Utilization Of Production Of Low-value Fish Seafood Fermented Soy Sauce

Low-value fish accounts for up to 28% of marine catches and low-value fish are nutritious and high protein content. However, in the production process, only 35% of the meat is processed and the remaining is wasted. The use of low-value fish to exploit seafood flavoring can increase the added value of low-value fish, solve environmental pollution problems and enrich the seasoning market. In this study, using low-value fish protein hydrolyzate to prepare brine, the traditional low-salt solid-state fermentation was used to obtain seafood fermented soy sauce.Low value fish (fish noodles,sardines) was defatted with isopropanol. Solvent:substrate of 1 : 1, 46? and 36 min were carried out for three times. The optimal enzymolysis conditions were determined by orthogonal experiment and the optimum conditions were as follows: fish: water (mass ratio) = 1 : 2, the enzyme quantity was 3000U /g, among which neutral protease: papain = 1 : 1,hydrolysis temperature at 45?and hydrolysis time was 5h - At this point the degree of hydrolysis of fish protein was 13.33%. 0.5% yeast extract was added to the fish protein hydrolyzate, treated at 35? for 45 min,then the yeast was inactivated in boiling water,cooled to 65?,1% ?-cyclodextrin was added. Under treatment for 30 min,the best de-fishy effect was obtained.Through the comprehensive analysis of the physical and chemical indexes, flavor substances and sensory evaluation of the seven soy fermented groups, the results showed that the third fermented group (the fish protein hydrolyzate with the ratio of 0.5: 1) was the best . The main physical and chemical indexes of the finished soy sauce in the third fermented group were determined as follows. Amino acid nitrogen was 1.10g/100mL, total nitrogen wasl.40g/100mL (This index reached the national low-salt solid-state soy sauce the first level), total acid was 2.15g/100mL and soluble salt-free content was 25.46g/100mL(This index reached the national low-salt solid-state soy sauce the highest level). For the organic acid type and content,5 kinds of organic acids from the fermented group 1 were detected , 6-7 kinds of organic acids from the fermentation group added and the fermentation group blended were detected whose content was relatively high. The content of free amino acid in the third fermented group was the highest, and the total amino acid content was 2392.90mg/L which was much higher than the fermented group 1 (only 535.50mg/L). The total amino acid content of the third fermented group was 7.04 times that of the frist fermented group. For improving the fish flavor and reducing the bitter taste of the low-salt solid-state fermented soy sauce , the fermentation group added and the fermentation group blended played a certain role . However, in the whole organoleptic evaluation,the comprehensive score of the third fermented group was the highest.