Effects of the storage conditions on cells viability, physicochemical and bioactivity of an antimicrobial ingredient derived from the starter of Benin opaque sorghum beer

Abstract

The present study assessed the stability and functionality of a heat-stabilized antimicrobial ingredient during storage at room temperature. Variations in viable microbial counts, pH, dry matter content, water activity, colour parameters, and antimicrobial activity were monitored at regular intervals over a 120-day storage period. The results indicated that lactic acid bacteria exhibited lower survival rates than yeasts, with survival percentages of 36.72% and 64.64%, respectively. No significant changes were observed in dry matter content or water activity throughout storage. In contrast, a significant variation was detected in lightness (L*), whereas the other colour parameters (a* and b*) remained unaffected by storage time and conditions. The antimicrobial ingredient effectively inhibited several indicator pathogens, including Gram-negative bacteria, Gram-positive bacteria, and a yeast, for up to 75 days of storage. Overall, these findings demonstrate that the heat-stabilized antimicrobial ingredient retains its antimicrobial functionality for up to 75 days under room temperature storage conditions.