Aplicação de revestimento de quitosana incorporado de óleo essencial de Mentha piperita L. para o controle de antracnose e alterações pós-colheita em mangas cultivar Tommy Atkins

• Autor(a) principal: Oliveira, Kataryne Árabe Rimá de
• Data de Publicação: 2018
• 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/123456789/13442
• topic: Mangifera indica L; Quitosana; Mentha spp; Revestimento comestível; Colletotrichum spp; Parâmetros de qualidade; Chitosan; Mentha spp; Edible coating; Colletotrichum spp; Quality parameters; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

The physiological deterioration and development of pathogens in mangos (Mangifera indica L.) limit their post-harvest life, hindering their preservation and maintaining quality during commercialization. Among the diseases causing pre and postharvest losses in mango, anthracnose caused by Colletotrichum fungi stands out among the most important because the severity of symptoms. The chitosan is a polysaccharide with antimicrobial activity, which presents gelling properties when in acidic medium, which allows its application to the formulation of fruit coatings. The incorporation of essential oils into chitosan coatings may increase the antifungal efficacy of the formed coating, reflecting lower postharvest disease severity and slower senescence in fruit. Therefore, this study aimed to evaluate the efficacy of the application of chitosan coatings incorporated with Mentha piperita L. essential oil for the control of anthracnose caused by C. asianum, C. dianesei, C. fructicola, C. tropicale and C. karstii, as well as post-harvest changes in mango cultivar Tommy Atkins. For this, analyzes were carried out to identify the constituents of Mentha piperita L. essential oil as well as the in vitro antifungal effects of chitosan and essential oil isolated and in combination on radial mycelial growth and the type of interaction established by these substances applied in combination. Tests were also performed to evaluate the effect of chitosan and Mentha piperita L. essential oil coating on the development of anthracnose caused by fungal strains tested on mangos stored at 25 ° C for 15 days. The effects of coating application on post-harvest quality parameters was evaluated through different physicochemical, enzymatic and sensorial analyzes. The use of chitosan (2.5, 5, 7.5 and 10 mg/mL) and Mentha piperita L. essential oil (0.3, 0.6, 1.25, 2.5 and 5 µL/mL) alone was effective in inhibiting the mycelial growth of all strains of Colletotrichum tested in synthetic medium. Mixtures of chitosan (5 or 7.5 mg/mL) and Mentha piperita L. essential oil (0.3, 0.6 or 1.25 µL / mL) were effective in inhibiting radial mycelial growth of the strains tested, with the establishment of additive or synergistic effects. The application of coatings containing chitosan (5 or 7.5 mg/mL) and Mentha piperita L. essential oil (0.6 or 1.25 µL/mL) resulted in reduction of severity of typical anthracnose lesions throughout storage in mangas cv. Tommy Atkins artificially contaminated with the tested strains. The severity of the anthracnose lesions in the mangos coated with chitosan and Mentha piperita L. essential oil in mixtures was similar to or less than that observed in mangoes treated with synthetic fungicides thiophanate-methyl (10 µg a.i./mL) and difenoconazole (0.5 µg a.i./mL). Application of chitosan coatings (5 mg/mL) and Mentha piperita L. essential oil (0.6 or 1.25 µl/mL) were also effective in delaying fruit ripening, with retention of pulp firmness, reduction of weight loss and increase in acidity, possibly as a consequence of the reduction of organic acid degradation. A decrease in the activity of the polyphenoloxidase, peroxidase and pectinamethylesterase enzymes and a delay in fruit color development were also observed. These characteristics interfered with sensory evaluation only on the 15th day of storage in which coated mangos received the lowest scores for color, taste and residual taste. These results demonstrate that the application of coatings containing mixtures of CHI and MPEO can be considered an alternative technology for the control of anthracnose, and post-harvest changes in mango cv. Tommy Atkins.