Development of molecular markers based on real-time PCR to detect flax and sesame in commercial amaranth products

Amaranthus, Sesamum indicum, and Linum usitatissimum are the most popular oilseed grains worldwide. Protein-rich Amaranthus contains bioactive peptides, is nutritious, and exhibits anti-allergic properties. Sesamum indicum is a primary trigger of anaphylaxis. Linum usitatissimum also displays allergenic properties. A DNA marker assessable using quantitative real-time PCR was developed to detect S. indicum and L. usitatissimum as allergenic contaminants of anti-allergenic Amaranthus. The efficiency of each primer set ranged from 90-98%, and high linear correlation (R² > 0.99) was obtained between crossover values and the log DNA concentration. We established a Ct value of 0.1% of the binary as a cutoff. The practical application of the designed marker was confirmed by analyzing 20 commercial products. The qPCR system developed for detecting flaxseed and sesame can be applied for regulatory monitoring of allergenic substances in commercial amaranth-containing foods, thus contributing to protecting public health and safety.

The online version contains supplementary material available at 10.1007/s10068-024-01584-2.