Objective Avoltammetric electronic tongue was applied to establish Bizhunziwei for evaluating the quality consistency between classical formulas Qingxin Lianzi Yin (QLY, 清心莲子饮) intermediate and explore its application in the pretreatment process optimization of QLY. Methods By comprehensively analyzing the precision of Euclidean distance (Ed), mean Euclidean distance (M-Ed), and standardized Euclidean distance (S-Ed) between the taste PCA score plots of intermediates and substance benchmark in combination with the discrimination index (DI), to construct the standard taste profile. The effects of the sample’s pH value, the salt ions and redox-active substances on Bizhunziwei were studied and the precision, repeatability and stability of Bizhunziwei were investigated. The application of Bizhunziwei in the pretreatment processes of QLY such as extraction and drying of classic famous prescriptions was explored and the correlation between Bizhunziwei and the similarity of fingerprint profiles was analyzed. Results The Bizhunziwei could be defined as “S-Ed*DI” which was the product of standardized Euclidean distance and the discrimination index of the taste PCA score plots. The RSD values for the precision, repeatability and stability of Bizhunziwei were 2.355%, 5.630%, 3.573%, respectively. The sample’s pH value, the salt ions and redox-active substances had a significant impact on Bizhunziwei (P < 0.05). The Bizhunziwei could distinguish the extraction and drying process parameters of QLY. The Bizhunziwei had a good correlation with the similarity of the fingerprint profile of QLY. Conclusion The Bizhunziwei provides a new approach for evaluating the quality consistency between intermediates and substance benchmark of QLY, and offers a new perspective for the development of classic famous prescriptions.

Bizhunziwei  /  quality consistency  /  classic famous prescriptions  /  Qingxin Lianzi Yin  /  electronic tongue  /  principal component analysis  /  Euclidean distance  /  discrimination index  /  fingerprint