Evaluation of Antioxidant Activity of Ethanolic Extract from Irradiated Sunflower (Helianthus Annuus L.) Seeds Hull

Abstract

Sunflower seeds hull are by-products of the sunflower industry that has low economic value despite its high content of antioxidants such as phenolic compounds and recently natural antioxidants have gained increased interest because natural food ingredients are safer than synthetic ones. Thus, the aim of investigation to evaluate the antioxidant efficacy of ethanolic extract of irradiated sunflower (Helianthus annuus L.) seeds hull (Sakha- 153 variety) at dose levels of 0, 3, 6 and 9 kGy on total phenolic compounds and total antioxidant activity were studied, and the composition of phenolic compounds of ethanolic extract of non-irradiated and irradiated samples was determined by HPLC. The results exhibited that the all extract of samples under investigation possesses high stronger antioxidant activity, especially samples ethanolic extracts of irradiated at dose level of 6 kGy. For further confirmation, the ethanolic extract of irradiated samples at dose level of 6 kGy was investigated on beef minced meat model system. Different concentrations of ethanolic extract of irradiated samples at dose level of 6 kGy and Tert-Butylhydroquinone (TBHQ) were added to beef minced meat and cooked at 100±2ºC for 30 min. after cooling at room temperature, the cooked samples were stored at cold storage 4±1ºC for 7 days. Thiobarbituric acid reactive substances (TBARS) values proved that ethanol extract of Sakha- 153 sunflower hulls had a power of inhibiting lipid oxidation comparable to TBHQ and exhibit antioxidant activity superior to TBHQ in the beef minced meat model system. Furthermore, the results showed that the ethanolic extract of irradiated sunflower seeds hull samples at dose level of 6 kGy were effective in inhibiting lipid oxidation of sunflower oil. Thus, these results are very beneficial for using the ethanolic extract of irradiated sunflower seeds hull samples at dose level of 6 kGy as natural stronger antioxidant and cheap price in food industry field.

Keywords: Antioxidant/ Ethanolic extract/ Sunflower  seeds hull.