Qualidade pós-colheita de uva de degrana revestidas com películas biodegradáveis e conservadas sob refrigeração

• Autor(a) principal: Tamura, Michel Shoiti
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1295
• topic: Uva (Vitis vinifera L.); Refrigeração; Conservação; Quitosana; Pós-colheita; Brasil.; Vitis vinifera L; Chitosan; Storage; Refrigeration; Postharvest; Brazil.; Ciências Agrárias; Agronomia

Since this is a perishable fruit, the grape is susceptible to damage to a variety of sources. The main problems of post-harvest conservation of fine table grapes are rotting, the dehydration of the stalk, the browning of the berries and shattering, causing losses and damaging the quality of products. Seeking to improve the grape berries observed and consequently the income of the producer, this study aimed to evaluate the postharvest quality of fine table grapes of different varieties of Vitis vinifera L. who suffered shattering and stored for 56 days, packed in trays of polyethylene terephthalate (PET) under refrigeration. The experiment was conducted in a completely randomized in factorial scheme composed of three factors: cultivars (Italy and Ruby), chitosan concentrations (control, 0.5, 1.0 and 1.5%) and storage period (0, 7, 14, 21, 28, 35, 42, 49, 56 days), with four replications. The analyzes were every seven days, performing physical and chemical analyzes. For physical analysis, we assessed: the weight loss, expressed in percentage staining, expressed as brightness, hue angle (h °) and chromaticity, the incidence of decay, expressed in percentage, and the appearance of the fruit through grading, where: 4 (good) = Berry turgid, without fungi, normal color, 3 (good) = Berry dull without fungi, normal color, 2 (acceptable) = berry lackluster and without fungi, but color darkened; 1 (poor) = berry wilt, and blackened with fungus. Chemical analysis, we assessed the levels of: soluble solids, expressed in ° Brix, titratable acidity, expressed as a percentage of tartaric acid ratio, total soluble solids to total acidity, vitamin C, expressed as mg of ascorbic acid 100 mL and pH. Coating with chitosan increased the shelf life by up to 14 days for both cultivars, with the best results were observed with grapes treated with chitosan 1.5% for cv. Rubi, and chitosan 1.0 and 1.5% for cv. Italy. Treatments with chitosan reduced the incidence of decay, and the best values for chitosan concentrations were 0.5 and 1.5%. For the appearance of the fruit, the best treatment was with 1.5% chitosan, which maintained fruit fit for consumption by up to 49 days in cv. Rubi and 56 days in cv. Italy. The chemical parameters did not differ significantly during the storage period, but among the studied cultivar were no statistical differences. The pH, soluble solids, vitamin C were higher for cv. Rubi, while the appearance, decay, loss of weight and shelf life of fruits were more effective in cv. Italy.