a b s t r a c t
The aim of this work was to check the efficacy of bovine lactoferrin hydrolyzed by pepsin (LFH) to
prevent blue discoloration of Mozzarella cheese delaying the growth of the related spoilage bacteria.
Among 64 Pseudomonas fluorescens strains, isolated from 105 Mozzarella samples, only ten developed
blue discoloration in cold-stored Mozzarella cheese slices. When Mozzarella cheese samples from dairy
were treated with LFH and inoculated with a selected P. fluorescens strain, no pigmentation and changes
in casein profiles were found up to 14 days of cold storage. In addition, starting from day 5, the count of
P. fluorescens spoiling strain was steadily ca. one log cycle lower than that of LFH-free samples. ESIOrbitrap-
based mass spectrometry analyses allowed to reveal the pigment leucoindigoidine only in
the blue LFH-free cheese samples indicating that this compound could be considered a chemical marker
of this alteration. For the first time, an innovative mild approach, based on the antimicrobial activity of
milk protein hydrolysates, for counteracting blue Mozzarella event and controlling psychrotrophic pigmenting
pseudomonads, is here reported.