Optimization of explosion puffing drying for pineapple at variable temperature and pressure difference

A three-factor quadratic regression rotation combination design was adopted to optimize the technical conditions of explosion puffing drying for pineapple at variable temperature and pressure difference based on the single factor experiment. The effects of puffing temperature(X1), puffing pressure(X2), vacuum drying time(X3) and the interaction of the three factors on water content(Y1), color(Y2), hardness(Y3) and crispness(Y4) of product were analyzed. Based on the experimental data, the quadratic regression models of four indexes were deduced, then variables were analyzed with response surface methodology (RSM). The optimized technical conditions of explosion puffing drying for pineapple at variable temperature and pressure difference were obtained. The results indicated the four indexes were affected evidently by the three factors, and the interaction of the three factors. The optimal technical conditions were obtained as follows: puffing temperature of 115-123℃, puffing pressure of 0.04-0.08 MPa, vacuum drying time of 2- 3 h.