茶叶籽油极性伴随物在自动氧化过程中抗氧化相互作用机制

Tea seed oil is storable, yet no one has explored the reason deeply and systematically. Based on related literature and our previous work foundation, polar components of tea seed oil are identified as one of the major factors. This project plans to select polar components of tea seed oil as the research object. To study their antioxidant contribution, interaction and interaction mechanism among different contents during automatic oxidation of tea seed oil, we intend to determine the method which can judge action type on a model of the auto-oxidation of tea seed oil. Then the monomer would be classified into interaction groups (enhancement, synergism, antagonism) or non-interaction group (additive). On this basis, the interaction type of two components, three components until the whole components from interaction groups in the different periods of the auto-oxidation would be explored. In non-interaction group, we would establish the INFCIM model in the model induction period and oxidation period respectively .What’s more, we want to combine interaction type with the kinetic changes of the fatty acid, free radical etc to illuminate the mechanism of interaction and non-interaction. Finally, combining with the results of the interaction and the non-interaction, we plan to expound the regulating mechanism of tea seed oil polar components when the tea seed oil oxidation automatically. The research train of thought proposed in this project is rarely reported in the antioxidant interaction basic research. The expected results are to provide new research though for making the antioxidant mechanism of the multicomponent mixtures in the oil clear.

茶叶籽油耐贮，但尚未有学者深入探究其原因。依据前人研究及课题组工作基础，极性油脂伴随物被确定为最主要抗氧化因素之一。本项目以茶叶籽油极性伴随物为研究对象，针对其于茶叶籽油自动氧化时的抗氧化贡献及组分间的作用类型与机制等关键问题，通过建立自动氧化模型，确定判定组分间作用类型的方法，并将极性油脂伴随物单体分类：互作组（增效、协同、拮抗）、非互作组（加和）。针对互作组依次探寻双组分、三组分直至全互作组分在不同氧化时期的抗氧化作用，逐步研明互作组分间的作用类型；非互作组，于自动氧化的不同时期分别建立INFCIM模型。结合脂肪酸及其一级、二级氧化产物、自由基等的动力学方程，阐明互作和非互作机制。综合互作和非互作结果，全面研明极性油脂伴随物抑制茶叶籽油自动氧化的作用机制。本项目的研究思路在油脂抗氧化相互作用基础研究领域鲜有报道。如取预期成果，将为揭示多组分混合物影响油脂自动氧化的作用机制提供借鉴。

茶叶籽毛油耐贮，可能与其中富含的极性伴随物特别是酚类化合物相关。首先，本项目通过猪油恒温加速储藏实验确认，茶叶籽油酚类化合物与VE均具有很强的抗氧化活性，两者呈协同作用，且抗氧化效果前者优于后者。然后，通过碱解法提取茶叶籽油中酚类物质(118.35±1.65 mg/kg)，经过AB-8大孔树脂初步分离后，采用UPLC-MS/MS技术鉴定出22种酚类化合物。在乙醇和猪油体系中，通过DPPH·清除和加速氧化实验，采用Chou-Talalay模型和S%指数对22种酚类化合物互作组分进行相互作用类型研究，发现其中四个组分（槲皮素/6,7-二羟基香豆素、咖啡酰酒石酸/龙胆酸、咖啡酰酒石酸/6,7-二羟基香豆素、6,7-二羟基香豆素/龙胆酸）在0.4IC50浓度、两种体系中均呈现显著的协同作用。通过Rancimat以及ESR方法将这四组协同组分用于油脂氧化进程研究，观察到单体及协同组分开始作用于氧化初期，通过抑制游离基的生成及生产稳定的自由基中间体，阻断链式反应，以达到延长诱导时间的目的。其中6,7-二羟基香豆素/龙胆酸对油脂氧化抑制作用最强，诱导时间延长率达15.74%，自由基峰强稳定在1.1×104左右。因酚类化合物的存在形态与其抗氧化活性相关，本项目同时研究了油茶籽油中不同形态酚类化合物在有机溶剂和油脂体系中的相互作用类型，含FP的组合在有机溶剂及油脂体系中均呈拮抗作用；含碱解ISP的组合在有机溶剂体系中均呈协同作用，但在油脂体系中均呈拮抗作用；含未碱解ISP组合在油脂体系中呈协同作用。本项目相关研究成果初步揭示了茶叶籽油耐贮机制，为研明多组分混合物影响油脂自动氧化的作用机制提供借鉴。