Effects of Different Freezing Methods on the Quality of Red Shrimp

JIANG Yang-yang; YANG Shui-bing; YU Hai-xia; YAO Jie-yu; SHAO Ying; CHEN Shi-guo; HU Ya-qin

doi:10.13982/j.mfst.1673-9078.2017.10.021

Abstract：To improve the quality of the red shrimp (Solenocera melanth),the shrimp samples were frozen by the liquid nitrogen spray and the conventional plate-freezing.The effects of different frozen methods on the quality of red shrimp during frozen periods were investigated by physiochemical indexes,such as total volatile basic nitrogen (TVB-N),thiobarbituric acid (TBA),Ca2+-ATPase activity,water holding capacity,and salt soluble protein content.The sensory scores and scanning electron microscopy (SEM) were used to compare the freezing effect as well.The results showed that TVB-N and TBA values of red shrimps gradually increased with the prolongation of storage time,but the freezing of liquid nitrogen increased slowly.After 176 d storage,the TVB-N values treated by liquid nitrogen frozen was 20.50 mg/100 g,while plate frozen reached 27.30 mg/100 g.The TBA values reached 0.74 mg/100 g,0.97 mg/100 g,respectively,suggesting that liquid nitrogen frozen could effectively suppress the increase of TVB-N and TBA;meanwhile,the Ca2+-ATPase activity,water holding capacity,salt soluble protein content and sensory indexes of red shrimp showed a decreasing trend,while that by liquid nitrogen decreased slowly;besides,the SEM profiles revealed that myofibril of red shrimp slightly damaged by the liquid nitrogen compared with that by plate-freezing method.In conclusion,the liquid nitrogen froze showed better effects than plate frozen on the quality of red shrimp.