Application of chemometrics to assess the influence of ultrasound and chemical sanitizers on vegetables: Impact on natural microbiota, Salmonella Enteritidis and physicochemical nutritional quality

This study aimed to evaluate the effects of acetic acid, lactic acid, peracetic acid, sodium dichloroisocyanurate and hydrogen peroxide combined with ultrasound in the sanitization process of arugula, kale, cucumber, and strawberry. The natural contaminant microbiota (mesophilic aerobic bacteria and molds and yeast), physicochemical and nutritional quality (pH, titratable total acidity, soluble solids, vitamin C, phenolic compounds and antioxidant capacity), and Salmonella Enteritidis inactivation were investigated using hierarchical cluster analysis, k-means clustering method, and principal component analysis. Among the physicochemical properties, total phenolic compounds were the most sensitive to sanitization processes. Overall, decimal reductions between 0.7 and 3.3 log CFU/g were obtained for natural microbiota. Moreover, ultrasound improved the sanitizer's efficacy. Lactic acid and hydrogen peroxide combined with ultrasound significantly inactivated S. Enteritidis, as confirmed by scanning electron microscopy, with a reduction of 4 logs CFU/g. Decontamination efficiency between leafy vegetables (kale and arugula) and non-leafy vegetables (strawberry and cucumber) was the same for all treatments investigated. Sodium dichloroisocyanurate and ultrasound showed low microbial inactivation efficiency. Ultrasound combined with non-chlorinated compounds can be considered a promising strategy for the minimally processed vegetable industry to increase food safety.

Automated summary

This study evaluated the effects of different disinfection treatments on arugula, kale, cucumber, and strawberry, showing that total phenolic compounds were most sensitive to the disinfection process. Ultrasound improved the efficacy of disinfectants, with lactic acid and hydrogen peroxide combined with ultrasound showing significant inactivation of Salmonella Enteritidis.