晒青毛茶液态发酵茶褐素特征及其对α-葡萄糖苷酶活性抑制作用

Characterization and inhibition of α-glucosidase activity of theabrownins from liquid-state fermentation with sun-dried green tea

中文关键词:  茶褐素  液态发酵  结构特征  α-葡萄糖苷酶

英文关键词:theabrownins  liquid-state fermentation  structural characteristics  α-glucosidase

中文摘要:

      目的 研究由茶泛菌(Pantoea camelliae, CCTCC AB 2021544T)液态发酵晒青毛茶所得茶褐素的组成结构与功能活性。方法 以固态发酵茶褐素(soild-state fermented theabrownins, S-TBs)为对照, 通过紫外可见光谱法(ultraviolet-visible spectroscopy, UV-Vis)、傅里叶红外光谱法(Fourier transform infrared spectroscopy, FT-IR)、居里点热裂解气相色谱-质谱法(Curie point pyrolysis gas chromatography-mass spectrometry, CP-Py-GC-MS)、扫描电子显微镜(scaning electron microscope, SEM)、Zeta电位测定仪等手段对液态发酵茶褐素(liquid-state fermented theabrownins, L-TBs)进行表征。同时, 检测了不同浓度L-TBs对α-葡萄糖苷酶活性的抑制作用。结果 与S-TBs相比, L-TBs颗粒较小、分散度及稳定性较好, 但二者都含有丰富的羟基和羧基, pH呈弱酸性, 总蛋白、总糖含量较高, 且没有显著差异; L-TBs和S-TBs热裂解产物主要是酚类物质, 含量分别为43.88%和35.69%; 进一步研究发现, L-TBs对α-葡萄糖苷酶活性具有一定的抑制作用, 并在一定范围内呈剂量关系。结论 茶泛菌L-TBs在组成结构方面与S-TBs较一致, 具有很好的开发和应用价值。

英文摘要:

      Objective To explore the composition, structure, and functional activity of the theabrownins obtained from the liquid-state fermentation with sun-dried green tea by Pantoea camelliae (CCTCC AB 2021544T). Methods With the solid-state fermented theabrownins (S-TBs) as a control, the liquid-state fermented theabrownins (L-TBs) was characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), Curie point pyrolysis gas chromatography-mass spectrometry (CP-Py-GC-MS), scanning electron microscopy (SEM), and Zeta potential determination. Meanwhile, the inhibitory effects of L-TBs with different concentrations on α-glucosidase activities were examined. Results Compared with S-TBs, L-TBs had smaller particles, better dispersion, and stability, but all contained abundant hydroxyl and carboxyl groups, weakly acidic pH, and higher total protein and total sugar content without significant differences. The pyrolysis products of L-TBs and S-TBs were mainly phenolics with content of 43.88% and 35.69%, respectively. It also revealed that L-TBs had a specific inhibitory effect on α-glucosidase activity with a dose relationship in a particular range. Conclusion The L-TBs by Pantoea camelliae are more consistent with S-TBs in terms of composition structure, which has good value for developing and applying theabrownins products.