EVALUATING QUALITY OF VARIOUS REFINED VEGETABLE OILS DURING STORAGE

Edible vegetable oils are important part of human diet providing several nutrients (antioxidants, essential fatty acids and vitamins).However, they are prone to quality deterioration by oxidation process leading to off-flavour and nutritional loss.Oil deterioration contribute to the formation of primary and secondary oxidation products that may pose health risk.Hence, it's of prime importance to determine the oil quality.This study used several standard methods (peroxide value, acid value, free fatty acids, thiobarbituric acid value, moisture content, fatty acid profiling, p-anisidine value and iodine value) to assess the quality of different refined vegetable oils thereby determining their shelf life.Most of the values fall within the permissible limits as prescribed by WHO.There was significant increase in the PV, p-anisidine value, acid value and total oxidation of oils during 90 days storage.Antioxidants are additives that retard the process of lipid oxidation thereby enhancing the shelf life of edible oils.However, higher concentration of -tocopherol shows pro-oxidant effect leading to increase in oxidation.