脂质水解和氧化影响新疆传统风干牛肉风味机制的研究

Xinjiang dried beef is a tranditional meat product with strong ethnic characteristics. Industrial production of dried beef is an urgent requirement of local food industry. To keep and enhance dried beef flavor and prevent spoilage during processing is a key technical problem for industrial production and large-scale development. This study is conducted to investigate the volatile flavor composition changes and mechanisms of Xinjiang dried beef during processing. Firstly, main volatile flavor compounds of dried beef will be analyzed by electronic nose and gas chromatograph-mass spectrophotometer (GC-MS), and flavor fingerprint spectrum will be built. Secondly, changes in the volatile composition and lipolysis and lipid oxidation in dried beef during processing will be examined by modern scientific research methods and instruments. Correlations between lipid oxidation and volatile flavour components will be developed by partial modern mathematical statistics analysis technology. Finally, activities changes of lipase related enzymatic properties and regulation of process factors will be examined during processsing of dried beef to explain effects of lipolysis and lipid oxidation on the mechanism of flavor formation. The purpose of this research is to establish theoretical foundation of modern production technique, quality control and the flavor enhancing of the Xinjiang tranditional dried beef. This study is significantly practical for the industrial development of traditional ethnic food.

新疆风干牛肉是极具民族特色的传统肉制品，提高其工业化生产程度已成为当地食品工业发展的迫切需求。如何保留、彰显风干牛肉原有特色风味已成为制约该产品产业化、规模化发展的关键技术难题。本课题以新疆传统风干牛肉为研究对象，利用电子鼻、气相色谱-质谱联用技术分析风干牛肉中主要挥发性风味成分，从而构建风味指纹图谱；利用现代科研手段和仪器，测定风干牛肉加工过程中脂质水解、氧化及挥发性成分的变化，利用现代数理统计分析技术，揭示脂质变化和挥发性风味成分之间的相互关系；通过对脂肪酶类活性变化、酶学性质及工艺因子调控研究，深入揭示脂质水解和氧化影响风干牛肉风味形成的机制，旨在为进一步开展风干牛肉生产工艺现代化、风味品质控制与改进等技术研究奠定重要理论基础，对传统民族食品的工业化发展具有十分重要的现实意义。

本课题以新疆风干牛肉为研究对象，采用气质联用技术分析风干牛肉中主要挥发性风味成分，构建了气味指纹图谱，可以实现不同类型风干牛肉之间的区分，研究结果为新疆风干牛肉质量标准的制定提供有益的参考，同时增强风干牛肉作为新疆地区特色食品的原产地保护；研究测定了风干牛肉加工过程中脂质水解氧化及挥发性成分的变化，通过统计分析发现，丙醛、己醛、顺-4-庚烯醛、反-2-癸烯醛、2-乙基呋喃及2-戊基呋喃等成分与脂质氧化显著正相关（p﹤0.05），感官嗅觉气味与丙醛、己醛、辛醛、2-壬烯醛也呈显著正相关（p﹤0.05）；研究表明脂肪氧合酶的活力与POV值和TBARS值显著正相关（p﹤0.05），在加工过程中对脂质的水解氧化起了很关键的作用，经分离纯化获得脂肪氧合酶的分子量为96 KDa，作用的最适底物浓度8.5 mM，最适温度40 ℃，最适pH 5.0。通过响应面优化实验获得风干牛肉制作的最佳条件是食盐添加量2.1%、风干温度7度、风干时间6天。