4. Conclusions
In first two cycles of oils used for frying, free fatty acid content, peroxide value and total polar materials increased, while radical scavenging activity decreased. Further increase in frying cycles did not result in any significant changes in these parameters (p > 0.05). The polar material correlated well with the change in oil viscosity of the frying oil. With regard to physical properties, the colour of the oil was found to increase with an increase in frying cycles. There was no significant increase in viscosity during heating or frying cycles. The convective heat transfer was found to decrease insignificantly but correlated well with viscosity of the frying oil. The marginal changes in the unsaturated fatty acid levels in rice bran oil subjected to heating or frying, indicated its utility as a stable oil useful as a frying medium.