Continuous saltiness enhancement in NaCl solutions and its potential impact on food products via anodal transcutaneous electrical stimulation

Abstract

Electric taste technology, which permits the adjustment of food flavors, has recently garnered attention as a method to reduce excessive salt intake. Electrical tongue stimulation, which modifies taste through electric cutlery, is user-friendly but only effective when the cutlery is in contact with the tongue via food. As transcutaneous electrical stimulation (TES) is expected to overcome the challenges of electrical tongue stimulation, this study investigated its usefulness. A time-intensity analysis was conducted to evaluate taste modification, specifically whether anodal TES (aTES)—where the anode was attached to the anterior part of the jaw and the cathode to the back of the neck—can enhance continuous saltiness during electric stimulation. Moreover, whether aTES could improve the perception of saltiness in NaCl solutions and five different foods for individuals on a low-sodium diet was investigated, utilizing a 9-point scale and paired comparison tests. The results indicated that aTES consistently enhanced the saltiness of the NaCl solution both during tasting and after swallowing. Notably, aTES at 3.0 mA significantly increased the saltiness perception of a 0.5% NaCl solution in individuals on a low-sodium diet. aTES significantly enhanced the taste of somen noodles with dipping sauce, miso soup, simmered hijiki seaweed, potato chips, and Chinese rice bowls. These results suggest that aTES may further reduce the burden of salt reduction in individuals on a low-sodium diet and contribute to a reduction in excessive salt intake.