Compared with the cold air freezing method, the liquid nitrogen freezing method has a faster freezing rate and is more conducive to maintaining the quality of frozen aquatic products. It has been used in the processing of aquatic products such as shrimp and pufferfish. In order to study the effect of different liquid nitrogen freezing temperature on the quality of seasoned grass carp fillets,the grass carp (Ctenopharyngodon idellus) were seasoned by vacuum dipping and frozen with liquid nitrogen at -60℃,-80℃,-100℃ and -196℃. The results showed that the liquid nitrogen freezing temperature significantly influenced the quality of seasoned fish fillets. As the freezing temperature decreased,the freezing rate of seasoned fish fillets significantly increased,and the hardness,chewiness,and salt-soluble protein content of the seasoned fish fillets increased,while the thawing loss rate and the cooking loss rate decreased. Moreover,the texture characteristics,cooking loss rate and salt-soluble protein content of fish fillets frozen by liquid nitrogen spraying at -80℃ were not significantly different from those frozen by liquid nitrogen spraying at -100℃ and liquid nitrogen dipping at -196℃,but significantly higher than those frozen at -18℃ and -60℃. Furthermore,the conditioning treatment could improve the freezing-thawing stability of fish fillets. And the quality stability of fish fillets seasoned for 6 h was the best. Grass carp fillets with high qualities could be obtained by freezing fish fillets with liquid nitrogen at -80℃ for 6 h.The study can provide technical support for the production of high-quality frozen and conditioned grass carp fillets,and the appropriate temperature for the processing of frozen conditioned aquatic products.
李想,任章睿,胡杨,刘茹,熊善柏. Effect of liquid nitrogen freezing temperature on quality of seasoned grass carp fillets[J]. Jorunal of Huazhong Agricultural University,2021,40(4):200-208.Copy