Applicability of an in vitro digestion model in assessing the bioaccessibility of mycotoxins from food

Food is considered a major route of exposure to many contaminants. Only the fraction of the contaminant that is released from the food (bioaccessibility) and is bioavailable can exert toxic effects. Insufficient knowledge on the bioavailability may hamper an accurate risk assessment of ingested contaminants in humans. This paper describes the applicability of an in vitro digestion model allowing for measurement of the bioaccessibility of ingested mycotoxins from food as an indicator of oral bioavailability. Bioaccessibility of aflatoxin B1 from peanut slurry and ochratoxin A from buckwheat was high, 94% and 100%, respectively, and could be determined reproducibly. With the in vitro digestion model, the bioaccessibilities of aflatoxin B1 and ochratoxin A in the presence of four different absorption modulators were in five out of six situations in accordance with the in vivo effects in humans and animals. By determining the effect of chlorophyllin on the transport of aflatoxin B1 across the intestinal Caco-2 cells, also the sixth combination was in agreement with data in humans. Hence, the in vitro digestion model, combined with Caco-2 cells, is a powerful experimental tool, which can aid to a more accurate risk assessment of ingested contaminants.