Coe Shelly, Fraser Ann, Ryan Lisa
Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK.
Int J Food Sci. 2013;2013:238216. doi: 10.1155/2013/238216. Epub 2013 Apr 4.
Tea (Camellia sinensis) is a widely consumed beverage and recognised for its potential enhancing effect on human health due to its rich polyphenol content. While a number of studies have investigated the quantity and type of polyphenols present in different tea samples, no study has reported the potential effect of digestive enzymes on the availability of tea polyphenols for human absorption or the subsequent impact on glycaemic response. The objectives of the present study were to assess the total polyphenol content of different teas, to assess the bioaccessibility of polyphenols in whole and bagged teas, and to determine the effect of black, white, and green tea infusions on sugar release. All of the teas were a significant source of polyphenols (10-116 mg Gallic acid equivalents/g). There was an overall increase in the release of polyphenols from both the bagged and the whole teas following in vitro digestion. Bagged green tea significantly (P < 0.05) reduced rapidly digestible starch from white bread samples compared to control and black and white bagged teas. The present study confirms that tea is a rich source of polyphenols and highlights the potential benefits it may have on modulating glycaemic response in humans.
茶（茶树）是一种广泛饮用的饮品，因其富含多酚类物质而被认为对人体健康具有潜在的增强作用。虽然已有多项研究调查了不同茶叶样品中多酚类物质的含量和种类，但尚无研究报道消化酶对茶多酚可供人体吸收的可用性的潜在影响，以及对血糖反应的后续影响。本研究的目的是评估不同茶叶的总多酚含量，评估整叶茶和袋泡茶中多酚类物质的生物可及性，并确定红茶、白茶和绿茶茶汤对糖分释放的影响。所有茶叶都是多酚类物质的重要来源（10 - 116毫克没食子酸当量/克）。体外消化后，袋泡茶和整叶茶中多酚类物质的释放总体上有所增加。与对照以及袋泡红茶和袋泡白茶相比，袋泡绿茶显著（P < 0.05）降低了白面包样品中快速消化淀粉的含量。本研究证实，茶是多酚类物质的丰富来源，并突出了其在调节人体血糖反应方面可能具有的潜在益处。
