Chitosan Coatings with Essential Oils against Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. in Annona muricata L. Fruits

Abstract

Anthracnose, which is caused by the fungus Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. (C. gloeosporioides), is the main disease that affects soursop fruits and causes accelerated deterioration due to the rotting process. The objective of this study was to evaluate the effect of chitosan-based coatings with essential oils on the physiological, antifungal, and shelf-life properties of soursop. Chitosan-based coatings were combined with essential oils of cinnamon and thyme and applied to soursop. The parameters evaluated were respiration and ethylene by gas chromatography, shelf life, weight loss, total soluble solids, color, maturity index, and titratable acidity. The chitosan obtained had a molecular weight of 169 kDa and an 83% degree of deacetylation; respiration and ethylene values showed significant reductions of 47 and 50% with coatings. Weight loss was reduced by up to 50%, even on inoculated fruits, and shelf life increased by two days. Chitosan-based coatings with essential oils are an appropriate alternative to improve the quality of soursop and decrease the effect of C. gloeosporioides.