Identification of Physically Refined Rice Bran Oil and Its Simple Detection in Other Oils

The issue of purity of the edible oils is becoming increasingly important in the food industry. Many branded oil products are being sold at a premium price on the basis of their purity and quality, or on the basis of their health-boosting effects. Undue financial advantage is also taken by deliberately mislabeling or adulterating the oils and presenting them as quality products in the market. In the present paper a new, very simple, rapid, reliable and highly economical qualitative technique is being reported. By means of this test, adulteration of rice bran oil in other oils can be detected within one minute. A small quantity of alkaline solution of suspected oil sample when treated with small quantity of benzenediazonium chloride solution at 0-5°C followed by shaking of the mixture, a brilliant orange-red colour of 5-phenylazo-γ -oryzanol or 5-phenylazoferulic acid (which is indeed a dye material) develops within the next few seconds indicating the presence of rice bran oil adulteration in the test sample. Upto 2.5% rice bran oil adulteration can be detected with this new technique.