Effect of vacuum impregnation temperature on the mechanical properties and osmotic dehydration parameters of apples

Abstract

The effect of sucrose solution temperature on the mechanical properties, water loss (WL), solids gain (SG) and weight reduction (WR) of apples (Fuji var.) treated by vacuum impregnation was studied. Temperatures were varied from 10 to 50 ºC, using a sucrose solution of 50 ºBrix. The mechanical properties were studied throughout a stress relaxation test. The results showed that the SG varied between 10.57 and 14.29 % and the WL varied between 10.55 and 14.48 %. The treated fruit soluble solids increased with the temperature probably due to the lower viscosity of the solution. The maximum stress was highest at 10 ºC, decreasing at higher temperatures, probably due the softening of the structure.