PESSOA, T.; http://lattes.cnpq.br/5706894782646059; PESSOA, Taciano.
Abstract:
Guava (Psiduim guajava L.) is used not only for fresh consumption as well as to attend a
substantial demand for industrial canning enabling, by its dehydration, a new ingredient in
food industry. In order to serve this market, this research was conducted with the aim of
processing the 'Paluma' guava using combined techniques of osmotic dehydration and
conventional drying to obtain raisin of guava Guavas were used in the maturity stages,
immature and mature, pretreated in sucrose solution, with two concentrations (40 and 50 °Brix)
and submitted to drying in an oven with air circulation, at four temperatures (40, 50, 60 and 70
°C). Data were treated according to the models of Henderson and Pabis; Midilli, Page and
Thompson. It was made the physicochemical characterization of fresh guavas after each
process step. The data of physicochemical analysis were treated following a completely
randomized experimental design with three replications for each step of the process of osmotic
dehydration and drying. For data analysis was used the Assistat 7.0 software. It was analyzed
the texture of the raisin of guavas as for tests of fiber rupture, resistance to compression and
cutting, using the TAXTplus equipment - "Texture Analyser", Stable Micro System. There
was a sensory analysis with the developed products through a 5-point hedonic scale, analyzing
the attributes of appearance, color, aroma and flavor and tests were applied for acceptance and
purchase intent. Data were interpreted by analysis of variance and means were compared by
applying the Tukey test. The main conclusions from this research were that the higher sucrose
concentration and high drying temperature leads to high water removal in osmotic dehydration
and drying, respectively. For the same drying temperature, the sucrose concentration on
osmotic pretreatment solution did not influence the drying time to obtain raisin of guavas; the
Page model represents better the experimental data of drying, with the lowest DQM; pH of
guavas at mature and immature stages was lower than 4.04 throughout all process, to obtain
raisin of guava; there is a concentration of acidity as the water content of guavas reduces;
immature guavas after osmotic dehydration lose vitamin C and, after drying process, there is a
concentration of this nutrient; In mature guavas there is an addition of vitamin C after
dehydration osmotic and loss after drying process; the ash content of immature guavas
throughout the process (in fresh way after osmotic dehydration and after drying) was higher in
percentage terms, than in mature guavas; the softer samples were those obtained in
temperatures of 40 °C disregarding maturation stage, being influenced by the osmotic solution
in which were immersed; the most accepted samples, according to sensory analysis, were those
that obtained the highest percentage for purchase intent, which were immature dehydrated
guava obtained in osmotic solution of 50 °Brix and drying at 40 °C, and raisin of guava,
osmotically dehydrated at 50 °Brix and drying at 50 and 70 °C, respectively.
