Integrated Assessment of Fungi Contamination and Mycotoxins Levels Across the Rice Processing Chain

This study investigated the occurrence of fungi and mycotoxins throughout the rice processing chain, from paddy rice to final white rice, in two rice varieties (variety I and variety II). A total of 75 fungal isolates were identified, belonging to the genera Penicillium, Alternaria, Aspergillus, Fusarium, and Talaromyces. Variety I exhibited a higher prevalence of Penicillium and Alternaria, whereas Variety II was dominated mainly by Alternaria, accounting for 63% of all isolates. Multi-mycotoxin screening of 22 mycotoxins revealed contamination by tenuazonic acid (TeA), zearalenone (ZEN), and 15-acetyl-deoxynivalenol (15-AcDON), with TeA concentrations exceeding 4000 µg/kg in whitened rice of variety II. Cluster analysis showed paddy and brown rice grouping together due to higher fungal loads and toxin levels, whereas whitened and final white rice clustered separately, reflecting reduced fungal counts but persistence of TeA, 15-AcDON, ZEN, and citrinin (CIT). The co-clustering of Alternaria with TeA and ZEN indicates strong field-related contamination. Although processing significantly decreased fungal loads, residual toxins persisted, emphasizing that rice polishing does not fully mitigate mycotoxin risks. These findings underscore the need for comprehensive surveillance and integrated management practices across the rice supply chain to minimize potential health hazards associated with fungal contaminants and their toxic metabolites.