Effect of konjac and gellan gum coatings on broth flavor adsorption, textural and sensory properties of rice noodles

The aim of this work was to investigate the impact of konjac gum and gellan gum as coating agents to enhance flavor adsorption by cooked fresh rice noodles. Uncoated noodles, Konjac gum coated noodles (KGN) and gellan gum coated noodles (GGN) were cooked and immersed in broth for 30-120 s and compared in terms of conductivity of soluble ions in artificial saliva during multiple extrusion cell (MEC) analysis, as well as color, texture and sensory attributes. Results showed that conductivities of KGN, GGN and uncoated noodles increased by 146%, 124% and 182% respectively after 30s of soaking in broth. No significant (p > 0.05) relationship between immersion time and conductivity was observed. Textural analysis showed significant (p < 0.05) differences between uncoated noodles and KGN in terms of hardness. KGN were the softest, followed by GGN and uncoated noodles. Coating of noodles significantly (p < 0.05) reduced noodles adhesiveness and tensile strength. Color analysis showed KGN as being significantly (p < 0.05) lighter, but no significant difference (p > 0.05) in redness and yellowness between samples. There was significant relationship (p < 0.05) between the immersion duration of noodles with the color changes. As the immersion duration of noodles in broth increased, the lightness (L-values) decreased, while redness and yellowness values increased. Sensory analysis showed that KGN had the highest intensity of overall flavor and saltiness (p < 0.05), were softer and preferable (p < 0.05) to the other two samples.