Jorhat, Aug. 3: It is a well known fact that the widely-consumed fermented rice, popularly known as poita bhat in Assam, panta bhath in Bengal and pokhalo in Orissa has cooling properties and produces a soporific effect. But it is only recently that the agricultural biotechnology department of the Assam Agricultural University here has unravelled the immense health benefits of this water-soaked rice.

What is of more importance is that the lactic acid bacteria isolated from poita bhat has the potential of removing anti-nutritional factors in fermented food.

Madhumita Barooah, who worked along with Gunajit Goswami of the department to isolate the bacteria, said cooked rice had an element that prevented the availability of minerals like iron, potassium, sodium and calcium in high quantities.

“About 100gm of cooked rice has only 3.4mg of iron, while for the same quantity of rice fermented for 12 hours, the iron content went up to 73.91mg. Likewise, sodium, which was 475mg came down to 303mg, potassium went up to 839mg and calcium went up from 21mg per 100gm of cooked rice to 850mg, after 12 hours of fermentation of the same quantity of rice,” Barooah said.

Even after slight fermentation (three hours), the breakdown of the nutritional inhibitor by the lactic acid bacteria increased the mineral content manifold, she added.

“Although rice is an important source of dietary energy and nutrients, it is not a good source of metabolic micro-nutrients because of the presence of anti-nutritional factors such as phytic acid. Cereal grains such as rice also contain oligosaccharides that are not easily digestible because of absence of an enzyme in the human intestinal mucosa. Fermentation allows for breakdown of this and easy digestion,” Barooah said.

Poita bhat, which is consumed by many people here and in other east Indian states, is prepared by soaking and fermenting cooked rice overnight in water in a covered container. It is popular in rural households where this method is used to preserve leftover rice, which is consumed as breakfast the following morning along with salt, chilli, lemon and curd, if available. The dish is slightly sweet and sour in taste because of fermentation by the lactic acid bacteria.

As it is considered to be a coolant during summer, in Assam there is a Bohag Bihu tradition of consuming a small portion of poita bhat, accompanied by whisking of a hand fan, to signify the onset of summer.