Effects of yellow mustard mucilage on functional and rheological properties of buckwheat and pea starches

The effects of yellow mustard mucilage (YMM) on the functional and rheological properties of buckwheat and pea starch were studied. Addition of YMM resulted in a marked increase of peak viscosity for both buckwheat and pea starches. Dynamic oscillation measurements showed that the storage modulus (G′), loss modulus (G″) and dynamic viscosity (η*) of buckwheat and pea starches were increased but tangent δ was decreased by addition of YMM. The gel textures of both starches were markedly changed by the presence of YMM, which resulted in an increase of hardness, adhesiveness and chewiness but a decrease of resilience. Differential scanning calorimetry showed that the presence of YMM slightly increased melting enthalpy (ΔH) and the phase transition temperature range (Tc–To) of buckwheat starch but these did not change much for pea starch. Addition of YMM–locust bean gum mixture (9:1) similarly increased the viscosity of buckwheat and pea starches but decreased gel hardness. The swelling powers of both starches and solubility of buckwheat starch were slightly decreased in the presence of YMM. Addition of YMM slowed the syneresis of buckwheat and pea starch gels.