Investigating the effect of growth age of the mint plant on the odor released from the leaves with the help of electronic nose and chemometrics methods

Medicinal plants are widely used in many fields around the world. Medicinal plants are an integral part of daily life and the increase in demand for these plants leads to fraud and reduced quality in the final product. Therefore, authentication is vitally important for consumers. Mint is valuable because of its medicinal properties and its essential oil, which is used in the food, pharmaceutical, cosmetic and health industries. In this research, the use of electronic nose to detect the age of mint plant by the odor emitted from its leaves was investigated. The main branches of mint plant with different ages of one to five years were taken from the distance of 4 to 5 cm from the ground. An electronic nose equipped with 8 metal oxide sensors was used to carry out experiments. To analyze the data, PCA, LDA and QDA analyzes were used. PCA results showed that 95% of the total variance of the data was explained by PC1 and 4% by PC2, and the two principal components expressed accounted for 99% of the variance of the normalized data. Also, the QDA method was 100% accurate in determining the age of the mint plant. The electronic nose has shown that it is a fast and effective tool to detect the quality parameters of plants and agricultural products.