Water Holding Capacity Profile that Governs Water Migration in Starchy Food During Boiling

Abstract

A starchy food that is initially a single-phase body turns into a multiphase body during boiling because of starch gelatinization. Fick's law is applicable only to a homogeneous system and is not applicable to such a multiphase system. Relative Water Content (RWC) model has been proposed as an alternative model that is able to describe water migration in multiphase food systems. In the RWC model, water migration is driven by the gradient of water content divided by the water holding capacity (WI-IC), m/m*. In this study a WHC profile (WHC plotted against water content with which starchy food is heat-treated) was assumed based on information concerning starch gelatinization. Using this WHC profile, the correlation between WHC profile and transient water content profile in a wheat flour dough slab during boiling was examined. A modified WHC profile was found to be applicable for describing certain characteristic features of the transient water content profile in a slab of wheat flour dough during boiling.