Effect of Novel Bacteriocinogenic BZ532 on Microbiological Shelf-Life and Physicochemical and Organoleptic Properties of Fresh Home-Made Bozai.

Bacteriocinogenic BZ532 with novel bacteriocin LF-BZ532 was originally isolated from Chinese cereal fermented drink, showing an antimicrobial characteristic during fermentation. This study aimed to explore the in situ antimicrobial activities of BZ532 and co-culturing investigation against key food pathogens, i.e., and K-12, was conducted during fresh bozai production. The growth of spoilage bacteria was suppressed and bacterial count was reduced to a significantly low level during 48 h of co-cultures. In situ production of antimicrobial compounds expressed positive activity against and K-12, but negative acitivity against sp. D104. The total viable count of bozai BZ- (bozai fermented with BZ532 strain) had a comparatively lower viable count than bozai BZ- (bozai as an experimental control without BZ532) during storage of 7 days. Titratable acidity of bozai treatments (BZ-, BZ-) was increased, while pH declined accordingly during storage of 7 days. The organoleptic quality of bozai BZ- had low sensorial scores as compared with BZ- during storage. In comparison with naturally fermented bozai (BZ-), BZ532 (BZ-) could significantly reduce the microbial spoilage and extend the shelf-life based on microbiological examination. Conclusively, BZ532 can be used as a bio-protective culture for improving the safety of bozai.