Toxoflavin contamination in rice samples from rice processing complexes in South Korea

• Published in: International journal of food microbiology 2023-01, Vol.385, p.110014-110014, Article 110014
• Main Authors: Choi, Okhee, Lee, Yeyeong, Kang, Byeongsam, Kim, Jinwoo
• Format: Article
• Language: English
• Subjects: Burkholderia glumae; Food safety; Rice; Toxoflavin contamination
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2022.110014

Toxoflavin contamination was investigated in broken rice produced as a by-product of domestic rice processing complexes (RPCs) in 2011 in South Korea. Of the 68 RPCs investigated, toxoflavin contamination was confirmed in 12 from three provinces: Gangwon, Gyeonggi, and Gyeongsang. Isolation of toxoflavin-producing bacteria independent of toxoflavin contamination was also performed in this study. We obtained 25 toxoflavin-producing bacterial isolates from rice samples; these samples were collected from the same 12 RPCs mentioned above. All 25 toxoflavin-producing bacteria were identified as Burkholderia glumae by 16S rRNA gene sequencing. Toxoflavin-producing ability differed slightly among the 25 isolates, but they all inhibited rice seed germination and induced seed rot. This is the first report of toxoflavin contamination and the toxin-producing bacterium B. glumae in broken rice produced during the rice milling process. Because toxoflavin has stable physical properties even above a boiling temperature of 100°C, it can pose a problem even if rice is cooked or processed. These results will serve as baseline data aiding comprehensive management of toxoflavin contamination during the post-harvest storage and processing of rice. •Toxoflavin contamination in rice by-products from processing complexes was first described.•Burkholderia glumae is also isolated from rice by-product samples.•There are no reports of food-poisoning toxoflavin and B. glumae.•This study will aid the comprehensive management of toxoflavin contamination in rice.