studying drying kinetics of button mushroom pretreated by osmotic dehydration

dehydration is one of the most common preservation methods for button mushroom. dried mushroom slice and powder is used in formulation of soups and sauces. in this study, the effect of osmotic pretreatment on drying kinetics of button mushrooms was studied. thin slices of mushroom were immersed in osmotic solution containing 5% sodium chloride and 0.5% calcium chloride at a temperature 40 °c for 120 min. pretreated samples were then hot air dried (with air speed of 1.8 m/s) at a temperature of 50 and 60 °c to a final desired moisture content. effective moisture diffusion coefficient, activation energy, shrinkage, rehydration ratio and colorimetric parameters were measured after dying. osmotic dehydration significantly (p