Effect of konjac glucomannan on physical and sensory properties of noodles made from low-protein wheat flour

In this study, the effects of konjac glucomannan (KGM) on Chinese noodles made from low-protein wheat flour were studied. Noodles were prepared from wheat flour/KGM blends by replacing low-protein flour at 1%, 2%, 3%, 4% and 5% with konjac glucomannan (KGM). The cooking and textural properties, microstructure and sensory characteristics were evaluated. KGM addition contributed to higher cooking yield and lower cooking loss for the resultant noodles. The sensory quality of KGM noodles was better than that of the control, although the control scored highest in stickiness. Sharp changes were observed around 5% substitution level in TPA parameters. Scanning electron microscopy (SEM) confirmed changes in noodle microstructure as KGM addition affect cooked starch granule structure and gluten network development. In general, noodles with 3% KGM were relatively desirable in textural properties and scored best in sensory evaluation, indicating the potential for improving textural defect of noodles prepared from low-protein wheat flour by using KGM.

► Konjac glucomannan contributes to better cooking quality for the resultant noodles. ► KGM reinforces gluten network and makes it compact, though KGM dilutes gluten. ► TPA parameters indicate sharp changes around 5% KGM. ► The mechanism relies on the distinct amounts of KGM incorporated into the system.