Abstract: To investigate the bactericidal effect of slightly acidic hypochlorous water (SAHW) against Pseudomonas fragi and Pseudomonas fluorescens, the major spoilage bacteria of chilled meat and, more broadly, to improve its effectiveness in killing spoilage bacteria on the surface of chilled meat, we studied the stability of 50 mg/L SAHW combined with 0.02% sodium caseinate in terms of changes in effective chlorine concentration and pH during storage, and determined the total number of Pseudomonas in suspension and in inoculated chilled meat after treatment with both SAHW and sodium caseinate. The results showed that the mixture of SAHW and sodium caseinate was most stable under sealed and dark conditions. The bactericidal effect of SAHW on P. fragi and P. fluorescens in suspension was stronger than that of the mixture. The number of P. fragi was reduced by 6.16 and 2.26 (lg (CFU/mL)) by SAHW and the mixture with lethality rate of 85.20% and 31.26%, respectively. The numbers of P. fragi and P. fluorescens in inoculated meat were reduced by 1.74 and 1.87 (lg(CFU/mL)) by the mixture, respectively, which were 55.4% and 62.7% higher than those obtained using SAHW alone, respectively. Therefore, addition of the emulsifier can improve the bactericidal effect of SAHW on spoilage bacteria on chilled meat.

Key words: slightly acidic hypochlorous water; sodium caseinate; stability; bactericidal effect