Discrimination of Saffron Based on Thin-Layer Chromatography and Image Analysis

Abstract

This paper presents a new method based on thin-layer chromatographic separation, and image analysis (TLC-IA) of saffron colorant compounds for the discrimination of saffron from different origins. The color compounds of dried and ground saffron stigmas are extracted and separated by thin-layer chromatography at optimum conditions. After chromatographic development, the chromatograms are photographed, and intensity profiles of RGB characteristics are produced and processed by specially designed image analysis software. The main factors such as the extraction procedure of color compounds, chromatographic system (stationary and mobile phase), and designing of image analysis software are described. This method includes a new and fast data acquisition and does not require expensive instruments. The method also allows for comparison of different types of saffron using R-F values, color range, and intensity of the separated color components. This method is successfully applied to determine the saffron from different regions of Iran and various adulteration colorants.