Effects of dough mixing time before adding konjac glucomannan on the quality of noodles.

In this study, effects of 5% konjac glucomannan (KGM) blended with low-protein flour at different dough mixing duration on the properties of dough and noodles were investigated. To prepare the KGM noodle samples, 5% KGM was added after low-protein flour mixed with water for 0, 2 and 4 min, respectively. The three samples above were defined as T0 KGM, T2 KGM and T4 KGM noodle samples, respectively. The results revealed that the elastic modulus (G') and viscous modulus (G″) of dough both increased with extending dough mixing time before adding KGM. T4 KGM samples showed the least cooking loss. Textural properties including hardness, cohesiveness and tensile strength of KGM noodles had a tendency to increase with a longer dough mixing time before adding KGM. Microstructure of dough and noodles confirmed that a longer dough mixing time before adding KGM made microstructure more compact with a thickened gluten matrix. The sensory quality of the T2 KGM and T4 KGM samples was better than that of the T0 KGM samples.