Microbiological Safety of Industrially Produced Plant-Based Meat Alternatives During Refrigerated Storage: A Descriptive Study Across Multiple Formulations

The growing consumption of plant-based meat alternatives (PBMAs) has increased attention to their microbiological safety, particularly under refrigerated storage conditions. Although the PBMA market has expanded rapidly, data on the microbiological status of industrially produced, heat-treated products remain limited. The present study aimed to evaluate, within a descriptive framework, the microbiological safety of industrially produced, heat-treated PBMAs during refrigerated storage. A total of 100 PBMA formulations, including salami-type and frankfurter-type ready-to-eat products, were manufactured under standardized industrial conditions and subjected to validated thermal processing (core temperature ≥ 92 °C for varying durations). Microbiological analyses were conducted at four predefined storage intervals (day 0, day 15, day 35, and day 60 at 0˗4 °C) to assess the presence of selected foodborne pathogens (Salmonella spp. and Listeria monocytogenes) and hygiene indicator microorganisms (generic Escherichia coli, Enterobacteriaceae, coagulase-positive Staphylococcus aureus, and Bacillus cereus). Intrinsic physicochemical parameters relevant to microbial survival and growth, including pH, water activity, moisture content were also determined. Salmonella spp. and Listeria monocytogenes were not detected (absence in 10 g) in any sample at any storage time point. Hygiene indicator microorganisms were not detected during early storage (day 0-15), while limited occurrence was observed at extended storage (day 60), including Escherichia coli (3%), coagulase-positive Staphylococcus aureus (20%), and Bacillus cereus (15%). Detected Staphylococcus aureus levels ranged between 103 and 105 CFU/g. These findings indicate strong microbiological stability during early refrigerated storage, with limited microbial occurrence at extended storage intervals (day 60). Overall, the evaluated products demonstrated a favorable microbiological safety profile under the applied processing and storage conditions. Given formulation heterogeneity and the absence of biological replication, findings are interpreted descriptively and provide an industrially relevant safety overview rather than inferential conclusions.