Mechanochemistry in thermomechanical processing of foods: kinetic aspects

In some food processing operations, raw materials sustain shearing and heating simultaneously. These thermomechanical treatments will induce chemical, physicochemical, and biochemical changes, such as starch degradation and gelatinization, protein denaturalization, loss of nutritious components, and inactivation of enzymes and their inhibitors. In this article, only kinetic aspects of these changes are reviewed. The Basedow and Zhurkov models are commonly used to describe shear effects on the rate constants of mechanochemical reactions. After a brief description of these 2 models, their applications in food are reviewed deeply, with emphasis on the activation energy reduction in the Zhurkov model and the shear activation energy in the Basedow model. Since the changes occurring in food systems often involve various interactions at the atomic, molecular, and supramolecular levels, they were described only phenomenonlogically by the mechanochemical kinetic models. The limitation, opportunity, and extension of the mechanochemical approach to modeling food kinetics are discussed.