Effects of saltiness enhancement and reduction of sodium intake by using brewed and brewed low-sodium soy sauces

The aim of this study was to compare the saltiness enhancement effect of brewed and low-sodium soy sauces by using sensory evaluation and an electronic tongue and evaluate the sodium reduction potential of low-sodium soy sauce under practical cooking conditions. A total of eight samples, including one Japanese brand (standard, S) and three domestic brands (A, B, and C), each comprising a general brewed soy sauce (GS) and a brewed low-sodium soy sauce (LS), were analyzed. Sensory evaluation and electronic tongue analysis confirmed a stronger saltiness enhancement effect in LS than in GS. The saltiness of the A-LS sample was approximately 31% higher than that of an NaCl solution of equal concentration. In bean-sprout soup application, LS required a higher addition level than GS, but it reduced the total sodium intake by 8%–15%. Overall, in this study, the saltiness enhancement effects of soy sauces were quantitatively evaluated, confirming the potential of low-sodium soy sauces for salt reduction in foods.