The corn influence on the adsorption levels of aflatoxin B1 and zearalenone by yeast cell wall

Abstract

Aims: To in vitro evaluate the influence of the corn on the adsorption levels of aflatoxin B1 (AFB1) and zearalenone (ZEA) by yeast cell walls (YCWs). Methods and Results: Two commercial YCWs were studied. The YCWs contain different percentages of polysaccharides. YCW1 and 2 contain 5·9 and 21% of mannans and 17·4 and 23% of β-glucans, respectively. Each YCW was resuspended in pH 2 and pH 6 buffer solutions. Corn was used to study the matrix influence. An aliquot of 500 μl YCW suspension was added to each microtube containing 500 μl of 0·1, 0·25, 0·5, 1, 2·5 and 5 μg ml−1 AFB1 or 0·5, 5, 10, 20 and 50 μg ml−1 ZEA. Microtubes were kept with mechanical agitation at 37°C for 30 min and then centrifuged for 10 min at 16 873 g and; the supernatants were quantified by high-pressure liquid chromatography. The amount of bound toxin was plotted as a function of the amount of added toxin according to mathematical expressions proposed by three theoretical models. Both YCWs were capable of adsorbing AFB1 and ZEA in amounts from 0·061 to 0·40 and from 0·10 and 0·26 g g−1, respectively. In the presence of the matrix, both adsorbents were not able to adsorb AFB1. However, they could adsorb ZEA at levels from 0·03 to 0·23 g g−1. Conclusions: Both YCWs adsorbed ZEA in the presence of corn and also under simulated gastrointestinal pH conditions. These results suggest that the studied YCWs are potential candidates for ZEA adsorption. Significance and Impact of the Study: Several in vitro assays have informed the ability of different substrates including yeast walls to adsorb AFB1 and ZEA; none of them have evaluated their ability to adsorb AFB1 and ZEA in the presence of the corn. The corn matrix can influence the adsorption phenomena of these mycotoxins.