How is rice adulterated and how can it be detected?
Rice is mainly adulterated with metanil yellow or turmeric. Consumption of Metanil yellow adulterated rice leads to degeneration of testis in males or cancer. If the adulterant turmeric contains lead chromate it may lead to anaemia, paralysis etc.
Detection: Rub a few grains in the palms of tow hands, yellow colour gets reduced or disappears. Add a few drops of concentrated Hydrochloric acid to a few rice grains mixed with little water presence of pink colour indicates presence of metanil yellow. Take a small amount of sample in test tube, add some water and shake Dip Boric acid paper (filter paper dipped in Boric acid solution).If it turns pink, turmeric is present.
Take some rice and sprinkle on it a small amount of soaked lime for some time. The rice grains will turn red if turmeric present