Development and characterization of pectin-based antifungal edible coatings with entrapped bio-control agent Meyerozyma guilliermondii LMA-Cp01 for the management of Colletotrichum gloeosporioides from papaya fruit

This study aimed to formulate gels using 1% (w/v) lowmethoxyl pectin, 0.5% (w/v) glycerol, and 0.5 mM calcium chloride to develop films, alone or in combination with M. guilliermondii, through the casting method, to obtain an antifungal edible coating. The gels obtained were characterized rheologically by frequency sweep and gelation kinetics. The effect of yeast addition on thickness, morphology, differential ΔE*, tensile strength, percent elongation at break, elastic modulus of films, and its antifungal activity against Colletotrichum gloeosporioides from papaya fruit were evaluated. The film-forming dispersions proved to be true gels, showing viscoelastic behavior and narrow molecular structure typical of cross-linked polymers. These gels presented structural stability, and their texture could allow immersion or atomization applications. Films alone and those added with M. guilliermondii showed thickness values of 0.034 and 0.02 mm, respectively. ESEM revealed changes in the film’s morphology with yeasts, demonstrating the entrapment of the biocontrol agent. The yeast’s addition to the films improved all the mechanical parameter values and achieved a complete inhibition of C. gloeosporioides. This research provides new pectin-based systems which are viable candidates to produce antifungal edible-coating with entrapped M. guilliermondii that could protect fruits and vegetables against postharvest diseases.