Effects of High Energy Mechanical Treatments on the Structure and Physicochemical Properties of Insoluble Dietary Fiber from Soybean

Soybean insoluble dietary fiber was degraded via ball milling and high pressure microfluidization,respectively,and their structure and physicochemical properties were investigated. The results showed milled cellulose showed dispersed block-shapes with average particle diameter at 28.06 μm,which was 22.83% of untreated samples. However,cellulosic cluster was observed after microfluidization treatment,with average particle diameter at 7.34 μm,which was 5.97% of untreated sample. Additionally,high pressure microfluidization disrupted the crystalline of dietary fiber,further transform β-I type into amorphous crystal structure,which exposed more inter-molecular hydrogen bonds. The relative crystallinity of SIDF decreased from 40.98% to 3.16%. Compared with ball milling,the water and oil holding capacity of soybean dietary fiber were improved significantly by micro fluidic homogenization. The water and oil holding capacity of pressure-treated soybean dietary fiber was 2.96 and 2.48 times that of control,respectively. Moreover,microfibre hydrogel showed higher oscillation stability,tan δ was 20.73% of control. This might be attributed to the strong hydrogen bonding ability of microfibre and the large space potential resistance formed by microfibre winding in morphology.