Quality Characteristics of Soymilk Developed by Hydrolysing Raffinose and Stachyose and Its Effect on Dyspepsia

The aim of this study was to develop soymilk in which raffinose and stachyose were effectively hydrolyzed through enzymatic treatment and to assess the resulting soymilk’s physical properties, taste, and potential for alleviating dyspepsia symptoms. Traditional soymilk (TS) was prepared without enzyme treatment, while enzymatically hydrolyzed soymilk (EHS) was produced with enzyme treatment, with all other conditions held constant. Effective hydrolysis of raffinose and stachyose in EHS was confirmed by high-performance liquid chromatography (HPLC) and reducing sugar analysis. Physical property analyses, including specific gravity, viscosity, brightness, and yellowness, showed no significant differences between TS and EHS. Although a difference in redness was observed, this variation did not affect the overall visual appeal of the product. In taste evaluations, EHS showed increased sweetness and overall improved palatability without the addition of sugars, attributed to the enzymatic hydrolysis of oligosaccharides like raffinose and stachyose, which elevated monosaccharide levels. Additionally, participants who typically experienced dyspepsia symptoms from soymilk reported symptom improvement after consuming EHS. These findings indicate that enzymatic treatment in soymilk production can yield a soymilk product suitable for individuals who experience indigestion with traditional soymilk while maintaining favorable sensory qualities.