Organoleptic Changes of the Fermented Autolysate of Fish

In Benin, fermented autolysates of fish are neglected. This neglect is largely due to their strong smell and lack of knowledge of their nutritional value. Knowledge of certain physicochemical parameters during the fermentation process may allow to know the chemical changes that occurred during the transformation of the fish autolysate. Thus, a kinetic fermentation study of three different autolysates based on electrical conductivity (EC), total dissolved solids (TDS) and pH is done to understand the origin of the consumption rejection of fermented autolysates in Benin. The obtained results show that the electrical conductivities vary between 3077μS and 3206μS for tuna, between 3049μS and 3216μS for the bass, between 2700μS and 2975μS for catfish. Tuna, bass and catfish have arerage TDS of 2040mg / L, 2029mg / L and 1847mg / L, respectively. As for pH, they vary from 7.70 to 8.71 for tuna, from 7.96 to 8.80 for the bass and from 7.92 to 8.29 for catfish. The analysis of the kinetics of electrical conductivities and of TDS reveals that the latter are identical and present three different phases, namely a regression which corresponds to a grouping of the particles in the medium, an increase which shows the fluctuation of the particles and a stabilization which indicates the end of the fermentation. Analysis of pH kinetics shows that the fermentation medium is basic. This proves that the particles in suspension of the fermentation medium are dimethylamine, trimethylamine, ammonia, etc. The fermented autolysates of fish are rich in amino acids and fatty acids (protein and lipid breakdown products), and their strong smell is due to volatile bases resulting from the reaction of amines