Optimization and validation of the protocol used to analyze the taste of traditional Chinese medicines using an electronic tongue

Abstract

Tools to define the active ingredients and flavors of Traditional Chinese Medicines (TCMs) are limited by long analysis times, complex sample preparation and a lack of multiplexed analysis. The aim of the present study was to optimize and validate an electronic tongue (E-tongue) methodology to analyze the bitterness of TCMs. To test the protocol, 35 different TCM concoctions were measured using an E-tongue, and seven replicate measurements of each sample were taken to evaluate reproducibility and precision. E-tongue sensor information was identified and classified using analysis approaches including least squares support vector machine (LS-SVM), support vector machine (SVM), discriminant analysis (DA) and partial least squares (PLS). A benefit of this analytical protocol was that the analysis of a single sample took <15 min for all seven sensors. The results identified that the LS-SVM approach provided the best bitterness classification accuracy (binary classification accuracy, 100%; ternary classification accuracy, 89.66%). The E-tongue protocol developed showed good reproducibility and high precision within a 6 h measurement cycle. To the best of our knowledge, this is the first study of an E-tongue being applied to assay the bitterness of TCMs. This approach could be applied in the classification of the taste of TCMs, and serve important roles in other fields, including foods and beverages.

Recent Advances in Bitterness-Sensing Systems

“…Many studies on the application of the Astree II E-tongue for bitter taste detection have been reported [ 62 , 63 , 64 ]. For instance, Li and coworkers used the Astree II E-tongue to measure the bitterness intensity of 35 different traditional Chinese medicines [ 65 ]. The bitterness measurement of the Astree II E-tongue was optimized with standard bitter substances.…”

Hot Melt Extrudates Formulated Using Design Space: One Simple Process for Both Palatability and Dissolution Rate Improvement

“…Based on the repeatability of measurement (relative standard deviation ¼ 0.47 to 1.51), the method was considered fitted for the study. 19 Distances between extrudates and placebo and between extrudates and unprocessed drug were calculated as indicative of formulation tastemasking power.…”

Electronic eye and electronic tongue data fusion combined with a GETNet model for the traceability and detection of Astragalus

“…In recent years, ET technology has been widely used in the field of traditional Chinese medicine, including classification of Pericarpium Citri Reticulatae of different ages, 5 determination of the bitterness of Andrographis Herba, 6 and analysis of the taste of traditional Chinese medicines. 7 The EE concept originated in the 1980s. It is a technology that adopts a high-definition camera and pattern recognition techniques to identify the overall shape, texture, color and other appearance features of the input sample.…”