Antioxidant properties of phenolic compounds in macadamia nuts
- 244 Downloads
Phenolic compounds in macadamia nuts and shells were identified, and their antioxidant activities were evaluated in refined macadamia nut oil. Thin-layer chromatography of oil extracted from macadamia nut kernels and shells indicated the possible presence of catechol, phrogallol, and 3,4,5-trihydroxy phenolic compounds. Four phenolic compounds were tentatively identified as 2,6-dihydroxybenzoic acid, 2′-hydroxy-4′-methoxyacetophenone, 3′,5′-dimethoxy-4′-hydroxyacetophenone, and 3,5-dimethoxy-4-hydroxycinnamic acid. Adding 0.01% of 2′-hydroxy-4′-methoxyacetophenone, 3′,5′-dimethoxy-4′-hydroxyacetophenone, or 3,5-dimethoxy-4-hydroxycinnamic acid to the oil significantly increased the Rancimat induction time against the control (P<0.0001). At this concentration, 3′,5′-dimethoxy-4′-hydroxyacetophenone was the most effective compound added. Although induction times of oils with 0.01%, 2,6-dihydroxybenzoic acid were not significantly different from the control, at 0.1% there was a significant difference from the control (P<0.0001). The activity was the same as that of 2′-hydroxy-4′-methoxyacetophenone at 0.1%.
Key WordsAntioxidant macadamia nuts oxidation phenolic compounds
Unable to display preview. Download preview PDF.
- 1.Tsumura, T., Factors Affecting Macadamia Nut Stability, M.S. Thesis, University of Hawaii, 1988.Google Scholar
- 2.Cavaletto, C., A. Dela Cruz, E. Ross, and H.Y. Yamamoto, Factors Affecting Macadamia Nut Stability I. Raw KernelsFood Tech. 20:108–111 (1966).Google Scholar
- 3.Dela Cruz, A., C. Cavaletto, H.Y. Yamamoto, and E. Ross, Factors Affecting Macadamia Nut Stability II. Roasted Kernels,20:123–124 (1966).Google Scholar
- 5.Ho, C.-T., Phenolic Compounds in Food: An Overview, inPhenolic Compounds in Food and Their Effects on Human Health, Vol. 1, Analysis, Occurrence and Chemistry, edited by C.-T. Ho, C.T. Lee, and M.-T. Huang, American Chemical Society, Washington, D.C., 1992, pp. 2–7.Google Scholar
- 6.Walker, J.R.,The Biology of Plant Phenolics, William Clowes & Son’s Limited, London, 1975, pp. 23–32.Google Scholar
- 7.Papadopoulos G., and D. Boskou, Antioxidant Effect of Natural Phenols on Olive Oil,J. Am. Oil Chem. Soc. 68:669–671 (1991).Google Scholar
- 8.Tyman, J.H.P., R.A. Johnson, and R. Rokhgar, The Extraction of Natural Nut-Shell Liquid from the Cashew Nut (Anacardium occidentale).66:553–557 (1989).Google Scholar
- 11.Van Sumere, C.F., Phenols and Phenolic Acids, inMethods in Plant Biochemistry, Vol. 1, edited by P.M. Dey and J.B. Harborne, Academic Press, New York, 1989, pp. 29–74.Google Scholar