新疆核桃贮藏过程中脂质氧化对其挥发性风味影响的分子机制研究

Walnuts as the first of the four nuts, its seeds contain rich unsaturated fatty acid, In the storage process is prone to product flavor deterioration caused by lipid oxidation, and lipid oxidation is the walnut flavor quality of the main factors. At present, the mechanism of lipid oxidation on its volatile flavor is also lack of systematic research, Based on the previous studies on the quality analysis and storage and preservation of walnut kernel and almond in Xinjiang, taking walnut kernel in Xinjiang as the research object, first, the changes of lipid oxidation kinetics and oxidation products during walnut storage were analyzed by using histology, spectroscopy and mass spectrometry to reveal the mechanism of lipid oxidation. Secondly, SPEM / GC-MS and E-nose were used to analyze the dynamic changes of the volatile compounds before and after lipid oxidation, and then the volatile flavor fingerprints of walnut were constructed. On the basis of this, the relationship between the main lipid oxidation products and the main components of the volatile flavor in the composition, content and structure of the lipid oxidative stress environment was monitored, and then the lipid oxidation the molecular mechanism of the effects on volatile flavor. The project will help to reveal the mechanism of nutrient oxidation of walnut and other nuts in the storage process, enrich the walnut and other nuts food storage processing theory, and thus promote the Xinjiang regional industrial development and social stability.

核桃是四大坚果之首，其种仁富含不饱和脂肪酸，在贮藏过程中极易发生脂质氧化而致使其产品风味劣变，目前在脂质氧化对其挥发性风味影响的机制还缺少系统研究。课题组在前期对新疆核桃仁、扁桃仁等坚果品质分析和贮藏保鲜研究的基础上，拟以新疆薄皮核桃仁为研究对象，首先，利用组学、光谱和质谱技术分析核桃仁贮藏过程中脂质氧化动力学和氧化产物等变化规律，以揭示其脂质氧化机制；其次，借助SPEM/GC-MS、E-nose等技术解析脂质氧化前后主要挥发性风味物质动态变化过程，进而构建核桃仁挥发性风味指纹图谱；在此基础上，跟踪监测在线和模拟脂质氧化应激环境下其主要脂质氧化产物与挥发性风味主成份在组成、含量和结构等方面量效和构效关系，进而揭示脂质氧化对挥发性风味影响的分子机制。项目研究将有助于揭示核桃仁等坚果类在贮藏过程中脂质氧化对挥发性风味影响的机理，丰富坚果类食品的贮藏加工理论，促进新疆区域产业发展和社会稳定。

核桃是四大坚果之首，其种仁富含不饱和脂肪酸，在贮藏过程中极易发生脂质氧化而致使其产品风味劣变，本研究旨阐明核桃贮藏过程脂质氧化对其挥发性风味影响的机制。通过新疆7个主栽核桃品种干制前后脂质组成和感官品质结合，筛选耐贮藏的新新2和不耐贮藏的问71品种。利用非靶向代谢组、脂质组学和挥发性风味组学结合，对筛选的品种及验证的品种温10和温185常温和低温贮藏过程中的脂质及其伴随物和风味进行测定并对其相关性进行分析，发现脂质氧化对风味的影响主要是通过脂质分子的断裂重组，影响了小分子的烷烃类和醇类物质导致风味物质中这些物质含量的升高。核桃次生代谢产物和多不饱和脂肪酸是影响抗氧化活性的主要物质，但也显著影响了核桃脂质的组成，有趣的是核桃抗氧化活性强并不意味着核桃脂质氧化程度高。本研究为核桃代谢物的鉴定提供基础数据；并为揭示以核桃为代表的坚果类在贮藏过程中脂质氧化对挥发性风味影响的机理提供理论依据，同时能够丰富坚果类食品的贮藏加工理论，促进新疆区域产业发展和社会稳定