Influência da geometria no processo de desidratação osmótica de abóbora

Abstract

Osmotic dehydration has been used as a pre-treatment technique for convection drying with the intention of providing the consumer with a more attractive product with less heat loss. Some parameters influence the mass transfer that occurs during osmotic dehydration, directly reaching other parameters such as water loss, solids gain and weight loss, obtaining from them a performance coefficient. Thus, the present study aimed to evaluate the influence of geometry on the process of osmotic pumpkin dehydration. Two treatments were compared, considering the cut of the pumpkin into slices and cubes. Osmotic dehydration occurred in an incubator at 30 ºC with agitation of 35 rpm for 3 hours, using a sodium chloride solution (20%) and sample ratio: 1:10 solution (m/m). During the process time, the samples were taken and the parameters of weight loss, solids gain, water loss and coefficient of performance were obtained gravimetrically. It was found that for water and weight loss, the largest losses were found in slice samples with 59% and 53%, respectively. For the solids gain, the cubes presented lower water and weight loss, and also showed a lower solids gain (6%). Regarding the coefficient of performance, the slices reached the maximum performance in a shorter process period, although the highest coefficient (14.39) was verified for the pumpkins in cubes.