The ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was employed to develop an effective technique for the extraction of flavonoids from jujube peels (JPs). The extraction conditions were further optimized as K₂HPO₄ 35% (w/w), ethanol 20% (w/w), solid–liquid ratio 1:30 g/mL (w/v), ultrasonic power 200 W, and extraction time 50 min. Moreover, rutin, quercetin 3-β-d-glucoside, and kaempferol-3-O-rutinosid were identified as the main flavonoids by UPLC-MS/MS. Finally, the extraction mechanism of UA-ATPE was explored, which is salting out effect, hydrogen bonding, van der Waals force, and ultrasound promoted the mass transfer of solvent to cells of JPs, then extraction behavior occurred. The mechanical destruction of JPs cells by ultrasound also further accelerated the release of flavonoids. Flavonoids were captured by W/W emulsion in the bottom phase and distributed to the top phase. Overall, this study proposes a green and clean method, UA-ATPE, to extract flavonoids from JPs, while revealing the mechanism of UA-ATPE.

采用超声辅助水相两相萃取 (UA-ATPE) 开发了一种从枣皮 (JPs) 中提取黄酮类化合物的有效技术。进一步优化提取条件为K ₂ HPO ₄ 35% (w/w), 乙醇20% (w/w), 固液比1:30 g/mL (w/v), 超声功率200 W,提取时间 50 分钟。此外，芦丁、槲皮素 3-β- dUPLC-MS/MS鉴定出-葡萄糖苷和山奈酚-3-O-芸香苷是主要的黄酮类化合物。最后探讨了UA-ATPE的提取机理，即盐析效应、氢键、范德华力和超声促进溶剂向JPs细胞的传质，进而发生提取行为。超声对JPs细胞的机械破坏也进一步加速了类黄酮的释放。黄酮类化合物被底相中的 W/W 乳液捕获并分布到顶相。总体而言，本研究提出了一种绿色、清洁的方法UA-ATPE，从JPs中提取黄酮类化合物，同时揭示了UA-ATPE的作用机制。