A combined hurdle approach of slightly acidic electrolyzed water simultaneous with ultrasound to inactivate Bacillus cereus on potato

Slightly acid electrolyzed water (SAcEW) and ultrasound (US) treatment have emerged as an environmental-friendly antimicrobial agent. However, SAcEW treatment alone shows low antimicrobial efficiency. Therefore, the aim of this study was to develop a hurdle approach that combined SAcEW and US to improve the antimicrobial effect against Bacillus cereus as well as inhibition of the growth on potato. US treatment under different conditions of dip times, acoustic energy densities (AED) and temperatures were conducted to obtain the optimal condition. Our findings demonstrate that 3 min of US with 400 W/L of AED at 40 degrees C treatment (US + 40 degrees C) significantly (p < 0.05) reduced B. cereus population by 2.3 +/- 0.1 log CFU/g with minimal change in the color of potato. In addition, 3 min of SAcEW (pH, 5.3-5.5; ORP, 958-981 mV; ACC, 28-30 mg/L) simultaneous with US+40 C treatment (SAcEW + US+40 degrees C) an approximately 3.0 log CFU/g reduction in B. cereus. Furthermore, SAcEW + US+40 degrees C treatment efficiently extended lag time of B. cereus by 0.2-10.5 hrs, reduced that of specific growth rate by 0.01-0.23 log CFU/h during storage at different temperatures from 5 to 35 degrees C. Therefore, this combined hurdle technology is capable of improving microbial safety of potato during storage and distribution. (C) 2016 Published by Elsevier Ltd.