基于脂质组学对贮藏过程中牦牛肉品质变化分子机制研究

Yak is a remarkable bovine species of economical importance in the Qinghai-Tibet Plateau region in China, but serious lack of the research on the quality characteristics of yak meat and the changing rule of beef quality during storage is one of the key factors that seriously hinder the advancement of the yak industry for a long time. The project is expected to study systematically the quality characteristics of yak meat and analyze comprehensively total lipid with the help of a 2D LC-ESI MS based on a lipidomics approach. Some special lipids in beef can then be found and their function will be analyzed completely, the process is able to acquire scientifically and completely the quality characteristics of yak meat at the molecular level. The project studies the compositions, differences and dynamic changing regularity of total lipid of yak meat during storage and analyses the internal correlation between lipid oxidation-hydrolysis and the change in beef quality parameters, then some special lipids who have high influence on the quality parameters of yak meat can be selected and obtainted. Furthermore, the association between the diversification of lipid and the change in yak meat quality will be also clarified. Finally, the formation mechanism of corruption based on lipid oxidation-hydrolysis will be obtained and a theoretical basis will be built for development of new preservation technologies for meat products and safe cold cut fresh beef products. It will be the first time to use lipidomics approaches to systematically study the quality changes in Yak meat during storage. Through strategy and method innovation, new biological evidence related to the molecular mechanism for change in yak meat quality during storage based on lipid oxidation and hydrolysis will be discovered. It will be theoretically and practically significant for the establishment of countermeasures for the preservation of fresh beef products.

牦牛是我国青藏高原特有的畜种资源，在藏区经济中占有重要地位，但长期以来，对牦牛肉品质特点及其在贮藏过程中的品质变化规律缺乏系统深入的研究，这成为严重制约牦牛产业发展的关键因素之一。本项目拟运用脂质组学方法，采用在线二维液相色谱电喷雾质谱方法对牦牛肉的脂质进行系统研究，寻找牦牛肉中独特的脂质并分析其功能，从而在脂质分子层面对牦牛肉的独特品质进行科学全面的认识；并且通过考察不同贮藏温度条件下牦牛肉脂质的组成、差异及变化对其肉品质变化的影响，揭示脂质氧化降解与牛肉品质变化的内在联系，筛选出与肉品质劣化密切相关的关键脂质；获得基于脂质氧化降解的牛肉劣化形成机制，为畜产食品贮藏保鲜新技术及冷鲜牛肉产品的开发提供理论依据。本项目在国内外率先运用脂质组学方法研究牛肉品质变化进程，从脂质分子变化角度为揭示牛肉的劣化机制提供新的生物学依据，对禽畜肉保鲜新对策的建立，具有重要的理论和实际指导意义。

牦牛是我国青藏高原特有的畜种资源，在藏区经济中占有重要地位，但长期以来，对牦牛肉品质特点及其在贮藏过程中基础研究相当缺乏，这成为严重制约牦牛产业发展的关键因素之一。本课题研究了牦牛肉在0 oC和-2 oC贮藏条件下，经历12天脂质组变化过程，对于变化特别显著的589个脂质代谢产物进行数据库匹配鉴定，通过生物信息学大数据处理分析，获得10个极为显著变化的代谢脂质化合物，他们分别是Bufadienolide（蟾蜍二烯羟酸内酯）、2-Arachidonoylglycerol、19-nor-5alpha-cholestan-3beta-ol、L-2-Hydroxyphytanate（2-甲基植烷酸）、2-Hydroxytetracosanoic、Campestanol、(4S)-4-[(2-hydroxyhexadecanoyl)oxy]-4-(trimethylazaniumyl)butanoate、Testosterone、Carnitine、3-{[(9Z)-3-hydroxyoctadec-9-enoyl]oxy}-4-(trimethylazaniumyl)butanoate。特别是Bufadienolide与牦牛肉贮藏品质非常相关，贮藏时间越长，Bufadienolide表达越多，温度越高，Bufadienolide表达越多，其可以作为评价牦牛肉新鲜程度非常重要指标，其次是L-2-Hydroxyphytanate，它为牦牛肉贮藏过程中脂肪酸代谢一种中间产物，一种支链脂肪酸，只能通过α氧化而代谢，其与牦牛肉贮藏品质非常相关，贮藏时间越长，L-2-Hydroxyphytanate表达越多，温度越高，L-2-Hydroxyphytanate表达越多，它也可以作为评价牦牛肉新鲜程度非常重要指标。 本项目研究发现了牦牛肉贮藏过程品质变化的深层机制，为牦牛肉合理、科学的贮藏保鲜奠定理论基础。 项目投入经费25万元，支出20.697万元，剩余经费计划用于本项目研究后续支出。.