Fractionation and characterization of soluble soybean polysaccharide esterified of octenyl succinic anhydride and its effect as a stabilizer in acidified milk drinks

Abstract

Abstract The objective of this research was to study the octenyl succinic anhydride (OSA) modified SSPS (OSA-SSPS) formed via SSPS esterified with OSA. Cross-flow ultrafiltration was used to separate polysaccharides after esterification process and then OSA-SSPS with high molecular weight (HMW) as well as OSA-SSPS with low molecular weight (LMW) were obtained. The formation of OSA-SSPS was confirmed by fourier transform infrared spectroscopy which showed a new characteristic peak at around 1730.05 cm−1 (C=O). The viscosity of OSA-SSPS (HMW) was up to 80 mPa s while the value of SSPS was close to 30 mPa s in the 10 wt% concentration. The size distribution of OSA-SSPS indicated that OSA-SSPS (HMW) had a concentrated size in 1 μm while SSPS expressed three characteristic peaks. Particle size distribution showed that SSPS cross-linked successfully with OSA via the esterification, meanwhile, the side reactions were produced small molecules. The zeta potential of OSA-SSPS (−38.23 ± 0.24 mV) were 1.5 times as much as SSPS (−26.67 ± 0.31 mV). Compared the stability of SSPS with OSA-SSPS (HMW) in the acidic milk drink (AMD), the measurement of dispersion state (e.g. precipitation percent and turbidity) after centrifugation confirmed that OSA-SSPS (HMW) stabilized protein better than SSPS (p