Identification of a Salt Blend: Application of the Electronic Tongue, Consumer Evaluation, and Mixture Design Methodology

Replacement of NaCl with other salts is becoming increasingly common as part of a salt reduction strategy, but these salts may confer unwanted sensory changes. Therefore, the objective of this study was to determine the relationship between consumer perception and electronic tongue detection of different salts and their mixtures currently used in salt reduction. NaCl and replacement salts (KCl and CaCl₂ ) were identified, and using mixture design methodology, mixtures (n = 10) were prepared in aqueous solutions and validated in tomato soup. A potentiometric electronic tongue, panelists with orientation (n = 30), and a consumer panel (n = 94 - solutions; n = 100 - soups) were used to evaluate the samples. Significant differences were found between salt mixtures in solutions and soups by both panelists and consumers (P < 0.05). Electronic tongue analysis showed a high discrimination index (D.I. = 96%) indicating distinct differences among the salt mixtures, and strong positive correlations (R² > 0.90) were found between sensory and electronic tongue data. Upon application of contour plots and desirability function analysis, an optimal replacement value was identified as one containing 96.4% NaCl, 1.6% KCl, and 2.0% CaCl₂ . Additional salt blends could be created to continue to reduce NaCl and increase the other two salts, for further potential health benefits, without significantly impacting predicted acceptance scores. Results from this study indicate the potential for the electronic tongue, sensory evaluation, and mixture design methodology to work together during product reformulations to achieve salt reduction targets. PRACTICAL APPLICATION: The results show that salt mixtures vary in perception and acceptance in different matrices, and thus should be evaluated on a product by product basis. With its ability to discriminate among various salts, the application of the electronic tongue could be useful for industry in the development of products with different salt formulations to reduce NaCl within processed foods. Additionally, mixture design can help find a predicted optimum mixture for the product under investigation.