Changes in Quality of Braised South American White Shrimp Prepared Dishes under Different Reheating Methods

In order to study the effect of different reheating methods on the quality of prepared dishes of braised white shrimp, microwave, steam and water bath were used to reheat frozen stored and braised South American white shrimp prepared dishes. The optimum reheating method was determined by measuring the water content, water activity, texture, sensory quality, free amino acids, flavorable nucleotides, volatile components and microstructure of the product after reheating. The results demonstrated that, in comparison to the other two methods, microwave reheating had the least negative impact on the product quality, with the least amount of moisture lost (4.00%), least amount of water activity lost (1.00%), least amount of hardness increase (6.44%), least amount of chewiness increase (1.00%), and elasticity decrease (2.03%). In terms of flavor, the flavor scores of the microwave reheating group were closest to those of the control group. The total amount of free amino acids increased significantly by 2.78% in the microwave reheating group while it decreased in the steam and water bath reheating groups. Microwave, steam, and water bath reheating groups detected 69, 61, and 64 volatile substances respectively. The microwave reheating group had a higher relative content of aldehydes (33.81%) compared to the steam reheating group (29.89%) and the water bath reheating group (29.15%). The contents of IMP and AMP of umami nucleotides in microwave reheating group were higher than those in other reheating groups. Combined with the value of MSG equivalent and taste intensity, the products in microwave reheating group had higher isofresh concentration. The arrangement of muscle tissue and the smoothness of fiber bundle of microwave reheating group were superior to the other two reheating methods. When all the signs are taken into account, microwave reheating proves to be a more suitable way of reheating braised South American white shrimp prepared dishes.