Patulin removal and biopreservation of apple by three lactic acid bacteria strains isolated from foods

Penicillium expansum contamination and patulin production can occur at various stages of the food chain, leading to detrimental effects on the quality and shelf life of food. Consequently, it is imperative to develop safe and efficient methods to control fungal growth and prevent mycotoxin contamination. The use of lactic acid bacteria (LAB) for food biopreservation has become one of the most promising alternatives. In this study, we investigated the antifungal activity of three LAB strains, namely Lactiplantibacillus plantarum 4F, Lactiplantibacillus plantarum 4JC, and Lacticaseibacillus paracasei 3MI3 against Penicillium expansum, and we further evaluated their biopreservative potential using apple as a food model against the blue mould. Moreover, their ability to remove patulin (10 mu g/mL) from MRS broth and apple juice was also examined. The mechanism involved in this decontamination was investigated using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and fourier transform infrared spectroscopy (FTIR). It was found that in vitro antifungal activity of the three strains was validated in vivo. All strains were able to reduce patulin from MRS medium, notably L. plantarum4F exhibited the highest rate of reduction (88.18%). This particular strain eliminated patulin from juice, with a reduction of 87.26%. The C = O, C-H, and N-H were the main functional groups engaged in patulin adsorption indicated by FTIR and SEM-EDS. Furthermore, in terms of morphological changes, SEM analysis revealed that bacterial cell wall became irregular. This research provides evidence of control of blue Penicilium growth on apple and patulin removal using antifungal LAB strains.{GRAPHIACAL ABSTRACT}

Automated summary

This study demonstrated the antifungal activity of three lactic acid bacteria strains against Penicillium expansum and their potential for biopreservation of apples. The strains were found to effectively reduce patulin levels in both MRS broth and apple juice. The mechanism of patulin removal was investigated using SEM-EDS and FTIR, revealing the involvement of specific functional groups. The results provide evidence for the control of Penicillium growth and patulin removal using antifungal LAB strains.