. Control of Mozzarella spoilage bacteria by using bovine lactoferrin pepsin-digested hydrolysate

In this work, bovine lactoferrin (BLF) and its pepsin-digested hydrolysate (LFH) were evaluated as potential control agents of High Moisture Mozzarella cheese spoilage. Five bacterial strains (Pseudomonas fragi 23A, P. gessardii 2A, Serratia proteamaculans 19A, Aeromonas salmonicida 22DB and Rahnella aquatilis 19B), isolated from cold-stored Mozzarella cheese and able to grow and promote caseinolytic activities in the governing liquid at 4 °C, were inoculated at 3 and 6 log cfu mL-1 in the governing liquid-based medium amended with BLF or LFH and incubated at 4 °C or 30 °C for two weeks. Interestingly, R. aquatilis 19B, inoculated at 3 log cfu mL-1, resulted completely inhibited up to day 14 of cold storage. The remaining strains were partially inhibited, depending on the strain, under the same conditions. Differently from LFH, BLF showed a very low antimicrobial activity. On the other hand, no antimicrobial activity was observed when strains were inoculated at 6 log cfu mL-1. This work demonstrates the efficacy of LFH to control some psychrotrophic proteolytic bacteria during the first days of cold storage and at a low initial microbial concentration.