Effect of controlled lactic acid bacteria fermentation on the microbiological and chemical quality of Moroccan sardines (Sardina pilchardus)

Lactic acid bacteria strains (LAB) were assayed for the conservation of fresh sardine "Sardina pilchardus". Lactobacillus delbrueckii subsp., delbrueckii was used of sardine fillets at NaCl (5% w/w) and glucose (4% w/w) concentration. Microbiological counts including standard plate count (SPC), lactic acid bacteria (LAB), yeasts, coliforms, Salmonella, staphylococci and Clostridium were followed during two weeks of storage at 30 degree C. Determination of chemical parameters including pH, dry matter, fat matter, ash, total nitrogen (NT), total volatile basic nitrogen (TVB-N) and trimethylamine (TMA-M was carried out under the same conditions. Chemical determinations showed a net pH decrease from an initial value of 6.08 in raw sardine fillets to 4.3 after 25 days of fermentation. Microbiological control showed that LAB counts increased during fermentation process. After two weeks, fermented fish was free of coliforms. No growth of Staphylococcus aureus, Salmonella spp. and sulfite-reducing Clostridia. The inhibition of spoilage microflora including standard plate count and yeasts was also observed. The results indicated that controlled LAB fermentation could be used as a successful process for biopreservation of sardines produced in huge quantities.