Tastes of Herbal Medicine Affecting on Principal Tastes (Ya Rot Prathan) Classification: A Discriminant Analysis

Abstract

The objectives of this study are to find out the tastes of herbal medicine that are important in discriminating
principal tastes of herbal formulas, or Ya Rot Prathan, by using Discriminant Analysis. Nineteen herbal formulas were selected from the National List of Essential Medicine B.E. 2561 and divided into 3 groups depending on Ya Rot Prathan: (1) Cold (6 formulas), (2) Sukhum (5 formulas), (3) Hot (8 formulas). The tastes of each herbal medicine were scored for calculation of a ratio of each taste in the formula. The result showed that most of the formulas in the Cold group had a ratio of bitter or bland tastes higher than the others. While the Sukhum group had a bitter, spicy and fragrant taste with a ratio of approximately 20-30% in the formula and a slightly sweet taste. The hot group had ratio of spicy of more than 40% in the formula. The important discriminant factors were sweet, spicy and fragrant tastes. Each score of these tastes were replaced in Fisher’s linear discriminant equations. These established equations can discriminate principal tastes from the selected herbal formulas, and the accuracy is as high as 94.7%. The obtained results not only provide a new method to discriminate principal tastes, but also help to further understand Thai traditional medicine formulations and clearly see a relationship between herbal tastes and a formula’s properties.