Introdução - A anemia por deficiência de ferro é a desordem nutricional de maior prevalência tanto em países desenvolvidos como em países em desenvolvimento. Crianças pequenas e mulheres em idade fértil são grupos populacionais mais expostos a esta deficiência. Objetivo - Comparar o perfil de concentração de hemoglobina das gestantes atendidas em um serviço público de saúde de São Bernardo do Campo, no período anterior à implantação do programa de fortificação das farinhas de trigo e de milho com ferro e após pelo menos um ano de sua efetiva implantação. Métodos - Trata-se de um subprojeto do estudo Impacto da Fortificação das farinhas de trigo e de milho com ferro e ácido fólico, na concentração de hemoglobina de gestantes atendidas em serviços de saúde da rede pública. Este estudo utilizou dados secundários coletados de prontuário das gestantes freqüentadoras do Programa de Atendimento Pré-Natal do município de São Bernardo do Campo. A amostra foi constituída por dois grupos: GRUPO NÃO FORTIFICADO (NF) formado por gestantes que freqüentaram os serviços de pré-natal e tiveram o parto realizado antes de junho de 2004, e GRUPO FORTIFICADO (F) - formado por gestantes cuja data da última menstruação (DUM) foi posterior a junho de 2005. O diagnóstico de anemia foi efetuado pela [Hb] segundo critério único da OMS; e de acordo com modelos de evolução de Hb por idade gestacional de gestantes não anêmicas e não ferro deficientes e recebendo ferro suplementar durante todo o período gravídico. A severidade da anemia foi classificada segundo o nível de [Hb]: grave - abaixo de 7,0 g/dL; moderada - entre 7,0 g/dL e 10,0 g/dL; leve - níveis entre 10,0 g/dL e 11,0 g/dL. Resultados A classificação do estado nutricional apontou em ambos os grupos diminuição da desnutrição.e aumento do sobrepeso/obesidade. A prevalência de anemia foi de 14,3 por cento no Grupo NF e de 8,1 por cento no Grupo F sendo essa diferença estatisticamente significativa. A anemia severa esteve ausente entre as gestantes amostradas, a maior parte delas foi classificada como leve. Verificou-se que idade (<20 anos) e escolaridade (<8 anos) atuam na determinação da anemia de forma significativa. O modelo de evolução da [Hb] nos dois grupos é similar entre si: constância de valores no primeiro trimestre seguido da diminuição de valores até praticamente o final do processo gravídico quando há um pequeno aumento na [Hb]. De acordo com os valores de referência de Szarfarc a prevalência de anemia foi 26,8 por cento e 24,5 por cento nos grupos NF e F respectivamente e pelo referencial CDC 30,7 por cento e 26,3 por cento. Conclusões - O perfil de [Hb] das gestantes melhorou quando comparando os dois grupos, no entanto a diferença estatisticamente significativa deve ser avaliada com cautela, uma vez que outros fatores podem ter contribuído para este resultado. O estudo permitiu avaliar a evolução deste problema, bem como aperfeiçoar os programas de intervenção vigentes. / Introduction The iron deficiency anemia is the biggest nutrition disorder in developed and developing countries. Preschool kids and women in fertile age are the most exposed population group to this deficiency. Objective To compare the pregnant hemoglobin concentration profiles between the pregnant that have been attended during the period without iron fortification flour and with attended after one year of the iron fortification flour program has been begun. Methods Thats a subproject from The impact of iron and folic acid fortification in wheat and corn flours in pregnant hemoglobin concentration attended in health public services. This study has used secondary data collected through pregnant individual medical chart from Prenatal Attending Program from São Bernardo do Campo city. The sample was made by two groups: NO FORTIFICATED GROUP the pregnant who made up the group had attended the prenatal services and got birth before June 2004, effective flour fortification date all over the country, and FORTIFICATED GROUP the pregnant who made up the group were who had the date from the last menstrual period (LMP) after June 2005, at least one year of the effective of the iron fortification flour program has begun. The World Health Organization criteria was used for diagnosing anemia by hemoglobin ranges [Hb]<11,0g/dL. References, such as, the hemoglobin evolution model trough no anemic women and no iron deficiency women, and the proposal for pregnant individual who is receiving iron supplements were used for analyzing. By hemoglobin ranges the anemia severity was classified as severe under 7,0 g/dL; moderate from 7,0 g/dL to 10,0 g/dL; mild from 10,0 g/dL to 11,0 g/dL. Results The anemia prevalence was 14,3 per cent in No Fortificated Group and 8,1 per cent in Fortificated Group, this difference was statistically significant. The severe anemia was absent between the studied pregnant, and the most of them was classified as mild. The age (less 20 years old) and scholarity (less 8 years) were checked and it was able to see that the both significant act over the anemia determination. The nutritional state classification has shown in both groups malnutrition decrease (No Fortificated Group and Fortificated Group 25 per cent and 18,2 per cent respectively). The evolution of hemoglobin concentration model, in both groups, is similar: constant value on the first term followed by value decrease until the end of the pregnancy process when there is a little hemoglobin concentration increase. Adopting references values based on evolution of hemoglobin concentration , the anemia prevalence increased, however there is no statistically significant association difference between groups. Conclusions The pregnant hemoglobin concentration profiles in São Bernardo do Campo got better when the two groups were compared, however the statistically significant difference should be carefully evaluated, because others factors could contributed or this result. This study let us know about this problem progress, as well as to improve the intervention programs.

Introdução - A anemia por deficiência de ferro é a desordem nutricional de maior prevalência tanto em países desenvolvidos como em países em desenvolvimento. Crianças pequenas e mulheres em idade fértil são grupos populacionais mais expostos a esta deficiência. Objetivo - Comparar o perfil de concentração de hemoglobina das gestantes atendidas em um serviço público de saúde de São Bernardo do Campo, no período anterior à implantação do programa de fortificação das farinhas de trigo e de milho com ferro e após pelo menos um ano de sua efetiva implantação. Métodos - Trata-se de um subprojeto do estudo Impacto da Fortificação das farinhas de trigo e de milho com ferro e ácido fólico, na concentração de hemoglobina de gestantes atendidas em serviços de saúde da rede pública. Este estudo utilizou dados secundários coletados de prontuário das gestantes freqüentadoras do Programa de Atendimento Pré-Natal do município de São Bernardo do Campo. A amostra foi constituída por dois grupos: GRUPO NÃO FORTIFICADO (NF) formado por gestantes que freqüentaram os serviços de pré-natal e tiveram o parto realizado antes de junho de 2004, e GRUPO FORTIFICADO (F) - formado por gestantes cuja data da última menstruação (DUM) foi posterior a junho de 2005. O diagnóstico de anemia foi efetuado pela [Hb] segundo critério único da OMS; e de acordo com modelos de evolução de Hb por idade gestacional de gestantes não anêmicas e não ferro deficientes e recebendo ferro suplementar durante todo o período gravídico. A severidade da anemia foi classificada segundo o nível de [Hb]: grave - abaixo de 7,0 g/dL; moderada - entre 7,0 g/dL e 10,0 g/dL; leve - níveis entre 10,0 g/dL e 11,0 g/dL. Resultados A classificação do estado nutricional apontou em ambos os grupos diminuição da desnutrição.e aumento do sobrepeso/obesidade. A prevalência de anemia foi de 14,3 por cento no Grupo NF e de 8,1 por cento no Grupo F sendo essa diferença estatisticamente significativa. A anemia severa esteve ausente entre as gestantes amostradas, a maior parte delas foi classificada como leve. Verificou-se que idade (<20 anos) e escolaridade (<8 anos) atuam na determinação da anemia de forma significativa. O modelo de evolução da [Hb] nos dois grupos é similar entre si: constância de valores no primeiro trimestre seguido da diminuição de valores até praticamente o final do processo gravídico quando há um pequeno aumento na [Hb]. De acordo com os valores de referência de Szarfarc a prevalência de anemia foi 26,8 por cento e 24,5 por cento nos grupos NF e F respectivamente e pelo referencial CDC 30,7 por cento e 26,3 por cento. Conclusões - O perfil de [Hb] das gestantes melhorou quando comparando os dois grupos, no entanto a diferença estatisticamente significativa deve ser avaliada com cautela, uma vez que outros fatores podem ter contribuído para este resultado. O estudo permitiu avaliar a evolução deste problema, bem como aperfeiçoar os programas de intervenção vigentes. / Introduction The iron deficiency anemia is the biggest nutrition disorder in developed and developing countries. Preschool kids and women in fertile age are the most exposed population group to this deficiency. Objective To compare the pregnant hemoglobin concentration profiles between the pregnant that have been attended during the period without iron fortification flour and with attended after one year of the iron fortification flour program has been begun. Methods Thats a subproject from The impact of iron and folic acid fortification in wheat and corn flours in pregnant hemoglobin concentration attended in health public services. This study has used secondary data collected through pregnant individual medical chart from Prenatal Attending Program from São Bernardo do Campo city. The sample was made by two groups: NO FORTIFICATED GROUP the pregnant who made up the group had attended the prenatal services and got birth before June 2004, effective flour fortification date all over the country, and FORTIFICATED GROUP the pregnant who made up the group were who had the date from the last menstrual period (LMP) after June 2005, at least one year of the effective of the iron fortification flour program has begun. The World Health Organization criteria was used for diagnosing anemia by hemoglobin ranges [Hb]<11,0g/dL. References, such as, the hemoglobin evolution model trough no anemic women and no iron deficiency women, and the proposal for pregnant individual who is receiving iron supplements were used for analyzing. By hemoglobin ranges the anemia severity was classified as severe under 7,0 g/dL; moderate from 7,0 g/dL to 10,0 g/dL; mild from 10,0 g/dL to 11,0 g/dL. Results The anemia prevalence was 14,3 per cent in No Fortificated Group and 8,1 per cent in Fortificated Group, this difference was statistically significant. The severe anemia was absent between the studied pregnant, and the most of them was classified as mild. The age (less 20 years old) and scholarity (less 8 years) were checked and it was able to see that the both significant act over the anemia determination. The nutritional state classification has shown in both groups malnutrition decrease (No Fortificated Group and Fortificated Group 25 per cent and 18,2 per cent respectively). The evolution of hemoglobin concentration model, in both groups, is similar: constant value on the first term followed by value decrease until the end of the pregnancy process when there is a little hemoglobin concentration increase. Adopting references values based on evolution of hemoglobin concentration , the anemia prevalence increased, however there is no statistically significant association difference between groups. Conclusions The pregnant hemoglobin concentration profiles in São Bernardo do Campo got better when the two groups were compared, however the statistically significant difference should be carefully evaluated, because others factors could contributed or this result. This study let us know about this problem progress, as well as to improve the intervention programs.

It has been shown that iron binds strongly to the proteins in milk, and our aim was to determine whether or not this binding was affected by lowering pH in the manufacture of yogurt. Iron-protein complexing was studied using two different techniques. 1) Skim milk was fortified with 10 mg iron/100 ml and the pH of the milk was adjusted to 6.7, 6.2, 5.8, 5.3, 4.5, and 4.0. The milk was fractionated by ultracentrifugation at 52,000 x g for 60 minutes. The pellets and serum were then analyzed for iron, calcium, and phosphorus content by inductively coupled plasma spectroscopy. SOS-PAGE gels were used to determine protein profiles in the pellets and serum. 2) Yogurt was made from milk fortified with FeCl3, iron complexed with casein, and iron complexed with whey proteins. Small samples of the yogurt were then freeze-dried on carbon coated grids and examined by transmission electron microscopy at 80 KV. Affinity of iron for milk proteins was independent of pH. Iron fortification of milk did not cause loss of calcium or phosphorus from casein micelles. Electron spectroscopic imaging (ESI) showed that iron was bound to casein when yogurt was fortified with FeC13 or iron-casein complex. When fortified with iron-whey protein complex, the iron was distributed throughout the non-micellar portion of the yogurt. To determine effects of iron on yogurt quality, low-fat (2%) and nonfat iron fortified yogurt was made with three sources of iron: FeCl3, iron complexed with casein, and iron complexed with whey protein, at three levels (10, 20, 40 mg/kg). Iron content and lipid oxidation were determined over one month of storage at 4°C. Iron fortification had no effect on the rate of fermentation by the lactic cultures. There was no significant increase in oxidation levels between iron-fortified yogurt and unfortified yogurt (P > .05). No differences in the appearance, mouth feel, flavor, and overall quality ,between iron-fortified yogurt and unfortified yogurt were detected in consumer sensory analysis. Our study showed that high quality iron-fortified yogurt could be manufactured without added food safety risks.

Mozzarella cheese was made from milk fortified with iron so that the cheese contained 25 and 50 ppm iron. Iron was added to the milk in three ways: (1) complexed to casein (ferric-casein), (2) complexed to whey protein (ferric-whey protein), and (3) ferric chloride (FeCl3·6H20) added directly to milk. Cheese quality was determined by chemical, physical, and sensory characteristics and compared with a control cheese. Chemical oxidation, during 28 days storage, was determined by absorbance of malondialdehyde at 535 nm using the thiobarbituric acid assay (TBA). Physical properties were assessed by the Arnott test for melt, helical viscometer for stretch, and b* value for cook color. Sensory properties were tested by panelists trained to detect metallic and oxidized off-flavors and by large, untrained consumer panels. There were no significant differences in iron-fortified cheeses based on the method of adding iron to milk. There were no significant differences in TBA-measured oxidation caused by adding iron, method of adding iron, or by storage ( α=.05). Stretch was increased by addition of iron. Melt and cook color were not affected by iron fortification. The trained sensory panel scored metallic and oxidized off-flavors slightly higher in the iron-fortified cheeses than in the controls, although at a level that was slightly perceptible. When cooked on a pizza, the iron-fortified cheese was rated comparable to the control cheese by consumer panels. Based on the popularity of pizza and on these observations, it was concluded that iron-fortified Mozzarella cheese can be used as an appropriate food vehicle to supplement the diets of populations that are at risk for iron deficiency anemia (e.g., children and pregnant women).

MELO, Cintia de Brito. Fortificação de alimentos com ferro: verificação do atendimento à RDC nº 344/2002/ANVISA no Estado do Ceará. 2016. 49 f. Dissertação (mestrado em ciência e tecnologia de alimentos)- Universidade Federal do Ceará, Fortaleza-CE, 2016. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-03-22T18:41:11Z No. of bitstreams: 1 2016_dis_cbmelo.pdf: 1003999 bytes, checksum: db40a2cc654e8358a812b453ba454998 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-18T18:38:11Z (GMT) No. of bitstreams: 1 2016_dis_cbmelo.pdf: 1003999 bytes, checksum: db40a2cc654e8358a812b453ba454998 (MD5) / Made available in DSpace on 2016-05-18T18:38:12Z (GMT). No. of bitstreams: 1 2016_dis_cbmelo.pdf: 1003999 bytes, checksum: db40a2cc654e8358a812b453ba454998 (MD5) Previous issue date: 2016 / Iron deficiency is the most prevalent nutritional disorder in the world. In Brazil, iron deficiency has been recognized as an important cause of anemia for more than two decades. Iron deficiency anemia sets up an epidemiological problem of great importance that has influenced the health public spending. Among the factors that contribute to this cause is the low intake of iron, influenced by poor living conditions. The iron has been used in foods widely consumed by the population as a strategy to improve the nutritional status of populations in several countries. This study was carried out to evaluate the iron content of wheat and corn flour products available in the State of Ceará through the Nutritional Content Assessment Program of Health Ministry (PATEN) in a quantitative and retrospective kind of study of iron content assessment through analysis realized by the Central Public Laboratory of Ceara State (LACEN). Thus, attempting to verify the compliance of the products sold in the state of Ceara to The Board Resolution Collegiate, RDC Nº 344/2002/ANVISA, which obligates the fortification of wheat and maize flour with iron and folic acid, as well as to compare the prevalence of iron deficiency anemia in the the last two decades in Brazil. It was concluded that approximately 58% of the samples analyzed in the last three years were considered unsatisfactory in relation to RDC No. 344/2002/ANVISA, ie having iron content of less than 4.2 mg per 100 g of flour. In turn, the prevalence of iron deficiency anemia in Brazil has not changed significantly over the last two decades, even with the mandatory fortification of flour with iron. / A deficiência de ferro é o distúrbio nutricional mais prevalente no mundo. No Brasil, a deficiência de ferro tem sido reconhecida como importante causa de anemia há mais de duas décadas. A anemia ferropriva configura um problema epidemiológico da maior relevância influindo nos gastos públicos de saúde. Dentre os fatores que contribuem para essa causa está a baixa ingestão de ferro que é favorecida por condições precárias de vida. A fortificação com ferro nos alimentos amplamente consumidos pela população vem sendo utilizada como estratégia para melhorar a situação nutricional nas populações de diversos países. O objetivo deste estudo foi avaliar os teores de ferro dos produtos obtidos com farinhas de trigo e milho comercializados no Estado do Ceará por meio do Programa de Avaliação do Teor Nutricional do Ministério da Saúde (PATEN) em um estudo do tipo retrospectivo quantitativo de avaliação dos teores de ferro em análises realizadas no Laboratório Central de Saúde Pública do Estado do Ceará (LACEN). A partir de então, buscou-se verificar o atendimento dos produtos comercializados no Estado do Ceará à Resolução da Diretoria Colegiada nº 344/2002/ANVISA, que torna obrigatória a fortificação de farinhas de trigo e milho com ferro e ácido fólico, assim como, comparar dados relativos à prevalência de anemia ferropriva das duas últimas décadas no Brasil. Concluiu-se que aproximadamente 58% das amostras analisadas, nos últimos três anos, foram consideradas insatisfatórias em relação ao atendimento da RDC nº 344/2002/ANVISA, ou seja, possuem teor de ferro menor que 4,2 mg por cada 100 g de farinha. Por sua vez, a prevalência de anemia ferropriva no Brasil não se alterou significativamente ao longo de duas décadas, mesmo com a obrigatoriedade da fortificação das farinhas com ferro.

nÃo hà / A deficiÃncia de ferro à o distÃrbio nutricional mais prevalente no mundo. No Brasil, a deficiÃncia de ferro tem sido reconhecida como importante causa de anemia hà mais de duas dÃcadas. A anemia ferropriva configura um problema epidemiolÃgico da maior relevÃncia influindo nos gastos pÃblicos de saÃde. Dentre os fatores que contribuem para essa causa està a baixa ingestÃo de ferro que à favorecida por condiÃÃes precÃrias de vida. A fortificaÃÃo com ferro nos alimentos amplamente consumidos pela populaÃÃo vem sendo utilizada como estratÃgia para melhorar a situaÃÃo nutricional nas populaÃÃes de diversos paÃses. O objetivo deste estudo foi avaliar os teores de ferro dos produtos obtidos com farinhas de trigo e milho comercializados no Estado do Cearà por meio do Programa de AvaliaÃÃo do Teor Nutricional do MinistÃrio da SaÃde (PATEN) em um estudo do tipo retrospectivo quantitativo de avaliaÃÃo dos teores de ferro em anÃlises realizadas no LaboratÃrio Central de SaÃde PÃblica do Estado do Cearà (LACEN). A partir de entÃo, buscou-se verificar o atendimento dos produtos comercializados no Estado do Cearà à ResoluÃÃo da Diretoria Colegiada n 344/2002/ANVISA, que torna obrigatÃria a fortificaÃÃo de farinhas de trigo e milho com ferro e Ãcido fÃlico, assim como, comparar dados relativos à prevalÃncia de anemia ferropriva das duas Ãltimas dÃcadas no Brasil. Concluiu-se que aproximadamente 58% das amostras analisadas, nos Ãltimos trÃs anos, foram consideradas insatisfatÃrias em relaÃÃo ao atendimento da RDC n 344/2002/ANVISA, ou seja, possuem teor de ferro menor que 4,2 mg por cada 100 g de farinha. Por sua vez, a prevalÃncia de anemia ferropriva no Brasil nÃo se alterou significativamente ao longo de duas dÃcadas, mesmo com a obrigatoriedade da fortificaÃÃo das farinhas com ferro. / Iron deficiency is the most prevalent nutritional disorder in the world. In Brazil, iron deficiency has been recognized as an important cause of anemia for more than two decades. Iron deficiency anemia sets up an epidemiological problem of great importance that has influenced the health public spending. Among the factors that contribute to this cause is the low intake of iron, influenced by poor living conditions. The iron has been used in foods widely consumed by the population as a strategy to improve the nutritional status of populations in several countries. This study was carried out to evaluate the iron content of wheat and corn flour products available in the State of Cearà through the Nutritional Content Assessment Program of Health Ministry (PATEN) in a quantitative and retrospective kind of study of iron content assessment through analysis realized by the Central Public Laboratory of Ceara State (LACEN). Thus, attempting to verify the compliance of the products sold in the state of Ceara to The Board Resolution Collegiate, RDC N 344/2002/ANVISA, which obligates the fortification of wheat and maize flour with iron and folic acid, as well as to compare the prevalence of iron deficiency anemia in the the last two decades in Brazil. It was concluded that approximately 58% of the samples analyzed in the last three years were considered unsatisfactory in relation to RDC No. 344/2002/ANVISA, ie having iron content of less than 4.2 mg per 100 g of flour. In turn, the prevalence of iron deficiency anemia in Brazil has not changed significantly over the last two decades, even with the mandatory fortification of flour with iron.

Le fer ajouté dans des systèmes complexes tels que les aliments induit divers problèmes comme l'oxydation des lipides ou la précipitation d’autres composés présents dans la matrice. Il s’en suit une diminution de sa biodisponibilité et des défauts de goût. L'utilisation de chélates de fer, comme le bisglycinate de fer ou l’EDTA de fer, constitue une voie intéressante : le fer ainsi protégé n’interagirait pas avec la matrice alimentaire. La stabilité des chélates de fer (bisglycinate de fer et NaFe EDTA), supposés peu réactif pour l’initiation de peroxydation, a été attestée sur des modèles d’émulsions huile dans eau stabilisées par du caséinate de sodium ou de la β lactoglobuline. Dans un second temps, le travail a consisté à vérifier la faible influence de ces complexes sur la nature de l’interface huile/eau (étude de la tension et de la rhéologie interfaciales). La stabilité du bisglycinate de fer en solution aqueuse et en présence de β lactoglobuline a également été évaluée en fonction du pH (pH 2, 3,5 et 6,5) par rayons X. Il a ainsi été montré que la nature des protéines formant l’interface huile/eau et le type de sels de fer jouent un rôle crucial sur la stabilité oxydative des émulsions enrichies en fer. L'affinité des protéines de lait pour les ions fer libres est le premier facteur qui contrôle la peroxydation des matières grasses par l’absence de transfert à l'interface huile/eau. La capacité du complexe bisglycinate à retenir les ions fer et donc à limiter la présence d’ions fer libres (ferriques ou ferreux) apparaît comme le second facteur principal à contrôler. La compétition pour les ions fer entre les groupes fonctionnels des protéines et les contre ions de chélates (glycinate ou EDTA) gouverne ainsi l'état d'oxydation du système dans des conditions acide/base proche de la neutralité. En milieu acide, l'oxydation est principalement gouvernée par l’instabilité du complexe bisglycinate de fer et par conséquent la lente libération fer ionique dans la phase aqueuse. Pour résumer, si le complexe de fer n’est pas déstabilisé et que la protéine à l’interface huile/eau ne présente pas de groupe fonctionnel ayant une forte affinité pour le fer, alors la peroxydation des lipides en émulsion est faible. Dans notre démonstration, si une protéine n’est pas phosphorylée et pour des pH proches de 7, alors l’émulsion ne sera pas peroxydée car le fer ne migre pas à l’interface huile/eau. / Iron incorporated into food systems induces oxidation and precipitation. The consequences are a reduced bioavailability and a modification of other food flavor. The iron chelates such as Fe-bisglycinate and Fe-EDTA represent a possibility to avoid side effects, since the iron is protected. The inertety of Fe bisglycinate and NaFe EDTA for lipid peroxidation has been verified in oil-in-water emulsion models stabilized by sodium caseinate or by β lactoglobulin through the following studies: i/ increase of primary and secondary products of oxidation, ii/ change of the properties of the oil/water interface (tension and interfacial rheology), iii/ the stability of the chelate iron (Fe-bisglycinate) in the aqueous phase with β lactoglobulin at different pH (pH 2, 3.5 and 6.5). The oil/water interface stabilized by proteins with phosphate groups has induced peroxidation, which was not observed with proteins containing no phosphate residue. These results demonstrate also that the type of iron salts plays a crucial role in the oxidative stability of emulsions. The ability of the complex to retain iron ion and to avoid “free” ferrous ion is the first important factor to be controlled. The affinity of milk proteins to bind these free iron ions is the second factor that controls the transfer to oil/water interface. To sum up, the competition for iron ions between functional groups of protein and salt counter ions (glycinate, sulfate or EDTA) governs the oxidation state of the system in neutral conditions. In acidic medium, the oxidation is mainly governed by the stability of the complex and the possibility to free iron in bulk.