Effect of thermal processing on the quality parameters of ghee incorporated with curry leaf (Murraya koeneigii) extract

Abstract

This study examined the effect of adding antioxidants, namely curry leaf extract (CLE) and butylated hydroxyanisole (BHA), on the physicochemical properties of ghee during deep frying. The results showed that the addition of CLE to ghee resulted in significant changes in the L*, a*, and b* values, likely due to the extraction of chlorophyll molecules during CLE preparation. Deep frying caused a decrease in L* values and an increase in a* and b* values of ghee, as well as an increase in the redness and yellowness indices, with control ghee experiencing the most significant changes. The viscosity of ghee increased during frying, and the increase was less in ghee with added antioxidants. Antioxidant-added ghee showed the least increase in total polar compounds (TPC) and thiobarbituric acid reactive substances (TBARS) during frying, which are indicators of oil degradation. CLE and BHA were found to inhibit the production of Cholesterol Oxidation Products (COPs) in ghee during deep frying for up to 45 minutes. Control ghee showed the presence of both COPs (5α, 6α-epoxide and 7β-hydroxy cholesterol) after 45 minutes of frying, whereas ghee with added CLE and BHA had only 5α, 6α-epoxide after 45 minutes of frying.