Specific, sensitive and rapid Curcuma longa turmeric powder authentication in commercial food using loop-mediated isothermal nucleic acid amplification

Abstract

Turmeric ( Curcuma longa ) is a rhizomatous plant of the ginger family Zingiberaceae that is usually dried and ground into powder for use as a seasoning. Because turmeric has become increasingly popular in the functional food market, adulteration of C . longa by other turmeric species is becoming an increasingly significant problem. In this study, loop-mediated isothermal amplification (LAMP) was developed for the detection of C. longa DNA for turmeric authentication. ITS2-26S rDNA was used for the LAMP primer designation. The results demonstrated that the specific primers exhibited high specificity, authenticated C. longa DNA within 30 min at 65 °C isothermally and had no cross-reaction with other adulterants. LAMP was sensitive to 0.1 ng of turmeric C. longa DNA, and only 0.01% of C. longa turmeric powder in the sample was required for DNA amplification. The sensitivity of LAMP was 10-fold higher than that of PCR (0.1%) from a previous report. Moreover, all the collected commercial turmeric products were positively detected by LAMP and RtF-LAMP (real-time fluorescence LAMP). The developed LAMP assay not only had higher specificity and rapidity than that of other methods but could also be applied to authenticate turmeric to prevent adulteration in food products.

Genetic Authentication of the Medicinal Plant Portulaca oleracea Using a Quick, Precise, and Sensitive Isothermal DNA Amplification Assay

“…Due to the higher sensitivity of the LAMP assay, even very few intact sequences of amplicon DNA in the heat-processed PO samples could be efficiently amplified to produce a specific LAMP product to confirm PO identities with respect to those commercial PO samples. This superiority of the LAMP assay has been similarly exhibited in earlier studies [19,23]. The 100-fold improved sensitivity of LAMP in this work was mainly attributed to the addition of the LF loop primer and DMSO reagent (Figure 5).…”

Food authentication, current issues, analytical techniques, and future challenges: A comprehensive review

“…The Asian regions—Southeast, East, and South Asia—face recurring food contamination issues due to dense populations, limited resources, and relatively less focus on food research. China, Malaysia, and India have encountered such incidents, prompting researchers’ increased development and validation of food safety protocols (Girish et al., 2020; Sheu et al., 2021; Wilwet et al., 2021; Xing et al., 2020). Mycotoxin contamination in various foods, from barley to processed meats, remains a significant concern (Lago et al., 2021; Rausch et al., 2021; Zadravec et al., 2020; Zhao et al., 2021).…”