Insight into the mechanism of enhancing myofibrillar protein gel hardness by ultrasonic treatment combined with insoluble dietary fiber from oat

The present study investigated the effects of ultrasonic treatment combined with insoluble dietary fiber (IDF) from oat on gelation and structural characteristics of myofibrillar protein (MP). Ultrasonic treatment combined with IDF promoted the deployment of the MP chain and significantly increased (P < 0.05) the solubility of MP. The samples treated with 120 W of ultrasonic power combined with IDF (U120 + IDF) formed a more continuous and dense gel microstructure, resulting the water-holding capacity (WHC) reached maximun values of 0.88 g/g. Moreover, compared with the U80 and U120 groups, MP treated by 80 W of ultrasonic power combined with IDF (U80 + IDF) and U120 + IDF groups had a higher β-sheet content of 46% and 40%, respectively. The gel hardness and chewiness of the U120 + IDF group reached maximum values of 2.14 N and 7.09 mJ, respectively. Ultrasonic treatment combined with IDF enhanced the texture and WHC of MP gel by expanding the secondary structure and increasing protein solubility. In conclusion, the U120 + IDF group had the highest value of gel hardness, chewiness, and a three-dimensional network structure.