Bar-HRM traceability of plants in food and medicine

H2020 MSCA-ITN-ETN Plant.ID network
Type of data: 
Project results
Source: 
Personal communication in an INCREDIBLE event (science to practice)
Objective: 

Barcoding is an important tool towards the solution of traceability issues. Plant.ID is a collaborative network within Europe and addresses the challenges of plant identification in 15 different projects. We focus on common edible, poisonous, allergenic and pharmaceutical plants of the Greek flora. Through sequencing of barcoding regions and metabarcoding techniques, specific barcoding markers will be developed to be used either with PCR and/or with the High Resolution Melting Analysis for species-specific identification.

Context: 

Illegal collection and trade accelerate plant extinction and accounts for economic losses. Species of restricted distribution are affected disproportionately and require special conservation measures. The same applies to natural hybrids, due to their unique characteristics. Substitution of wild species, due to misidentification, can lead to severe adverse reactions. Poisonous plants can cause a variety of severe intoxications. Food adulteration harms the consumer in many ways. Based on the above, there is a need for efficient identification for edible, toxic, and endangered plant species.

Main results: 

In the first part within this project, seventy-one herbal medicinal products were randomly purchased throughout Greece and analyzed using metabarcoding to identify species. The aim was to investigate possible adulteration and assess the ability of metabarcoding for plant based product authentication. Of the detected species in our analyses we found species that were not listed on the product labels. This indicates a high level of adulteration and/or contamination during processing and distribution. We also identified the presence of toxic species, as major ingredients of two herbal mixtures for medicinal purposes. The detection of the latter two species was also confirmed through Bar-HRM analysis.

Main practical recommendations: 

The study revealed a need for stricter quality control of herbal products, especially because of the presence of toxic species. Low fidelity was found to be an issue, also in short chains of commercialization. We state that standardization of protocols is necessary before DNA metabarcoding can be implemented as a routine analytical approach and approved by competent authorities for use in a regulatory framework. Also, the availability of a rich and reliable DNA reference database is a prerequisite for successful implementation.

Impacts and weaknesses: 

The presence of toxic plant species in herbal products can pose serious health problems. Unexperienced pickers collecting edible plants in the field are particularly sensitive (Cornara et al., 2018). The harvest of salep orchids in Greece are threatening the natural orchid populations of Northern Greece (Kreziou et al., 2015). Fast and efficient species-specific detection methods for Greek orchids is required for biodiversity conservation.

Future developments: 

The standardization of protocols is necessary before DNA metabarcoding can be implemented as a routine analytical approach and approved by competent authorities for use in a regulatory framework. Also, the availability of a rich and reliable DNA reference database is a prerequisite for successful implementation.

Organisation: 
CERTH

Further information

PLANTID PROJECT website, page of the specific project (ESR13): https://www.plantid.uio.no/research/projects/esr13.html

Cornara, L., Smeriglio, A., Frigerio, J., Labra, M., Di Gristina, E., Denaro, M., … Trombetta, D. (2018). The problem of misidentification between edible and poisonous wild plants: Reports from the Mediterranean area. Food and Chemical Toxicology, 119(April), 112–121. https://doi.org/10.1016/j.fct.2018.04.066

Kreziou, A., De Boer, H., & Gravendeel, B. (2016). Harvesting of salep orchids in north-western Greece continues to threaten natural populations. Oryx, 50(3), 393-396. doi:10.1017/S0030605315000265

Figure 1 credit: 

H2020 MSCA-ITN-ETN Plant.ID network

Figure 2: 
The Plant.ID project network
Figure 2 caption and credit: 

The Plant.ID project network