Department of Food Science Laboratory of Food Biotechnology, University of Massachusetts, Amherst, Massachusetts, USA.
J Med Food. 2010 Dec;13(6):1313-23. doi: 10.1089/jmf.2009.0273. Epub 2010 Sep 27.
The well-known health benefits of apples have been attributed in part to the presence of polyphenols and related antioxidant capacity. The consumption of apples could provide health benefits by reducing the risk for chronic diseases such as metabolic syndrome disease, including type 2 diabetes. Thus, the objective of this study was to investigate the phenolic-linked antihyperglycemia bioactive factors in aqueous and 12% ethanol extracts of peel and pulp from 10 different freshly harvested apple varieties commonly consumed in the United States. The extracts were analyzed for total soluble phenolics, 2,2-diphenyl-1-picrylhydrazyl-linked antioxidant activity, and their associated in vitro α-glucosidase and α-amylase inhibitory activities. In general, peel extracts had higher total soluble phenolic content and related antioxidant capacity than pulp extracts. Quercetin derivatives, protocatechuic acid, chlorogenic acid, and p-coumaric acid were detected, and the amount varied significantly between aqueous and ethanolic extracts. Honeycrisp and Red Delicious varieties had the highest total phenolic contents and a significant correlation with antioxidant capacity (r = 0.91). In addition, high α-amylase and α-glucosidase inhibitory activities in aqueous pulp extracts were found. However, the peel extracts had the highest α-glucosidase inhibitory activity along with low α-amylase inhibitory activity. No correlation between α-amylase inhibitory activity and total phenolic content was observed. However, positive correlations between α-glucosidase inhibitory activity and total phenolics in aqueous (r = 0.50) and ethanolic (r = 0.70) extracts were observed. This study provides the biochemical rationale for animal and clinical studies to determine the suitable varieties with optimum bioactive factors with antihyperglycemia potential.
苹果的诸多有益健康的特性部分归因于多酚类物质和相关抗氧化能力的存在。食用苹果可以降低患慢性病的风险，如代谢综合征疾病，包括 2 型糖尿病。因此，本研究的目的是研究美国常见的 10 种不同新鲜收获的苹果品种的果皮和果肉的水提物和 12%乙醇提取物中与多酚相关的降血糖生物活性因子。对提取物的总可溶性酚类物质、2,2-二苯基-1-苦基肼（DPPH）自由基相关抗氧化活性以及体外α-葡萄糖苷酶和α-淀粉酶抑制活性进行了分析。一般来说，果皮提取物的总可溶性酚含量和相关抗氧化能力均高于果肉提取物。检测到槲皮素衍生物、原儿茶酸、绿原酸和对香豆酸，其在水提物和醇提物之间的含量差异显著。Honeycrisp 和 Red Delicious 品种的总酚含量最高，与抗氧化能力呈显著正相关（r = 0.91）。此外，在水提果肉提取物中发现具有高α-淀粉酶和α-葡萄糖苷酶抑制活性。然而，果皮提取物具有最高的α-葡萄糖苷酶抑制活性，同时α-淀粉酶抑制活性较低。未观察到α-淀粉酶抑制活性与总酚含量之间存在相关性。然而，在水提物（r = 0.50）和醇提物（r = 0.70）中，α-葡萄糖苷酶抑制活性与总酚含量呈正相关。本研究为动物和临床研究提供了生化依据，以确定具有潜在降血糖作用的最佳生物活性因子的适宜品种。
