Antioxidant property of palm oil blended ghee and its fractions

Abstract

Ghee is a high-priced product that costs three to six times than the edible vegetable oil. Dry fractionation is one of the cost-effective methods of modifying the physical properties of milk fat. Natural antioxidant present in palm oil is believed to enhance the oxidative stability of ghee. Therefore, in the current study, ghee was intentionally blended with palm oil at levels of 0,5, 10, and 20%. Then the ghee was fractionated to separate liquid and solid portions by dry fractionation technique. The antioxidant activity accessed by the 2, 2-diphenyl-1-picrylhydrazyl (DPPH)method shows that as the palm oil (especially tocotrienols and tocopherols) level increased the antioxidant activity in the prepared samples. This could be due to carotenoids and vitamins E which act synergistically as powerful natural antioxidants which also contribute better towards stability against auto oxidation(peroxide value). The liquid fraction (L20 with palm oil 20%) has a high level of antioxidant activity. Fractionated ghee, especially the liquid fraction showed higher antioxidant activity as compared to ghee could be due to its higher vitamin E activity. The peroxide value and free fatty acid content of ghee were determined during storage at 30°C and 60°C for 90 days. Liquid fractions showed more peroxide value and FFA as the storage day increased than solid fractions, which contained more peroxide value and FFA than control samples.