Effects of High-Speed Shearing Treatment on the Physical Properties of Carbohydrate-Binder Mixture during Gelatinization for Preparing Freeze-Dried Soup Products.

Modernization has led to a large convenience food market, and the demand for freeze-dried (FD) soup products is increasing in the Republic of Korea. FD soup products are easy to eat without cooking and can be stored for long periods. However, it is often difficult to ensure sensory satisfaction after rehydration of FD soup products; in particular, the ingredients are not evenly dispersed. Therefore, a stable dispersion or reconstitution of the FD soup products is required after rehydration. Here, the effects of high-speed shearing homogenization on the physical properties of a carbohydrate-binder mixture comprising maltodextrin, potato starch, and rice flour were investigated during hydrothermal gelatinization. To find a suitable treatment condition, different homogenization eras, speeds, and concentrations of the binder mixture were considered; in particular, the homogenization eras were set by considering the hydrothermal property of the binder mixture profiled using differential scanning calorimetry. The viscosity of the binder mixture and the compression strength and microstructure of the FD binder block, including the dispersion stability after rehydration, were evaluated. The quality of the FD binder block was improved by homogenization above 5000 rpm when the core temperature of the binder mixture reached approximately