Refrigerated, ready-to-eat (RTE) vegetable foods are widely consumed. Microorganisms may proliferate in these foods during cold chain breaks, increasing the risks for food spoilage and foodborne disease. Despite the increasing use of novel non-thermal preservation technologies, the comprehensive impact of these hurdles on the broad taxonomic structural dynamics of the food microbiota during temperature abuse remains poorly understood. To address this gap, we determined the impact of bacteriocin AS-48 and a high hydrostatic pressure (HHP) treatment, both individually and in combination, on the microbial load and bacterial diversity of a refrigerated vegetable cream upon temperature abuse. Counts of aerobic mesophilic bacteria (37 °C, 24 h) increased significantly (p < 0.05) in controls during temperature abuse, but not in samples treated with bacteriocin, HHP or both. Amplicon-sequencing analysis indicated that the initial microbiota of control samples was composed mainly of Pseudomonadota (74.50%), followed by Bacillota (21.19%) and Actinobacteriota (3.69%). Bacillota became the predominant group during refrigerated storage (87.21 to 99.48%). After temperature abuse, control samples had lower relative abundances of Bacillota during storage and higher relative abundances of Pseudomonadota, Bacteroidota and Actinobacteriota. All treated samples (irrespective of the treatment) showed lower relative abundances of Bacillota during storage compared to untreated controls without temperature abuse. Genus Bacillus was the predominant group in the control samples during storage. Acinetobacter was associated with temperature abuse. In conclusion, both enterocin AS-48 and HHP can be effective hurdles, not only by preventing bacterial proliferation but also by influencing the dynamics of the microbial community associated with spoilage in vegetable creams exposed to inappropriate temperature conditions.
López et al. (Thu,) studied this question.