Radiolytic and storage stability study of soybean and red palm oils

The effects of gamma irradiation using Cobalt-60 source and storage on the carotene contents and consequent quality of soybean and red palm oils were studied. The oil samples were radiated with (ISSLEDOVATEL, CIS) source of gamma radiation, with different doses. The non-radiated oil was used as a control. The oil samples were kept for the interval of 8 weeks in the ambient condition, after irradiation. The results illustrate that the peroxide, free fatty acids and anisidine values increase whereas the beta-Carotene and Iodine values decrease, with increase of radiation doses for both oils. It was found that the red palm oil radiated with doses of 1, 5, 10, 15 and 20kGy gamma radiation has tolerable stability due to the presence of high level of beta-carotene as compared to soybean oil; however the rancidity was moderately diminutive at the lower radiation doses in red palm oil and was little more significant in soybean as the increase in radiation doses. The control sample shows fairly high stability. The radiated stored samples illustrate decrease of stability with increase of radiation doses and also with the duration of storage.