Effect of Kudzu Flour on the Quality of Fresh Wet Rice Noodle

Kudzu flour was recognized as a rich source of isoflavonoids, amino acids, and trace elements, which could be integrated into food products to enhance their nutritional value and provide a unique flavor. In this study, kudzu flour was incorporated into fresh wet rice noodles at different levels (0~20%, w/w) to investigate its effect on fresh wet rice noodle quality. The results indicated that the pasting transition temperatures (including onset, peak, and end temperatures) and the amylose content of the kudzu-enriched fresh wet rice noodles progressively increased with the addition of kudzu flour. However, quality attributes such as hardness, enthalpy (ΔH), setback, and breakdown showed a gradual decrease. Notably, compared to the fresh wet rice noodles without kudzu flour, those samples with the 10% addition demonstrated a reduction in cooking loss rate and strip breakage rate, decreasing from 24.12% to 12.21% and 5.16% to 1.90%, respectively, which enhanced the overall edible quality. The relative crystallinity (RC) reached its lowest value of 7.85% at the 10% addition level, indicating the highest resistance to retrogradation. Additionally, the infrared peak intensity ratio of 1047/1022 peaked at 0.823, while the ratio of 1022/995 reached a minimum value of 1.037, suggesting that the short-range order at the 10% addition level was superior to that of the other samples. Following the incorporation of 10% kudzu flour, significant changes were observed in the relative content of three starch types within the rice noodles. Rapidly digestible starch (RDS) decreased by 30.2%, while slowly digestible starch (SDS) and resistant starch (RS) increased by 20.5% and 81.9%, respectively. Furthermore, the microstructure and protein-starch cross-linking of the noodles with 10% kudzu flour addition were superior to those in the other samples. In sensory evaluations, the fresh wet rice noodles with 10% kudzu flour addition also received the highest ratings. In conclusion, the optimal overall quality of kudzu-enriched fresh wet rice noodles was achieved with a 10% incorporation level.