Quality index of oils extracted from gamma-irradiated peanuts (Arachis hypogaea L.) of the golden and bari varieties.

Two varieties of peanuts were irradiated to 4, 6 and 8 kGy with Co(60). Their proximate compositions remained unaffected, but microbes were eliminated completely after irradiation to 8 kGy. HPLC was used to study tocopherols of irradiated and unirradiated oil samples. There were dose-dependent differences in physico-chemical values between the control and irradiated samples. Significant changes in tocopherol concentrations and peroxide values in the oils were observed after irradiation to 8 kGy. Fatty acid compositions did not change significantly. The study has shown that irradiation is an effective tool in preservation of peanut oil.