Reaction kinetics in food extrusion: methods and results |
| |
Authors: | Zhao Xuewei Wei Yimin Wang Zhangcun Chen Fengliang Ojokoh Anthony Okhonlaye |
| |
Affiliation: | School of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450002, China. zhao xuewei30@yahoo.com.cn |
| |
Abstract: | Extrusion cooking is a highly efficient food processing technology. During the extrusion process, there are many desirable and undesirable reactions which will determine final product quality. While being heated and sheared simultaneously, food raw materials experience a non-isothermal process and their residence time in the extruder is distributed. All these factors contribute to the difficulties in determining the kinetic parameters for those reactions. Therefore, this paper attempts to review the reaction kinetics in food extrusion. First of all, the kinetic models for the reactions are outlined. After elucidating how to determine reaction time in an extruder, the methodological approaches for determining the reaction order, rate constant, and activation energy of a reaction under isothermal or non-isothermal conditions with or without residence time distribution (RTD) are presented. Then, different models relating the rate constant to its various impact factors, with especially focusing on shear stress, are reviewed. Subsequently, how shear stress is estimated in an extruder, is illustrated. In the last part of this paper, the reported data of rate constant, reaction order, and activation energy for the reactions occurring during food extrusion are summarized, with detailed impacts of temperature, moisture content, shear stress, and determination method on these kinetic parameters. Finally, future research needs are suggested. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|