Heating chicken breast muscle reduces the amount of dialyzable iron after extraction and digestion.

摘要

Effect of heating chicken breast muscle on the amount of dialysable Fe derived from added ferric Fe was investigated. Chicken meat was homogenised and heated to 130-195 degrees F. The heated muscle was mixed with ferric Fe, and either extracted with acid or digested with pepsin and pancreatin. Similar amounts of dialysable Fe were observed after extraction and proteolytic digestion. However, digestion led to more dialysable ferrous Fe. Heating caused markedly reduced levels of dialysable Fe and dialysable ferrous Fe both by extraction and digestion. At 130-165 degrees F, the losses were due mainly to reduced levels of ferrous Fe. At 195 degrees F, both ferric and ferrous dialysable Fe levels were markedly reduced (>80%) compared to raw muscle. At 165 degrees F, losses in dialysable Fe after extraction were much greater than after digestion. Heating caused progressive losses in sulfhydryl and histidine residues, and mostly lowered protein digestibility. It was demonstrated that heating chicken meat at >130 degrees F causes losses in dialysable Fe, coincident with (and possibly due to) losses in amino acid residues that reduce and chelate Fe. Results suggested that cooking chicken meat will reduce its ability to promote non-haem Fe uptake, and that the magnitude of the reduction will tend to increase with increasing temp.