under a pressure of 0.025 MPa, at room temperature 20e22 C. After vacuum impregnation mushroom in a single layer(thickness about 3 cm) were frozen in a Feutron 3626-51 blast freezer at 35 C for 120 min in order to achieve a temperature of 25 C at the thermal centre of the samples. After freezing,mushrooms were placed in 0.5 L polyethylene containers.Products were stored for 8 months at 25 C.