研究了软枣猕猴桃粗蛋白酶提取及对牛肉的嫩化效果,对酶用量、处理温度、处理时间对牛肉嫩化的影响进行了实验,并进一步通过L9(33)正交试验选择出最佳嫩化工艺并且通过测定其显微结构阐明其嫩化机制.结果表明:软枣猕猴桃粗蛋白酶的比活力为2098U/mg,对牛肉的剪切力、烹饪失水率和持水力均有影响,有较好的嫩化效果,通过正交试验确定软枣猕猴桃粗蛋白酶对牛肉嫩化的最佳工艺条件为酶用量0.05％、处理温度50℃、处理时间1.0h,影响因素次序为:处理温度＞酶用量＞处理时间,蛋白酶处理后的肉样和未处理的肉样相比肌原纤维直径变小,密度变大,小片化指数变大,其Z线断裂,肌间隙变大,肌间质增多,肌节长度变大,嫩度增加.%This study investigated the extraction of crude protease from Actinidia arguta fruit and its tenderization effect on beef.The influence of enzyme dosage,temperature and time on beef tenderization was examined.An orthogonal array design involving 9 experiments of the three variables at three levels was applied to optimize the tendedzation conditions of beef with the crude protease.The mechanism underlying this effect was elucidated by microscopic observation of structural changes.The specific activity of the crude protease from Actinidia arguta fruit was 2098 U/mg and it had a desired tenderization effect on beef by improving the shear force,cooldng water loss and water-holding capacity.The best conditions for beef tenderization were found to be hydrolysis with 0.05％of the crude protease at 50 ℃ for 1.0 h.Temperature was the most important parameter for beef tenderization followed by enzyme dosage and time.Compared with non-treated beef,beef myofibrils treated by this method showed a smaller diameter,a larger density,a greater myofibrillar fragmentation index and broken Z line; in addition,the intermuscular space became broader,more materials existed in the interstitium and the sarcomere length was increased.As a result,beef was tenderized.
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