Formation of volatile acids in the various stages of fish sauce fermentation.

Abstract

The rate of production of volatile acids present in the intermediate products at 3, 4, 10 and 15 months of fermentation of commercial Patis obtained in the Philippines and fish sauce of small scale preparation made in the laboratry was investigated. Also, an attempt to clarify the origin of these acids was conducted. Results of these experiments showed that concentrations of low molcular volatile acids were found to be higher in gut than in the whole and in flesh of fish in the both 24hours and 1 week incubations. It was also found that acids increased quantitatively and qualitatively with the progress of fermentation. It seems that almost all the acids identified in the sauce were formed within 3 months of fermentation. In this study, when fish was incubated without the addition of salt, most of the acids found reached very high levels compared with that in the fish incubated with the addition of salt. This might suggest involvement of bacterial action in the production of volatile acids.