Synergistic effect of high hydrostatic pressure pretreatment and osmotic stress on mass transfer during osmotic dehydration Original Research Article

During osmotic removal of water from foods, the osmotic dehydration front moves from the surface of the food in contact with the surrounding osmotic solution to the centre, which results in disintegration of cells due to osmotic stress. When the food is pretreated with high hydrostatic pressure (HHP), it also results in cell permeabilisation. The cell permeabilisation index (Zp, as measured by an electrophysical measurement based on electrical impedance analysis) after high pressure treatment increases with time. Osmotic dehydration of HHP-treated foods is faster than that of untreated foods. The state of the cell membrane during osmotic dehydration of high-pressure-pretreated samples can change from being partially to totally permeable, which leads to significant changes in the tissue architecture resulting in increased mass transfer rates during osmotic dehydration as compared to untreated samples.