EFFECT OF Lactobacillus acidophilus 1 M METABOLITES ON MICROBIAL AND BIOCHEMICAL QUALITY CRITERIA OF FROZEN BASA FISH (Pangasius bocourti) FILLETS

Abstract

The present work was planned to investigate the effect of different Lactobacillus acidophilusfiltrate levels on microbial and biochemical quality criteria of imported basa fish (Pangasius bocourti) fillets and heavy metals concentrations i.e. lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn) and iron (Fe). Fish fillets were immersed in cold distilled water containing (vv) 1%, 1.5% and 2% metabolites for 2 min. Each treatment was packed in polyethylene bags, put in foam dishes and all treatments were stored at -18°C for 30 days. Results showed that frozen contained low residue levels of cadmium (Cd 0.06), copper (Cu 0.42), zinc (Zn 3.0) and iron (Fe 4.98) but lead not detected. Also, basa fillets contained (on wet weight basis) high moisture (81.76 %) and low protein (11.24%), high lipid (4.99%) and ash (1.88%) contents. During frozen storage, Lb. acidophilusfiltrate levels decreased total plate count (TPC), psychrophilic, proteolytic and lipolytic bacteria in all treatments compared to control samples. Besides, the highest reduction rate in total volatile bases nitrogen (TVB) ranged 27.50–38.70 % in treatment 1% metabolites extract than other ones in particularly control samples under the same conditions. In case of trimethylamin (TMA), it was 29.73% in treatment 2% at first day and 33.33% in treatment 1.5% after 15 days storage. The high reduction rate in thiobarbituric acid (TBA) was 28.42% in treatment 2% at first day while it was 29.30% in treatment 1.5% after 15 days storage. In conclusion, the concentrations of Pb, Cd, Cu, Zn and Fe were lower than the maximum permissible limit and hence safe for human consumption. Bio-preserved techniques of fish fillets using Lb. acidophilus are controlled the change rate of bacterial and chemical quality aspects.