Preparation and stabilizing behavior of octenyl succinic esters of soybean soluble polysaccharide in acidified milk beverages.

Soybean soluble polysaccharide (SSPS) is anionic polysaccharide extracted from the by-product of isolated soy protein production. In this study, a simple and eco-friendly procedure had been developed to prepare high-molecular-weight octenyl succinic esters of SSPS (OSA-SSPS) via the esterification between SSPS and octenyl succinic anhydride (OSA). The absolute molecular weights of OSA-SSPS and SSPS were 620 kDa and 53 kDa, respectively. OSA-SSPS had some similar properties to SSPS, such as microstructure and viscosity of 1 wt% concentration. However, compared to SSPS, OSA-SSPS showed different milk protein stabilization properties. The stabilizing behavior of OSA-SSPS was better than that of SSPS at pH range of 3.8–4.6, and poorer at pH 3.6. The model mixture of OSA-SSPS had smaller particle sizes at pH range of 3.8–4.6 and larger absolute negative charges at pH 2.0–10.0. In addition, from the molecular diameter measured by DLS and AFM image, the surface concentration of OSA-SSPS was larger than that of SSPS, which indicated that the thicker OSA-SSPS layer produces larger steric repulsion to milk protein particles. The mechanism for the greater ability of OSA-SSPS to stabilize milk proteins was proposed on the basis of the results discussed in this research. [ABSTRACT FROM AUTHOR]