Abstract:Shrimp processing wastes (heads, shells and tails) were fermented at differet salinity (16%, 20% and 24% ) to make shrimp sauce. The changes of protease composition, bacterial population and quality during fermentation were investigated. The results showed that the spoilage of shrimp sauce was effectively inhibited by using 20% or higher salinity. The protease composition and bacterial population varied during fermentation. The activities of most endogenous proteases gradually decreased. Meanwhile, some new microbial proteases appeared and showed relatively high activity. In the initial phase of fermentation, the non-halotolerant bacterial were dominant, while in the later phase the halotolerant bacteria increased. Thus, the bacteria played a significant role in fermentation. High salinity significantly inhibited the growth of bacteria and suppressed the production of the related putrefactive substance, such as total volatile basic nitrogen (TVB-N) and trimethylamine (TMA). It also decreased the protease activity and reduced the production of amino acid nitrogen (AAN). The shrimp sauce fermented at 24% salinity has a balanced ratio in terms of amino acids and flavor, and hence tastes better.
