The evaluation of overall umami intensity in Takifugu obscurus and Ctenopharyngodon idella based on the Steven’s law

A quantitative equation of umami intensity based on sensory evaluation was established and verified in this study using Steven’s law. The method was applied to establish the relationship between the perceived umami intensity (UI) and the concentration of monosodium glutamate (C MSG ) using magnitude estimation by 30 panelists. After total rescaling, the proposed formula was verified by evaluating the umami intensity of Takifugu obscurus and Ctenopharyngodon idella combined with paired comparison test by 12 panelists. As a result, a logarithmic linear regression was performed. The UI values of both muscle and broth were significantly higher for Takifugu obscurus (muscle: 31.28 ± 0.20, broth: 37.83 ± 0.32) than Ctenopharyngodon idella (muscle: 26.66 ± 0.21, broth: 26.66 ± 0.21). A significant higher UI value was observed in T. obscurus broth compared to muscle. This method was proved to be a quantitatively evaluation way to measure the overall umami intensity of foods rather than the accurate contents of the umami substances using a reliable sensory quantitative equation.