Comprehensive analysis of the effects of fresh Spirulina microcapsules on protein cross-linking and structural changes in wheat noodles

Fresh spirulina microcapsules (SP-MICs) are a viable strategy to prolong the preservation of fresh spirulina . This study aims to investigate the effects of SP-MICs on noodle quality, focusing on physicochemical properties and wheat gluten structures. Compared to the control group, the addition of 3 % SP-MICs significantly improved the sensory and textural properties of the noodles. Chewiness and hardness increased by 14.40 % and 32.36 %, respectively. In terms of glutenin subunits, HMS and B/C-LMS contents increased by 6.10 % and 5.39 %, respectively. Additionally, the gliadin-to-glutenin ratio reached its lowest at 1.19. Surface hydrophobicity decreased by 6.41 %, disulfide bond content increased by 31.60 %, and non-covalent interactions (hydrogen bond and hydrophobic interactions) were enhanced. The secondary structure of gluten protein became more ordered, with a 6.86 % increase in β-sheet content and a 1.10 % decrease in random coil content. SEM and CLSM results showed that 3 % SP-MICs significantly reinforced the gluten network and protein-starch cross-linking.