Poster: Biology & Disease Mgmt: Postharvest Pathology & Mycotoxins
Development of edible composite coatings with antifungal GRAS salts for reduction of postharvest gray mold of cherry tomato fruit
L. PALOU (1), C. Fagundes (2), A. Monteiro (2), M. Pérez-Gago (3) (1) Institut Valencià d'Investigacions Agràries (IVIA), Spain; (2) Universidade Federal de Santa Catarina, Brazil; (3) IVIA, Spain
GRAS (generally regarded as safe) salts were preliminary selected in in vitro tests against Botrytis cinerea, the causal agent of tomato postharvest gray mold, and added at 2% wet basis (wb) to emulsion matrixes prepared with hydroxypropyl methylcellulose (HPMC) and glycerol (ratio 3:1 dry basis, db), beeswax (BW) and oleic acid (ratio 5:1 db), and tween 80 (1.5% wb). The final emulsion solid concentration was modified to 7-10% wb in order to obtain formulations with a viscosity range of 100-150 cp. Selected stable coatings were tested in vivo against gray mold on cherry tomatoes cv. Josefina artificially inoculated with B. cinerea 24 h before coating (curative activity) and incubated at 20ºC for up to 15 days. Among these edible coatings, the most effective were those containing sodium propionate (SP), potassium carbonate (PC), ammonium phosphate (APh), and ammonium carbonate (AC), and they were further tested in vivo with fruit subjected to cold storage. Gray mold incidence and severity were determined on cherry tomatoes inoculated with B. cinerea, coated 24 h later, and stored at 5ºC for 7 and 14 days followed by a shelf life period of 7 days at 20ºC. The antifungal activity of the coatings was fungistatic rather than fungicidal. Although the HPMC-BW coatings formulated with SP were the most effective in reducing gray mold on cold-stored cherry tomatoes, coatings containing AC were selected due to their better performance for overall fruit quality preservation.