Effects of electrolyzed water treatment on pre-cut green onion at pre-cut vegetables processing plant and its influences to quality of pre-cut green onion (enhancement of sterilization effect on pre-cut vegetable using electrolyzed water part II).

摘要

Many cases of microbial food contamination are caused by cross-contamination at the food processing stage. In this study, application of electrolysed water to pre-cut vegetables was examined for its bacterial control ability at the processing stage. In addition to microbial food contamination, chemical contamination was also studied and the rinsing effect of electrolysed water was examined for the purpose of reducing residual pesticides used during cultivation. To establish an effectual washing process in actual applications, a washing tank was installed in a pre-cut vegetable processing plant, and routine bacterial counting was performed. As the result of a preservation study on green onions treated in the washing tank, 5degC storage was more effective than room temp. or 20degC storage in controlling bacterial growth. Before the washing tank was installed, bacteria attached to green onions varied to some degree but counted 105-106 cfu/g for total bacteria and 101-105 cfu/g for total coliforms. Washing tank treatment successfully reduced the bacterial count to 104-106 cfu/g for total bacteria and -104 cfu/g for total coliforms. A commercial pesticide was used to determine the effect of electrolysed water in rinsing residual pesticides. Mixture with acidic electrolysed water resulted in reduced detection of an organic P pesticide PhenthoateTM. In a model experiment, combined treatment with hot alkaline electrolysed water and cold acidic electrolysed water was most effective. Results indicated that electrolysed water may be effective in the rinsing of residual pesticides.