milk that need not be boiled and can be readily consumed.