Development of an Electronic Tongue Based on a Nanocomposite for Discriminating Flavor Enhancers and Commercial Salts

Diets with a high sodium chloride (NaCl) intake are indicated by doctors to be a factor responsible for causing cardiovascular disease. This has led to the search for NaCl substitutes used to prepare meals and process industrialized products, resulting in the food industry using new compounds. In this context, flavor enhancers appear to be able to maintain the sensory characteristics of food and reduce the amount of NaCl used. Substituting NaCl with other light commercial salts may also represent an alternative to reducing its consumption. Thus, it is of great importance to have a sensitive, portable, reliable, and cost-effective sensors for monitoring salt and flavor enhancers. For that reason, developing methodologies and devices able to chemically analyze salts and capable of establishing a relationship with human taste perception has become relevant for quality control and product development. In this context, this study proposes developing and applying an e-tongue system that can analyze aqueous solutions containing different concentrations of flavor enhancers (monosodium glutamate, disodium guanylate and disodium inosinate), light commercial salts and NaCl. The e-tongue comprised four gold interdigitated electrodes (IDEs) modified with layer-by-layer films of copper tetrasulfonated phthalocyanine (CuTsPc), polyaniline (PANI), reduced graphene oxide (rGO), poly(allylamine hydrochloride) (PAH) and silver nanoparticles (AgNPs) with different architectures. Data were statistically analyzed using principal component analysis (PCA). The e-tongue system proved to be efficient for identifying and discriminating flavor enhancers and commercial salts at different concentrations and is a possible alternative for quality control analysis and product development in the food industry.