Pistachio Skin Phenolics Are Destroyed by Bleaching Resulting in Reduced Antioxidative Capacities

详细信息    查看全文

• 作者：Navindra P. Seeram ; Yanjun Zhang ; Susanne M. Henning ; Rupo Lee ; Yantao Niu ; Grace Lin ; David Heber
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2006
• 出版时间：September 20, 2006
• 年：2006
• 卷：54
• 期：19
• 页码：7036 - 7040
• 全文大小：194K
• 年卷期：v.54,no.19(September 20, 2006)
• ISSN：1520-5118

文摘

Pistachio shells split naturally prior to maturity leading to their unique crack-shell form. Within 24 hof harvest, hull-trapped moisture may cause shell staining. The illegal process of bleaching has beenused to restore a desirable white color to pistachio shells. It is not known whether bleaching adverselyaffects phytochemical levels in pistachios. Therefore, we identified for the first time multiple pistachioskin phenolics as quercetin (14.9 mages/entities/mgr.gif">g/g), luteolin (10.0 mages/entities/mgr.gif">g/g), eriodictyol (10.2 mages/entities/mgr.gif">g/g), rutin (1.6 mages/entities/mgr.gif">g/g),naringenin (1.2 mages/entities/mgr.gif">g/g), apigenin (0.2 mages/entities/mgr.gif">g/g), and the anthocyanins, cyanidin-3-galactoside (696 mages/entities/mgr.gif">g/g)and cyanidin-3-glucoside (209 mages/entities/mgr.gif">g/g). We investigated the effects of bleaching (0.1-50% hydrogenperoxide) on phenolic levels and antioxidative capacities in raw and roasted nuts. Because of theirflavylium cation structures, anthocyanins were the most sensitive to bleaching. Bleaching decreasedtotal anthocyanin levels [mages/entities/mgr.gif">g/g of skins (% hydrogen peroxide)]: 905 and 549 (0%); 653 and 145(0.1%); 111 and 18.4 (5%); 6.1 and 3.2 (25%); 0 and 0 (50%) for raw and roasted nuts, respectively.Bleaching also reduced antioxidative capacity [mages/entities/mgr.gif">M/g of Trolox (% hydrogen peroxide)]: 945 and 725(0%); 940 and 472 (0.1%); 930 and 455 (5%); 433 and 370 (25%); 189 and 173 (50%), for raw androasted nuts, respectively. Raw nuts preserved phenolic levels and antioxidant capacity better thanroasted nuts, suggesting contributing effects of other substances and/or matrix effects that aredestroyed by the roasting process. The destruction of bioactive phenolics in pistachio skins maynegatively impact the potential health benefits arising from pistachio consumption.