Distribution of Fusarium Mycotoxins Deoxynivalenol and Zearalenone in Milling Fractions of Rice (Oryza sativa) Harvested from Korea

Introduction:  Korea, where rice is the cereal most consumed, has set maximum limits for Fusariummycotoxins deoxynivalenol (DON) and zearalenone (ZEN). The maximum permitted level decreases from unprocessed rice, through intermediary products, to finished products. It is, therefore, important to understand the effects of milling process on the mycotoxin distribution.

Purpose:  In this study, the fate of DON and ZEN during milling of Korean rice cultivars was investigated.

Methods:  Rice (n = 80) grown under different field production conditions were collected and milled using a laboratory-scale test mill to produce four fractions: white rice, bran, brown rice and hulls. The four milling fractions were analyzed for DON and ZEN with a validated analytical method using high-performance liquid chromatography (HPLC) with UV absorbance and fluorescence detection.

Results:  The contamination levels in white rice, bran, brown rice and hulls were 0, 0.5, 4.1 and 1.9 µg/kg for DON, and 0.6, 33.0, 156.6 and 923.1 µg/kg for ZEN, respectively. Among 320 milling fractions, the incidence of DON was ranged from 0 to 8.8%. In contrast, ZEN was detected in all milling fractions, but exponentially reduced through milling process.

Significance:  Understanding the effect of milling that impact on the fractionation of DON and ZEN milling will help rice processors and/or risk managers to control rice-based products within legislative limits.