FUMONISIN B₁ LEVELS IN CEREALS AND FEEDS FROM SOUTHERN BRAZIL

NÍVEIS DE FUMONISINA B₁ EM CEREAIS E ALIMENTOS DO SUL DO BRASIL

ABSTRACT

A survey was conducted to evaluate fumonisin B₁ (FB₁) contamination in cereals and feeds of southern Brazil. A total of 407 samples was obtained from different local warehouses and feed industries between January 1996 and June 1998. Extraction of FB₁ was performed with acetonitrilewater (50+50, v/v) and cleanup with end-capped C₁₈ silica columns; the extracted mycotoxin was resolved by liquid chromatography with o-phthaldialdehyde and 2-mercaptoethanol derivatization, and identified by fluorescence. Positive results were found in 32.2% of the samples assayed. FB₁ concentrations varied from 0.086 to 78.92 µg/g, and the highest levels recorded were: 14.21 µg/g in rice; 68.33 µg/g in feed; 78.92 µg/g in corn; 24.35 µg/g in wheat; 0.17 µg/g in oat; and 2.43 µg/ g in barley. No detectable levels of this mycotoxin were found in soybean meal samples. The results demonstrate that cereals harvested in southern Brazil were contaminated with FB₁. Considering that these products are consumed in large amounts either directly or as components of foods and feeds, the levels of contamination reported herein indicate a potential threat to animal and public health.

KEY WORDS:
Fumonisin; mycotoxin; cereals; feeds.