不同腌制方式对羊肉肌原纤维蛋白结构和特性的影响

Effect of different curing methods on structure and properties of myofibrillar protein in mutton

研究干腌、湿腌和超声波腌制对羊肉肌原纤维蛋白结构和特性的影响,以羊肉肌原纤维蛋白为试验对象,通过总巯基、表面疏水性、羰基、Zeta电位、粒径、傅里叶变换红外光谱、肌纤维小片化指数(myofibrillar fragmentation index,MFI)和凝胶电泳分析。结果表明,随腌制时间的延长,干腌羊肉肌原纤维蛋白总巯基增加、表面疏水性降低,湿腌组羊肉肌原纤维蛋白表面疏水性降低,总巯基增加,羰基含量增加,超声波腌制羊肉肌原纤维蛋白表面疏水性、羰基增加,总巯基降低,蛋白氧化程度最高;超声波腌制和湿腌的Zeta电位绝对值增加,干腌Zeta电位绝对值降低;3种腌制方式粒径均下降;与对照组相比,3种腌制方式羊肉肌原纤维蛋白中β-折叠结构含量显著降低,β-转角含量增加;超声波腌制的MFI降低,干腌和湿腌的MFI增高;凝胶电泳显示,干腌蛋白条带随着时间延长而变浅,湿腌和超声波腌制羊肉肌原纤维蛋白肌球蛋白重链、肌动蛋白条带处有加深现象。以上指标表明,超声波腌制会加快肌原纤维蛋白结构氧化与降解,改善羊肉嫩度,对提高羊肉深加工产品有着重要作用。

This study focused on the effects of dry curing,wet curing,and ultrasonic curing on the structure and properties of mutton myofibrillar protein.The total sulfhydryl group,surface hydrophobicity,carbonyl group,Zeta potential,particle size,Fourier transform infrared spectroscopy,muscle fiber fragmentation index(MFI),and gel electrophoresis were used to analyze the structure and properties of mutton myofibrillar protein.Results showed that with the prolongation of curing time,the total sulfhydryl group of dry-cured mutton myofibrillar protein increased and the surface hydrophobicity decreased.The surface hydrophobicity of wet-cured mutton myofibrillar protein decreased with the total sulfhydryl group increased and the carbonyl content increased.The ultrasonic-cured mutton myofibrillar protein was found with the increased surface hydrophobicity and carbonyl group,while its total sulfhydryl group decreased,and the protein oxidation degree was the highest among the 3 methods.The absolute value of the Zeta potential of ultrasonic curing and wet curing increased,and the absolute value of the Zeta potential of dry curing decreased.The particle size of the three curing methods decreased compared with the control group,and the content ofβ-sheet structure in mutton myofibrillar protein in the three curing methods was found to have a significant reduction,and the content ofβ-turn was increased.The MFI of ultrasonic curing decreased while the MFI of dry curing and wet curing increased.Gel electrophoresis showed that the dry-cured protein bands tended to be shallower with time,and the wet-cured and ultrasonic-cured mutton myofibrillar protein myosin heavy chain and actin bands deepened.The above indicators showed that ultrasonic curing would accelerate the oxidation and degradation of myofibrillar protein structure,improve the tenderness of mutton,and play an important role in improving the deep processing products of mutton.