冬瓜片渗透脱水平衡分配系数研究

Equilibrium distribution coefficients during osmotic dehydration of white gourd slices

为了深入理解渗透脱水的机理，优化、控制渗透脱水工艺，必须获取水分与固形物的平衡分配系数。测定冬瓜片在30--50℃、40％--60％麦芽糖浆中渗透脱水的失水率与固形物增加率，经方程回归得到冬瓜片的水分和固形物平衡分配系数，并用9种模型拟合平衡分配系数与温度、麦芽糖浆浓度的关系。结果表明：冬瓜片的水分和固形物平衡分配系数分别在0．3411-0．8406g／g、1．2392～1．5754g／g内。麦芽糖浆浓度固定时，冬瓜片的水分平衡分配系数随温度升高而减少，冬瓜片的固形物平衡分配系数随温度增加而增加。温度固定时，冬瓜片的水分平衡分配系数随麦芽糖浆浓度增加而减小，冬瓜片的固形物平衡分配系数随麦芽糖浆浓度增加而增加或减少。以R。、SSE、RMSE与x。评价9种模型的拟合结果，模型4的拟合精度最高。模型4适用于预测冬瓜片的水分和固形物平衡分配系数。

In order to understand osmotic dehydration mechanism thoroughly, the equilibrium distribution coefficients of water and solids were obtained to optimize and control osmotic dehydration process. In this paper, water loss and solid gain of white gourd slices were determined during osmotic dehydration at temperature （30-50 ~C） and concentration （40%~60%, w/w） of maltose syrup solution. The equilibrium distribution coefficients of water and solids for white gourd slices were determined through equation regression, nine models were used to fit the relationship between equilibrium distribution coefficients and temperature and maltose syrup concentration. Results showed that the equilibrium distribution coefficients of water and solids for white gourd slices ranged from 0.3411 gig to 0.8406 gig and from 1.2392 g/g to 1.5754 g/g, respectively. At a constant maltose syrup concentration, the equilibrium distribution coefficients of water for white gourd slices decreased with the increasing temperature, whilethe equilibrium distribution coefficients of solids for white gourd slices increased with the increasing temperature. At a constant temperature, the equilibrium distribution coefficients of water for white gourd slices decreased with the increasing maltose syrup concentration, while the equilibrium distribution coefficients of solids for white gourd slices increased or decreased with the increasing maltose syrup concentration. The fitting results of the nine models were evaluated by using statistical analyses such as determination coefficient （R2）, sum squared error （SSE）, root mean square error （RMSE） and chi-square （X2）. The fitting accuracy of the fourth model is the highest. The fourth model was suitable to predict the equilibrium distribution coefficients of water and solids for white gourd slices.