Determination of hydrolysed fumonisin B₁in alkali‐processed corn foods

Abstract

Treatment of fumonisin B1 (FB1)-contaminated corn with calcium hydroxide solution is known to cause large losses of FB1 and formation of the aminopentol AP1 by hydrolysis. Methodology was developed for determination of AP1 in foods manufactured from calcium hydroxide-processed corn. The ground food (tortilla chips, nacho chips, taco shells, or air-dried corn tortillas) was extracted with methanol-water (8:2) or methanol-acetonitrile-water (25:25:50), which also extracted FB1 and fumonisin B2 (FB2). Clean-up for fumonisin determination was carried out on a 1 ml strong anion exchange (SAX) solid phase extraction (SPE) column. The water wash from this column, containing AP1, was cleaned up on a 1 ml C-18 SPE column. AP1 and, separately, FB1 and FB2 were determined as their o-phthaldialdehyde-mercaptoethanol (OPA/MCE) and, in some cases, 4-fluoro-7-nitrobenzofurazan (NBD-F) derivatives by gradient reverse phase liquid chromatography with fluorescence detection. Recoveries of AP1, FB1 and FB2 from spiked samples were generally satisfactory, but FB1 and FB2 recoveries were low with some samples. Better recovery of FB1 with the methanol-acetonitrile-water (25:25:50) extraction solvent compared with methanol-water (8:2) was observed for naturally-contaminated samples. Detection limits were about 10 ng AP1 per g and 20 ng FB1 and FB2 per g with OPA/MCE derivatization, but there were interferences for FB2. Analysis of 31 samples of alkali-processed corn foods (including three known already to contain FB1) showed measurable levels of AP1 in nine samples, all < 100 ng/g and lower than the corresponding FB1 concentrations.

Occurrence of fumonisins in foods

“…However, the resulting products, when strong alkaline solutions are used, are still regarded as toxic compounds (Murphy et al, 1996). Scott and Lawrence (1996) and Sydenham et al (1995) found a ratio for FB1 to AP1 nd: not detected. a Parenthesis indicate importing country.…”

Fluorogenic and fluorescent labeling reagents with a benzofurazan skeleton

“…The suppression of the derivatization reaction by the metal ions could be avoided by the addition of ethylenediaminetetraacetic acid (EDTA) to the reaction medium (Miyano et al, 1985a). The derivatization using NBD-F as a pre-column fluorogenic reagent was applied to the determination of amino acids Imai et al, 1982;Imai, 1983, 1984;Kotaniguchi et al, 1987), amines, amino acids and imino acids , amines and proteins (Miyano et al, 1985b), hexosamines and hexosaminols (Imanari et al, 1985), neutral sugars as their glycamines (Shinomiya et al, 1987), aminophospholipids (Kaneko et al, 1987), Ssulfocysteine and S-sulfoglutathione (Togawa et al, 1988), phosphatidylethanolamine and its lysoform (Saris and Somerharju, 1989), amphetamine-related compounds (Hayakawa et al, 1989), selenium (Nakagawa et al, 1989), cyclamate (Hauck and Köbler, 1990), penicillins (Iwaki et al, 1990), ammonia (Kobayashi et al, 1992), peptides Arg-Gly-NH 2 and Arg-Pro-Lys-Pro (Yoshinaga et al, 1994), cholinergic channel activator A82695 (Hui and Marsh, 1995), dipeptides (Beijersten and Westerlund, 1995), hydrolyzed fumonisin B 1 (Scott and Lawrence, 1996), anatoxin-a (James and Sherlock, 1996;James et al, 1997), proteines (Wise et al, 1996), peptides (Kanazawa et al, 1997) (Jiménez and Mateo, 1997), anatoxin-a, homoanatoxin-a and their degradation products (James et al, 1998), methamphetamine and related compounds , imine-linked opines (Zhang et al, 1998), L-arginine (Prados et al, 1999), D-penicillamine (Al-Majed, 2000) and neurotoxin domic acid (James et al, 2000). Furthermore, after the derivatization with NBD-F, the enantioselective separation of amino acids were achieved on the chiral stationary phases ...…”

Effect of alkaline cooking of maize on the content of fumonisins B1 and B2 and their hydrolysed forms

“…Human exposure to fumonisins is therefore to be expected, especially in areas where nixtamalized maize is a diet staple. Surveys conducted on nixtamalized products originating from Mexico indicated that fumonisin levels were up to 1.8 mg/kg (De Girolamo, Pascale, & Visconti, 2011;Dombrink-Kurtzman & Dvorak, 1999;Scott & Lawrence, 1996).…”