Effect of soya-bean protein on meat iron solubility and absorption in rats

Abstract

1. Soya-bean proteins were used to replace 30 and 50% of the protein from 59 Fe-labelled pigeon (Columbn L.) and chicken meat, and the solubility of the meat 59 Fe in vitro and its absorption in vivo in rats in the presence and absence of soya-bean proteins were measured. 2. Replacement of part of the chicken meat by soya-bean proteins reduced 59 Fe solubility from chicken meat at all stages during simulated in vitro digestion. 3. 59 Fe absorption from 59 Fe-labelled chicken meat when given to both Fe-replete and Fe-deficient rats was reduced in the presence of soya-bean proteins but was unaffected by the presence of casein or bovine serum albumin. 59 Fe-absorption from pigeon meat in the presence of soya-bean proteins was not reduced to the same extent as that from chicken meat. 4. There was no significant effect of soya-bean proteins on 59 Fe-labelled haemoglobin Fe absorption in vivo in Fe-replete rats. 5. Absorption of 59 Fe from the isolated haemoproteins from chicken meat was unaffected by soya-bean proteins but 59 Fe absorption from the main non-haem-Fe fractions was strongly inhibited, particularly from haemosiderin.