Drying and Grinding Characteristics of Four-Day-Germinated and Crushed Wheat: A Novel Approach for Producing Sprouted Flour

The purpose of this study was to examine the drying and grinding characteristics of sprouted and crushed wheat. The four-day-germinated wheat kernels were crushed, dried, and ground in a micro hammer mill. The drying kinetics of sprouts were best described by the Page and two-factor models. The crushing of wheat sprouts before drying decreased the drying time by about half. Sprouting and crushing of wheat sprouts have a significant influence on the grinding process, both on the particle size distribution and on the grinding energy requirements. It was observed that the ground sprouts showed significantly lower values of average particle size compared with the samples of sound kernels. Sprouting caused an increase in the amount of fine particles (<0.2 mm) and a decrease in the mass fraction of coarse particles (>1.0 mm). All values of grinding indices showed that sprouting and crushing significantly reduced the grinding energy requirements. Moreover, sprouting significantly increased the total phenolics content (from 26 to 31%) and antioxidant activity (from 33 to 72%) of wheat kernels. The results showed that sprouting and crushing of sprouts followed by their drying and grinding may provide a practical method for preparing sprouted flour.