Antioxidant activity of a rosemary extract and its constituents, carnosic acid, carnosol, and rosmarinic acid, in bulk oil and oil-in-water emulsion
Antioxidant activity of a rosemary extract and its constituents, carnosic acid, carnosol, and rosmarinic acid, in bulk oil and oil-in-water emulsion
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DOI：
10.1021/jf950374p
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发表时间：
1996-01-01
影响因子：
6.1
通讯作者：
Prior, E
中科院分区：
文献类型：
--
作者：
Frankel, EN;Huang, SW;Prior, E
本研究旨在评价商业迷迭香提取物和活性成分鼠尾草酚、鼠尾草酸和迷迭香酸的抗氧化活性，以抑制脱生育酚玉米油和相应的水包玉米油乳剂中氢过氧化物的形成和分解。在散装玉米油中，迷迭香提取物、鼠尾草酸、迷迭香酸和α-生育酚的活性显著高于鼠尾草酚。相比之下，在水包玉米油乳剂中，迷迭香化合物的活性低于散装油，而迷迭香提取物、鼠尾草酸、鼠尾草酚和α-生育酚的活性高于迷迭香酸。在pH 5的水包玉米油磷酸盐缓冲液乳液中获得了类似的结果，但α-生育酚的活性较低。鼠尾草酚和鼠尾草酸在pH 4和5缓冲的水包玉米油乳剂中比在pH 7时更有活性的抗氧化剂。极性亲水性迷迭香化合物在乳液体系中的抗氧化活性降低可以通过它们在水中的界面分配来解释，因此变得比在本体油中保护性更低。系统pH的影响可能与迷迭香抗氧化剂的稳定性有关。
This study was aimed at evaluating the antioxidant activity of a commercial rosemary extract and the active constituents carnosol, carnosic acid, and rosmarinic acid, in inhibiting the formation and decomposition of hydroperoxides in tocopherol-stripped corn oil and in the corresponding corn oil-in-water emulsions. In bulk corn oil, the rosemary extract, carnosic acid, rosmarinic acid, and alpha-tocopherol were significantly more active than carnosol. In contrast, in corn oil-in-water emulsion, the rosemary compounds were less active than in bulk oil, and the rosemary extract, carnosic acid, carnosol, and alpha-tocopherol were more active than rosmarinic acid. Similar results were obtained in corn oil-in-water phosphate buffer emulsion at pH 5, but alpha-tocopherol was less active. Carnosol and carnosic acid were much more active antioxidants in corn oil-in-water emulsions buffered at pH 4 and 5 than at pH 7. The decreased antioxidant activity of the polar hydrophilic rosemary compounds in the emulsion system may be explained by their interfacial partitioning into the water, thus becoming less protective than in the bulk oil. system. The effect of pH may be related to the stability of the rosemary antioxidants.