HOW DOES HEAT OR FRYING PROCESS AFFECT DETERIORATION OF VARIOUS EDIBLE OILS IN INDIAN COOKING CONDITIONS AND HOW THE COMPOSITION OF OILS LEAD TO PEROXIDE FORMATION?

摘要

This investigation aims at finding to what extent does heat affect the deterioration of cooking oils used in Indian cooking conditions and to what effect does their composition have on peroxide formation? The current project studies the impact of Indian frying conditions with respect to various commercially available edible oils. The smoking point and peroxide value of five Indian edible oils in frying conditions; namely, Rice Bran Oil, Blend of Rice Bran and Safflower Oil, Cow Ghee, Safflower Oil and Olive Oils were estimated. Five samples of each brand were purchased from retail outlets in Mumbai. The Smoke point values of fresh unheated refined edible oil were Rice bran Oil 260°C, Safflower oil 223°C, Olive oil 197°C, Cow's ghee 170 °C and blend of rice bran oil and safflower oil was 270 °C. The value of Peroxide is measured by standard AOCS Official Method Cd 8-53 (2003). The peroxide value of fresh Rice bran oil was L6, Safflower oil is 1.9, Olive oil is 2.1, Cow's ghee is 0.6 and Rice-bran oil and Safflower blend (70:30) is 1.3. Heating and frying multiple times clearly increased peroxide values of them. It was concluded that high temperature cooking like that in Indian cooking need edible oils with a low smoke point. This study clearly showed the thermo labile nature of Indian cooking conditions and need to blend edible oils for stability. Research Question To what extent does heat affect the deterioration of cooking oils used in Indian cooking conditions and to what extent does their composition have an effect on peroxide formation?