Quality enhancement of sweet potato puree oat mixed-grain noodles based on curdlan: recommended addition level and mechanism

Abstract The inherent poor cooking quality and poor texture of mixed-grain pasta limit consumer acceptance. This study systematically investigated the effect of curdlan in the processing of sweet potato puree oat mixed-grain noodles, and comprehensively analysed a number of key indicators such as cooking characteristics, moisture state, texture properties, microstructure, starch crystallinity characteristics, short-range ordered structure and thermal properties. At the production practice level, the study clearly indicated that the 0.6% curdlan addition ratio was the best solution in sweet potato puree oat mixed-grain noodles processing. This finding not only significantly reduces the fracture rate, water absorption rate and cooking loss rate during the cooking process, but also significantly improves the quality and yield of the product, and brings significant improvement in the taste and texture of the noodles, which is of great significance for industrial production. In the microstructural and molecular studies, we revealed how curdlan could enhance the structural stability and mechanical strength of noodles by promoting the uniform distribution of starch granules in the gluten protein network. Further, through X-ray diffraction, ordered structure and thermal property analyses, we have found that colchicine can effectively regulate the interactions of hydrogen bonding between starch and the content of straight-chain and branched-chain starch, which significantly reduces the crystallinity, ordered short-chain structure and enthalpy of pasting of starch in the pasta. These in-depth research results not only help us to understand more comprehensively the formation mechanism of the modification of pasta quality by curdlan, but also provide a solid theoretical foundation and practical guidance for the improvement of pasta quality in mixed grains.