Molecular structure of varietal rice starch modulates the supramolecular structure of rice noodle gels: implications...

Rapid rehydration and desirable textural properties are key quality attributes of rice noodles, largely governed by starch molecular structure. However, how starch molecular structure regulates the supramolecular structure of rice noodle gels and, in turn, determines their quality attributes remains insufficiently understood. To address this issue, five representative rice varieties were selected from 17 Early indica samples through principal component analysis and processed into rice noodles for structural and quality evaluation. It was revealed that larger amylopectin molecules reduced single-helix formation, thereby shortening rehydration time and decreasing cooking loss for the first time. A higher proportion of long-chain amylose enhanced rehydration by reducing fractal dimensions, V-type crystal content, and amorphous regions while increasing double-helical structures. Additionally, greater amylose content improved rehydration, hardness, and resilience by forming a thicker gel network and inhibiting amylopectin retrogradation. Collectively, this study elucidates a mechanistic framework linking starch molecular structure, the supramolecular stucture of rice noodle gels, and macroscopic quality attributes, bridging the gap between starch molecular structure and product performance. These findings offer a scientific foundation and practical reference for breeders and rice noodle manufacturers in selecting and developing rice varieties optimized for rice noodle processing.