Physical properties and antifungal activity of bioactive films containing Wickerhamomyces anomalus killer yeast and their application for preservation of oranges and control of postharvest green mould caused by Penicillium digitatum

This study assessed the ability of two bio-based films, obtained from sodium alginate (NaAlg) and locust beangum (LBG), to protect the viability of Wickerhamomyces anomalus cells and control the growth of Penicilliumdigitatum. The effect of microbial cell incorporation on physical properties of the developed films was evaluatedin terms of barrier, mechanical and optical properties. Furthermore, the application of these two matrices as bioactivecoatingswas investigated in order to evaluate their efficacy in preserving the postharvest quality of ‘Valencia’oranges and inhibiting the growth of P. digitatum on artificially inoculated fruits. Results showed that NaAlgand LBG films were able to maintain more than 85% of the initial W. anomalus yeast population and that the developedfilms incorporating the killer yeast completely inhibited the growth of P. digitatumin synthetic medium.Likewise, NaAlg and LBG coatings enriched with W. anomalus yeast were effective at reducing weight loss andmaintaining firmness of ‘Valencia’ oranges during storage, and reduced green mold in inoculated fruits bymore than 73% after 13 days.