In vitro: |
Journal of the American Oil Chemists' Society, 1996, 73(11):1585-1588. | Antioxidant properties of phenolic compounds in macadamia nuts.[Reference: WebLink] |
Phenolic compounds in macadamia nuts and shells were identified, and their antioxidant activities were evaluated in refined macadamia nut oil.
METHODS AND RESULTS:
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%. |
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