本文研究了乳酸菌发酵对龙眼果浆糖类、酚类和黄酮类物质以及单体酚的影响。结果表明，龙眼果浆经乳酸菌发酵后，总糖和还原糖含量分别下降了48.59%和38.42%（p<0.05）。龙眼果浆的总酚和总黄酮含量在发酵过程中均呈先下降后上升趋势，发酵后总酚含量为47.8 mg GAE/100 g，与未发酵前相比无显著性差异（p>0.05），而发酵后总黄酮含量为13.7 mg CE/100 g，较未发酵前提高28.0%，差异显著（p<0.05）。乳酸菌发酵显著增加了龙眼果浆中没食子酸、阿魏酸和槲皮素的游离态含量，其结合态含量显著下降，同时，原儿茶酸和芦丁的含量显著增加且只以游离态形式存在，结合态香草酸的含量显著降低。以上结果表明乳酸菌发酵可以显著降低龙眼果浆中的总糖和还原糖含量，提高其总黄酮含量，同时还提高了没食子酸、阿魏酸、槲皮素、原儿茶酸和芦丁等游离态单体酚的含量。该研究可以为龙眼果浆乳酸菌产品的研发提供指导。

The effect of lactic acid bacteria fermentation on the sugars, phenolics, flavonoids, and mono-phenols of longan pulp was investigated in this study. The results showed that after lactic acid bacteria fermentation, the amounts of total and reduced sugar in longan pulp decreased markedly by 48.59% and 38.42%, respectively (p<0.05). The concentrations of total phenolics and flavonoids in longan pulp showed an upward trend after an initial decrease during fermentation. The concentration of total phenolics after fermentation was 47.8 mg GAE/100 g, which showed no significant difference compared with that before fermentation (p>0.05). The amount of total flavonoids after fermentation was 13.7 mg CE/100 g, which significantly increased by 28.0% compared to that before fermentation (p<0.05). In addition, lactic acid bacteria fermentation could increase the concentrations of free gallic acid, ferulic acid, and quercetin, as well as reduce the amounts of bound gallic acid, ferulic acid, and quercetin. The concentrations of protocatechuic acid and rutin, which only existed in free forms, markedly increased in the process of fermentation, and the amount of bound vanillic acid decreased dramatically. These results suggest that lactic acid bacteria fermentation can significantly reduce the amounts of total sugars and sugars, increase the total flavonoid content, and increase the amounts of gallic acid, ferulic acid, quercetin, protocatechuic acid, rutin, and free mono-phenols. This study could provide guidance for the development of longan pulp products fermented by lactic acid bacteria.

国家自然科学青年基金项目（31301459）；国家重点研发计划（2016YFD0400702-2）；广东省自然科学基金项目（2014A030313568）；广东省省级科技计划项目（2016B070701012）；广州市珠江科技新星专项项目（201506010028）；广州市科技计划项目(201704020039)