The effect of drying method on the physical and chemical properties and antioxidant activity of extruded wheat bran

Abstract

Objective: Using wheat bran as raw material, the extruded bran is obtained by extrusion stabilization treatment, and the best drying method for extruded bran is determined. Methods: The effects of three drying methods （fluidized bed drying, microwave drying, hot air drying） were studied on the basic components of extruded bran, water holding capacity, water solubility, swelling power, oil holding power, color value and other physical and chemical properties, oxidation resistance, total phenols and total flavonoids; Using antioxidant, total phenols and total flavonoids as indicators to determine the best drying method for extruded bran. Results: The three drying methods have no significant effect on the crude protein, crude fat, ash and TDF of the extruded bran; Compared with fluidized bed drying, microwave drying and hot air drying can increase the content of starch and crude fiber; Drying has an effect on extrusion, and the influence of the water solubility of extruded wheat bran is: hot-air drying ＞ fluidized bed drying ＞ microwave drying; Compared with microwave drying and hot-air drying, fluidized bed drying can improve the expansion force and oil holding capacity of extruded bran; Compared with fluidized bed drying and hot-air drying, microwave drying can improve the water holding capacity, oxidation resistance, total phenol and total flavonoids content of extruded bran, and reduce brightness and whiteness. Conclusion: The best drying method is determined to be microwave drying.

Keywords

• extruded wheat bran
• fluidized bed drying
• microwave drying
• hot air drying
• physicochemical properties
• antioxidant activity