Influence of Salt and Millet Treatments during Meat Fish Fermentation in Senegal

Abstract

Microbial growth in meat from traditional handled Arius heudelotti fish during fermentation at 25-30°C in Senegal has been determined. Microorganisms involved in fermentation and pathogen microorganisms were analyzed in function of salt and millet addition [1/1 (w/v)]. Total viable microorganisms, lactic acid bacteria, H2S-producing Enterobacteriaceae, staphylococci, fungi and spore-forming bacteria counts in the crude meat fish reached 6.34 ± 0.28, 4.10 ± 0.61, 4.33 ± 0.45, 3.71 ± 0.69, 1.50 ± 0.3 and 1.33 ± 0.58 Log10 CFU/g. H2S-producing bacteria predominated (8.3 ± 0.25 Log10 CFU/g) after 24 h incubation at 25-30°C of untreated meat fish or that immersed in saline [14% NaCl (w/v)]. The pH of raw meat fish was 6.32 ± 0.1. It increased during unsalted fermentation, while it slightly decreased for the saline procedure. Meat fish fermentation in salty water added with NaCl at 80% (w/v), widespread in Senegal, allowed weak acidification in addition to growth inhibition of H2S producing Enterobacteriaceae which dropped to 3.53 ± 0.45 Log10 CFU/g after 24 h of fermentation. The fish fermentation in water added with malted millet flour at 15% (w/v) enabled significant growth of lactic acid bacteria and pH dropping to 4.9 ± 0.19. SH2-producing Enterobacteriaceae, Staphyloccoci and spore-forming bacteria showed a weak growth in the meat fish significantly acidified in millet solution, indicating preservative factor improvement when compared to the abusive salting traditional procedure which is a dietetic concern.