High pressure assisted osmotic dehydrated ginger slices

Experiments were conducted to investigate osmotic dehydration of ginger slices suspended in three different osmotic agents at 0.1–600 MPa and 40 °C for various pressure holding times. A Weibull distribution mathematical model was employed to predict the kinetics of moisture and solute transport during osmotic dehydration of ginger. Increased process pressure accelerated the water loss and solid gain and removed significant amount of water within a shorter time period. The effective moisture diffusivity values for glucose, fructose, and sucrose at 0.1 MPa and 40 °C were 0.322 × 10−9, 0.362 × 10−9 and 0.396 × 10−9 m2/s respectively. Pressure treatment at 600 MPa increased these values by approximately by 11–12 folds (3.725 × 10−9, 4.027 × 10−9 and 4.293 × 10−9 m2/s respectively). Among the osmotic agents tested, solute diffusivity was maximum in glucose followed by fructose and sucrose, whereas the moisture diffusivity was greatest in sucrose and lowest in glucose.