气流膨化过程中马铃薯方便粥水分变化动力学模型及品质变化分析

以双螺杆挤压微膨化工艺开发的马铃薯方便粥为原料，采用气流膨化技术处理马铃薯方便粥，通过测定干基水分含量、水分有效扩散系数、活化能以及色泽、膨化度、孔隙率和复水时间等研究膨化温度和气流速率对马铃薯方便粥水分及品质特性的影响，并建立气流膨化过程中马铃薯方便粥水分变化的动力学模型。结果表明：膨化温度和气流速率对马铃薯方便粥的水分变化均有明显影响。Page模型水分比预测值与实测值的拟合度较高，可以较好地预测马铃薯方便粥气流膨化过程中不同膨化温度、气流速率条件下的水分变化。水分有效扩散系数随着膨化温度、气流速率的升高均增大，气流膨化过程中马铃薯方便粥的活化能为18.96 kJ/mol。膨化时间、膨化温度和气流速率对马铃薯方便粥的亮度L*值、黄蓝度b*值、膨化度、孔隙率和复水时间均有明显影响。由相关性分析可知，气流膨化过程中马铃薯方便粥各品质特性指标间存在极显著相关性（P＜0.01）。本研究可为气流膨化过程中马铃薯方便粥水分实时监测及实现高品质气流膨化提供理论依据。

Effects of Different Thawing Methods on the Quality of Frozen Horse Mackerel

The effects of hot air puffing treatments at different temperatures and air velocities on the moisture and quality properties of potato-rice instant porridge developed by twin-screw extrusion technology were explored by measuring the dry basis moisture content, effective water diffusion coefficient and activation energy as well as the color, swelling degree, porosity and rehydration time. Furthermore, a kinetic model for the variation of the moisture content in the instant porridge was established during the puffing process. The results showed that both puffing temperature and air velocity affected the variation of the moisture content. The Page model was well fitted to the experimental values of moisture ratio, and it could accurately forecast the variation of the moisture content as a function of puffing temperature and air velocity. The effective water diffusion coefficient increased with increasing either puffing temperature or air velocity, and the activation energy was calculated as 18.96 kJ/mol. Puffing time, puffing temperature and air velocity all had a significant effect on the brightness value L*, yellowness-blueness value b*, expansion ratio, porosity and rehydration time of the instant porridge. According to the correlation analysis, the quality properties of the puffed instant porridge had significant correlations with each other (P < 0.01). The findings from this study may provide a theoretical basis for real-time monitoring of the variation of the moisture content in potato-rice instant porridge during hot air puffing for improved product quality.