Coarse tea is made of mature tea plant (Camellia sinensis L.) shoots and is generally discarded as a worthless crop product, but has been proved an excellent material for the treatment of diabetes. This study aims to evaluate the effects of the extraction techniques WE (water extraction), UAE (ultrasound-assisted extraction), MAE (microwave-assisted extraction), and EE (enzyme extraction) on the physicochemical properties and antidiabetic activities of polysaccharides from coarse tea (CTPSs). The results showed that all four CTPSs had homogeneity in the monosaccharide types and similar IR (Infrared spectroscopy) characteristic absorption peaks, but differed in monosaccharide proportion and molecular weight distribution. Compared with the other three extraction techniques, CCTPS extracted by EE had the lowest protein content, the highest total sugar content of 71.83% and a polysaccharide yield of 4.52%. In addition, EE-CTPS had the best hypoglycemic activity that was better than ordinary green tea polysaccharides, the α-glucosidase and α-amylase inhibitory activities of EE-CTPS were highest in the range of 2–10 mg/mL compared with the other three CTPSs, which may be related to its smaller molecular weight and porous structure. The results suggested that the EE method was a good way to extract polysaccharides from coarse tea for food and pharmaceutical production.

中文翻译：

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提取方法对粗绿茶多糖理化性质和降血糖活性的影响。

粗茶是用成熟茶树（茶花）制成的L.）芽，通常作为一文不值的农作物丢弃，但已被证明是治疗糖尿病的极佳材料。这项研究旨在评估提取技术WE（水提取），UAE（超声辅助提取），MAE（微波辅助提取）和EE（酶提取）对粗多糖多糖的理化性质和抗糖尿病活性的影响茶（CTPS）。结果表明，所有四种CTPS在单糖类型上具有均一性，并且具有相似的IR（红外光谱）特征吸收峰，但单糖比例和分子量分布不同。与其他三种提取技术相比，EE提取的CCTPS蛋白质含量最低，总糖含量最高，为71.83％，多糖收率为4.52％。此外，EE-CTPS的降血糖活性最好，优于普通绿茶多糖，EE-CTPS的α-葡萄糖苷酶和α-淀粉酶抑制活性最高，在2-10 mg / mL范围内。三种CTPS，可能与其分子量较小和多孔结构有关。结果表明，EE法是从粗茶中提取多糖用于食品和药品生产的好方法。