Interaction Study between Umami and Salty Based on Electronic Tongue Technology and σ-τ Model

Salt and salty foods play a crucial role in enhancing flavor and are integral to traditional cuisine. Salt control and intake reduction are particularly important in a sodium reduction policy. To investigate the relationship between umami ingredients and salty taste in food, as well as the impact of different amounts, and to establish a theoretical foundation for developing salty foods with reduced sodium content while maintaining their salty flavor, the effects of umami ingredients (such as monosodium glutamate (MSG), glutamate (Glu), glycine (Gly), aspartate (Asp), alanine (Ala), inosine disodium (IMP), guanylate disodium (GMP), lysine (Lys), and arginine (Arg)) at different concentrations of saltiness were studied using electronic tongue intelligent sensory technology. An analysis was conducted using the σ-τ model to examine the interaction and dose effect of five flavoring ingredients MSG, calcium glutamate (GAC), I+G, lysine (Lys), and arginine (Arg)) with sodium chloride. The results showed a positive correlation between the response value of a sodium chloride solution and its concentration as measured by the electron tongue. Furthermore, the increasing trend became less steep as the concentration increases. The amino acid components Lys and Arg showed the most positive effects for increased saltiness, followed by Gly and Ala. Conversely, Glu and Asp did not elicit any discernible effects. Among the nucleotide ingredients, IMP and GMP could significantly increase saltiness. The analysis using the σ-τ model demonstrated that umami ingredients, when present in low concentrations, could significantly enhance the perception of saltiness in salt, indicating a synergistic impact. However, once a specific threshold was reached, the saltiness cannot be further increased, and the addition of umami ingredients only had a minimum effect.