Tocopherol Content in Peanuts after gamma-Irradiation: Effect of Ascorbyl Palmitate Addition on Oil Stability

Abstract

Food irradiation has a number of advantages over the other conventional preservation technologies like canning, freezing, pasteurization and addition of chemical preservatives. It is a fast and inexpensive treatment which can be performed in the original packaging eliminating the risk of re-pollution. Unfortunately, changes as a result of irradiation may occur in biologically active compounds, especially lipids and antioxidants, thus decreasing the oil oxidative stability. So, this study is focused on the evaluation of changes in the content of tocopherols in oil, extracted from peanuts subjected to gamma-irradiation with a dose of 10 kGy. The effect of ascorbyl palmitate added to the oil in different proportions has been studied as well. The results showed decreasing of tocopherols in the oil from irradiated peanuts. On the other hand, addition of ascorbyl palmitate in 1:1 ratio to the native γ-tocopherol indicated synergistic effect which not only compensated the negative effect of irradiation but decreased twice the oxidation rate compared to that of non-irradiated oil.