The effect of irradiation process on chemical properties of chia (Salvia hispanica L.) seed oils

In this study, the effect of irradiation on the chemical properties of chia seed oils was investigated. The samples used in the research were obtained from a private company that imported this product from Argentina. Samples divided into 5 separate sections of 300 grams, were subjected to gamma irradiation with the doses of 2,5, 5, 7,5 and 10 kGy in GAMMA-PAK Sterilizasyon San. ve Tic. A.Ş. located in Tekirdağ/Çerkezköy. After the irradiation process, the oils of chia seeds were obtained by using cold press technique. The oils obtained as a result of pressing were filtered and tocopherol value, sterol composition, peroxide number, free fatty acidity, phenolic substance, changes in fatty acid composition of the samples were investigated. Compared to the control group, it was found that phenolic and tocopherol levels decreased, free fatty acid and peroxide count increased with the increase of irradiation dose and these changes were statistically significant (p<0.01). Palmitic acid and stearic acid ratios increased and oleic acid and linoleic acid ratios decreased with increasing irradiation dose. In parallel with the increase of irradiation dose, total monounsaturated and polyunsaturated fatty acids decreased. When evaluated in terms of sterol compositions; β-sitosterol was determined as the highest and β-sitosterol ratio decreased with increasing of irradiation dose. No statistically significant difference was found in the amount of campestrol in the sterol composition depending on the irradiation doses applied (p>0.01). It was observed that the total amount of sterol decreased due to the increased irradiation dose.