Comparative study on textural and rheological properties between dry white salted noodle and yellow alkaline noodle as influenced by different tea extracts

Green tea extract, black tea extract, and oolong tea extract (0.0%–2.0% of flour weight) were added into white salted noodle (WSN) and yellow alkaline noodle (YAN) to compare their effects on textural and rheological characteristics in two different noodle systems. The incorporation of tea extract (TE) yielded dry WSN and YAN yellowish-brown color and reddish-brown color, respectively. At 2.0% TE addition level, hardness, cohesiveness, chewiness, resilience, and tensile strength were reduced by 1.15–1.28 N, 0.00–0.03, 0.77–1.11N, 0.00–0.03, and 0.04–0.06 N, respectively, in cooked WSNs, but they were increased by 2.44–3.26 N, 0.05–0.09, 2.15–3.54 N, 0.07–0.12, and 0.05–0.08 N, respectively, in cooked YANs. Maxwell models showed better performance in detecting stress relaxation property changes in TE-incorporated noodles. The stress relaxation results confirmed that TE induced opposite effects on the viscoelasticity of cooked WSN and YAN. Practical applications Tea extract (TE) can significantly enhance the antioxidant capacity and starch digestion inhibitory ability of noodles, but noodle texture is critical to consumer's acceptance of the product. The effects of TE on noodle textural and rheological properties were compared in dry white salted noodle (WSN) and dry yellow alkaline noodle (YAN). Noodle color was greatly affected by the type of TE and its addition level. TE-incorporated dry WSNs exhibited softer and less elastic texture, while TE-incorporated dry YANs had harder and more elastic texture. Results of this study suggested that TE at 0.5%–1.0% in WSN would have less influence on noodle texture, and at 1.0%–2.0% in YAN would improve noodle texture properties. These results will provide useful information on the application of TE in noodles as well as potential problems that may occur during noodle manufacturing.