Abstract: In order to explore the effects of the treatment with re-steaming and secondary retrogradation on the quality of Liuzhou Luosifen rice noodles, rice noodles were subjected to re-steaming and secondary retrogradation after initial retrogradation for 2 or 4 h and evaluated for cooking quality, texture characteristics, color, thermodynamic characteristics and microstructure. The results showed that the treatment with re-steaming and secondary retrogradation significantly changed the cooking quality of rice noodles, reducing the cooking loss rate by more than 21.6%, extending the rehydration time by more than 2 min, and increasing the rehydration rate by more than 10.0%. Texture analysis of rehydrated rice noodles showed that this treatment increased the hardness, elasticity and chewiness. The treatment slightly decreased the brightness value L* and increased the yellow/blue value b*. Furthermore, it increased the starting, peak and end temperature of rice noodles, and elevated the enthalpy value by more than 12.2%. Microstructure analysis indicated that the treatment promoted the short-range ordered rearrangement of starch chains, densifying the internal structure of rice noodles. In summary, the treatment with re-steaming and secondary retrogradation significantly impacted the quality and microstructure of Liuzhou Luosifen rice noodles. This study provides theoretical support for the quality improvement of Liuzhou Luosifen rice noodles.

Key words: rice noodles; Liuzhou Luosifen; retrogradation; re-steaming; quality