Amber alert: Swetha Sivakumar on the benefits of parboiled rice

But even with India being the largest exporter of parboiled rice to the world, the glory days of it here at home are long gone. Are we overlooking a brilliant food processing technique?

The process of parboiling rice can be traced back 2,000 years and is said to have originated in the Indian subcontinent. Parts of Africa seem to have adopted similar techniques around the same time, but it was in India that the elaborate process of soaking, steaming and drying rice in large stone or iron jars was developed.

Parboiling (short for partial boiling) of rice within the husk proved to be very useful. Soaking and steaming the freshly harvested grain with the husk allows water to soak into the grain and gelatinise the starch. This converts the starch structure from an irregular, crystalline phase to a harder, uniform phase. The subsequent drying (which brings the moisture level down to 13%) enables the grain to have a longer shelf life. The resultant hardened grain becomes easier to dehull. It also doesn’t break as easily, and it resists attacks from weevils and other insects during storage and distribution.

By the way, parboiling is not exclusive to rice. In a different part of the world, the Babylonians and Jews were using a similar process on wheat grains about 2,000 years ago, and that resulted in bulgur.

Interestingly, China, Japan and a range of South-East Asian countries, which typically championed food processing techniques in ancient times, did not embrace the practise of parboiling rice. While it is hard to say exactly why, historians speculate that the practice of parboiling yielded fluffy, separate grains when cooked, which worked better for cultures that used their hands to scoop up the rice rather than chopsticks. So the Chinese, et al used hand-pounded raw rice instead.

The came the industrial revolution. By the mid-1800s, with the spread of mechanised milling and rice-polishing machines, the cost of processing dropped and the working classes could finally access pure, white rice. What they didn’t realise was that they were losing a much-needed vitamin in the switch: thiamine. Before automation, trace elements of this vitamin were ingested in the bits of bran that stuck to hand-pounded rice.

The genius of parboiling was only then understood, in a series of events that played out rather tragically in British Malaya, in 1896. That year, 25% of all hospital admissions and 27% of all hospital deaths were attributed to beriberi, a condition caused by lack of Vitamin B1 or thiamine. A large number of Chinese and Indian immigrants had newly arrived to work in the rubber plantations, and many were falling sick. Oddly, the Tamil immigrants who ate parboiled rice seemed immune to beriberi.

The doctors couldn’t quite understand why. Eventually, it took 40 years to isolate and synthesise thiamine in the laboratory. But even before the final piece of the puzzle was found, doctors could tell that parboiled rice contained the answer.

You see, Vitamin B1 along with other nutrients and colouring pigments, seeps into the endosperm from the bran and husk during the soaking and steeping stages of the parboiling process. In fact, when ailing patients’ diets were altered to include parboiled rice, they made a full recovery, a study conducted at the time by a Dr WL Braddon found.

Sadly, in India, consumption of parboiled rice has declined sharply over the past 50 years. There is a sense that it is “not pure” since it has already been “cooked once”, which is an absurd argument. (By that logic, sugar would have to be avoided too.) There is a fuss over the colour. Yes, parboiled rice is a pale amber, and not a clear white, but few realise that this colour comes from the goodness it contains.

I wish more people knew about the history of beriberi and how this millennia-old technique kept Indian immigrants safe all those years ago. Where do we get thiamine today? Well, the labourers back then were eating mainly rice and little else, hence the fatal deficiency. Aside from whole grains, thiamine is found in meat, fish, legumes, pulses, nuts, seeds and fortified cereals.

Look at the food pyramid and you’ll see that, no matter what the question, a mixed diet is often the simplest answer.