板栗壳多酚的超声波辅助低共熔溶剂提取工艺优化及其成分分析

采用低共熔溶剂（Deep eutectic solvents，DESs）-超声波辅助提取法对废弃板栗壳中的多酚进行提取并进行成分鉴定。本实验成功合成8种不同的DESs，并用傅里叶红外变换光谱表征氢键供体和氢键受体之间氢键的形成。基于单因素实验，采用响应面法优化超声波功率、液固比、低共熔溶剂水分含量三个因素对总酚得率的影响，经大孔吸附树脂纯化后进行多酚成分鉴定。结果表明，8种DESs中，氯化胆碱-草酸（摩尔比1:1）合成的DES-1总酚得率最高，且明显高于传统溶剂（水和40%乙醇）；最佳提取工艺参数为:超声波功率348 W、液固比42:1 mL/g、水分含量32%，总酚得率为（99.66±2.63） mg/g，与理论总酚得率99.44 mg/g接近，采用AB-8大孔树脂从DESs提取物中回收多酚，回收率高达97.92%±1.78%。UHPLC-ESI-Q-TOF-MS/MS从粗提物中初步鉴定出13种酚类物质。本研究提供了一种绿色、高效的从板栗壳中提取多酚的方法，可为板栗壳废弃物的开发利用提供技术支撑。

Optimization of Deep Eutectic Solvent-Ultrasonic Assisted Extraction and Component Analysis of Polyphenols from Chestnut Shells

In this study, deep eutectic solvents (DESs) coupled with ultrasound-assisted extraction (UAE) were applied to extract polyphenol from chestnut shells and the components were identified. Eight different DESs were evaluated as candidate solvents and fourier transform infrared spectroscopy (FTIR) was performed to confirm the formation of hydrogen bonds between hydrogen bond acceptor and hydrogen bond donor. Based on the single factor experiments, the response surface methodology (RSM) was applied, ultrasonic power, liquid-solid ratio and water content were further evaluated in order to optimize the total ployphenol yield. Besides, the extracts were recovered by macroporous resin for the identification of phenolic compounds. As a result, DES-1 (choline chloride:oxalic acid=1:1) exhibited a highest extraction yield. After that, DES-1-based UAE process was optimized and the optimal conditions were as follows: Ultrasonic power 348 W, liquid-solid ratio 42:1 mL/g and water content 32%. The extraction yield (99.66±2.63) mg/g of the model validation experiment was demonstrated to be in accordance with the predicted value 99.44 mg/g, which was significantly higher than that obtained by using traditional solvents (water and 40% ethanol). In addition, phenolic compounds was efficiently recovered from DES extracts with high recovery yield (97.92%±1.78%) by using AB-8 macroporous resin. 13 phenolic compounds were preliminarily identified from DES-1-based UAE extracts by UHPLC-Q-TOF-MS/MS. In conclusion, this study would provide a green and efficient method to extract polyphenols from chestnut shells, providing technical support for the development and utilization of chestnut shells waste.