基于食品组学的藏香猪肉特色风味形成机制研究

Tibetan pork is the unique food ingredients resources, its market has a great potention because of its unique flavor. However, the basic research on tibetan pork is scarce, which has severely restricted the development of Tibetan pork industry. Based on the trend of current consumption upgrade and the key product characteristics of Tibetan pork - unique flavor, this project intends to explores the formation mechanism of the unique flavor of Tibetan pork by using foodomics technologies, and give a view from a molecular perspective and from an overall perspective. Firstly, the edible quality of Tibetan pork is comprehensively evaluated, and to form a scientific evaluation of its unique flavor. Secondly, the composition, synthesis and metabolism of flavor-related metabolites are studied using metabonomics techniques, and the degradation of lipid and formation of volatile components was carried out by using lipidomics technologies. Based on these, the unique flavor substances in Tibetan pork were systematically and completely identified, and the formation process was revealed. After that, quantitative analysis of the flavor-related enzymes in Tibetan pork were performed using proteomics technologies, combing with the flavor-related synthesis-metabolism networks and regulating-interacting networks, clarifying the formation mechanism of the unique flavor of Tibetan pork. The research results of the project will boost the development of the whole industrial chain of Tibetan pork, and provide industrial support for the implementation of precision poverty alleviation in Tibet and the realization of well-off living standards.

藏香猪肉是青藏高原特色食品原料资源，其风味独特，市场前景广阔。然而，基础研究薄弱严重制约了藏香猪肉产业的发展，本项目以当前消费升级的趋势和需求为导向，以藏香猪肉的核心产品特质——独特风味——为研究对象，拟借助食品组学技术，从分子层面和全局角度探索藏香猪肉独特风味的形成机制，助推产业发展。首先，对藏香猪肉的食用品质进行全面分析，形成对其独特风味的科学认识和评价；在此基础之上，利用代谢组学技术研究滋味相关代谢产物的组成及其合成、代谢规律，借助脂质组学技术研究脂质降解和挥发性成分的生成规律，系统全面地鉴定藏香猪肉中的特色风味物质，揭示其形成过程；进一步基于蛋白质组学技术，定量分析藏香猪肉中与风味物质代谢相关的酶类，梳理风味物质相关的合成-代谢网络和调控-互作网络，阐明藏香猪肉特色风味的形成机制。项目研究成果将助推藏香猪全产业链的发展，为藏区精准扶贫的实施和小康生活水平的实现提供产业依托。

研究了藏猪肉冷藏期间的品质变化规律，结果显示新鲜藏猪肉具有较深的色泽，在冷藏过程中藏猪肉的pH值较高，而水分含量、蒸煮损失率和TVB-N值较低，整体上藏猪肉具有更高的感官接受度。进行了藏猪肉全蛋白质组分析，共鉴定到藏猪肉蛋白质1723个，基于鉴定蛋白质的功能注释和分析表明，藏猪背最长肌中能量生成和蛋白质代谢是最为重要的生理过程。通过对比藏猪与商品猪（约克夏）的蛋白质组差异，以探究藏猪肉特色风味的形成机理。差异蛋白的筛选和分析结果表明，差异蛋白质在呼吸（氧化磷酸化，糖酵解/糖异生，三羧酸循环，丙酮酸代谢）和蛋白质合成与代谢（蛋白酶体，氨基酸生物合成，内质网蛋白质加工，核糖体）中显着丰富，表明能量生产和蛋白质代谢是最重要的生理过程。研究结果从蛋白质的分子水平为研究藏猪和约克夏猪肉品质差异提供基础的理论指导。通过藏猪肉不同冷藏时期转录组分析，挖掘出不同冷藏期下影响藏猪品质有关的差异表达基因，发现能量代谢过程是藏猪肉冷藏品质变化的关键代谢通路。对藏猪肉不同冷藏期的差异脂质分子进行定量分析，进一步明确了脂质氧化参与能量代谢进而影响肉质品质的潜在机理。开展了藏猪肉冷藏过程中的定量代谢组分析，从藏猪肉样品中鉴定到898种代谢产物，不同冷藏时期之间的差异代谢物共有172种。针对差异代谢物的分析显示，冷藏过程中藏猪肉中代谢活动持续进行，小分子代谢物丰度持续增加，氨基酸代谢和脂质代谢过程对肉质的滋味和气味产生潜在重要影响。通过对藏香猪肉的转录组、蛋白质组、代谢组、脂质组进行全面分析和鉴定，探明了藏香猪肉特色滋味和气味的物质基础，并解析了宰后成熟过程中藏香猪肉滋味、风味相关物质的变化规律，揭示了藏香猪肉特色品质的形成过程。