Functional and pasting properties of pea starch and peanut protein isolate blends.

The functional and pasting properties of pea starch (PS) and peanut protein isolate (PPI) blends mixed at different proportions were studied. With the increasing ratio of PPI in PS/PPI blends, the solubility of the blends determined at 90°C was increased from 16.38 to 31.28% whereas both of the water absorption capacity and the swelling power decreased. The pasting temperature of the blends increased from 72.5 to 77.5°C while the peak viscosity decreased from 276.33 to 39.92 RVU upon the increasing level of PPI. The hardness of the PS/PPI blends gel decreased from 9.67 N to 0.96 N when the PPI content was increased from 0 to 50% in the blend. Scanning electron microscopy exhibited a honeycomb feature at the ratio of 90:10 and 80:20. The large fragmentary structure of the blending gels was formed at the ratio of 70:30 and became more loosed with the increased ratio of PPI in the blends.