This study investigated physicochemical properties of soy soluble polysaccharide (SSP) and pectinase-hydrolysed soy soluble polysaccharide (PH-SSP) from okara, the residue from soy milk production, and their influences when used as a fibre source in oil-in-water (o/w) emulsions. Although pectinase hydrolysed only the carbohydrate fraction in SSP, it resulted in the self-association of PH-SSP to the large-size aggregates. When PH-SSP was added to liquid emulsion containing 3.33% (w/v) rice bran oil and 3.75% (w/v) heated soy protein, it regulated the contents of protein in serum phase, sediment phase and at oil-water interface. The types and contents of soy proteins in the serum phase and sediment phase could be manipulated by pre-heating of soy proteins at 80°C for 30 min and the addition of PH-SSP. The presence of PH-SSP (0-6% w/v) induced different distribution of proteins to the sediment phase and subsequent in vitro protein digestion in the emulsion. Overall, this study proposed the means to design the distributions of proteins in different phases of o/w emulsion for different degrees of oil release, emulsion stability and protein-polysaccharide coacervation during the course of in vitro peptic and tryptic digestion.

We r epor t for the first time on wor mlike micelle for mation in aqueous mixtur es of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC). The viscosity of mixtures of these two phospholipids at total concentrations ≥56 mM showed a marked maximum around LPC molar fraction 0.5-0.7, which was ascribed to wormlike micelle formation. The diffusion coefficient of the lecithin, as measured using pulsed-field-gradient stimulated spin echo NMR, suggests that LPC and PC form spherical micelles and vesicle structures, respectively. In mixtures of LPC and PC, individual spherical micelles of LPC and a vesicle structure of PC were found at low temperature. Wormlike micelle formation was manifested in a steep decrease of the diffusion coefficient at temperatures above 55℃. The results indicate that a minimum concentration of both LPC and PC, as well as a molar ratio of LPC to PC close to 0.5-0.6, are prerequisite for thermally induced formation of lecithin wormlike micelles in aqueous solutions. Following formation on heating, the wormlike micelles remained stable on cooling, and no population of smaller spherical micelles could be detected.

We have elucidated the heat induced formation of wormlike micelles in the mixture solutions containing two different geometric amphiphiles of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC), where LPC and PC have one and two alkyl chains as hydrophobic groups, respectively. The mixture solutions showed the increases in viscosity and transparency by heating, and showed the highest viscosity at the ratio of LPC/PC = 1.67, suggesting the formation of long wormlike micelles attained by the average cpp around 0.5 favorable. From the dynamic rheological measurements, it was found that the elasticity was proportional to the square of total concentration of LPC and PC, indicating the existence of entanglement among long wormlike micelles. Other mixture solutions seem to be mixtures of spherical, lamellar and wormlike micelles with different sizes judging from the viscoelastic behavior and transparency, where the sizes changed reversibly with the temperature changes.