Evaluation of single and combined antimicrobial treatments to inhibit Salmonella in queso fresco

Hispanic style soft non-fermented cheeses, such as queso fresco (QF) have been linked to outbreaks and recalls. Salmonella is one of the main causes of these incidents. Due to lack of ripening or post-processing antimicrobial treatments, incorporating GRAS antimicrobials to production process may be a suitable approach to minimize microbial risk in QF. The aim of this study was to evaluate the efficiency of nisin (N), caprylic acid (CA) and trans-cinnamaldehyde (CN) as single or combined treatments to reduce Salmonella populations in QF during storage. Batches of QF were inoculated after curding with approx. 4 Log CFU/g of 5-strain cocktails of Salmonella and stored at 8 °C for 20 days. The final Salmonella counts in control samples ranged from 6.96 to 7.14 Log CFU/g. Application of CN at 0.6 g/kg inhibited Salmonella growth during storage, resulting in at least 3 Log CFU/g difference with the untreated controls (p