Abstract
The thermal and rheological properties of lupin flour were investigated by DSC and rheometry. DSC study showed that whole and defatted lupin meal had identical thermal properties, and lupin had the same glass transition as the wheat protein gluten. By measuring the linear rheological properties of a series of concentrations of defatted lupin suspensions, we found that defatted lupin suspensions exhibited strong viscoelastic solid properties, which were to some extent similar to those of gluten. Both storage (G′) and loss (G″) moduli increased dramatically over a narrow range of lupin concentrations. The linear range of the rheological properties of lupin was very small. The stress relaxation studies showed that the lupin suspensions did not relax a decade within a thousand seconds, indicating that the molecules of lupin have strong physical interactions. This research offered new insight into physical properties of lupin and will be useful for further studies on applications for lupin.