Effect of Salt Addition at Different Processing Stages on the Quality and Volatile Flavor Components of Marinated Crayfish Tails

In this study, the effects of the addition of different amounts of salt (0%, 1%, 2% and 3%) at five stages of processing: raw shrimp, blanching, marination, soaking for 2 h and soaking at 4 ℃ for 24 h, on the quality and volatile flavor compounds of marinated crayfish were investigated. The results showed that L^* values increased and then decreased as the processing stages proceeded, while a^* and b^* values both continued to increase. But salt addition had little effect on the color difference. Additionally, moisture content decreased and then increased, and was affected little by salt addition. For 1%, 2%and 3% salt addition, hardness, elasticity, chewiness and adhesion showed an initial increasing and subsequent decreasing trend. Without salt addition, hardness and chewiness continued to increase. For each group, elasticity and cohesiveness increased and then did not show any significant change. The electronic nose results could be roughly divided into four parts, raw shrimp and blanching, marination, soaking for 2 h, and soaking at 4 ℃ for 24 h. There were also some differences between the less and more salt addition groups. The electronic tongue results showed that as salt addition increased or the processing stages proceeded, saltiness, astringency, and umami taste increased, and other taste attributes changed little. Gas chromatography-ion mobility spectrometry (GC-IMS) analysis showed that salt addition and marination had a positive effect on the volatile flavor of crayfish. However, excessive salt addition and too long processing time were detrimental to volatile flavors. In conclusion, the addition of salt and processing stages can affect the quality and flavor of marinated crayfish.