Development of conventional PCR and real‐time PCR assays to discriminate the origins of Chinese pepper oil and herbal materials from Zanthoxylum

Abstract

BACKGROUND To ensure the safety, quality and therapeutic efficacy of processed foods and herbal medicines, it is important to identify and discriminate economically motivated adulterants. Zanthoxylum schinifolium is sold at a higher price than other Zanthoxylum species and is frequently adulterated with closely related Zanthoxylum species because of its high demand as a Korean food ingredient and medicinal material in markets. In addition, the pericarps of three Zanthoxylum species ( Z. schinifolium , Z. bungeanum and Z. piperitum ) are defined as herbal medicine Zanthoxyli Pericarpium in Korean pharmacopoeias, but not Z. piperitum in Chinese pharmacopoeias. Further confusion arises in the morphological similarity between Z. armatum (adulterant) and Z. bungeanum . Therefore, the aim of this study was to develop a sequence characterized amplified region (SCAR) marker for discrimination of four Zanthoxylum species. RESULTS With the goal of developing rapid and reliable tools for genetic discrimination of authentic Zanthoxyli Pericarpium, we designed species‐specific SCAR markers, based on ITS2 sequences, that generate amplicons of less than 200 bp. Using these markers, we established both conventional and real‐time PCR assay methods capable of differentiating samples at the species level. We validated the ability of SCAR markers to authenticate edible oil and herbal medicine, and confirmed that some herbal medicines contaminated with Z. armatum are being distributed as Zanthoxyli Pericarpium in Korean and Chinese markets. CONCLUSIONS The SCAR markers and PCR methods described represent powerful tools for protecting against adulteration and ensuring standardization of processed foods and herbal medicine. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Accurate and Rapid Identification of Longan Arillus and Litchi Semen by a Multiplex PCR Assay

“…DNA barcoding analyses are widely used for species identification in plants (based on internal transcribed spacer [ITS], mat K, and rbc L), animals (COI), fungi (ITS), and microorganisms (ITS) [ 9 , 10 , 11 ]. Most herbal medicines are derived from plant taxa.…”

“…Therefore, DNA analysis methods with high sensitivity are necessary for accurate species identification in herbal medicines in which mixed, broken, dried, and chemically treated samples are typical [ 8 ]. Sequence characterized amplified region (SCAR) markers have recently been applied as an alternative to DNA barcoding for analyses of herbal medicines, such as Zanthoxyli Pericarpium, Araliae Continentalis Radix, Angelicae Dahurica Radix, and Adenophorae Radix [ 8 , 9 , 12 , 14 ]. SCAR markers involve short species-specific sequence fragments, unlike DNA barcoding, requiring analyses of full-length target sequences.…”

“…Adulterants in herbal medicines vary in quantity from trace amounts to entire samples, and can be explained by economical motivation or unintended processing [ 9 , 15 ]. Therefore, DNA markers should have high sensitivity and species-specificity for applications to mixed herbal medicines.…”

DNA barcoding coupled with high‐resolution melting analysis for nut species and walnut milk beverage authentication

“…DNA barcoding is a newly discovered approach to species identification using a standard region of DNA that is widely employed in the large‐scale identification of animal species . DNA barcoding has also been applied in taxonomic identification of flowering plants . Several DNA barcode regions, such as internal transcriber spacers ( ITS1 and ITS2 ) and plastidial genes psbA‐trnH , trnL‐F , matK , and rbcL , have become the most promising loci in plant differentiation .…”

“…17 DNA barcoding has also been applied in taxonomic identification of flowering plants. [18][19][20] Several DNA barcode regions, such as internal transcriber spacers (ITS1 and ITS2) and plastidial genes psbA-trnH, trnL-F, matK, and rbcL, have become the most promising loci in plant differentiation. 21 The psbA-trnH sequence has a faster evolution rate and higher species-identification efficiency, and it is becoming a commonly used and reliable chloroplast barcode gene in the study of plant molecular phylogeny.…”