• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.33-36
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• 2001

V. parahaemolyticus possessed an extracellular alkaline protease activity during the stationary growth phase. Various factors such as initial pH of medium, incubation temperature and shaking rate were investigated far optimizing the production of alkaline protease from V. parahaemolyticus ATCC 17802. Maximal activity of the protease was obtained when the bacteria were grown in 2% skim milk medium in 0.1M tris/HCl buffer (pH 7.6). Maximal activity of the protease was obtained when the bacteria were growls at initial pH of 7.6, incubation temperature 37$^{\circ}C$ and shaking rate of 250 rpm.

• Journal of Fisheries and Marine Sciences Education
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• v.20 no.1
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• pp.135-145
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• 2008

Biogenic amines are naturally occurring anti-nutrition factors. They are causative agents in food poising episodes and act as catalysts to allergic reactions. The most commonly occurring biogenic amines in foods are: Histamine, tyramine, putrescine, cadaverine, tryptamine, ${\beta}$-phenylethylamine, spermine, spermidine and agmatine. The objective of this study was to identify changes and content levels of specific biogenic amines at selected storage temperatures $20{^{\circ}C}$, $4{^{\circ}C}$, and $-25{^{\circ}C}$, respectively. This study will focus on histamine, cadaverine, and putrescine concentrations in the following dark-fleshed fishes: Mackerel (Scomber japonicus), Horse Mackerel (Trachurus japonicus), Mackerel Pike (Cololabis saira), and Spanish Mackerel (Scomberomorus niphonius). Biogenic amines were determined using a method based on an extraction procedure described in the derivatisation and HPLC(High Performance Liquid Chromatography). The the recovery rate of individual amines was higher than those found in ion exchange chromatography. The results from the dark fleshed fish stability trial showed that high content of histamine (cadaverine and putrescine) were produced within a short period of time at $20{^{\circ}C}$. Fish stored at lower temperatures $4{^{\circ}C}$, showed lower content of biogenic amines. At $-25{^{\circ}C}$ the production of histamine, cadaverine and putrescine did not initiate until after day 100. All fish recorded the content of histamine below 1 mg/kg with the exception of the Horse Mackerel.