Effect of Konjac Glucomannan Addition on Quality of Black Buckwheat Noodles

In order to improve the quality of black buckwheat noodles, this paper systematically investigated the effects of konjac glucomannan (KGM) addition on the solvent retention capacity (SRC) and mixing characteristics of black buckwheat mixed powder, as well as the texture, cooking, digestive properties of the noodles were determined. Results showed that the SRC of black buckwheat mixed powder increased with the KGM addition. The water absorption rate, development time, and stability time of the dough also increased, while the weakening degree C1-C2 values and starch retrogradation characteristics C5-C4 values showed a decreasing trend, decreasing by 0.18 N·m and 1.14 N·m respectively at 3%. The cooking time, cooking broken rate, and cooking loss rate of black buckwheat noodles decreased with the addition of KGM, while the tensile strength and shear force showed an overall increasing trend, reaching their maximum at 2.5% addition, at 31.11 g and 426.07 g respectively. Furthermore, there was no significant difference in the sulfhydryl content of black buckwheat noodles after KGM addition, while the disulfide bond content significantly increased (P<0.05). In the study of digestion properties, there was no significant difference in starch hydrolysis rate, resistant starch content, and eGI value of black buckwheat noodles after KGM addition, which were similar to those prepared by conventional methods. The quality of buckwheat dough was best at 3% of KGM, because the SRC and mixing characteristics of the flour blend were best at this level of addition, while the quality of noodles was most improved at 2.5% of KGM, and the cooking and textural characteristics of the noodles were best at this level of addition.