Comparative analysis of Illumina and Ion Torrent high-throughput sequencing platforms for identification of plant components in herbal teas

The rapid development of high-throughput sequencing (HTS) methods offers new opportunities for food quality control and identification of food components using the DNA barcoding approach (metabarcoding in cases of complex mixes). However, the protocols of DNA barcoding applied to food analysis are not yet fully established; testing and optimization are required to achieve the highest accuracy and cost efficiency. We report here a comparative study of the two most widely used sequencing platforms - Illumina and Ion Torrent - for composition analysis of herbal teas, and show that both technologies yield congruent results, both qualitatively and quantitatively. They have revealed the substitution of fireweed (Epilobium angustifolium L.) by Lythrum sp. in one of the samples. It was confirmed by classic methods of botanical analysis (anatomy and palynology). In most samples, undeclared components have been detected, such as bindweed (Convolvulus) and ragweed (Ambrosia), which are known toxic and allergy-causing plants.