香菇冷冻干燥工艺参数的试验研究

Experimental study on technological parameters of freeze-drying of mushroom

确定了最优的香菇冷冻干燥工艺参数,以提高冻干效率和冻干香菇品质。通过单因素试验以及4因素5水平的二次回归正交试验,研究了冻干室压力、加热板温度、预冻降温速度和物料厚度等因素对冻干时间、干燥前后物料体积收缩率及复水比等几个指标的影响;建立了各指标与试验因子之间的回归数学模型;最后利用多目标非线性优化理论与方法,在保证香菇干燥品质的情况下,得到了香菇(厚度6～10mm)冷冻干燥的最优工艺参数,干燥室压力111Pa,加热板温度42.5℃,降温速率-0.29℃/min。

The purpose of this paper is to determine the most efficient freeze-drying technological parameters of mushroom in order to improve its efficiency and quality. The relationship between the drying time, ratio of volume shrinkage, ratio of water absorption, as well as the drying pressure of drying chamber, temperature of the board, the velocity of decreasing temperature during the process of freezing, the material thickness through the two orthogonal experiments with four factors and five levels and single factor experiment, and the mathematical models were established to describe the parameters. At last the optimal combination of the parameters for the freeze-drying technology of mushroom was obtained through optimized theory in many targets and in nonlinear method. They are as follows: under ensuring quality, the drying pressure of drying chamber is 111 Pa, the temperature of the board is 42.5℃, the velocity of decreasing temperature during freezing is -0.29℃/min, and material thickness is 6~10 mm.