Studies on Bactericidal Activity of Acidic and Slight Basic Electrolyzed Water on Histamine-producing Bacteria

• Main Authors: Li, Yu-Chen, 李禹辰
• Other Authors: Hwang, Deng-Fwu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/5s7f7x

碩士 === 國立臺灣海洋大學 === 食品科學系 === 102 === Scombroid poisoning is a common intoxication resulted from ingesting histamine-contaminated fish. Decarboxlation of histidine by histamine-producing bacteria (HPB) is the major source of histamine in fish. Since histamine is rather stable, it will not be decomposed in processing such as cooking, freezing or smoking. Therefore, using bactericidal agents to diminish HPB growth and histamine formation is a potential useful method against histamine-related food intoxication. Recently, electrolyzed oxidizing (EO) water was developed as a new sanitizer with excellent antibacterial activities against many foodborne pathogans. Whereas, there is few evidence indicated that slight basic electrolyzed water (SBEW) possessed capacity to inhibit HPB growth and histamine production in fish meat. Hence, the goal of current study is to assess the potential of SBEW on application for prevention of histamine intoxication. Meanwhile, acidic electrolyzed oxidizing (AEW) is used to be a comparative sanitizer in the experiments. The results of this study demonstrated that both AEW and SBEW exhibited bactericidal activity against two common HPB, Staphylococcus capitis and Morganella morganii with a dose and time dependent manner. Meanwhile, S. capitis and M. morganii, could not survive in plate culture after treatment by 200 ppm available chlorine concentration in AEW for 60 and 30 seconds, respectively. After treatment with 200 ppm available chlorine concentration in SBEW, M. morganii could not survive in plate culture. Whereas, the amount of S. capitis is reduced from 9 to 3.4 log CFU/ml. Moreover, the results revealed that the bactericidal activity have a positive correlation with amounts of available chlorine concentration (ACC) which elucidated the ACC is the major bactericidal factor for EO. In the test of cell integrity of AEW-treated and SBEW-treated HPB, the results showed gram negative bacterium cells are more sensitive than gram positive bacterium cells. The Thunnus tonggol fillets contaminated with S. capitis soaked in AEW for 1 hour reduced the populations of approximately 3.22 log CFU/ml. Soaking the contaminated fillets in SBEW reduced the populations of approximately 2.21 log CFU/ml. Using AEW to treat the fillets contaminated with M. morganii showed better bactericidal activity. Soaking the contaminated fillets in AEW reduced the populations of approximately 3.82 log CFU/ml, and in SBEW reduced the populations of approximately 2.15 log CFU/ml. As the processing time was increased, the residual of HPB in the solutions treated to contaminated fillets increased. The levels of histamine was significantly reduced by treatment with AEW and SBEW in HPB-infected fish fillets. Although the TVBN of AEW-treated and SBEW-treated fillets were increased, the level of TVBN are still under statutory standards in Taiwan. As the processing time increased, Hunter color values in AEW-treated and SBEW-treated fillets were both increased. It may affect the sensory evaluation of fillets. To solve the problems, there needs further experimental design to encounter the chromatic aberration in fillets while the treatment could also provide the bactericidal activity of EO water. These data will facilitate the application of AEW and SBEW on factories of marine products as well as to prevent people from intoxication of pathogenic bacteria and histamine.