Bacteriological quality and heavy metals in edible meat portion of Japanese threadfin bream (Nemipterus japonicas)

Abstract

One hundred and fifty samples of Japanese threadfin bream (Nemipterus japonicus) were screened for bacteriological quality and for content of heavy metals. Out of 150 samples, 40.7% had the count above the stipulated limits for TVB ( 5.7 log cfu per g.) The samples harboured 28.7% of faecal coliforms which were present in the range of 2-3 log cfu per g, while 32 and 6% of the samples contained 3 - 4 and ≥5 log cfu per g of the sample. Fecal Streptococci was present in 40% at 2-3-log cfu per g and 29.3% at 3-4 log cfu per g. The samples contained coagulase positive Staphylococci, E. coli, Salmonella and V. cholerae (Non 01) at 14.7, 44, 10 and 14%, respectively. The samples showed a significant decrease in TVB (3 - 4 log cfu per g of the sample), faecal coliforms and faecal Streptococci during 2 months storage at -18 plus or minus 1°C. Pathogenic bacteria were also not present after the 2 months storage. The samples were free from hazardous levels of heavy metals, like Cd, Cu, Hg and Pb.