Osmotic dehydration of guava: Influence of operating parameters on process kinetics

An empirical model was obtained to predict the effect of solution temperature (T), process time (t) and pressure regime (P) on the kinetics of water loss (Mw), solids gain (Ms) and weight loss (M) of osmotically dehydrated guava. Hard ripened guavas were peeled, cut in halves, cored, manually cut in eighths, weighed in 110 g fractions and put in a 1 L glass flask containing 880 g of a of 65 Brix sucrose solution. The flask was then connected to a vacuum rotary evaporator. The system was then subjected to temperatures of 30, 40 and 50 °C for 30, 60, 90, 120, 150 and 180 min, at atmospheric pressure, pulsed vacuum (5 min under vacuum, then atmospheric pressure) and continuous vacuum. Experimental data were fitted to a second order polynomial by means of a multiple regression analysis. Results show that T, t and the pressure regime significantly affect Mw, Ms and M values of osmotically dehydrated guavas.