Bacteriological quality and histamine-forming bacteria associated with fish meats and environments in HACCP and non-HACCP fish processing factories

Twenty fish meats and 21 environmental surface samples obtained from a Hazard Analysis Critical Control Points (HACCP) fish processing factory and two non-HACCP fish processing factories in Pingtung, southern Taiwan were tested to determine the hygienic quality and histamine-forming bacteria. The levels of aerobic plate count (APC), total volatile basic nitrogen and total coliform in fish samples obtained from the HACCP factory were significantly lower than those of fish samples obtained from the two non-HACCP factories. The average content of the eight biogenic amines in HACCP fish samples was less than 1.0 mg/100 g, while that in non-HACCP fish samples was less than 1.5 mg/100 g. In environmental surface samples, the average levels of ATP bioluminescence and APC (swabbing method) of HACCP processing factory were significantly (P < 0.05) lower than those of non-HACCP processing factories. Fifteen histamine-forming bacterial strains isolated from fish meats and environmental samples producing 2.3-561.5 ppm of histamine in trypticase soy broth supplemented with 1.0% l-histidine (TSBH), belonged to Enterobacteriaceae (thirteen strains) and Staphylococcus spp. (two strains).