Desidratação de laranja em diferentes cortes e temperaturas

Abstract

Dehydration of fruits is an important method of preservation, making them more resistant, especially to deteriorations caused by microorganisms. The objective of this study was to perform orange-pear (Citrus sinensis) dehydration, in different cuts and temperatures, in order to verify the influence of the process on the physical-chemical quality, as well as to determine the kinetics of dehydration. The experiment was carried out in a randomized block design in a 3 x 3 factorial scheme (3 cutting types: slice with mesocarp, slice without mesocarp, and orange wedges, in 3 dehydration temperatures: 45, 65 and 85 ºC) in 6 repetition. The orange wedges and orange slices were organized in aluminum trays, in 6 orange wedges and 4 slices were placed in each tray, constituting the experimental unit. Dehydration was carried out in stove with forced circulation of air, followed by dehydration through the loss of water mass. The in natura or dehydrated oranges were evaluated for moisture content, total soluble solids (°Brix), pH and color. For all cuts of orange subjected to dehydration at 85 °C, the average time of 12 h was observed, and at 65 °C, 21 h. At 45 ºC, the time varied between cuts, averaging 79 h for the orange in orange wedge and 52 h for the oranges in slices. For the observed data of water loss as a function of time, the best fit model was the nonlinear exponential profile of two terms. The pH of the samples did not show great variation in relation to the in natura product, however a reduction of the amount of total soluble solids - SST was observed, thus reducing the sugar content. Regarding color, we observed an increase of the coordinate a * and the angle Hue, and a reduction of the coordinate b *. No darkening of the samples was recorded due to the dehydration process.