Mechanism of the synergistic enhancement of digestive resistance in steamed cold noodles by V-type starch-tea polyphenols interactions

In this study, V-type wheat starch-tea polyphenols complexes (VS-TP) were used to improve the digestive properties and quality characteristics of steamed cold noodles. With TP content increasing from 2.5 % to 10.0 %, the storage modulus of VS-TP complexes decreased from 580.59 to 1341.85 Pa to 379.90-859.61 Pa, likely due to TP disrupting starch chain entanglement via noncovalent interaction (hydrogen bonds and CH-π bonds). TP also enhanced both short-range and long-range ordered structures of V-type starch, and the complexation index rose from 23.76 % to 84.61 % as TP content increased. Notably, the VS-10 %TP group showed a 47.28 % higher resistant starch content than the control group, which may be attributed to TP-V-type starch interactions and TP's amylase inhibition. However, the lightness, hardness, and gumminess of the steamed cold noodles decreased by 7.84 %, 51.46 %, and 49.84 % when adding 10 %TP. Balancing functionality and quality, 5 %TP was optimal for preparing low-digestibility steamed cold noodles with excellent textures.