Optimization of osmotic pretreatment of tomato slices using response surface methodology and further hot-air drying

Tomato is one of the most cultivated vegetables, playing important role in human feed. Due to its characteristics and composition, tomatoes present reduced shelf life, preservative techniques are required. In this study, response surface methodology was used optimize process conditions during osmotic dehydration (OD) tomato slices, through desirability function. Optimization factors were absolute pressure (21-89 kPa), vacuum application period (7-15 min), solution water activity (0.893-0.943), while investigated responses sodium incorporation (NaI), loss (WL), solid gain (SG), weight reduction (WR), osmodehydrated product (ODaw). The optimized achieved, a further hot-air drying (HAD) conducted at different temperatures air velocities. During OD, lower pressure, led NaI higher WL WR. Shorter time diffusivity obtained temperature velocity, HAD. dried slices with evaluated regard final activity, rehydration color, which no significant differences (p > 0.05) observed between treatments.