Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Aug 29;12(9):555.
doi: 10.3390/toxins12090555.

Determination of Fungi and Multi-Class Mycotoxins in Camelia Sinensis and Herbal Teas and Dietary Exposure Assessment

Ingars Reinholds  1   2 , Estefanija Bogdanova  1 , Iveta Pugajeva  1 , Laura Alksne  1 , Darta Stalberga  3 , Olga Valcina  1 , Vadims Bartkevics  1   2
Affiliations

Determination of Fungi and Multi-Class Mycotoxins in Camelia Sinensis and Herbal Teas and Dietary Exposure Assessment

Ingars Reinholds et al. Toxins (Basel). .

Abstract

In this paper, a study of fungal and multi-mycotoxin contamination in 140 Camellia sinensis and 26 herbal teas marketed in Latvia is discussed. The analysis was performed using two-dimensional liquid chromatography with time-of-flight mass spectrometry (2D-LC-TOF-MS) and MALDI-TOF-MS. In total, 87% of the tea samples tested positive for 32 fungal species belonging to 17 genera, with the total enumeration of moulds ranging between 1.00 × 101 and 9.00 × 104 CFU g-1. Moreover, 42% of the teas (n = 70) were contaminated by 1 to 16 mycotoxins, and 37% of these samples were positive for aflatoxins at concentrations ranging between 0.22 and 41.7 µg kg-1. Deoxynivalenol (DON) and its derivatives co-occurred in 63% of the tea samples, with their summary concentrations reaching 81.1 to 17,360 µg kg-1. Ochratoxin A (OTA), enniatins, and two Alternaria toxins were found in 10-37% of the teas at low concentrations. The dietary exposure assessment based on the assumption of a probable full transfer of determined mycotoxins into infusions indicated that the analysed teas are safe for consumers: the probable maximum daily exposure levels to OTA and the combined DON mycotoxins were only 0.88 to 2.05% and 2.50 to 78.9% of the tolerable daily intake levels.

Keywords: 2D-LC-TOF-MS; Camellia sinensis teas; MALDI-TOF-MS; dietary exposure assessment; fungi; herbal teas; mycotoxins.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The range of the total fungal colony-forming unit counts per gram of tea and their mean levels (unfilled round markers). The upper line (green) indicates the quality level recommended by the THIE organisation, while the lower line (red) shows the recommended maximum levels of total fungi and yeasts in commercial teas according to Regulation No. 461 of the Cabinet of Ministers (Republic of Latvia) [29].
Figure 2
Figure 2
Number of contaminated tea samples with predominant fungi genera.
Figure 3
Figure 3
Distribution of the four most prevailing fungal species in different tea varieties.
Figure 4
Figure 4
Summary of the distributions of individual mycotoxins in the samples of different tea varieties.
Figure 5
Figure 5
The range of individual mycotoxins’ concentrations and the mean levels (unfilled triangle markers) determined in the 70 mycotoxin-positive tea samples (concentrations given on a logarithmic scale).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. EFSA Comprehensive Food Consumption Database. [(accessed on 12 January 2020)]; Available online: http://www.efsa.europa.eu/en/food-consumption/comprehensive-database.
    1. Sedova I., Kiseleva M., Tutelyan V. Mycotoxins in tea: Occurrence, methods of determination and risk evaluation. Toxins. 2018;10:444. doi: 10.3390/toxins10110444. - DOI - PMC - PubMed
    1. Ng K.W., Cao Z.J., Chen H.B., Zhao Z.Z., Zhu L., Yi T. Oolong tea: A critical review of processing methods, chemical composition, health effects, and risk. Crit. Rev. Food Sci. Nutr. 2018;58:2957–2980. doi: 10.1080/10408398.2017.1347556. - DOI - PubMed
    1. Zhu Y., Luo Y., Wang P., Zhao M., Li L., Hu X., Chen F. Simultaneous determination of free amino acids in Pu-erh tea and their changes during fermentation. Food Chem. 2016;194:643–649. doi: 10.1016/j.foodchem.2015.08.054. - DOI - PubMed
    1. Rocha-Miranda F., Venâncio A. Mycotoxigenic fungi in plant-based supplements and medicines. Curr. Opin. Food Sci. 2019;30:27–31. doi: 10.1016/j.cofs.2018.08.003. - DOI

Publication types