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

Turmeric () is a rhizomatous plant of the ginger family 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 . by other turmeric species is becoming an increasingly significant problem. In this study, loop-mediated isothermal amplification (LAMP) was developed for the detection of 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 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 DNA, and only 0.01% of 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.