MICROBIOLOGICAL PROFILE OF CHARQUE THROUGHOUT THE PROCESSING STAGES: FROM RAW MATERIAL TO FINAL PRODUCT

Charque (CH) is a salted, dried meat product of great socioeconomic relevance in Brazil, whose preservation relies on reducing water activity (Aw) through salting with NaCl. In Brazil, production is regulated by Normative Instruction SDA/MAPA No. 92/2020, which sets identity and quality standards, including a minimum NaCl content of 12% and microbiological criteria defined in specific legislation. Nevertheless, halotolerant pathogens such as Staphylococcus aureus and Listeria monocytogenes may persist throughout processing, posing a food safety risk. Knowledge of the microbiota present at each manufacturing stage supports control strategies and improves Hazard Analysis and Critical Control Point (HACCP) programs. This study aimed to identify and quantify the main microbial groups present throughout the processing stages of CH. Samples were collected in triplicate at the stages of raw material receiving, tenderization, tumbling (wet salting), dry salting, washing, drying, and final product (n = 42) in an industry in the state of São Paulo (SP), Brazil. Aerobic mesophilic, halotolerant, and halophilic bacteria, xerophilic molds, S. aureus, Escherichia coli, Salmonella spp., and L. monocytogenes were quantified by plating on selective/differential media, with results expressed as log CFU/g. Mesophilic counts ranged from 7.3 to 3.1 log CFU/g, with highest values at initial stages. Halotolerant and halophilic bacteria showed counts of 6.6 to 4.2 and <1 to 4.7 log CFU/g, respectively, reflecting adaptation to increasing salinity, while xerophilic molds reached 4.8 log CFU/g, mainly during drying. S. aureus was not detected; E. coli was found only prior to salt addition, with counts of up to 2.2 log CFU/g. L. monocytogenes and Salmonella spp. were detected in 7.1% and 2.3% of samples, respectively. These results show that, although salting and drying significantly reduce microbial load, halotolerant and halophilic subpopulations adapt and persist throughout the process, and the detection of L. monocytogenes, E. coli, and Salmonella spp. at specific stages highlights the need to reinforce critical control points, particularly those preceding drying, per current regulations. This study provides relevant information on microbial dynamics during charque processing, an understudied topic, contributing to the understanding of microbiological safety, regulatory compliance, and microbial populations adapted to high-salinity conditions.