OSMOTIC DEHYDRATION OF MANDARINS: INFLUENCE OF REUTILIZED OSMOTIC AGENT ON BEHAVIOUR AND PRODUCT QUALITY

Background. Osmotic dehydration (OD) is a technology that allows the concentration mainly of fruits and vegetables, without change of phase, through partial water removal, when immersed in a hypertonic solution of sugar, salt or others. It can be successfully ap-plied to some products whose production is not fully marketed in fresh form. However, an additional process is necessary to stabilize the product. The process leads to the achievement of high quality alternative products, with an extended shelf-life, economy in storage and transport. The aim of this work was to study, at a pilot scale, the behaviour evaluation of a sucrose dehydration solution, during twelve OD reuses, and the quality of processed mandarins. Material and methods. The process was carried out using mandarins (Citrus reticulata Blanco) cv Clementina Nova, from Algarve, Portugal, manually peeled and segments chemically skinned. In assays a 60°Brix sucrose solution was used, conducted in thermo--stabilized baths, at 45°C, 16 h, 40 oscillations per minute and a fruit:solution ratio of 1:2 (m/m). After each OD cycle, the solution was filtered and reconcentred to 60°Brix by sucrose addition, and adjusted to original volume. The osmodehydrated mandarins were stabilized by pasteurization. The drying solution behaviour and mandarins ‟ qualit