食品科学 ›› 2021, Vol. 42 ›› Issue (13): 17-25.doi: 10.7506/spkx1002-6630-20200717-229

• 基础研究 • 上一篇    下一篇

烹饪熟度对牛肉肌原纤维蛋白结构特性和氧化特性的影响

万红兵,李海鹏,雷元华,谢鹏,张松山,丰永红,刘璇,王欢,孙宝忠   

  1. (中国农业科学院北京畜牧兽医研究所,畜产品质量安全研究室,北京 100193)
  • 出版日期:2021-07-15 发布日期:2021-07-27
  • 基金资助:
    现代农业产业技术体系建设专项(CARS-37); 河北省现代农业产业技术体系肉牛产业创新团队建设资助项目(HBCT2018130204)

Effect of Degree of Doneness on Structural and Oxidation Properties of Beef Myofibrillar Protein

WAN Hongbing, LI Haipeng, LEI Yuanhua, XIE Peng, ZHANG Songshan, FENG Yonghong, LIU Xuan, WANG Huan, SUN Baozhong   

  1. (Laboratory of Quality and Safety of Livestock Products, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China)
  • Online:2021-07-15 Published:2021-07-27

摘要: 为了研究烹饪过程肌原纤维蛋白结构的变化规律,本研究以不同熟度(未加热处理(对照组)、一分熟、三分熟、五分熟、七分熟、全熟和过熟)的牛背最长肌肌原纤维蛋白为研究对象,分析比较在熟制过程中,烹饪熟度对蛋白聚集特性、氧化程度的影响,并检测蛋白二级结构相对含量的变化。结果表明,烹饪过程明显影响肌原纤维蛋白的聚集行为、氧化特性和结构特性。从对照组到过熟,随着烹饪熟度的增加,肌原纤维蛋白在溶液中的状态逐渐由聚集向解聚转化;蛋白羰基含量逐渐升高,表面疏水性、巯基含量呈现先升高后降低的变化趋势;二酪氨酸荧光强度、内源荧光强度随熟度的变化呈现先升高后降低然后又升高的U型变化趋势;衰减全反射傅里叶变换红外光谱分析结果表明,五分熟是肌原纤维蛋白二级结构相对含量发生变化的拐点,从对照组到五分熟,蛋白β-折叠相对含量降低,α-螺旋相对含量保持稳定,蛋白主要以分子内聚集为主,从五分熟到过熟,β-折叠相对含量逐渐增加,α-螺旋相对含量先升高后降低,蛋白以分子间聚集为主。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析发现,肌球蛋白重链、α-肌动素和肌动蛋白3 种蛋白参与了肌原纤维蛋白的热聚集行为,在熟制过程中,肌球蛋白重链和肌动蛋白灰度总体呈现先升高后降低的变化趋势,α-肌动素的灰度则总体呈现持续增大的变化趋势,具体变化机制有待进一步研究。本研究结果可为西餐牛排煎制工艺优化和品质控制提供理论依据。

关键词: 肌原纤维蛋白;熟度;聚集特性;结构特性;氧化特性

Abstract: This study aimed to compare the differences in myofibrillar protein aggregation, oxidation and structural properties among beef M. longissimus dorsi cooked to different degrees of doneness (control, rare, medium rare, medium, medium well, well done, and over cooked). The results showed that the cooking process significantly affected myofibrillar protein aggregation, oxidation and structural properties. As the degree of doneness increased, myofibrillar protein solutions gradually changed from an aggregated state to a cleaved one; the content of protein carbonyl increased gradually, and the surface hydrophobicity and sulfhydryl content increased first and then decreased; the fluorescence intensity of dityrosine and intrinsic fluorescence intensity increased first, then decreased and finally increased again. The results of attenuated total reflection Fourier transform infrared spectroscopy analysis showed that the degree of medium cooking was the turning point in the evolution of protein secondary structure. As the degree of doneness increased from control to medium, the β-sheet relative content decreased, while the α-helix relative content remained stable, the aggregation of protein was mainly through intramolecular interactions; as the degree of doneness further increased to over cooked, the β-sheet relative content increased gradually, the α-helix relative content increased first and then decreased, and the protein was mainly intermolecularly aggregated. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) studies indicated that myosin heavy chain, α-actin and actin were involved in the thermal aggregation of myofibrillar proteins. As the degree of doneness increased, the gray values of myosin heavy chain and actin increased first and then decreased, and the gray value of α-actin increased continuously. The exact mechanisms need further study. The results from this study can provide a theoretical basis for the optimization of the frying process and the quality control of steak.

Key words: myofibrillar protein; degree of doneness; aggregation properties; structural properties; oxidation properties

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