Detection and quantification of white and black sesame as potential allergenic ingredients in processed foods: A comparative gene marker study

White and black sesame seeds are widely used as technological ingredients in processed foods, but they are also considered as important allergenic foods. This work aims at exploiting several molecular markers for developing highly sensitive/specific real-time PCR methods for sesame detection/quantification in complex matrices. Three allergen-encoding genes and 4 multicopy regions of sesame were extensively evaluated, from which two, tar-geting CO6b1 and ITS sequences, provided the best sensitivity and specificity. Both markers allowed the suc-cessful development of real-time PCR approaches using white/black sesame seeds and raw/processed model mixtures of sesame-containing biscuits. The ITS region (0.02 pg of DNA and 1.0 mg/kg) provided higher sensitivity for sesame detection than the CO6b1 gene (2 pg of DNA and 50 mg/kg). Both methods presented optimal performance parameters for sesame detection, even after processing, but only the CO6b1 gene showed precise and accurate determinations of sesame in blind mixtures.

Automated summary

This study developed a highly sensitive and specific real-time PCR method for sesame detection and quantification in complex matrices. By evaluating multiple molecular markers, two markers with the best performance were identified. The methods showed excellent detection performance for white sesame, black sesame, and sesame-containing biscuits.