Impact of protein network restructured with soy protein and transglutaminase on the structural and functional characteristics of whole-grain highland barley noodle

Creating nutritional noodle with high quality has become a new research hotspot in the field of food science. In this study, heat-moisture treated whole-grain highland barley was selected to prepare noodle, and the synergistic effects of transglutaminase (TG) and soy protein (SP) on the quality and nutritional characteristics of highland barley noodle were investigated. The results showed that as the extrinsic protein, SP had a weak interaction with original protein network, nevertheless TG could promote protein cross-linking through ε-(γ-Glu)Lys bonds. When both TG and SP were added into noodle, the synergistic effects improved the formation of dense and strong protein network, which wrapped the starch granules tightly, thus enhancing the water-holding capacity and thermal stability and endowing the noodle with optimal rheological properties and texture properties. Moreover, due to the inhibition of restructured protein network, the predicted glycemic index (pGI) of noodle decreased and the antioxidant properties increased, meanwhile the noodle with the SP addition of 10% and the TG addition of 1.5–2.5% could be identified as the low GI noodle. Overall, this study has guiding significance for the creation and improvement of highland barley noodle.