Influência de revestimentos comestíveis incorporados de prebióticos na qualidade de mamão pronto para consumo

Abstract

Papaya is a fruit of economic importance for Brazil and can be consumed raw or processed form. This fruit can be offered in the ready-to-eat form in which papaya is subjected to processing steps, such as peel and slicing, which can cause physiological changes in plant tissue. The application of the edible coating on the surface of ready-to-eat fruits is a strategy that minimizes possible changes and allows to extend the shelf life of these products. In addition to acting in the maintenance of characteristics of processed fruits, the edible coating can add components of interest to the consumer, such as prebiotics. The study's objective was to develop and evaluate the effect of the edible coating based on cassava starch incorporated with prebiotics on the physical-chemical, microbiological, and sensory quality of ready-to-eat papayas stored at 6ºC for 12 days. The experiment was carried out in duplicate with three repetitions. Cassava starch was used to prepare coatings and was associated, separately, with inulin or fructooligosaccharide (FOS). The treatments performed were uncoated (SR); cassava starch 3% and FOS 3% (F3F3); cassava starch 4% and FOS 3% (F4F3); cassava starch 3% and inulin 3% (F3I3); cassava starch 4% and inulin 3% (F4I3). Fresh-cut papayas were coated by immersion for 5 minutes, drained for 2 minutes at 22ºC. After this procedure, they were stored in polypropylene packages previously cleaned, at 6º C for 12 days. The analyzes were performed on days 1 (day of application of the coating), 4, 8, and 12. For physical-chemical analysis, total titratable acidity, pH, soluble solids content, weight loss, antioxidant capacity, total phenolic compounds were evaluated, vitamin C content, total carotenoids, instrumental color, and firmness. The contamination of aerobic mesophiles, molds, and yeasts, and psychrotrophic was assessed. The coated fresh-cut papayas were submitted to a sensory evaluation by acceptance test. For the physical-chemical characteristics of bioactive and microbiological compounds, the data obtained were subjected to analysis of variance (ANOVA). Quantitative data with a significant difference (p <0.05) were conducted in regression analysis. Linear and quadratic equation models were tested in the regression analysis as a function of the storage time in qualitative variables. The sensory evaluation results were submitted to ANOVA, and the Tukey test compared the means at 5% probability. The data were stored in spreadsheets in Microsoft Excel and then analyzed with SAS® software online. F3I3 coated papayas showed a significant pH reduction. There was an increase in total titratable acidity and total soluble solids during storage. For phenolic compounds, fruits covered with FOS compared to those without coating, there was the preservation of phenolic compounds. For mass loss, uncoated papayas showed a reduction for this parameter. The antioxidant activity remained constant for all samples during storage time. For total carotenoids and vitamin c, the coated samples did not differ from the samples without coatings. As for microbiological quality, papayas covered with F3F3 showed a significant reduction in aerobic mesophiles' contamination compared to papayas without coating. The coated samples showed molds and yeast counts below 1 log CFU/g compared to the uncoated one. For psychotrophics counts, not difference was detected. The fruits maintained firmness. However, about color, there was a significant reduction in the luminosity of the coated samples. In the sensory analysis, papaya samples coated with F4I3 received the lowest scores in the appearance attribute. The attributes of flavor, color, aroma, firmness, and purchase intention were well evaluated by consumers. Edible coatings were able to maintain physical-chemical characteristics, microbiological and sensory quality in ready-to-eat papayas.