Effect of citric acid addition on histamine accumulation and component extraction during processing of Sakana MISO fish paste

Abstract

We have developed a method for preventing histamine accumulation during fish paste processing. In this study, we investigated the suppressive effect of citric acid addition on histamine accumulation in fish paste. Furthermore, we tried to determine the optimal time for citric acid addition with respect to both suppression of histamine accumulation and the effects on the taste of the fish paste produced. We found that on adding citric acid during the preparation of fish paste (addition of citric acid anhydrous to obtain a 0.6% [w/w] final concentration), both the growth of histamine-producing bacteria and the accumulation of histamine were inhibited. The earlier citric acid was added during processing, the greater was its effectiveness in suppressing histamine accumulation. Furthermore, early addition of citric acid during the fermentation process suppressed the accumulation of various metabolic products of microorganisms, such as lactic acid and citric acid. Therefore, early addition of citric acid contributed to a reduction in sourness, which could be attributed to lower subsequent production of acidic metabolic products by microorganisms, without influencing the .umami. taste of the fish paste. We conclude that the ideal strategy for preventing histamine production without altering the taste of fish paste is to add citric acid to obtain a final concentration of 0.6% (w/w), as early as possible during processing.