挤压引起食品特性变化的数学模型研究综述

Review on mathematical models of food property changes induced by extrusion

挤压是一项有效的食品加工技术,物料在挤压机内既受到加热又受到剪切,经历的是一个非等温过程,且停留时间出现分布。正确建立挤压食品特性变化的数学模型是对产品质量进行预测和控制的基础,可以将描述挤压引起的食品特性变化的数学模型分为6类:流变模型、动力学模型、降解模型、膨胀模型、质构模型和统计模型。含水率、温度、停留时间分布(RTD)、时温历程、剪切历程等因素都可能对产品特性产生影响。该文详细论述了在建立前3种模型的过程中如何考虑这些因素的影响。该文最后简要论述了今后的研究方向。

Extrusion is an effective food processing technology. Feed materials are heated and sheared simultaneously during extrusion, and experience a nonisotherrnal process, in addition, their residence time in extruder is distributed. Predicting and controlling the quality of extrudates need properly establish mathematical models describing their property changes induced by extrusion. All the models can be divided into six classes, namely, rheological, kinetic, and degradative, expansion, texture and statistic models. This review discusses deeply how to incorporate process and material parameters like moisture content, temperature, residence time distribution（RTD）, temperature-time history, shear history etc, into the former three models. Finally, future research needs are outlined.