Progress 06/01/07 to 10/01/11
Outputs
OUTPUTS: Chicken breast muscle can promote the formation of dialyzable iron from added ferric iron by both extraction and proteolytic digestion. We found that cooking the chicken severely reduced these effects and that there was very little difference between boiling, baking, sauteing and deep-frying the chicken. Furthermore cooking procedures reduced the levels of critical iron binding amino acid residues such as sulfhydryls and histidines in the muscle proteins. PARTICIPANTS: Raymond Mahoney,PI who supervised the project.Aditya Gokhale,graduate student, who worked on the project and received post-graduate training. TARGET AUDIENCES: Nutritionists and dieticians who advise on the effect of dietary iron to combat anemia. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Consumption of muscle foods enhances the uptake of dietary iron and can help prevent anemia. Our studies show that muscle contains two sources of components that promote the production of dialyzable iron (an in-vitro indicator of iron bioavailability): extraction of the muscle with acid and also digestion of the muscle with enzymes. However, digestion produced more dialyzable iron than extraction. Cooking the muscle by several methods caused large decreases in dialyzable iron from both sources, coincident with the destruction of iron-binding amino acids. It is therefore likely that cooking of meat will significantly impair its ability to enhance iron uptake.
Publications
- Karava N.B. and Mahoney R.R. 2011.Lyophilization decreases the formation of dialyzable iron by extraction and digestion of chicken breast muscle.Int.J.Food Sci.Nutr.,62:397-403
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: Chicken muscle can promote the formation of dialyzable iron from ferric iron after digestion and extraction. We studied the effect of heating ground chicken breast muscle on this promotion effect. Chicken muscle slurry was heated to temperatures in the range 130-195 degrees F and compared to raw, unheated muscle. Digestion of raw muscle caused an eleven -fold increase in dialyzable iron and an eighteen- fold increase in dialyzable ferrous iron. Heating caused a progressive decrease in both iron forms. At 195 degrees F there was an 87% drop in dialyzable iron and an 89 % drop in dialyzable ferrous iron. Extraction of raw muscle without digestion led to an eleven- fold increase in dialyzable iron and a seven- fold increase in dialyzable ferrous iron. However the amounts of iron obtained without digestion were less than 50 % of the amounts for digested muscle. Heating to 195 degrees F caused the effect to be essentially eliminated, i.e. values were similar to the control. Both sulfhydryl and histidine content of the muscle fell progressively as the temperature was raised. At 195 degrees F only 20% of the original sulfhydryls and 50% of the original histidines remained. Heating had no discernable effect on the amount of soluble or dialyzable protein in digested samples indicating that digestion was not impaired. Our results indicate that dialyzable iron is produced by both acid soluble extractable components and by peptides resulting from digestion of proteins. Both of these were heat labile. The effect of heat is likely related to the destruction of critical iron- binding amino acids PARTICIPANTS: Individuals: Raymond Mahoney, PI, who supervised the project. Aditya Gokhale, graduate student who worked on the project and received professional, post-graduate training. TARGET AUDIENCES: Nutritionists, dieticians and others who advise on the effect of diet on iron uptake or means to combat anemia PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Consumption of muscle foods enhances the uptake of dietary iron and can help prevent anemia. Our studies show that muscle contains two sources of components that promote the production of dialyzable iron (an in-vitro indicator of iron bioavailability): extraction of the muscle with acid and also digestion of the muscle with proteolytic enzymes. However, digestion produced more dialyzable iron than extraction. Heating the muscle to typical cooking temperatures caused a significant reduction of this effect for both sources, coincident with the destruction of iron-binding amino acids. It is therefore likely that high temperature cooking of meat will significantly impair its ability to enhance iron uptake.
Publications
- No publications reported this period
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: We studied the effect of freezing and lyophilization of chicken breast muscle on the formation of dialyzable iron from ferric iron. Using chilled but never frozen chicken muscle we found that similar amounts of dialyzable iron were formed after acid extraction and after proteolytic digestion (12-15 times the amount of the iron only control); however, digestion led to more dialyzable ferrous iron ( the more bioavailable form). Freezing had no effect but lyophilization of the homogenized muscle caused large decreases in dialyzable iron and especially dialyzable ferrous iron, for both extraction and digestion processes. Lyophilization also resulted in decreased extraction of peptides, decreased digestion of muscle proteins and reduced levels of reactive sulfhydryl and histidine residues; freezing had no effect on these parameters so the effect was due solely to changes during the drying step. Our results demonstrate that dialyzable iron is produced both by acid soluble low molecular weight muscle component(s), possibly including but not limited to glutathione, and also by peptides resulting from digestion of muscle proteins: both of which reduce and chelate iron. Reduced formation of dialyzable iron by both mechanisms following lyophilization could be explained by sulfhydryl oxidation and protein crosslinking. PARTICIPANTS: Individuals: Raymond Mahoney, PI who supervised the project. Aditya Gokhale,Graduate student who worked on the project and received professional,post graduate training TARGET AUDIENCES: Nutritionists and other scientists who advise on dietary means to combat anemia PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Consumption of muscle foods enhances the uptake of iron and thereby helps prevent anemia. Our studies show that extraction of chicken muscle produces components that enhance production of dialyzable iron (an indicator of absorbable iron), and so does digestion of the muscle. Muscle foods are routinely frozen during storage and are often lyophilized (freeze dried) prior to feeding studies with animals or humans. We found that freezing per se had no effect but that freeze drying caused large decreases due to alteration in the iron binding proteins. Caution should therefore be observed when freeze drying muscle foods that are to be used to produce components which will increase iron uptake
Publications
- Shinde,R.M. and Mahoney,R.R.(2008).Production of Dialyzable iron by In Vitro Digestion of Whey and Whey Components,Nutrition and Food Science,38(4):341-346
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Progress 07/01/08 to 09/30/08
Outputs
OUTPUTS: Outputs for the short initial period included training a new graduate student in experimental procedures for digestion of muscle foods and production of bioavailable forms of iron PARTICIPANTS: Individuals-PI: Raymond Mahoney,- Graduate student who worked and received professional training:Aditya Gokhale TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Due to the very short intial period, used for training a student, there were no outcomes/impacts for this period
Publications
- No publications reported this period
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