High-throughput detection, dietary exposure assessment, and producing Fungi of 16 masked mycotoxins in dried longan in Asia.

Abstract

Dried longan is highly vulnerable to fungal infection and masked mycotoxin (MM) contamination, posing a potential health risk for consumers. However, limited data are available on the co-occurrence, dietary exposure assessment, and fungal sources of MMs in this product across Asia. In this study, a high-throughput analytical method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated for the simultaneous detection of 16 MMs in 90 dried longan samples collected from major Asian producing regions. Results showed that the optimized UPLC-MS/MS method exhibited a good linear relationship ranging from 5 to 800 ng/mL with correlation coefficients R2 above 0.99026. Twelve MMs were 100% positively detected in all samples. The maxima of neosolaniol (NEO), 3-acetyl-deoxynivalenol (3ADON), and 15-acetyl-deoxynivalenol (15ADON) in all samples were 3346.42, 1768.67, and 971.91 μg/kg, respectively. Dietary exposure assessment indicated that the hazard index (HI) of all MMs was 65.382% (100% threshold), indicating a relatively low risk for consumers in the five surveyed Asian countries (China, Thailand, Vietnam, Malaysia, and Myanmar). Fungal community and correlation analysis further revealed that Fusarium croci was significantly (P < 0.05, Pearson r = 0.99) positive with NEO, 3ADON, and 15ADON, suggesting it as a potential producer of these mycotoxins. This work provided a comprehensive understanding of the contamination of MMs in dried longan.