Aflatoxin B₁ and sterigmatocystin: method development and occurrence in tea

Area of Science:

• Food Science
• Analytical Chemistry
• Toxicology

Background:

• Tea consumption is widespread globally.
• Tea can be contaminated with fungi and mycotoxins during processing.
• Mycotoxins pose potential health risks to consumers.

Purpose of the Study:

• To develop a simple, fast, sensitive, and reliable method for analyzing aflatoxin B1 (AFB1) and sterigmatocystin (STC) in tea.
• To assess the prevalence and levels of AFB1 and STC in Chinese tea samples.

Main Methods:

• Development and validation of a mycotoxin analysis method.
• Quantification of AFB1 and STC using the developed method.
• Analysis of 126 randomly collected tea samples from Chinese markets.

Main Results:

• The method demonstrated high recoveries (95.9%–118.0%) and acceptable RSDs (0.3%–11.2%).
• AFB1 was not detected in any of the analyzed tea samples.
• STC was detected in 17 samples (13.5% detection rate) at levels ranging from 0.13 to 4.48 µg/kg.
• STC detection rates were 5% in black tea, 8.9% in green tea, and 33.3% in Oolong tea.

Conclusions:

• The developed method is suitable for routine analysis of AFB1 and STC in tea.
• STC is present in some Chinese teas, with Oolong tea showing a higher contamination rate.
• Further research on mycotoxin contamination in tea is warranted to ensure food safety.