Yi-Chen Lee

Determination and Frying Loss of Histamine in Striped Marlin Fillets Implicated in a Foodborne Poisoning

An incident of foodborne poisoning causing illness in 67 victims due to ingestion of fried fish fillets occurred in June 2011, in southern Taiwan. Of the five suspected fish fillets, one fried sample contained 62.0 mg/100 g and one raw sample contained 89.6 mg/100 g histamine, levels which are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fish samples, this foodborne poisoning was strongly suspected to be caused by histamine intoxication. Five histamine-producing bacterial strains capable of producing 59 to 562 ppm of histamine in Trypticase soy broth supplemented with 1.0% L-histidine were identified as Enterobacter aerogenes (two strains), Raoultella ornithinolytica (two strains), and Morganella morganii (one strain). The degradation loss of histamine in suspected raw fillets was 28% after they were fried at 170°C for 5 min.

The effect of vacuum packaging on histamine changes of milkfish sticks at various storage temperatures

The effects of polyethylene packaging (PEP) (in air) and vacuum packaging (VP) on the histamine related quality of milkfish sticks stored at different temperatures (-20°C, 4°C, 15°C, and 25°C) were studied. The results showed that the aerobic plate count (APC), pH, total volatile basic nitrogen (TVBN), and histamine contents increased as storage time increased when the PEP and VP samples were stored at 25°C. At below 15°C, the APC, TVBN, pH, and histamine levels in PEP and VP samples were retarded, but the VP samples had considerably lower levels of APC, TVBN, and histamine than PEP samples. Once the frozen fish samples stored at -20°C for 2 months were thawed and stored at 25°C, VP retarded the increase of histamine in milkfish sticks as compared to PEP. In summary, this result suggested the milkfish sticks packed with VP and stored below 4°C could prevent deterioration of product quality and extend shelf-life.

Degradation of Histamine by Lactobacillus plantarum Isolated from Miso Products

Histamine is a toxic chemical and is the causative agent of food poisoning. This foodborne toxin may be degraded by the oxidative deamination activity of certain microorganisms. In this study, we isolated four histamine-degrading Lactobacillus plantarum bacteria from miso products. Among them, L. plantarum D-103 exhibited 100% degradation of histamine in de Man Rogosa Sharpe (MRS) broth containing 50 ppm of histamine after 24 h of incubation at 30°C. The optimal growth, histamine oxidase, and histamine-degrading activity of L. plantarum D-103 were observed in histamine MRS broth at pH 7.0, 3% NaCl, and 30°C. It also exhibited tolerance to broad ranges of pH (4 to 10) and salt concentrations (0 to 12%) in histamine MRS broth. Therefore, the histamine-degrading L. plantarum D-103 might be used as an additive culture to prevent histamine accumulation in miso products during fermentation.