Effect of Grape Seed Procyanidins on Rheological Properties of Wheat Dough and Noodles Quality

To improve the application of wheat flour and the quality of noodles, in this study, 0.25%, 0.50%, 0.75%, 1.00% (w/w) grape seed proanthocyanins (GSP) were added to wheat flour. Rheology, moisture distribution and texture quality of the dough, as well as the cooking, digestive and sensory properties of the noodles were determined. The microstructure of the noodles added GSP was observed by scanning electron microscopy (SEM) to analyze the effect of GSP on the structure of wheat gluten proteins. As the results shown, with the addition of GSP rising (0~0.75%, w/w), the modulus of elasticity (G'), viscosity (G") (G'>G"), hardness, springiness and adhesiveness of the dough increased, The maximum tensile resistance and stretching distance increased by 7.22 g and 11.16 mm, respectively. It demonstrated that the rheology and texture quality were improved. The lateral relaxation time T₂ shifted to the lower and the free water content declined, which exhibited the water-holding capability was enhanced. The cooking resistance of the noodles was improved, and the hydrolysis rate and glycemic index (GI) were obviously decreased which reduced from 68.45 with no additional GSP to 61.73 (1.00% addition). At the addition of GSP of 0.75%, the highest disulfide bond content and the lowest free thiol group content occurred, moreover, the score of sensory quality was the highest. The noodles exhibited the soft, chewy, and smooth mouthfeel. In conclusion, GSP could enhance the edible quality of the product by improving the structure of the gluten protein network and lowering the glycemic index (GI) value of noodles, which illustrated GSP could be used as a potential natural flour improver.