天然补铁剂-血红素铁的研究进展

缺铁性贫血是我国人群普遍存在的营养性疾病之一，虽然传统的补铁剂在日常生活中起到一定的治疗效果，但其副作用大、吸收率低，而血红素铁是一种生物态铁，可以直接被肠粘膜细胞吸收，生物利用率高，在国外已作为食品营养强化剂广为使用，本文就血红素铁的特性及研究进展作以综述。     

生物态补铁剂-血红素铁研究进展

血红素铁是一种生物态铁,可直接被肠粘膜细胞吸收,不产生任何消化道刺激症状,生物利用率高,是理想补铁剂。该文综述血红素铁结构与性质、功能、提取、测定方法和在食品工业中应用情况。     

生物态补铁剂-血红素铁的研究进展

血红素铁是一种生物态铁,可以直接被肠黏膜细胞吸收,不产生任何消化道刺激症状,生物利用率高,是理想的补铁剂.本文综述了血红素铁的结构与性质、功能、提取、测定方法和在食品工业中的应用情况.     

生物态补铁剂—血红素铁的研究进展

血红素铁是一种生物态铁,可以直接被肠黏膜细胞吸收,不产生任何消化道刺激症状,生物利用率高,是理想的补铁剂。本文综述了血红素铁的结构与性质、功能、提取、测定方法和在食品工业中的应用情况。     

Sorption of oxytetracycline to iron oxides and iron oxide-rich soils

The sorption interactions of oxytetracycline with goethite, hematite, and two iron oxide-rich soils were investigated using batch sorption experiments. Oxytetracycline sorption coefficients for goethite and hematite increased with pH to maximum values at pH approximately 8. The sorption edge shape and desorption treatments were consistent with a surface complexation mechanism and could be described by the interaction of divalent anion species with the oxide surface. Oxytetracycline sorption to Georgeville and Orangeburg Ultisol soils decreased with pH. Chemical digestion treatments were used to deduce that soil sorption occurred by complexation to oxide coatings on clay and quartz grains. These results indicate that sorption models must consider the interaction of oxytetracycline, and other similar ionogenic compounds, with soil oxide components in addition to clays and organic matter when predicting sorption in whole soils.     

Influence of dietary phenolic acids on redox status of iron: Ferrous iron autoxidation and ferric iron reduction

We investigated the effect of dietary phenolic acids on the oxidation of Fe²⁺ caused by molecular oxygen. All phenolic acids bearing 3,4-dihydroxy (catechol) or 3,4,5-trihydroxy (galloyl) moiety formed chelates with ferric iron and significantly increased the rate of Fe²⁺ autoxidation. The carboxylate group and catechol substitution instead of galloyl moiety facilitated the ferrous ion oxidation more effectively. Caffeic acid and protocatechuic acid, the strongest accelerators of Fe²⁺ autoxidation, were able to facilitate autoxidation at concentrations lower than 1% of the initial amount of Fe²⁺. Therefore chelates of these catecholic acids with iron displayed ferroxidase-like activity. Conversely, when we started from ferric ions, catechols partially formed ferrous ions in the presence of ferrozine. Thus, catecholic acids formed stable chelates with iron, in which ferric ion is the dominant species, but the redox cycling of iron between Fe²⁺ and Fe³⁺ in chelates probably plays a crucial role in the catalysis of ferrous iron autoxidation. Interestingly, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid and vanillic (4-hydroxy-3-methoxybenzoic) acid protected ferrous ions from autoxidation as effectively as ascorbic acid and cysteine. These monophenolic acids, differently from ascorbic acid and cysteine, were not able to reduce ferric ions. Syringic (3,5-dimethoxy-4-hydroxybenzoic) acid did not alter the redox state of iron, only in a large excess over metal, syringic acid slightly inhibited ferrous ions autoxidation and partially reduced ferric ions. Therefore, the effects of syringic acid at high concentration were similar but much lower to those of ascorbic acid and cysteine. The biological importance of ferroxidase-like activity of polyphenols, especially the influence on iron absorption, is also discussed.     

Sensory characteristics and iron dialyzability of gluten-free bread fortified with iron

The objectives of the present study were (a) to produce gluten-free bread, fortified with iron (GFB-Fe), using selected iron compounds (ferric pyrophosphate, ferric pyrophosphate with emulsifiers, NaFeEDTA, electrolytic iron, ferrous gluconate, ferrous lactate and ferrous sulphate) (b) to test sensory characteristics of the GFB-Fe (feel-mouth texture, crumb colour, aroma and taste) (c) to compare iron dialyzability of various iron compounds in GFB-Fe. The most acceptable products were those fortified with ferric pyrophosphate with emulsifiers and ferric pyrophosphate. Ferrous dialyzable iron (ferrous iron with molecular weight lower than 8000 Da, an index for prediction of iron bioavailability) was measured under simulated gastrointestinal conditions. Ferrous dialyzable iron in GFB-Fe fortified with ferric pyrophosphate with emulsifiers, NaFeEDTA, ferrous bis-glycinate, ferrous gluconate or ferrous sulphate was higher than that in GFB-Fe fortified with electrolytic iron, ferrous lactate or ferric pyrophosphate (P < 0.05). These results are promising for the development of GFB-Fe products in the future.     

富铁豆蛋白中铁的结合形态的研究

富铁豆蛋白[1]是一种用特殊方法得到的高铁物质,它提供了一条补铁的新途径。本文利用生化分析方法,研究了铁在豆蛋白中的分布状态,并分析了它们的含量,游离铁为88.1μg/g,结合于蛋白中的铁为908.14μg/g,结果表明,铁主要以结合于蛋白质上的有机铁的形式存在。     

Effects of iron supplementation versus dietary iron on the nutritional iron status: Systematic review with meta-analysis of randomized controlled trials

ABSTRACT

This meta-analysis compared the effects of dietary intervention versus iron supplementation on biochemical parameters related to the iron nutritional status in humans. The PubMed, CENTRAL, LILACS, SCIELO, OPENGREY.EU and ClinicalTrials.gov databases were searched for randomized clinical trials that assigned individuals to a dietary intervention or to an iron supplementation regimen, for 12 weeks or more. The primary outcome was the hemoglobin concentration, and secondary outcomes were ferritin, RDW, mean corpuscular volume, soluble transferrin receptor, total iron binding capacity, serum iron, and transferrin saturation. From the 6095 records identified, twelve studies were included, six with children, five with adolescents/adults, and one with pregnant women. In the subgroup of studies that included anemic/iron deficient children, supplementation significantly increased the hemoglobin concentration (weighted mean difference (WMD): 3.19 g/L [95% CI: 1.31, 5.07]) and induced a significantly greater reduction of the soluble transferrin receptor (WMD: ?0.46 mg/L [95% CI: ?0.70, ?0, 21]), when compared to dietary intervention. It also induced a greater reduction of the total binding capacity of iron in adolescents/adults (WMD: ?6.96 μmol/L [95% CI: ?12.70, ?1.21]). Supplementation showed a better effect on hemoglobin recovery in anemic/iron deficient children, while no differences were observed between supplementation and dietary intervention in treating adolescents/adults.     

Plant genetic factors for iron homeostasis affect iron bioavailability in Caco-2 cells

The Caco-2 cell model is standardised for testing Fe uptake capacities of human epithelial cells from various food sources. Here, we used this system to study the impact of plant genetic Fe homeostasis factors on Fe bioavailability. The tomato fer mutant produces yellow Fe-deficient leaves due to the inability of the plant mutant to acquire Fe from soil. The chloronerva mutant lacks the metal chelator nicotianamine that is necessary for proper distribution and internal mobilization of Fe within the plant. We found that Fe uptake by Caco-2 cells was significantly compromised when mutant fer and chloronerva tomato leaf extracts had been supplied as Fe source. However after supplementation with Fe, no difference in Fe uptake were observed between fer and wild type tomato samples, whereas increased Fe uptake was obtained for chloronerva samples.Hence, our work suggests that genetic factors for plant Fe contents are important determinants for food quality.     

大包角烫光机原理及烫光效率分析

介绍了大包角烫光机的结构组成,并对大包角烫光机与普通烫光机的烫光效率进行分析 比较。     

缺铁性贫血与补铁剂研究概况

缺铁性贫血是世界范围内最普遍的营养素缺乏症之一,严重影响着人们的身体健康。铁摄入不足和过大消耗是造成缺铁性贫血的常见原因。因此,摄入足量的铁是预防和治疗缺铁性贫血的有效办法。科学工作者们一直致力于安全、有效的补铁剂的研究。目前补铁剂主要包括:以硫酸亚铁为代表的第一代补铁剂,以乳酸亚铁为代表的第二代补铁剂和近些年兴起的以大分子螯合铁为代表的第三代补铁剂。第三代补铁剂较第一、二代不仅具有吸收利用度好、副作用少、性质稳定等优点,而且其中大分子螯合剂还具有抗氧化、抑菌、免疫调节等生物活性,因而越来越受到人们的青睐,也成为了科研工作者的重点研究对象。本文围绕缺铁性贫血与人类健康、补铁剂研究历史、多糖铁复合物、多肽铁复合物以及富铁酵母等新型补铁剂的研究现状进行综述。     

The use of food enriched with iron and vitamins for iron deficiency correction

The data on the usage of fortified with iron food products for iron deficiency correction are summarized. Efficiency of enrichment with different iron forms (heme, organic and inorganic salts etc.) combining with one or several vitamins and possible undesirable effect of iron excess intake are discussed.     

Green rust and iron oxide formation influences metolachlor dechlorination during zerovalent iron treatment

Electron transfer from zerovalent iron (Fe0) to targeted contaminants is affected by initial Fe0 composition, the oxides formed during corrosion, and surrounding electrolytes. We previously observed enhanced metolachlor destruction by Fe0 when iron or aluminum salts were present in the aqueous matrix and Eh/pH conditions favored formation of green rusts. To understand these enhanced destruction rates, we characterized changes in Fe0 composition during treatment of metolachlor with and without iron and aluminum salts. Raman microspectroscopy and X-ray diffraction (XRD) indicated that the iron source was initially coated with a thin layer of magnetite (Fe3O4), maghemite (gamma-Fe2O3), and wüstite (FeO). Time-resolved analysis indicated that akaganeite (beta-FeOOH) was the dominant oxide formed during Fe0 treatment of metolachlor. Goethite (alpha-FeOOH) and some lepidocrocite (gamma-FeOOH) formed when Al2(SO4)3 was present, while goethite and magnetite (Fe3O4) were identified in Fe0 treatments containing FeSO4. Although conditions favoring formation of sulfate green rust (GR(II); Fe6(OH)12SO4) facilitated Fe0-mediated dechlorination of metolachlor, only adsorption was observed when GR(II) was synthesized (without Fe0) in the presence of metolachlor and Eh/pH changed to favor Fe(III)oxyhydroxide or magnetite formation. In contrast, dechlorination occurred when magnetite or natural goethite was amended with Fe(II) (as FeSO4) at pH 8 and continued as long as additional Fe(II) was provided. While metolachlor was not dechlorinated by GR(II) itself during a 48-h incubation, the GR(II) provided a source of Fe(II) and produced magnetite (and other oxide surfaces) that coordinated Fe(II), which then facilitated dechlorination.     

Goat milk during iron repletion improves bone turnover impaired by severe iron deficiency

The effect of goat or cow milk-based diets, with either normal Fe content or an Fe overload, on bone turnover and the mineralization process was studied in control and anemic rats during chronic Fe repletion. One hundred eighty male Wistar rats were studied during a pre-experimental period of 40 d in which they were randomly divided into 2 groups, a control group receiving the AIN-93G diet with normal Fe content (45 mg/kg of diet) and the Fe-deficient group receiving the AIN-93G diet with low Fe content (5 mg/kg of diet) for 40 d. After the pre-experimental period, the rats were fed for 10, 30, or 50 d with goat or cow milk-based diets with a normal Fe content (45 mg/kg of diet) or an Fe overload (450 mg/kg of diet). In anemic rats, goat milk with normal Fe content increased levels of the biomarker of bone formation N-terminal propeptides of type I procollagen and diminished parathyroid hormone levels after only 10 d of supplying this diet, indicating the beginning of restoration of the bone demineralization induced by the anemia, which was not observed with cow milk. After 30 d of supplying the milk-based diets with normal Fe content or an Fe overload, biomarkers of bone formation and bone resorption were not different between control and anemic rats, indicating that the bone demineralization induced by the Fe-deficiency anemia had recovered, although the process of stabilization of bone turnover began earlier in the animals fed goat milk. In addition, a higher Ca deposit was observed in femur, which positively affects bone mineralization, as well as an increase of Fe in sternum, which indicates that the hematopoietic process essentially recovered earlier on the goat milk diet compared with the cow milk diet.     

硫氰酸钾分光光度法快速测定多维铁口服液的铁含量

目的建立硫氰酸钾分光光度法快速测定多维铁口服液中铁含量的分析方法。方法样品经酸化氧化处理,考察了硫氰酸钾分光光度法的最大吸收波长、显色剂的最佳用量、最佳显色时间、精密度和加标回收率,并与国标法进行了比较。结果方法的最大吸收波长为480 nm,最佳显色剂用量为1.00 m L 50%的硫氰酸钾溶液,最佳显色时间是10 min,方法线性回归方程为Y=0.12037X+0.00357,相关系数为0.99988,检出限为0.020μg/m L,回收率为99.5%～100.94%,相对标准偏差为0.15%～0.48%。结论与国标法比较,该方法具有良好的精密度、准确度和重复性,且成本较低、易于控制、操作简单、快速、稳定等优点。     

羰基铁粉在安全毒理学与铁营养强化剂应用方面的研究进展

羰基铁粉是一种黑灰色、粉末状还原型元素态铁粉,在国外大量应用于铁营养强化剂和补铁药品;美国食品化学品法典(FCC)规定食品用羰基铁粉的粒度须100%通过200目标准筛,且95%通过325目标准筛,铁含量在98%以上;安全毒理学数据证实羰基铁粉的大鼠急性经口毒性LD50为30g/kg;美国、欧盟、澳大利亚和新西兰等已允许羰基铁粉在食品中应用;目前我国食品营养强化剂GB14880名单中可用元素态铁粉有还原铁和电解质铁,羰基铁粉尚未列入.本文介绍了羰基铁粉的起源、理化性质,安全性毒理学研究和生物利用率等情况,以及作为铁营养强化剂在食品方面政策法规和国际应用状况.     

农村寄宿制学校用铁强化酱油状况及铁含量分析

贫血在我国属于中度公共卫生问题,铁强化酱油是安全有效的人体铁营养改善方法。本研究采集了24个省寄宿制学校使用的43个铁强化酱油产品,采用原子吸收分光光度法测定铁强化酱油总铁含量。结果显示,抽样地区农村寄宿制学校用铁强化酱油产品铁含量均值为（216.1±17.9） mg/kg,铁含量分布范围为191.5～263.8 mg/kg。农村寄宿制学校铁强化酱油中一级酱油占51.2%,桶装酱油占60.5%,高盐稀态发酵工艺的酱油占88.4%,生抽占55.8%。铁含量与酱油保存时间没有相关性,不同等级、不同包装形式铁强化酱油中铁含量无显著性差异,不同品种酱油中铁含量有显著差异,生抽中铁含量显著高于老抽。所有农村寄宿制学校铁强化酱油中铁含量均符合我国相应的食品安全国家标准。     

分光光度法测定铁质叶酸片中铁元素的含量

建立测定铁质叶酸片中铁含量的方法.用1∶1的盐酸溶液和10％的盐酸羟胺处理样品,使样品中的铁全部转化成Fe2+,Fe2+与0.15％的邻菲罗啉显色剂络合生成稳定的橙红色化合物,按分光光度法,在511 nm处测定吸光度.结果表明,铁离子浓度在0.022 4～0.112 0 mg/mL范围内呈现良好线性.平均回收率为99.2％.RSD为1％(n=6).该方法操作简单,样品前处理简便,结果稳定、精确,适用范围广,可用于铁质叶酸片中铁元素含量的测定.