A comparative study on physicochemical and emulsifying properties of white and red ginseng dietary fibers from ginseng residues

To achieve high-value development of ginseng residue, white ginseng dietary fiber (W-DF) and red ginseng dietary fiber (R-DF) were obtained from ginseng residues, and their physicochemical properties, emulsifying properties, and their applications in emulsions were comparatively investigated. The results demonstrated that W-DF, whose smaller particle size facilitated its rapid adsorption at the oil-water interface and exhibited better emulsifying activity, coupled with stronger electrostatic repulsion, prepared emulsions with superior centrifugal, heating, and refrigeration stability. In contrast, the R-DF obtained showed excellent solubility, foamability, and crystallinity as the red ginseng steaming process helped to improve the soluble fractions. Meanwhile, the storage stability of the R-DF stabilized emulsion was more prominent. Furthermore, the increase in pH reduced the fiber aggregation and increased the absolute potential and soluble protein content, causing the D 3,2 values of emulsions to decrease. However, the structure of the fibers got loose when the aqueous phase environment near neutral pH, which led to a decrease in the emulsifying activity, resulting in an increment in the large droplets and a bimodal distribution of droplets. Therefore, the emulsions near neutrality showed higher D 4,3 values. The findings pave the way for exploring ginseng dietary fiber as a natural and effective emulsifier. • W-DF and R-DF from ginseng fibrous root residues were used as effective emulsifiers. • W-DF had smaller particle size, higher absolute potential and emulsifying activity. • R-DF exhibited higher solubility, foamability, and crystallinity. • The pH could regulate the aggregation degree and properties of DF. • The emulsion performances varied relying on the microstructure and properties of DF.