Evaluation of a DNA-based method for spice/herb authentication, so you do not have to worry about what is in your curry, buon appetito!

Abstract

It is long believed that some spices may help protect against certain chronic conditions. Spices are usually parts of plants that have been powdered into small pieces. Have you ever wondered what the curry powder in your dish is made of? The aim of this work was to develop an appropriate DNA-based method for assessment of spice identity. Selecting the best marker for species recognition in the Zingiberaceae family. Six DNA regions were investigated in silico, including ITS, matK, rbcL, rpoC, trnH-psbA and trnL. Then, only four regions (ITS, matK, rbcL and trnH-psbA) were included in the simulated HRM (High-resolution Melting) analysis as the results from previous analysis showed that rpoC and trnL may not be suitable to be used to identify Zingiberaceae species in HRM analysis based on both the percentage of nucleotide variation and GC content. Simulated HRM analysis was performed to test the feasibility of Bar-HRM. We found that ITS2 is the most effective region to be used for identification of the studied species and thus was used in laboratory HRM analysis. All seven tested Zingiberaceae plants were then able to be distinguished using the ITS2 primers in laboratory HRM. Most importantly the melting curves gained from fresh and dried tissue overlapped, which is a crucial outcome for the applicability of the analysis. The method could be used in an authentication test for dried products. In the authentication test, only one of seven store-sold Zingiberaceae products that were tested contained the species listed on their labels, while we found substitution/contamination of the tested purchased products in the rest.

Bar-HRM: a reliable and fast method for species identification of ginseng (Panax ginseng, Panax notoginseng, Talinum paniculatum and Phytolacca Americana)

“…The matK was excluded from this study as it has a historically low success rate (Hollingsworth, 2011). The psbA-trnH contains a high indel in the region that could affect HRM analysis (Osathanunkul et al, 2015; Osathanunkul et al, 2017). Although other works have found the indel polymorphism useful for discrimination of Panax species (Kim et al, 2013; Jung et al, 2014).…”

Technologia HRM-PCR; denaturacja DNA z wysoką rozdzielczością opis oraz zastosowanie

“…Charakterystyka struktury społeczności drobnoustrojów przy użyciu technik molekularnych staje się popularnym podejściem w badaniach próbek środowiskowych. Do skutecznego monitorowania i kontroli społeczności drobnoustrojów w próbkach opracowano metodę molekularnego odcisku palca w połączeniu z HRM, MFin-HRM, opartą na analizie topnienia w wysokiej rozdzielczości [20].…”

“…Analizy HRM ze względu na niski koszt i zastosowanie dostępnego oprzyrządowania prawdopodobnie wypełnią niszę w regionach i laboratoriach o mniejszych zasobach, ale także będą uzupełnieniem technologii sekwencjonowania. Genotypowanie gatunków roślin [24][25][26][27][28][29] Identyfikacja gatunkowa mikroorganizmów [30,31] Genotypowanie w obrębie gatunków drobnoustrojów [32] Bar-HRM Uwierzytelnianie żywności i produktów ziołowych [19,20] Kontrola jakości warzyw, rozróżnienie roślin jadalnych i trujących [21,33] MS-HRM Wykrywanie biomarkerów nowotworowych [34,35] Diagnozowanie chorób imprintowanych [35] Kliniczna weryfikacja wyników badań epigenomu [36] Ocena metylacji w zastosowaniach diagnostycznych i badawczych [22,37] MFin-HRM Identyfikacja i uwierzytelnianie gatunków [23,38] High Resolution Melting Analysis (HRM-PCR) -method and its application…”

Review of Recent DNA-Based Methods for Main Food-Authentication Topics

“…A similar mislabeling rate (e.g., 48.5%) was found when analyzing commercial curry powders with a Bar-HRM developed for identifying seven Zingiberaceae curry species. 81 The combination of HRM and DNA barcoding has also been applied to the authentication of wines. 82 In the study, 13 grapevine varieties could be differentiated in musts and wines.…”