| Summary: | A new method was proposed to produce alginate bio-films containing <i>Pichia membranifaciens</i> and <i>Wickerhamomyces anomalus</i> killer yeast to control the post-harvest fungal decay in organic apples caused by <i>Botrytis cinerea</i> and <i>Penicillium italicum</i>. Coatings with <i>W. anomalus</i> killer yeast effectively controlled the growth of <i>P. italicum</i> during storage at 22 °C. <i>W. anomalus</i> killer yeast incorporated in alginate reduced the <i>P. italicum</i> incidence from 90% (control) to 35% after 14 days of storage at 22 °C. Alginate biofilms with <i>W. anomalus</i> or <i>P. membranifaciens</i> also limited the incidence of the fungal decay of apples inoculated with <i>B. cinerea</i> compared with the control fruits, although the antagonistic capability against <i>B. cinerea</i> was lower than against <i>P. italicum</i>. The survival of <i>W. anomalus</i> cells in alginate coating was higher than <i>P. membranifaciens</i>. The incorporation of killer yeasts into alginate had no significant effect on the mechanical properties (tensile strength, percent elongation at break) of alginate coating, however, they increased the thickness of the biofilm. The bioactive coating reduced the fruit weight loss and had no significant effects on the fruit firmness during storage at 2 °C. As organic apples, produced without any synthetic fungicides, are especially prone to fungal decay during storage, the proposed alginate biofilms containing killer yeast seem to be a very promising solution by offering non-chemical, biological control of post-harvest pathogens.
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