Influence of Extruded Hemp-Rice Flour Addition on the Physical Properties of Wheat Bread

Functional foods play an important role in daily diet, human health and the food industry. Hemp was reported to have many advantages for nutritional and medicinal usage. In this study, extruded hemp-rice (EHR) flour, containing 30% hemp, was mixed with the wheat flour to create bread loaves at the concentrations of 5, 10 and 15%. Bread made from 100% wheat flour (with no added EHR flour) was used as a control. The physical parameters, including expansion ratio, specific volume and crust/crumb color were evaluated separately. In addition, changes in hardness of the bread during storage at ambient temperature for 3 days were also studied. The results showed that 10%-EHR bread exhibited the highest hardness value, while 15%-EHR bread presented the lowest. The bread containing EHR flour had lower specific volume and bigger air cells compared to the control. Moreover, the crust and crumb color of EHR-containing bread was significantly darker than those of the control. In this study, the 15%-EHR bread showed higher specific volume, lower hardness and bigger air cell structures.