Submitted to: European Journal of Lipid Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2015
Publication Date: 9/9/2015
Publication URL: http://handle.nal.usda.gov/10113/5226489
Citation: Fhaner, M., Hwang, H.-S., Winkler-Moser, J.K., Bakota, E.L., Liu, S.X. 2016. Protection of fish oil from oxidation with sesamol. European Journal of Lipid Science and Technology. 118(6):885-897.
Interpretive Summary: Omega-3 oils are well known for their beneficial health effects such as reducing the incidence of heart attacks, reducing inflammation and the brain development in fetuses. Therefore, the use of omega-3 oil supplements and foods fortified with these oils has increased in recent years. The major drawback of using omega-3 oils is that polyunsaturated fatty acids in omega-3 oils oxidize much faster than unsaturated and monounsaturated fatty acids. The oxidation of polyunsaturated fatty acids results in negative impacts on the flavor and odor of the final product and on the amount of these fatty acids available to the body. Therefore, protecting omega-3 oils from oxidation during manufacturing processes and storage of the omega-3 oil supplements and foods fortified with omega-3 oils has always been a serious challenge and is critical to the product development. In this study, we evaluated antioxidant activity of sesamol, a natural compounds found in sesame oil, towards fish oil. It was found that sesamol had higher antioxidant activity than a synthetic antioxidant, butylated hydroxytoluene (BHT), and a leading commercial natural antioxidant, rosemary extract, at a certain concentration. Considering problems of flavor, odor, and color associated with a rosemary extract and that a rosemary extract product is typically sold in solution form for oil applications due to the low solubility of active ingredients in oil, sesamol offers advantages over the rosemary extract as it can be used in solid form.
Technical Abstract: The aim of this study was to determine whether sesamol may provide antioxidant protection for functional foods containing marine omega-3 fatty acids. We tested the effectiveness of sesamol at two temperatures, 30 and 50 ºC and compared its antioxidant activity with butylated hydroxytoluene (BHT), a commercial rosemary extract and gamma-oryzanol. Each antioxidant system was tested at two concentration, 0.84 mM and 8.4 mM and compared to 0.84 mM BHT (200 ppm, the regulatory limit allowed in oils). The molar concentration of rosemary extract was calculated based on its phenolic content. The antioxidant effects of each treatment were determined through various oxidation tests including peroxide values, conjugated diene values, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels, and volatile compounds formation. In this study, at 0.84 mM, sesamol was not as effective as the commercial rosemary extract in protecting fish oil from oxidation. However, 8.4 mM sesamol performed better than the rosemary extract containing 8.4 mM phenolic diterpenes in peroxide values and headspace volatiles compounds and it showed similar results as the rosemary extract in conjugated diene values and EPA and DHA levels. Gamma-oryzanol was less effective than the other antioxidants tested in this study.