Drying of plums (Prunus sp, c.v Gulfblaze) treated with KCl in the field and subjected to pulsed vacuum osmotic dehydration

Abstract

The pulsed vacuum osmotic dehydration (PVOD) promotes more homogeneous concentration profiles in the product and quality improvement of several fruits. The objective of this work was to study the drying of plums submitted to treatments of plants manure with KCl and PVOD (5’’ c.a., 10 min). Experimental planning was done with the following independent variables: doses of KCl (400, 700 and 1000 g ⁄ plant), concentration of sucrose solution (40; 50 and 60 oBrix) and drying temperature (50, 60 and 70C). The tested variables were: color, shrinkage, visual quality and rehydration. Temperature leads to a skin browning at fruit pulps and lower visual quality. The treatment with KCl leads to final products with lower moisture content. The higher the values of all the independent variables, the lower the shrinkage and the rehydration capacity. Plums submitted to convective drying with previous PVOD promote a new product with good visual quality and satisfactory shrinkage.