真空滚揉工艺优化对复合低钠替代盐调理牛肉的品质改善

为了满足复合低钠替代盐调理牛肉的工业化生产需求，该研究在单因素试验基础上，研究液料比、滚揉时间、真空度对腌制吸收率和蒸煮损失率的影响，通过中心组合（Box-Behnken）和响应面法确定调理牛肉真空滚揉的最佳工艺，并对静置腌制和滚揉腌制调理牛肉的质构特征、剪切力、水分分布、微观结构进行分析。结果所得最佳滚揉工艺参数：液料比32%、滚揉时间3.0 h、真空度0.06 MPa，在此条件下得到腌制吸收率24.65%，蒸煮损失率为26.39%。滚揉组调理牛肉的硬度、弹性、咀嚼性和剪切力均显著低于静腌组（P<0.05），不易流动水和自由水弛豫时间显著低于静腌组（P<0.05），并且自由水弛豫峰面积显著高于静腌组（P<0.05）。扫描电镜图显示，滚揉组的肌原纤维结构更加松散，并且有碎片化结构附着表面。结果表明，滚揉处理能够改善调理牛肉的质构特征，提高嫩度，提高保水性，微观上使肌原纤维产生碎片化结构。该研究为复合低钠替代盐调理牛肉的滚揉工艺提供技术支持，为营养型低钠调理肉制品工业化生产提供理论依据。

Optimization of the Vacuum Tumbling Process for Quality Improvement of Beef Processed with Complex Low-sodium Salt Substitutes

To meet the industrial production requirements of beef processed with complex low-sodium salt substitutes, based on the results of single-factor experiments, the effects of curing liquid/meat ratio, tumbling time, and vacuum degree on the absorption rate of curing and rate of cooking loss were investigated. Subsequently, the vacuum tumbling process was optimized using the Box-Behnken design and response surface methodology, and the textural characteristics, shear force, moisture distribution, and microstructure were compared between beef cured statically and by tumbling. The optimal vacuum tumbling process parameters were the curing liquid/meat ratio of 32%, tumbling time of 3.0 h, and vacuum degree of 0.06 MPa. Under these conditions, the absorption rate of curing was 24.65%, while the rate of cooking loss was 26.39%. The firmness, elasticity, chewiness, and shear force of beef cured by tumbling were significantly lower than those of beef cured statically (P<0.05), and the relaxation time of bound and free water was also significantly lower in the former group (P<0.05). However, the peak area of free water relaxation was significantly higher in the tumbling group than in the static curing group (P<0.05). Scanning electron micrographs showed that the myofibril structures in the tumbling group were looser, with more fragmented structures attached onto the surface. Therefore, vacuum tumbling treatment can improve the textural characteristics, tenderness, and water retention of processed beef and induce microscopic fragmentation of myofibril structures. These findings provide technical support for the tumbling treatment of beef processed with complex low-sodium salt substitutes and build a theoretical basis for industrial production of nutritional low-sodium processed meat products.