Grass pea (Lathyrus sativus L.) starch as an alternative for cereal starches: Rheological properties and retrogradation susceptibility

The study compares selected rheological properties of starch isolated from two cultivars of grass pea with those of wheat and corn starch. The phase transition temperatures on pasting (TO, TP, TE) of both grass pea starches were lower in comparison to normal corn starch, but higher when compared to wheat starch. Pasting temperature of the starch slurries were significantly lower for grass pea as compared to cereals, and paste viscosity of grass pea starch was significantly higher than of wheat starch. Grass pea starches, exhibit much higher values of storage and loss moduli during heating of starch suspensions. Higher values of shear stress as a function of shear rate obtained during the determination of flow curves for grass pea starch pastes are confirmed by high consistency coefficients in the Herschel-Bulkley model. The mechanical spectra of starch gels allow us to state, that grass pea starch gels are characterised by higher values of storage and loss moduli in comparison to cereal starches.