Estudo da desidratação osmótica de tomate em soluções ternárias pela metodologia de superfície de resposta

Abstract

The objective of this work was to study the influence of temperature (20-40°C), solution composition (0% NaCl/65% sucrose - 10% NaCl/55% sucrose) and agitation level (0 - 1000 rpm), on the osmotic dehydration of tomato's halves. The process was carried out in a jacketed tank connected to a thermostatic bath, and osmotic solution agitation was promoted by a mechanical stirrer and measured by a digital tachometer. Results were analyzed through response surface methodology, according to a 23 factorial experimental design. Water loss, salt and sucrose gain and final water activity of the product were positively influenced by temperature and by increasing salt content on the solution. Agitation influenced only on water loss, indicating that in this case, mass transfer is not governed only by a diffusion internal mechanism. Equilibrium proximity reached in each test was verified through the relationship between solution and samples water activities. The samples processed in solutions with higher salt content seemed to be more distant of equilibrium, after 3 hours of process.