Freeze drying preparation method of fruit and vegetable crisp slices

The invention discloses a preparation method for freeze-drying fruit and vegetable crisp slices. The preparation method comprises the following steps: blanching cleaned and split raw materials for enzyme deactivation, rapidly placing the raw materials after enzyme deactivation into a pre-cooling color-protecting liquid for cooling, pulping, homogenizing, paving material layers with thickness of 5-10mm in a metal material plate, inserting to an integrated metal grid mould, precooling at temperature of -30 DEG C, performing vacuum freeze drying according to the following process: when the temperature is lower than 10 DEG C, increasing temperature at the rate of 3-5 DEG C per hour, when the temperature reaches 10 DEG C, keeping the temperature for 1 hour, increasing temperature at the rate of 5-7 DEG C per hour, when the temperature reaches 40 DEG C, keeping for 2 hours, and then finishing the vacuum freeze drying. According to the invention, a proper amount of water is added into the raw materials for pulping and homogenizing, then curing is carried out, the integrated metal grid mould is used for accelerating the process that heat is conducted inside the material layers, the whole material plate is divided into a plurality of independent evaporation units, so that sublimation of water is greatly accelerated, obtained fruit and vegetable crisp slices are crisp and porous, good in reconstitution property, and the defect that the traditional freeze-drying fruit and vegetable crisp slices are poor in reconstitution property so as to stick teeth is overcome.