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

• Bacillus cereus was detected in raw potato with approximately 3.0 log CFU/g.
• SAcEW combined with US treatment caused synergistic effect against B. cereus.
• Antimicrobial effect was enhanced by increasing acoustic energy density in ultrasound treatment.
• SAcEW + US+40 °C treatment not only extended the lag time but also reduced specific growth rate of B. cereus.

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 °C treatment (US + 40 °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 °C) an approximately 3.0 log CFU/g reduction in B. cereus. Furthermore, SAcEW + US+40 °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 °C. Therefore, this combined hurdle technology is capable of improving microbial safety of potato during storage and distribution.