Bound phenolic compounds have rarely been reported in vegetable oils and this may be due to little research about the extraction. Deep eutectic solvents (DESs), recently applied in the extraction of phenolic compounds as alternatives to organic solvents, were adopted in the extraction of free and bound phenolic compounds from tea seed oil in this work. First, the phenolic compounds were analyzed by ultra-high-performance liquid chromatography with quadrupole-time-of-flight and triple-quadrupole tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) for characterization and UHPLC-QqQ-MS/MS for quantification and 25 phenolic compounds were found to exist in both free and bound forms. Then, DESs were screened for extraction of free and bound phenolic compounds from tea seed oil as the pretreatment for analysis and the results showed that hydrogen bond donors (HBDs) and temperature significantly affected the extraction efficiency of DESs. Finally, free phenolic compounds (83.91 µg/g) and bound phenolic compounds (25.71 µg/g), extracted by the DES with glycerol as HBD at 50 °C, were 51.0% and 93.2% higher than those extracted by methanol/water (60%, v/v), respectively. This work not only advanced the basic data of phenolic compounds in tea seed oil but also explored an efficient extraction method for scientific analysis of free and bound phenolic compounds.

中文翻译：

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用低共熔溶剂萃取茶籽油中游离和结合的酚类化合物

在植物油中很少报道结合酚类化合物，这可能是由于对提取的研究很少。在这项工作中，在提取茶籽油中游离和结合的酚类化合物时，采用了最近用于提取酚类化合物作为有机溶剂替代品的深共熔溶剂 (DESs)。首先，通过超高效液相色谱与四极杆飞行时间和三重四极杆串联质谱 (UHPLC-Q-TOF-MS/MS) 进行表征和 UHPLC-QqQ-MS/用于定量的 MS 发现 25 种酚类化合物以游离和结合形式存在。然后，DESs 被筛选用于从茶籽油中提取游离和结合酚类化合物作为分析的预处理，结果表明氢键供体 (HBDs) 和温度显着影响 DESs 的提取效率。最后，游离酚类化合物 (83.91 µg/g) 和结合酚类化合物 (25.71 µg/g)，用甘油作为 HBD 在 50 °C 下由 DES 提取，比用甲醇/水提取的高 51.0% 和 93.2%（ 60%，v/v)，分别。这项工作不仅推进了茶籽油中酚类化合物的基础数据，而且探索了一种科学分析游离和结合酚类化合物的有效提取方法。用甘油作为 HBD 在 50 °C 下由 DES 提取的 51.0% 和 93.2% 分别比用甲醇/水（60%，v/v）提取的高。这项工作不仅推进了茶籽油中酚类化合物的基础数据，而且探索了一种科学分析游离和结合酚类化合物的有效提取方法。用甘油作为 HBD 在 50 °C 下由 DES 提取的 51.0% 和 93.2% 分别比用甲醇/水（60%，v/v）提取的高。这项工作不仅推进了茶籽油中酚类化合物的基础数据，而且探索了一种科学分析游离和结合酚类化合物的有效提取方法。