Antibacterial action of slightly acidic electrolytic water against Cronobacter sakazakii and its application as a disinfectant on high-risk contact surfaces.

Powdered infant formula (PIF) is prone to Cronobacter sakazakii (C. sakazakii) contamination, which can result in infections that endanger the lives of newborns and infants. Slightly acidic electrolytic water (SAEW) has shown antibacterial effects on a variety of foodborne pathogens and has a wide applicability in the food industry. Here, the antibacterial activity of SAEW against C. sakazakii and its use as a disinfectant on contact surfaces with high infection transmission risk were investigated. The inactivation of SAEW on C. sakazakii was positively correlated to the SAEW concentration and treatment time. The antibacterial effect of SAEW was achieved by decreasing the intracellular adenosine triphosphate (ATP), K+, protein, and DNA contents of C. sakazakii, reducing the intracellular pH (pHin) and destroying the cell morphology, which led to inactivation of C. sakazakii ultimately. To test the applicability of this study, the results showed that approximately 103 CFU/cm2 of C. sakazakii were successfully inactivated on stainless steel and rubber surfaces after a 30 mg/L SAEW treatment for 20 s. These results indicate the antibacterial mechanism and potential application of SAEW against C. sakazakii, as well as a new strategy for the prevention and control of C. sakazakii on stainless steel and rubber surfaces.

Casein hydrolysate's effects on the fermentation properties, texture, and chemical characteristics and the bacterial microbiota of fermented glutinous rice dough.

To investigate how casein hydrolysate affected the physicochemical properties and microbiological diversity of the glutinous rice dough (natural fermentation and yeast fermentation), we analyzed its fermentation properties, carbohydrate, protein degradation, texture, and bacterial composition. According to the findings, casein hydrolysate increased the total LAB number, as well as organic acid content, in naturally fermented and yeast fermented glutinous rice dough by 3.59 and 8.19%, respectively, and reduced the fermentation time by at least 2 h. Meanwhile, casein hydrolysate enhanced the content of reducing sugars by 4.46 and 13.53% and increased protease activity by 29.9 and 27.7%. In addition, casein hydrolysate accelerated protein breakdown and regulated the hardness of the dough to improve the texture. Casein hydrolysate enriched the bacterial richness and diversity of dough. After adding casein hydrolysate, it promoted the growth of Pediococcus, Enterococcus, Lactobacillus, and Streptococcus. According to the Spearman correlation analysis, environmental factors (pH, lactic acid, acetic acid, reducing sugar content, and protease activity) exhibited the major driver for the abundance of bacterial species (Spearman correlation coefficient: -0.71 to 0.78). As a potential food additive, casein hydrolysate can improve the fermentation and quality of glutinous rice dough, increase consumer acceptance of cereal foods, and give consumers healthier options.