A Study on the Bactericidal Process of Tilapia Using Chorine Dioxide

• Main Authors: Hao-Hsun Huang, 黃浩薰
• Other Authors: Ho-Hsien Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/34285290879099178284

碩士 === 國立屏東科技大學 === 食品科學系所 === 95 === Chlorine dioxide (ClO2) is a kind of strong oxidizer which has been extensively utilized in sterilization、disinfection、and waste water treatment. Chlorine dioxide has been advocated in food industries because of the low generation of trihalomethanes (THMs)、and the low toxicity due to its high volatility. In Taiwan、production of Tilapia cultivation is the third place among the whole world、being one of the Taiwan most important economical industries. However、concerns of safety and hygiene、and using of sodium hypochlorite (NaClO) has been arisen. It is easy to reside on the food and organic substance and therefore can result in trihalomethanes (THMs). This study aims at to study the generation of high concentration ClO2 via a single-electrolyzer、sterilization of Tilapia fillets、and physical chemistry property of chlorine dioxide solution (NaCl). Experimental variables for the generation of high concentration chlorine dioxide include the voltage、current、and time duration during electrolysis、as well as the temperature and feeding rate. The results showed that the highest purity of chlorine dioxide (4720 ppm total chlorine、98% purity) were obtained with adjusted ratio of sodium chlorite (NaClO2) to sodium chloride. Generation of chlorine dioxide solution was applied for sterilization of Tilapia fillets. Chlorine dioxide concentrations of 50 ppm、100 ppm and 200 ppm were use for Tilapia bactericide (dipping and shaking at 5、15 and 25 mins、respectively). A solution of 200 ppm、purity 98% could attain a significant reduction of microorganisms by shaking washing for 5 min. The residue of total trihalomethanes (TTHMs) is 6.4 ppb. Physical chemistry property of chlorine dioxide solution was investigated based on stirring and storage. Results showed that by stirring with 500 rpm a solution of 4,684 ppm、purity 98% was down to 79 ppm after 1 hour storage、and volatilized completely after the 3 hours storage. A solution of 4,684 ppm、purity 98% was storaged at 11 ℃ for 31 days. The concentration of chlorine dioxide was decreased to 4,478 ppm. Under light exposure under light、it would accelerate the volatility speed、and produce ClO2- and ClO3-. It also affects pH and oxidation reduction potential (ORP). Therefore、chlorine dioxide solution has to storaged at low temperature and gloomy place to extend its the performance.