Effect of flaxseed gum on the rheological properties of peanut protein isolate dispersions and gels

• The addition of flaxseed gum increases the apparent viscosity of mixed dispersions.
• The presence of flaxseed gum enhances the shear sensitivity of mixed dispersions.
• The addition of flaxseed gum changes gelling time and gel strength of mixed gels.

The effect of addition of flaxseed gum (FG) on the rheological and thermal gelation properties of peanut protein isolate (PPI) was studied. Small quantity (1–5 g/kg) of FG was added to PPI solution (140 g/kg) and the resultant rheological properties were studied using steady shear and small amplitude oscillatory measurements. The apparent viscosity of all samples increased with the increase from 1 to 5 g/kg in the concentration of FG and was fitted well by the Herschel-Bulkley model (R2 > 0.99). The addition of FG reduced the gelling time almost from 1000 to 500 s and increased the strength of FG-PPI mixed gels from 2000 to more than 3000 Pa. These FG-PPI gels showed the behavior of physical gels since their storage modulus (G′) was much higher than the loss modulus (G″) and G′ was only slightly frequency dependent.