Abóboras cabotiá minimamente processadas oriundas de cultivo orgânico e convencional

Abstract

The pumpkin is a native species of the Americas, with easily adaption to the planting process, so with the various regions where it is planted. One of the main hybrids produced is the Cabotia type pumpkin, that have juicy stem, thick and rigid green skin which encourages its marketing in a minimally processed way. The nutritional content and the variability of compounds found in pumpkin may be related to the way it is cultivated, highlighting the conventional and organic planting systems. But there are no descriptions in the literature that indicates that the packaging can extend the shelf life of the food, preserving its nutritional and sensory characteristics. Thus, the general objective of this dissertation is to verify the influence of organic and conventional cultivation systems on the physical chemical characterization and nutritional composition of minimally processed Cabotia pumpkin, stored in different types of packaging and periods. It is hypothesized that the planting systems will influence the physical and chemical characterization, and the organic system will provide higher nutritional concentration, and the plastic packaging, with the use of vacuum, will prolong the shelf life of the minimally processed Cabotia pumpkin, preserving the nutritional and microbiological content. As plant material, Cabotia pumpkin from organic and conventional cultivation system were used. In Chapter 1, pumpkins were minimally processed and characterized for color (L, a, b, ° Hue), firmness (N), acidity (% citric acid), pH, soluble solids (%), SS / AT ratio (%), phenolic compounds (g EAG g of dry weight pumpkin), carotenoids (g β carotene g of dry weight vegetable), moisture (%), ash content (%), protein content (%), and lipid content (%). Then, in Chapter 2, the pumpkins were processed and wrapped in three types of packaging: polystyrene trays covered with polyvinyl chloride film, high-density vacuum polyethylene packaging and plastic bags. Each package contained 250 g of sample, which was stored for 15 days at 5 ° C ± 1 ° C. Every three days, staining (L, a, b, ° Hue), firmness (N), soluble solids (%), titratable acidity (% citric acid), SS / AT ratio (%), pH, chlorophylls (mg g-1), carotenoids (g βcarotene of dry weight vegetable), phenolic compounds (g dry weight Pumpkin EAG g) and humidity (%). Every six days, the mold and yeast were counted at 45 ° (CFU / g). The statistical design applied was entirely causualized in a factorial experiment. The data presented in this study were the mean values of three independent repetitions, analyzed using one-way analysis of variance (ANOVA), regression analysis, and significant differences were detected by Tukey test (p <0.05). In chapter 1, a difference was found in the physical chemical composition of pumpkin as a function of crop management, and organic pumpkins had higher carotenoid content than conventional ones. However, for both managements, the results are asexpected for the crop. Then in the second chapter, the color (coordinate a), phenolic compounds, chlorophyll b and total evaluations showed significant interaction as a function of storage periods. The firmness variable was influenced by the interaction between cropping systems and storage periods. For Hue angle, SS / AT ratio, carotenoid content and humidity, there was no interaction between the studied factors. There was a triple interaction between cultivation systems, storage periods and packaging for the other variables analyzed. Pumpkins from both cultivation systems showed viability of the evaluated compounds until the ninth day of storage. The packaging that provided the lowest postharvest conservation of minimally processed pumpkins was plastic. The vacuum packaging was not superior to the other packages studied for all analyzes and periods. Even so, it presented satisfactory results for the storage of minimally processed Cabotiá pumpkins, as expected. Higher carotenoid concentration in the organic production system may have positively acted in equalizing the shelf life between the cultivated systems of the processed product.