Abstract:

The effect of dynamic high-pressure microfluidization (DHPM) treatment on compositions, morphology, component change of sugar and molecular weight of soluble soybean polysaccharides (SSPS) were investigated. Results showed that soybean soluble polysaccharides were treated by DHPM, and then purified by DEAE-cellulose ion exchange column to obtain two components, which were SSPS-1 and SSPS-2. High performance gel permeation chromatography (HPGPC) analysis exhibited that SSPS-1 was a heteropolysaccharide containing a small amount of protein and SSPS-2 was a homogeneous polysaccharide associated to protein with high molecular weight. The molecular weight of SSPS-1 was reduced from 733 to 511 kD by microfluidization treatment. Scanning electron microscopy observation of SSPS-1 showed that feature of DHPM-treated SSPS-1 sample was changed from the disordered flake-like to ordered "match stick"-like structure, which swelled into sphere at the end of structure. The major components, Rha and GalA, in the main chain of SSPS-1 exhibited a decrease by 9.4% and 17.1%, respectively. While the components such as Ara, Gal, Fuc and Man in side chain of SSPS-1 exhibited a significant reduction, which were decreased by 14.3%, 26.3%, 41.7% and 60%, respectively. There were no detectable Xyl, Glc and GlcA due to the break of chains and hydrolysis.

Key words: dynamic high-pressure microfluidization, soluble soybean polysaccharide, component, molecular weight, morphology