Journal of Food: Microbiology, Safety & Hygiene
Open Access

Abstract

Efficiency of Neutralized Antibacterial Culture Supernatant from Bacteriocinogenic Lactic Acid Bacteria Supplemented With Salt in Control of Microorganisms Present in Senegalese Artisanally Handled Fish by Immersion Preservative Technology During Guedj Seafood Processing at 10°C and 30°C

Michel Bakar Diop, Valente B Alvarez, Amadou Tidiane Guiro and Philippe Thonart

Senegal is a Western African country known for the importance of its marine resources. Artisanal fisheries contribute 85% of the total annual catch reaching 403,911 tons. Preserving approach during traditionally marine resource processing into indigenous seafood products is based on salt overuse. Guedj, a popular fermented indigenous seafood product, is the typical 30°C over salted transformed marine resource commodity across the country. One of the procedures for guedj production is immersing fish in water with sodium chloride at a concentration of over 30% (w/v) for preliminary fermentation during 24 hr to 48 hr to develop flavor followed by additional dry-salting and sun drying.
This study presents the level of microorganisms in fillets from lean, moderately fat and fatty artisanally handled fish, the efficacy of immersion in over salted [NaCl 60% (w/v)] water and 30°C incubation to control spoilage bacteria present in the fish matrixes, compared to those of lower salted [NaCl 14% (w/v)] antibacterial neutralized cell free culture supernatants (NCFCS) from two bacteriocinogenic lactic acid bacteria (LAB) and 10°C refrigeration. The two bacteriocinogenic bacteria (Lactococcus lactis subsp. lactis CWBI-B1410 and Lactobacillus curvatus CWBI-B28) were characterized in previous studies. Microbial population reduction in the treated fish was monitored using a 6 log10 CFU/g level at the end of storage.
The levels of the total viable microbial counts of raw flesh were similar for the three fish, and barely with the acceptable limit of 6 log10 CFU/g. The over salting preservation at 30°C did not enable reduction of microbial populations present in the fish. The total viable microbial, enteric and LAB counts of fillets immersed in the salted antimicrobial NCFCS from the bacteriocinogenic strains decreased and were maintained under the acceptable limit for 13 days to 18 days during incubation at 10°C.
These results indicate that the new preservative approach can reduce the need of abusive salt for guedj like products.