In vitro hypoglycemic, cholesterol-lowering and fermentation capacities of fiber-rich orange pomace as affected by extrusion.

Our previous study suggested that extrusion can enhance the soluble dietary fiber (SDF) and improve the physicochemical properties of fiber-rich orange pomace (OP). The aim of this study was to determine the predictive indices for the hypoglycemic, hypocholesterolemic, and fermentation capacities of extruded orange pomace (EOP) with several in vitro assays. The results revealed that EOP could effectively retard glucose diffusion and inhibit α-amylase activity relative to OP. Moreover, EOP had the binding capacities of cholesterol micelles and bile acids. During the in vitro fermentation of EOP, a high content of short chain fatty acid was produced. Scanning electron microscope images showed a more porous and irregular shaped structure of the EOP, which may influence physiological activities, relative to OP. The morphological alterations in the EOP were caused by mechanical shear. Thus, EOP has potential to become a functional food additive for glycemic control and the attenuation of blood cholesterol.