Efficient Taste Analysis via Single-Channel Hybrid Electronic Tongue
Authors: Yadav Sarika , Pala Raj Ganesh 
Published: August 2024

The prospective applications of electronic tongues (e-tongues) in the food, water, beverage, and pharmaceutical industries have long been hampered by the inconvenient nature of series measurements using expensive and specialised sensor arrays. A cost-efficeint and easier solution to this problem arises in the shape of a single-channel hybrid e-tongue, presenting a novel approach to overcoming restrictions. This progress uses data fusion from potentiometry and impedimetry to combine these measures into a single channel made up of unfunctionalized metal electrodes supported by a pH electrode.

The hybrid e-tongue combines potentiometric response, which includes pH and open circuit potential, with impedimetric response, which takes into account comparable electric circuit parameters such as charge transfer resistance and double-layer capacitance. The taste discriminability of this low-cost single-channel hybrid e-tongue is validated using two metal electrodes, Pt and Ni, and two separate sample preparations of basic taste analytes, each at concentrations around the human tongue threshold.

Principal component analysis (PCA) plots are used to test qualitative discrimination by reducing dimensionality and clustering analytes. Silhouette coefficients (SC) and hierarchical cluster analysis are used to assess clustering quality. Even without particular sample preparation, the Pt and Ni electrodes exhibit substantial clustering with SC values of 0.83 and 0.74, respectively. This significant outcome highlights the efficacy of the hybrid e-tongue in improving taste discriminability.

Comparisons with potentiometric and impedimetric measurements performed independently show that the hybrid e-tongue, assisted by data fusion at a single channel, improves accuracy and clustering significantly. This finding not only speeds up the analysis process, but it also improves the overall effectiveness of taste discrimination.

Correlations between taste analytes and physicochemical factors are formed using heatmap plots and PCA loading plots to provide a fuller knowledge of the hybrid e-tongue's mechanics. These visualisations provide vital insights into the complex interplay of several physicochemical processes, offering insight into the mechanism underlying the hybrid e-tongue's excellent performance.discrimination.

Despite its remarkable capabilities, the study acknowledges that taste discriminability diminishes due to the buffer activity of the standard reference solution used for sample preparation. This recognition prompts further exploration and optimization of the solution to ensure the broad applicability of the hybrid e-tongue across various scenarios.

In conclusion, the reported single-channel hybrid e-tongue represents a significant advancement in taste analysis technology. By addressing the challenges associated with series measurements on complex sensor arrays, this innovation opens new avenues for commercial e-tongues in diverse industries. The amalgamation of potentiometry and impedimetry in a single channel not only enhances accuracy and clustering but also provides valuable mechanistic insights. As the research community continues to refine and optimize this technology, the future holds great promise for the widespread adoption of single-channel hybrid e-tongues in analytical applications, advancing how we perceive and understand taste.