Physicochemical and in vitro digestion characteristics of size-different red ginseng powders

The aims of the present study were to prepare different-sized red ginseng powders and investigate the particle size effect on the release property of ginsenosides in in vitro digestion conditions. Ultrafine powder showed bimodal particle size distribution with a large peak at around 100 μm and small peak at around 10 μm, differently from fine powder showing unimodal distribution at 100 μm. The specific surface areas of fine- and ultrafine powders were 48.72 ± 6.41 and 86.74 ± 5.96 m²/g, respectively. Time-dependent release property of the powders in the simulated gastrointestinal fluids was determined by quantifying ginsenoside Rg1 released. The initial and final concentrations of ginsenoside Rg1 released was higher in ultrafine powder than fine one. It is expected that particle size reduction and corresponding increase in the specific surface area have a potential to improve the release of ginsenosides in the gastrointestinal tract and enhance the chances to be absorbed in human body.