Isochoric moisture heating as a tool to control the functionality of soy protein

In this study, we investigated the effect of isochoric moisture heating on the functionalities of simply fractionated soy protein. Soy protein-rich fractions (SPFs) were produced through a simplified wet fractionation process, in which the defatting and intensive washing steps were omitted. After a neutralization step, the protein-rich dispersions were heated up to various temperatures ranging from 60 to 100 °C and subsequently freeze-dried. It was found that the denaturation level, the water holding capacity and the viscosity of SPFs increased as the processing temperature rose, whereas the solubility of SPFs decreased. Additionally, among the different conditions, an intermediate heating temperature of 70 °C resulted in SPFs having a gel network with the highest elasticity. Overall, isochoric moisture heating coupled to simplified fractionation can be used to precisely control the functionality of soy protein ingredients with mild heating conditions. This work provides insights on the production of ingredients with desired functionality for novel soy-based applications like soy meat analogues.