Validation of a peracetic acid-based sanitizer for microbial control and physicochemical quality of fresh blueberries

Abstract

Effective washing of fruits is crucial for safety and quality, especially because of microbial contamination. This study investigates the effects of varying concentrations (0, 40, and 80 ppm) and contact period (60 s and 120 s) of SaniDate®, a hydrogen peroxide-peracetic acid antimicrobial solution, on the reduction of Listeria innocua, yeast, mold, and native microbial populations on blueberries and in washing water. Additionally, the effect of these treatments on blueberry physicochemical properties was assessed by measuring the percentage water loss and visible damage over time. Initial L. innocua load of 8 log colony-forming units (CFU)/mL was significantly reduced by more than 4 logs CFU/mL with 80-ppm SaniDate (P < 0.05), with similar efficacy at 60 s and 120 s. A comparable trend was observed for native bacteria. In contrast, longer exposure to water without antimicrobial solution increased microbial survival, indicating the potential for cross-contamination. Yeast and mold reduction was considerably greater in SaniDate-treated samples compared to controls, although not significantly affected by concentration or contact time. All treatments caused negligible water loss and minimal surface injury, except at 80 ppm for 120 s (P < 0.05). Overall, SaniDate treatment, particularly at 80 ppm for 60 s, demonstrated potential as an effective approach for microbial control on blueberries while maintaining product quality.