scholarly journals Effect of phytate and iron-binding phenolics on the content and availability of iron and zinc in micronutrients fortified cereal flours

Author(s):  
E Towo ◽  
C Mgoba ◽  
GD Ndossi ◽  
S Kimboka
2002 ◽  
Vol 184 (11) ◽  
pp. 2931-2939 ◽  
Author(s):  
Yuji Yamamoto ◽  
Leslie B. Poole ◽  
Roy R. Hantgan ◽  
Yoshiyuki Kamio

ABSTRACT The dpr gene is an antioxidant gene which was isolated from the Streptococcus mutans chromosome by its ability to complement an alkyl hydroperoxide reductase-deficient mutant of Escherichia coli, and it was proven to play an indispensable role in oxygen tolerance in S. mutans. Here, we purified the 20-kDa dpr gene product, Dpr, from a crude extract of S. mutans as an iron-binding protein and found that Dpr formed a spherical oligomer about 9 nm in diameter. Molecular weight determinations of Dpr in solution by analytical ultracentrifugation and light-scattering analyses gave values of 223,000 to 292,000, consistent with a subunit composition of 11.5 to 15 subunits per molecule. The purified Dpr contained iron and zinc atoms and had an ability to incorporate up to 480 iron and 11.2 zinc atoms per molecule. Unlike E. coli Dps and two other members of the Dps family, Dpr was unable to bind DNA. One hundred nanomolar Dpr prevented by more than 90% the formation of hydroxyl radical generated by 10 μM iron(II) salt in vitro. The data shown in this study indicate that Dpr may act as a ferritin-like iron-binding protein in S. mutans and may allow this catalase- and heme-peroxidase-deficient bacterium to grow under air by limiting the iron-catalyzed Fenton reaction.


Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.


2001 ◽  
Vol 14 (2) ◽  
pp. 111-113
Author(s):  
Arthur L. Schade ◽  
Liona Caroline

2004 ◽  
Vol 74 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Lombardi-Boccia ◽  
Lanzi ◽  
Lucarini ◽  
Di Lullo

This study was undertaken to estimate the contribution of meat and meat products consumption to the daily intakes of trace elements (Fe, Zn, Cu, Se), heme iron, and selected B vitamins (thiamine, riboflavin, niacin) in Italy. Meat and meat products were selected on the basis of their consumption frequency reported by the most recent nationwide dietary individual survey carried out in Italy (INN-CA study). The daily intakes of total iron and heme iron were 1.65 and 1.13 mg/person/day. Zinc intake was 3.65 mg/person/day. Beef made the main contribution to iron, heme iron, and zinc daily intakes. Copper daily intake was 107.3 mug/person/day, with meat products provided the highest contribution (40 mug/person/day). Daily intake of selenium (7.14 mug/person/day) was provided mainly by poultry consumption. Thiamine intake was 228 mug/person/day, and meat products were the main source (110 mug/person/day). Riboflavin intake was 136 mug/person/day, with both beef and meat products as the main contributors (40 mug/person/day). Niacin intake was 7.53 mg/person/day, and poultry was the main source (2.28 mg/person/day). Meat and meat products were a valuable source of micronutrients, supplying 47, 48, and 24% of zinc, niacin, and thiamin daily requirements, respectively, and over 10% of iron, copper, selenium, and riboflavin daily average requirement values of the italian RDAs calculated for the population involved in the survey (INN-CA study).


1991 ◽  
Vol 30 (06) ◽  
pp. 290-293 ◽  
Author(s):  
P. Maleki ◽  
A. Martinezi ◽  
M. C. Crone-Escanye ◽  
J. Robert ◽  
L. J. Anghileri

The study of the interaction between complexed iron and tumor cells in the presence of 67Ga-citrate indicates that a phenomenon of iron-binding related to the thermodynamic constant of stability of the iron complex, and a hydrolysis (or anion penetration) of the interaction product determine the uptake of 67Ga. The effects of various parameters such as ionic composition of the medium, nature of the iron complex, time of incubation and number of cells are discussed.


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