Assessment of anti microbial and anti oxidant properties of walnut green husk extract of Hezarjerib in refined soybean oil

In this study, the antioxidant properties of walnut green husk extract of Hezarjerib area of the city of Behshahr in northern Iran was compared with TBHQ and BHA on the refined soybean oil. Chemical parameters of oil including acidity, peroxide value (PV), thiobarbituric acid value (TBA), dien conjugates and the percent of polar compounds were measured during incubation at 60 degree centigrade for a period of 32 days. Moreover, antimicrobial effect of walnut green husk extract was evaluated on gram positive and gram negative bacteria. The results showed that the antioxidant properties of a solution of 1000 ppm of walnut green husk extract was more effective than the synthetic antioxidants of BHA with a concentration of 200 ppm. The walnut green husk extract with 80 mg/ml concentration had inhibitory effect only on Staphylococcus aureus. The walnut green husk extract with 160 mg/ml concentration had inhibitory effects on all grams negative and grams positive bacteria and also a bactericidal effect on Staphylococcus aureus, Listeria monocytogenes and Salmonella typhi.