Occurrence and Dietary Risk Assessment of Alternaria Toxin in Edible Mushrooms: An Application of a Hydrophilic Solid-Phase Microextraction Fiber

Edible mushrooms are widely consumed across the globe. However, the critical lack of reliable detection methods has led to severely limited data on the contamination profiles and dietary exposure risks of Alternaria toxins in edible mushrooms. This study utilized a hydrophilic–lipophilic balanced solid-phase microextraction fiber for the detection of Alternaria toxins in edible mushrooms. The employed VIM/DVB fiber exhibited superior performance with a wide linear range (1–200 μg/kg), low limits of detection (0.01–0.26 μg/kg) and satisfactory recoveries (80.6–111.6%). Applying this method to 63 edible mushrooms (6 species) from Guiyang (Guizhou, China) revealed varying degrees of contamination, with all samples containing at least one of four target toxins (alternariol, alternariol monomethyl ether, altenuene, tentoxin). Tentoxin (1.86 ± 2.6 μg/kg, 76.2% detection frequency) and alternariol (1.61 ± 1.24 μg/kg, 55.6% detection frequency) were the predominant toxins. Toxin distribution varied by mushroom species. Lentinula edodes was prone to tentoxin contamination, while Pleurotus eryngii was even more susceptible to alternariol-tentoxin co-occurrence. Dietary risk assessment indicated that alternariol posed the highest risks, with 51% samples exceeding the toxicological threshold (2.5 ng/kg bw/day). This study provides a reliable detection tool for Alternaria toxins in edible mushrooms and highlights the signal that continuous attention needs to be paid to Alternaria toxins in edible mushrooms.