Interaction between potato starch and barley β-glucan and its influence on starch pasting and gelling properties

The interactions between potato starch (PtS) and barley beta-glucan (BBG) were investigated by preparing PtS-BBG mixtures, and the pasting, rheological, gelling and structural properties were evaluated. Rapid viscosity analysis suggested that BBG reduced the peak and breakdown viscosity, while increasing the setback viscosity of PtS. PtS-12%BBG showed the lowest leached amylose content (12.02 +/- 0.36 %). The particle size distribution pattern of PtS was not changed with the addition of BBG, and the median diameter of PtS-12%BBG (88.21 +/- 0.41 mu m) was smaller than that of PtS (108.10 +/- 6.26 mu m). Rheological results showed that PtS and PtS-BBG gels exhibited weak gel behaviors, and BBG could remarkably affect the elastic and viscous modulus of PtS gels. Textural analysis suggested that the strength and hardness of PtS gels were increased when few BBG (<6 %, w/w) was present in the system. BBG improved the freeze-thaw stability of PtS gels. Structural analysis indicated that hydrogen bonds were the main force in the PtS-BBG systems. These results indicated that BBG interacted with starch via hydrogen bonds, which delayed starch gelatinization and improved gelling properties of PtS gels. Overall, this study gained insights into starch-polysaccharide interactions and revealed the possible applications of BBG in food processing.