响应面法优化木瓜蛋白酶-复合磷酸盐嫩化低档部位牛肉工艺

采用响应面回归设计来探究复合磷酸盐与木瓜蛋白酶复配使用嫩化低档部位烧烤牛肉的最佳条件。以单位肉中木瓜蛋白酶活力、复合磷酸盐质量浓度和作用时间为嫩化因子，以剪切力值和感官评价得分为响应值，运用Design-Expert 8.05软件对测得的结果建立二次回归模型。结果表明，复合磷酸盐与木瓜蛋白酶配合使用可以有效降低中低档部位牛肉的剪切力值，同时适当减少酶的用量，提高肉的保水性，得到更好的感官评价效果。最佳嫩化条件为：木瓜蛋白酶活力9.44 U/g、复合磷酸盐质量浓度18.35 mg/mL、作用时间9.09 h。在此条件下，低档部位烧烤牛肉的剪切力预测值为17.25 N，感官得分为5.02，整体感受较满意。经过实验验证，实测值与预测值吻合良好，说明响应面模型具有较好的预测能力，能有效用于剪切力值和感官评分的预测。

Response Surface Methodology for Optimization of Tenderization Conditions for Low-grade Beef Using Papain and Composite Phosphate

The purpose of this study was to establish the optimal tenderization conditions using papain and compositephosphate together for low-grade roast beef production. Response surface methodology (RSM) was used to model andoptimize responses. Three parameters including enzymatic specific activity, phosphate concentration and time wereselected as the main tenderization conditions. The responses were Warner-Bratzler shear force and sensory evaluation.The experimental data were statistically analyzed for the establishment of quadratic regression models using the Design-Expert 8.05 software. According to the results of RSM, the Warner-Bratzler shear force could be reduced remarkably byusing papain and composite phosphate, and higher water retention and sensory evaluation scores were achieved by properlyreducing papain dosage. The optimal tenderization parameters were determined as follows: papain activity, 9.44 U/g;phosphate concentration, 18.35 mg/mL; and tenderization time, 9.09 h. Under these conditions, the shear force was17.25 N and the sensory evaluation was 5.02. The predicted values were proved to coincide well with the measured values.Accordingly, the developed regression models were reliable and could be used to predict the changes in shear force andsensory evaluation.