Production and Properties of Soluble Dietary Fiber from Edamame Shell Using Combined Physical and Chemical Treatments

Soluble dietary fiber (SDF) is widely used as a food ingredient due to its superior physicochemical and functional properties. Edamame shells, a byproduct of edamame bean processing, are rich in dietary fiber but have a low SDF content, limiting their food applications. This study explores the effects of combined ball milling and citric acid treatment on the yield and properties of SDF from edamame shells. The results showed that the highest SDF yield (19.5%) was achieved when the edamame shells were pretreated with a ball mill. The combined treatment altered several SDF properties, including the particle size, morphology, and crystallinity. Moreover, the ball milling treatment led to a better SDF thermal stability. Furthermore, all produced SDFs significantly increased short-chain fatty acid production during in vitro fermentation, suggesting their potential benefits of promoting gut health. This study demonstrated that ball-milling-assisted citric acid processing is an effective green technique to produce SDF from edamame shells.