Fungal diversity and mycotoxins in retail polished and unpolished rice in Thailand.

Authors

Supeecha Waiya, Saranya Poapolathep, Donnaya Thanakitpipattana, Nattawut Boonyuen, Onuma Piasai, Johanna F Gremmels, Sarah De Saeger, Antonio F Logrieco, Amnart Poapolathep

Published in

Frontiers in nutrition. Volume 13. Pages 1828938. Epub Jun 25, 2026.

Abstract

Rice is a major dietary staple food across Asia, including Thailand, and is susceptible to fungal invasion and mycotoxin contamination. Because rice is consumed daily, even low-level contamination may have public-health implications. This study aimed to identify fungal diversity on unpolished and polished rice samples and to analyse the occurrence of mycotoxins in retail rice from Thailand. To this end, 50 retail rice samples (25 polished and 25 unpolished) were collected from markets across various districts of Bangkok, Thailand. Using the blotter method, 12.6% of rice proved to be contaminated by fungi with a slightly higher contamination rate observed in unpolished rice than in polished rice (13.28% and 11.92%, respectively). Morphological and molecular examination using multi-locus sequencing revealed various taxa belonging to Aspergillus, Neocosmospora (Fusarium solani species complex) and Penicillium/Talaromyces. Chemical analysis by liquid chromatography-tandem mass spectrometry detected beauvericin (BEA; n = 2) and zearalenone (ZEN; n = 2) only in unpolished rice, with concentrations up to 1.77 μg/kg and 65.57 μg/kg, respectively. None of the samples exceeded the acceptable ZEN threshold set by the Thai Food and Drug Administration (100 μg/kg). In conclusion, the results of this study confirmed that unpolished is prone to fungal contamination originating from environmental, as well as handling during harvesting, sorting and packaging. The occurrence of mycotoxin was limited to a small percentage of unpolished rice samples. No regulated carcinogenic mycotoxins such as AFs, OTA, or FB₁ were found. Using validated LC-MS/MS methods, only ZEN and BEA were detected at low levels in unpolished rice, and no mycotoxins above the LOQ were found in polished rice. The results show low contamination in the rice samples from Bangkok retail markets. However, further studies are needed to confirm these findings at a broader level. The multi-toxin analytical method described enables routine, validated monitoring of rice from various harvests, helping to support food safety objectives.

PMID:
42428605
Bibliographic data and abstract were imported from PubMed on 10 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.