INTERLABORATORY TRIAL ON THE DETERMINATION OF THE IN-VITRO IRON DIALYZABILITY FROM FOOD

An in vitro method for the estimation of iron bioavailability was subj ected to an interlaboratory trial. The method involved a simulated gas trointestinal digestion using pepsin for the gastric stage followed by pancreatin and bile salts for the intestinal stage. The proportion of iron diffused through a semipermeable membrane (molecular mass cut-of f 10 kDa) was used to measure the iron dialysability. An interlaborato ry trial between nine laboratories was conducted to evaluate the repea tability and reproducibility of the agreed method. The reproducibility of the method among the participating laboratories was 20-30% and dep ended on the content of dialysable iron. Several factors contributing to the variation in the in vine dialysability among laboratories are d iscussed. The pH adjustment in the intestinal digestion was identified as one of the critical parameters. The present in vitro method was us ed to evaluate the iron dialysability from three meals. The dialysabil ity data were in reasonable agreement with human absorption data. The usefulness of the in vitro dialysability method is discussed.