Useful waste

Organic farmers in India can now look forward to a new class of bio-pesticides. Researchers at Annamalai University, Tamil Nadu, have turned fly ash, a waste material generated by thermal power stations, into an excellent bio-pesticide by spiking it with some plant products. They found that fly ash can kill winged and crawling pests that attack rice and vegetable crops when a dash of powdered neem, eucalyptus or tulsi leaves, or turmeric, pepper or chilli is added to it. The optimum quantity of the plant product needed for effectiveness is 10 per cent. The mortality of the insects ranged from 50 to 75 per cent with any of the mixtures, the researchers report in the latest issue of Current Science.

Cooking makes spice not nice

The next time you pressure cook or boil your favourite chicken or rajma curry, you can be sure of one thing: you have lost at least a third of the beneficial ingredients present in flavour-rendering spices such as turmeric, pepper and chilli to the heating process. A team of researchers from the Central Food Technological Research Institute, Mysore, checked out the effect of heating on curcumin, capsaicin and piperine (the active ingredients in turmeric, red chilli and black pepper respectively) by subjecting each to 10 minutes of pressure cooking, and boiling for 10 and 20 minutes. The maximum loss was found to be 57 per cent — in the case of curcumin when cooked for 10 minutes along with red gram and tamarind using a pressure cooker. Boiling for 10 minutes, on the other hand, entailed minimum losses, in the range of 15-26 per cent.