Effect of the inclusion of adsorbents on aflatoxin B₁ quantification in animal feedstuffs

Antonio Gallo (1) , Francesco Masoero (2) , Terenzio Bertuzzi (3) , Gianfranco Piva (2) , Amedeo Pietri (2)

1 Istituto di Scienze degli Alimenti e della Nutrizione
2 Istituto di Scienze degli Alimenti e della Nutrizione
3 Istituto di Scienze degli Alimenti e della Nutrizione

The extraction efficiency of aflatoxin B₁ (AFB₁) in cattle feeds containing 9 adsorbents (ADSs), was investigated using two organic/aqueous solvents, composed of methanol/water (80/20 v/v; MeOH) and acetone/water (85/15 v/v; AC). Feed samples were obtained including in a high (HC) and a low (LC) AFB₁ contaminated feedstuffs (15.33 and 7.57 µg kg^-1, respectively), nine ADSs (4 clay minerals; 1 yeast cell wall-based product; 1 activated carbon and 3 commercial ADS products) at two different doses of inclusion (10 and 20 g kg^-1). After solvent extraction and immunoaffinity column clean-up, all the samples were analysed for AFB₁ by HPLC with fluorescence detection. For each contamination level (HC and LC), the data obtained were analysed using a factorial arrangement in a completely randomized design. Means were compared to the correspondent controls using the Dunnett's test. No statistical difference was found in AFB₁ levels of feedstuffs non containing ADSs, when extracted with AC or MeOH, even if numerically higher values were obtained with AC. A dose-dependent effect (P < 0.01) of ADSs inclusion was observed on AFB₁ recoveries, that were lower when the higher ADS dose (20 g kg^-1) was included in the HC and LC feedstuffs. Higher AFB₁ recoveries were obtained using AC with respect to MeOH, both in HC (75.0 vs. 12.0%, respectively) and in LC (84.0 vs. 22.8%, respectively) ADSs containing feedstuffs. However, when the activated carbon and the sodium bentonite were included into feeds, lower AFB₁ concentrations with respect to control values (P < 0.001 and P < 0.05, respectively) were measured also using AC. The data obtained in this study indicate that a routine use of the MeOH solvent for AFB₁ analysis of unknown feedstuffs, can produce misleading results if they contain an ADS.

Mots clés: Life Sciences

Antonio Gallo, Francesco Masoero, Terenzio Bertuzzi, Gianfranco Piva, Amedeo Pietri. Effect of the inclusion of adsorbents on aflatoxin B₁ quantification in animal feedstuffs. Food Additives and Contaminants, 2009, 27 (01), pp.54-63. ⟨10.1080/02652030903207219⟩. ⟨hal-00573908⟩