Meehye Kim
Ministry of Food and Drug Safety
South Korea
Title: Quantitative determination of carmine in foods by high performance liquid chromatography
Biography
Biography: Meehye Kim
Abstract
Carmine is a lake pigment used in many different products such as juice, candies, and confectioneries. Carminic acid also is a major component of cochineal extract, which is used as a natural food colour in Korea. However, there is no analytical method to distinguish them so far. In this study, we have developed a simple and quantitative method for the analysis of carmine in food products by high-performance liquid chromatography coupled to a diode array detector. Samples were homogenized and extracted with 0.05 M NaOH, followed by centrifugation. The resulting solution was filtered and injected to HPLC. Carmine was separated by HPLC using an NovaPak C18 column coupled to a photodiode array detector. The contents of carmine were finally quantified using corresponding calibration curves over ranges of 1.0 to 100 μgml-1, with good correlation coefficients (r2 =0.9999). The recoveries of carmine from foods spiked at levels of 10, 50, and 100 μgg-1 which ranged from 90.4 to 96.2% with relative standard deviations between 2.8 and 6.8%. Limit of detection and limit of quantification of carmine were 0.4 and 1.0 μgml-1, respectively. To the best of our knowledge, no chromatographic method which can separate carmine from carminic acid in foods, has been reported in the literature for the determination of this dye by high-performance liquid chromatography. This method was found to be useful to distinguish carmine from carminic acid, a major component of cochineal extract. The method has been successfully applied to various foods.