微酸性电解水杀灭菠菜表面微生物的影响因素

摘要

采用微酸性电解水对菠菜进行杀菌处理,考察微酸性电解水对菠菜的杀菌效果及影响因素,包括不同杀菌剂杀菌效果比较、浸泡时间、处理方式及与强碱性电解水预处理、超声波辅助处理联用对杀菌效果的影响,同时对处理过程中微酸性电解水有效氯浓度（ACC）、pH值、氧化还原电位（ORP）的变化进行分析。结果表明：微酸性电解水（ACC 31.73mg/L、pH 5.92、ORP 836.5mV）的杀菌效果明显优于相同ACC的次氯酸钠溶液;随着ACC的升高微酸性电解水的杀菌效果逐渐增强,当ACC增至31.37mg/L时可使微生物数降低1.69（lg（CFU/g））,ACC继续升高至67.96mg/L,杀菌效果则无显著性增强;分别对菠菜进行浸泡处理1、3、5、10min,微酸性电解水的杀菌效果无显著性差异,随着浸泡时间的延长微酸性电解水的ACC及ORP呈显著下降趋势,pH值无明显变化;采用强碱性电解水预处理和超声波辅助处理,能使微酸性电解水的杀菌效果分别提高约0.5（lg（CFU/g））、1.0（lg（CFU/g））;采用微酸性电解水浸泡处理杀菌效果优于冲洗处理。%In this study,slightly electrolyzed oxidizing water（SEOW） was used to treat fresh spinach.The bactericidal effect of SEOW and its factors were explored through the comparison among different antiseptics.Meanwhile,the effects of soaking time,treatment mode and pretreatment of strong alkali electrolyzed water on bactericidal activity were investigated.Moreover,the changes in available chlorine of concentration（ACC）,pH and oxidation-reduction potential（ORP） during the treatment process were also analyzed.The results showed that the bactericidal effect of SEOW with ACC 31.73 mg/L,pH 5.92 and ORP 836.5 mV was obviously higher than sodium hypochlorite solution with the same concentration of ACC.In addition,increasing ACC could gradually improve the bactericidal effect of SEOW.The number of microorganisms on spinach surface was decreased by 1.69（lg（CFU/g））when the concentration of ACC was increased to 31.37 mg/L;however,no obviously enhanced bactericidal effect was observed when the concentration of ACC was increased to 67.96 mg/L.Similarly,the bactericidal effect of SEOW did not reveal a significant difference among the soaking times of 1,3,5min and 10 min,respectively.But both ACC and ORP exhibited a significant declination during the extension of soaking time although the pH still remained stable.Furthermore,the pre-treatment of strong alkali electrolyzed water and ultrasonic-assisted treatment could result in the enhancement of sterilization rate by 0.5（lg（CFU/g）） and 1.0（lg（CFU/g））,respectively.Therefore,better bactericidal effect was observed for fresh spinach by soaking in SEOW than flushing with SEOW.