Comparison of antioxidant and antimicrobial effects of some vegetable oils

Fixed oils extracted from from plants, are considered rich sources of bioactive compounds with antioxidative and antimicrobial properties. The health benefits of seed oils have been known and used since ancient times, and they continue to be widely used today. In this study, it was aimed to compare the free radical scavenging and antimicrobial effects of the oils obtained from raw or roasted samples in the market. Peanuts (Arachis hypogaea L.), sunflower seeds (Helianthus annuus L.), hazelnuts (Corylus avellana L.), sweet almonds (Prunus amygdalus (Batsch)) and walnuts (Juglans regia L.), supplied from a single known company in the market, were extracted using the Soxhlet apparatus in both unroasted and roasted powdered forms. Antioxidant capacities of 10 different oil samples belonging to five different seeds were determined and compared with DPPH and ABTS radical scavenging activity tests. The antimicrobial activities of these oils on the reference strains Escherichia coli ATCC8739, Salmonella typhimurium ATCC14028, Pseudomonas aeruginosa ATCC9027, Staphylococcus aureus ATCC6538, Staphylococcus epidermidis ATCC12228, Micrococcus luteus ATCC9341, Bacillus subtilis ATCC6633 and Candida albicans ATCC14053 were determined by the Kirby Bauer disk diffusion method. The highest extraction yield was found in the unroasted hazelnut seed, while the lowest extraction yield was found in the unroasted sunflower seed. It was found that radical scavenging activities of both unroasted and roasted walnut seed oils were higher (Inhibition for unroasted walnuts; 45,48 ± 0,09% and 33,34 ± 3,38%: Inhibition for roasted walnuts; 44.10 ± 0.35% and 30.82 ± 0.78%))compared to other samples. Antimicrobial activity was not determined in any of the oils. The findings of this study demonstrated that certain vegetable oils exhibited higher potential in terms of antioxidant and antimicrobial activities. This study has shown that fixed plant oils can be a source of potential for use in health, cosmetics and cosmeceutical preparations in future research.