Development and validation of a probe-based qPCR method to prevent parsley leaf material misidentification

Abstract

Parsley (Petroselinum crispum) leaf is an herb widely consumed for its health benefits. Due to similar morphological and chemical profiles, celery leaf may be a source of substitution in commercial parsley materials. In order to detect this substitution, the present work characterized parsley and celery leaf at the cultivar level by physical, chemical and DNA approaches. In contrast to the variations observed in physical appearances and chemical profiles that make verification of authenticity difficult, consistent differences observed between their DNA sequences are suitable for verifying parsley material authenticity. To identify parsley and detect celery simultaneously, a multiplex qPCR assay was developed and validated with respect to efficiency and specificity. Further testing indicated the assay can be used to detect 1% (w/w) celery in parsley materials with a probability of detection greater than 0.9. The developed method is well-suited for routine quality control to prevent parsley material misidentification in commercial trade.

Keywords: Botanical authentication; Celery; DNA; Parsley; Quality control; qPCR.