Desenvolvimento e aplicação de revestimentos com goma arábica e óleo essencial de Conyza bonariensis (L.) Cronquist para controle de antracnose em banana

• Autor(a) principal: Lundgren, Giovanna Alencar
• Data de Publicação: 2021
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/22508
• topic: Musa acuminata; Colletotrichum; Efeito antifúngico; Doenças pós-colheita; Revestimento comestível; Antimicrobial; Antifungal; Postharvest diseases; Edible coating; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

Banana is a popular fruit because of its pleasant taste and texture and ease of consumption. However, bananas rapidly enter into senescence due to biochemical alterations and the occurrence of microbial deterioration, especially anthracnose, which is characterized as a highly severe postharvest disease caused by the fungus Colletotrichum musae. The application of natural compounds with antifungal activity, such as essential oils, has been studied as an alternative for the control of postharvest diseases in fruits, mainly in the formulation of edible coatings. Conyza bonariensis is a plant found throughout Brazil and its essential oil has shown antimicrobial activity. This study resulted in two products, one theoretical, with the development of a review article with the aim of assisting research on edible coatings made with polysaccharides and essential oils and assisting in their optimized application as a post-harvest treatment of fruits. The results of this theoretical work indicated that the application of coatings made with polysaccharides and essential oils reduce post-harvest losses and maintain the physicochemical and sensory characteristics of fruits during storage. A second experimental product aimed to evaluate the development and application of coatings with gum arabic (GA) and essential oil of C. bonariensis (OECB) to delay the development of anthracnose in bananas cv. 'Silver'. Identification analyzes of OECB constituents, in vitro antifungal effects of GA and OECB on radial mycelial growth of six C. musae isolates, OECB effects on membrane permeability and enzymatic activity of C. musae conidia were carried out. , of the effects of coatings formulated with GA and OECB on the development of anthracnose in bananas artificially contaminated with C. musae isolates tested during storage at room temperature (25 ± 0.5 ºC), as well as on physical-chemical aspects (pH, soluble solids, titratable acidity, color and weight loss) indicators of postharvest quality of these fruits. The major compounds in the OECB were sesquicineol (48.43%), sesquisabinene (10.87%), limonene (9.63%) and thymol (6.15%). GA (0.1 g/mL) was not effective in inhibiting the mycelial growth of C. musae, while OECB (0.1; 0.2; 0.4; 0.6; 0.8 and 1 µL/ mL) was effective in inhibiting fungal mycelial growth. OECB (0.6 µL/mL) caused changes in membrane permeability (28.8 – 43.2%) and enzymatic activity (59.5 – 84.6%) of C. musae conidia. The application of coatings with GA (0.1 g/mL) and OECB (0.4; 0.6; 0.8; 1 µL/mL) caused a reduction in the development of anthracnose lesions in bananas, with reduced values of lesion diameter of up to 45.8% on the 5th day of storage, which were mostly similar to the effects caused by the commercial fungicide used as a positive control. Uncoated bananas showed higher rates of disease severity. The coating with GA + OECB was able to delay changes in physicochemical parameters indicative of postharvest quality in bananas, particularly of mass loss and color change. These results indicate that the application of coatings formulated with GA and CBEO can be considered a possible strategy to delay the development of anthracnose and prolong the storage period of bananas.