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1.
Multi‐micronutrient‐fortified rice could be an effective and sustainable approach to combat micronutrient deficiencies. We produced hot‐extruded artificial rice grains fortified with 10 mg iron (as micronised ground ferric pyrophosphate), 5 mg zinc (as oxide, sulphate or carbonate) and 750 μg vitamin A/g [as retinyl palmitate (RP)] and measured RP stability. The rice was designed to be mixed 1:200 with natural rice. Mean RP losses were 5.3% during extrusion, 28.5% during storage and 9.8% during cooking. Storage losses after 18 weeks at 30 °C in plastic packages exposed to light were ca 40% with iron and zinc causing no further losses. In aluminium packages (no light), mean RP losses were ca 20%. Iron, but not zinc, increased RP degradation. Zinc sulphate increased the negative effect of iron. The relatively good stability of RP during hot extrusion can be explained by the closed surface and dense nature of the artificial grain protecting RP from oxidation.  相似文献   

2.
食醋生产过程中铁、锌、铜的迁移变化   总被引:1,自引:1,他引:0       下载免费PDF全文
本文研究了食醋发酵过程中铁、锌、铜的产生途径及影响因素。采用原子吸收分光光度法对镇江香醋不同发酵阶段液相、固相中的铁、锌、铜含量变化进行分析。结果表明铁、锌、铜在发酵各阶段液相中主要以可溶态存在,沉淀的形成对Fe、Zn、Cu具有富集作用。随着发酵的进行,发酵设备、管道由于长期受醋酸、有机酸等的腐蚀使铁、锌、铜游离和在发酵生产过程中添加了含有铁、锌、铜的辅料,是醋醅中铁、锌、铜含量上升的主要因素。醋中铁主要来源于醋酸发酵和封醅陈酿阶段,在淋醋时铁浓度达到最高,59.69 mg/L。醋中的锌、铜主要来源于酒精发酵阶段,浓度分别达到18.12 mg/L和0.60 mg/L。由于醋醅对铁、锌、铜元素具有强吸附力,醋醅对醋液中的金属元素浓度具有一定的调控作用。通过本研究表明改进设备材质、采用合理的过滤措施及在发酵过程中使用金属离子吸附剂将是控制食醋中金属含量的有效措施。  相似文献   

3.
L Nagy 《Die Nahrung》1987,31(1):3-10
The Fe, Cu- and Zn contents of the daily menu of teen-agers were examined over two years with 124 samples taken. The samples were homogenized, subsequently dried at 104 degrees C finally incinerated at 480 degrees C. The ash was dissolved by heating with 3 N HCl. Determination of the three micro-elements was carried out by atomic absorption spectrophotometry. It was found that the daily intake of the micro-elements investigated is much below the value proposed by FAO/WHO, however, somewhat higher than the calculated Hungarian data. According to measurements, the average daily micro-element intake is 10.77 +/- 4.42 mg for iron; 1.23 +/- 0.65 mg for copper and 9.44 +/- 2.39 mg for zinc. With enumeration of iron, copper and zinc sources, dietary recommendations are given in order to increase the average values.  相似文献   

4.
The uptake of iron, zinc, copper and lead by food cooked under domestic conditions in utensils made of different metals (cast iron, aluminium, plain and tinned copper) was investigated. It was found that the metal content of the food was generally related to the metal in immediate contact with the food during cooking. Daily dietary intake could vary from 11 to 6 mg of iron, 11 to 9 mg of zinc, 2 to 1 mg of copper and 0.4 to 0.1 mg of lead, depending on the cooking utensils used. Dietary intake of the metals was also related to sources and domestic practices regarding water supply. Consistent use of municipal water from a domestic hot water system could contribute a daily intake of 32 mg iron, 29 mg zinc and 12 mg copper. Rainwater stored in a galvanized iron tank could provide 23 mg of zinc per day when used for domestic purposes. The nutritional and toxicological significance of such adventitious sources of metals in the diet are discussed. The need to consider them when investigating the metal intake of individuals is stressed.  相似文献   

5.
The incidence of iron deficiency anemia, rickets, and zinc deficiency is very high in Chinese preschool children and a method for prevention is urgently needed. From our studies, it can be seen that a soft drink powder is a convenient vehicle for the supplementation of iron, zinc, calcium, vitamin D, riboflavin, and ascorbic acid. Table salt is also a good, low-cost carrier for iron and zinc, and cow's milk can only be used for the enrichment of vitamins A and D. In our study the therapeutic dose of iron was lower than 3 mg/kg body weight recommended by the WHO Expert Committee. As ascorbic acid can enhance the absorption of iron in the body, so 300 mg vitamin C was added to 100 g of soft drink powder containing 100 mg of elemental iron. Ten g of powder is not only enough for the prevention of iron deficiency anemia but it can also cure iron deficiency anemia within 3 months. One hundred mg of iron in 100 g of table salt is an adequate level, because an adult or a child taking 10 or 5 g of salt will receive 10 and 5 mg of elemental iron respectively. This dosage is adequate for the prevention of anemia. From our results, 10 mg of zinc daily is enough for the prevention and treatment of zinc deficiency in preschool children. Four hundred IU of vitamin D (from fortified soft drink powder or enriched fresh cow's milk) orally-administered daily, is a good way to prevent rickets in infants and young children.  相似文献   

6.
Addition of corrosion promoters, such as sodium and potassium chloride, accelerated TNT degradation during water treatment using zerovalent zinc and iron. It was theorized that corrosion promoters could be used to accelerate electron generation from metallic species, create new reactive sites on the surface of metals during contaminated water treatment, and minimize passivating effects. The surface area normalized pseudo-first-order rate constant for the reaction of zerovalent zinc with TNT in the absence of KCl was 1.364 L x m(-2) x h(-1). In the presence of 0.3 mM and 3 mM KCI, the rate constant increased to 10.5 L x m(-2) x h(-1) and 51.0 L x m(-2) x h(-1), respectively. For the reaction with zerovalent iron and TNT, the rate constant increased from 6.5 (L/m2 x h) in the absence of KCl to 37 L x m(-2) x h(-1) using 3 mM KCl. The results demonstrate that chloride based corrosion promoters enhance the rate of TNT degradation. The in-situ breakage of the oxide layer using corrosion promoters was applied as a treatment to maintain the long-term activity of the metallic species. Zinc maintained a high reactivity toward TNT, and the reactivity of iron increased after 5 treatment cycles using 3 mM KCI. Zinc and iron scanning electron micrographs indicate that TNT degradation rate enhancement is caused by the pitting corrosion mechanism.  相似文献   

7.
The investigation aimed at studying the influence of soya proteins on in vitro dialysability of exogenous iron and zinc. Soyabean was processed into various components like soya flour (SF), concentrate (SC) and isolate (SI) and two peptides (<30 kDa and >30 kDa). The protein contents of SF, SC and SI were 51, 62 and 78 g/100 g, respectively. Their iron contents ranged between 9.7 and 15.8 mg/100 g and zinc contents from 3.3 to 6.7 mg/100 g. Phytic acid contents (mg/100 g) of the soya components were SF 339, SC 226, SI 186 and peptides 18–20. In SF, percent dialysable iron and zinc were 12.6 and 50, respectively, this reduced to one-third and one-fifth in SC and SI. Dialysability of exogenously added minerals was found to be significantly lower in all soya protein components. However, the inhibitory effect was less pronounced in peptides. The protein component/matrix effect needs to be investigated to counteract the inhibitory effect of soya on iron dialysability.  相似文献   

8.
Iron deficiency anaemia and zinc deficiency have been persistent public health problems worldwide. Both deficiencies are attributed to poor bioavailability of minerals. The investigation was undertaken to study the effect of oilseed protein concentrates and exogenous amino acids on the dialysability of iron and zinc. Corn flour matrices with 10–20 g protein/100 g were formulated using groundnut and sesame protein concentrates. Dialysability of iron and zinc in natural and mineral fortified matrices was analysed. The effect of exogenous cysteine, histidine, glycine and lysine on mineral dialysability was analysed in groundnut and sesame protein concentrates. Dialysability of iron was enhanced with increasing protein concentration in matrices with groundnut protein but decreased in matrices with sesame protein. Dialysability of zinc increased with increasing protein concentration with both the protein concentrates. Among the amino acids, histidine enhanced dialysability of iron in natural groundnut and sesame protein concentrates, glycine in fortified groundnut and lysine in fortified sesame protein concentrates to a considerable extent. Dialysability of zinc was enhanced in natural groundnut, natural and fortified sesame protein concentrates by all amino acids. Amino acids definitely promotes the dialysability of iron and zinc, but its enhancing ability is highly specific to the food matrix.  相似文献   

9.
探讨了利用电感耦合等离子体发射光谱法(ICP-AES)同时测定食品中钙铁锌含量的测定方法。应用ICP-AES对奶粉成分标准物质(GBW 10017)中的钙铁锌含量进行测定,结果表明:方法具有灵敏度高、检测限低、高效、稳定的优点,方法的检出限分别为钙0.1mg/kg,铁0.02mg/kg,锌0.01mg/kg,相对标准偏差低于6%。  相似文献   

10.
The Fe, Cu-and Zn contents of the daily menu of teen-agers were examined over two years with 124 samples taken. The samples were homogenized, subsequently dried at 104 °C finally incinerated at 480 °C. The ash was dissolved by heating with 3 N HCl. Determination of the three micro-elements was carried out by atomic absorption spectrophotometry. It was found that the daily intake of the micro-elements investigated is much below the value proposed by FAO/WHO, however, somewhat higher than the calculated Hungarian data. According to measurements, the average daily micro-element intake is 10.77 ± 4.42 mg for iron; 1.23. ± 0.65 mg for copper and 9.44 ± 2.39 mg for zinc. With enumeration of iron, copper and zinc sources, dietary recommendations are given in order to increase the average values.  相似文献   

11.
Oat and soy-based nutrition bars were fortified with 4 levels of fish oil (0, 6, 12, or 18 g per approximately 600 g batch), representing 0%, 20%, 40%, or 60% replacement of canola oil. The commercially available purified fish oil was not emulsified nor encapsulated, and contained tocopherols. Baked nutrition bars were evaluated for proximate composition, water activity, alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic (DHA) content, and consumer acceptance using a 9-point hedonic scale. The bars were sealed in opaque bags and stored in a stability chamber at 25 °C and 50% relative humidity for 10 wk to assess oxidative stability. There were no significant (P > 0.05) differences in proximate composition, water activity, or ALA levels among treatments. EPA and DHA levels were significantly (P < 0.05) different among treatments, averaging 178.1 mg/serving (20-FO), 488.3 mg/serving (40-FO), and 664.6 mg/serving (60-FO), but none changed during storage. Headspace hexanal and propanal levels decreased over time but were not significantly different among treatments until week 10. Peroxide values were not significantly different except between the control and 60-FO bars. Low values obtained for these analyses suggest negligible oxidation in the bars. Consumer acceptance scores did not differ significantly between the control and lowest fortification level (20-FO), ranging from 6.4 to 6.6 for aroma, texture, flavor, and overall acceptability. These results suggest that nonemulsified, nonencapsulated fish oil can successfully replace canola oil in intermediate moisture nutrition bars to provide EPA and DHA levels as high as 178 mg/serving without affecting consumer acceptability or oxidative stability. Practical Application: Omega-3 fatty acid rich fish oil has been shown to have numerous health benefits, but there are limitations to its use in shelf-stable food products. In this study, nutrition bars were successfully fortified with nonencapsulated, nonemulsified fish oil to deliver 178 mg EPA and DHA per 35 g serving. The fortified bars were oxidatively stable over 10 wk and acceptable to consumers.  相似文献   

12.
Abstract: Iron and zinc deficiencies are the most prevalent nutrient deficiencies worldwide. They often coexist as the dietary factors, especially phytate, which impairs iron absorption also affects zinc absorption. Therefore, suitable strategies are required to control multiple micronutrient deficiencies in populations that subsist on high‐phytate foods such as the whole wheat flour based Indian bread (chapatti). The objective of the study, therefore, was to test the bioavailability of iron and zinc in 2 multiple micronutrient beverage premixes in the absence and presence of chapatti. The premix‐1 contained iron, zinc, and vitamin A while premix‐2 contained all micronutrients in premix‐1, plus folic acid and ascorbic acid. Ferritin induction and 65Zn uptake were assessed using coupled in vitro digestion/Caco‐2 cell line model as the surrogate markers of iron and zinc bioavailability, respectively. The results show that iron bioavailability from premixes‐1 and 2 was similar in the absence of chapatti. However, premix‐2 showed significantly higher iron bioavailability compared to premix‐1 in the presence of chapatti. In contrast, the zinc uptake was similar from both premixes‐1 and 2 in the absence or presence of chapatti. These results suggest that both the premixes provide bioavailable minerals, but premix‐2 appears to be promising in the presence of foods that have high phytate.  相似文献   

13.
The dialyzability method has been considered a convenient option for screening a large number of samples for iron bioavailability. A new setup that allows the rapid and efficient application of the dialyzability method has been recently proposed. To evaluate the new setup for its applicability in predicting iron and zinc bioavailability, dialyzable iron or zinc were compared with iron or zinc absorption. A series of solutions and meals that have been employed in published studies on iron or zinc absorption were prepared as described in the literature and digested in vitro using the new setup. Dialyzability was measured and correlated with published data on absorption. Iron or zinc dialyzability measured with the proposed setup correlated well with iron or zinc absorption. These results suggest that the new setup can be employed in the future applications for the prediction of iron or zinc bioavailability.  相似文献   

14.
Lead, cadmium, iron, copper and zinc contents of Ka?ar cheese sold in the markets of Ankara, Turkey, were determined over 12 months. A total of 240 samples comprising 10 different brands were analysed. Graphite-furnace atomic absorption was employed for the determination of lead and cadmium, and flame atomic absorption for iron, copper and zinc. The mean (range) of the lead, cadmium, iron, copper and zinc content of the samples were 86 (10-421) microg kg(-1), 1.8 (0.3-8.3) microg kg(-1), 4.2 (1.0-14.1) mg kg(-1), 0.7 (0.3-1.6) mg kg(-1) and 37.7 (26.5-63.0) mg kg(-1), respectively. The samples in November, December and January contained higher amounts of lead than those in other months (p < 0.01). Moreover, important differences existed in lead content of the samples between different cheese producers (p < 0.01). The differences in cadmium and iron content of the samples for different months were important (p < 0.01). The iron content of the samples among manufacturers also varied significantly (p < 0.01). However, there were no significant differences in copper and zinc contents of the samples over 12 months (p > 0.05). These findings suggested that some contamination occurred during milk production and/or manufacturing of cheese depending on the equipment used. For a consumption of 100 g Ka?ar cheese, one would ingest approximately 8.6 microg (4% of the provisional tolerable daily intake, PTDI) of lead, 0.2 microg (0.3%) of cadmium, 0.4 mg (0.9%) of iron, 0.07 mg (2%) of copper and 3.8 mg (6%) of zinc. Therefore, it was concluded that Ka?ar cheese is not a significant contributor to the intake of investigated heavy metals.  相似文献   

15.
Arsenic removal is often challenging due to high As(III), phosphate, and silicate concentrations and low natural iron concentrations. Application of zerovalent iron is promising, as metallic iron is widely available. However, removal mechanisms remained unclear and currently used removal units with iron have not been tested systematically, partly due to their large size and long operation time. This study investigated smaller filter columns with 3-4 filters, each containing 2.5 g of iron filings and 100-150 g of sand. At a flow rate of 1 L/h, these columns were able to treat 75-90 L of well water with 440 microg/L As, 1.8 mg/L P, 4.7 mg/L Fe, 19 mg/L Si, and 6 mg/L dissolved organic carbon (DOC) to below 50 microg/L As(tot), without addition of an oxidant. As(III) was oxidized in parallel to oxidation of corrosion-released Fe(II) by dissolved oxygen and sorbed on the forming hydrous ferric oxides (HFO). The open filter columns prevented anoxic conditions. DOC did not appear to interfere with arsenic removal. Manganese was reduced after a slight initial increase from 0.3 mg/L to below 0.1 mg/L. About 100 mg of Fe(0)/L of water was required, 3-5 times less than that for larger units with sand and iron turnings.  相似文献   

16.
Souring by lactic acid fermentation and lactic acid acidification as well as inclusion of amaranth were explored as ways of improving the protein quality and iron and zinc bioaccessibilities of non-alcoholic sorghum-based beverages. The bioaccessible iron and zinc increased by 128–372%, 24–194%, respectively, in the fermented and chemically acidified beverages compared to the beverages without fermentation or acidification. The protein digestibility, reactive lysine, and bioaccessible iron in sorghum-amaranth beverages increased by 14–58%, 24–52% and 34–64%, respectively, compared with the 100% sorghum beverages. Both fermentation and acidification with lactic acid have the potentials for improving the nutritional quality of cereal-based foods as a means of combating protein malnutrition and iron and zinc deficiencies.  相似文献   

17.
Standard plate counts of 5085 drinking water samples gathered in the Region of Basle were carried out over a period of 9 years (1977 to 1985). Two conditions of incubation were evaluated: 20 degrees C and 30 degrees C for 72 h. In ground water samples (3048 samples) colony forming units (cfu) at 30 degrees C were found to be higher than counts at 20 degrees C incubation, 45% of the samples contained greater than or equal to 2 cfu/ml at 30 degrees versus 35% at 20 degrees C. The median was 1 cfu/ml at both temperatures. In spring water samples (2036 samples) bacterial counts at 20 degrees C were found to be higher than counts at 30 degrees C incubation, 61% of the samples contained greater than 10 cfu/ml at 20 degrees C versus 51% at 30 degrees C. The median was 19 cfu/ml at 20 degrees C incubation versus 11 cfu/ml at 30 degrees C. These differences were statistically significant with p less than 0.001 (Wilcoxon matched-pairs signed-rank test). No correlation was found between bacterial counts at 20 degrees C and bacterial counts at 30 degrees C, nor between bacterial counts and original water temperatures. It appears that incubation temperatures of 20 degrees C and 30 degrees C favor the growth of different populations of bacteria and temperature is not the only factor. However, from a practical point of view the use of only one incubation temperature seems to be justified for the purpose of judging the sanitary quality of drinking water.  相似文献   

18.
The objective of the present study was to analyze iron and zinc in major lean meat cuts in order to estimate the contribution of the average lean meat consumption in Switzerland (1995) for these trace elements. Iron, heme iron and zinc contents were analyzed in following muscles: pork (longissimus dorsi muscle and shoulder), beef (longissimus dorsi muscle and shoulder), veal (longissimus dorsi muscle) and chicken (breast and thigh). Beef and pork shoulder were the best sources of iron, heme iron and zinc. Pork and veal longissimus dorsi muscle and chicken were relatively poor in these trace elements. With an average daily lean meat consumption of 105 g, iron and zinc intake were about 1.1 mg/d and 3.8 mg/d, respectively. Recommendations for daily iron intake were met to 11% (men) and 7% (women) and for zinc to 25% (men) and 32% (women). Applying a modified Monsen model, the requirements for absorbed iron were met in the range of 10-30% and 7-20% for men and women, respectively. Taking into account a zinc absorption rate from meat of about 20-36%, the daily requirements for absorbed zinc were covered to 32-56%. In conclusion, the average amount of lean meat as consumed in Switzerland was high enough to be an important source of available iron and zinc, particularly for people with low iron and zinc status.  相似文献   

19.
Widespread deficiencies of iron and zinc, commonly found in populations dependent on plant foods, necessitate food-based strategies to maximise their bioavailability from plant foods. In this study, β-carotene-rich vegetables were evaluated for their effects on the bioaccessibility of iron and zinc from cereals and pulses by employing a simulated gastrointestinal digestion procedure involving equilibrium dialysis. Addition of carrot or amaranth (2.5 g and 5 g per 10 g of grain) significantly enhanced the bioaccessibility of iron and zinc from the food grains, the percent increase being 13.8–86.2 in the case of carrot and 11–193% in the case of amaranth. Pure β-carotene added at an equivalent level also enhanced the bioaccessibility of iron (19.6–102% increase) and zinc (16.5–118.0% increase) from the cereals examined. This is the first report on the beneficial influence of β-carotene on iron and zinc bioaccessibilities.  相似文献   

20.
Common bean (Phaseolus vulgaris L.), the staple crop of Nicaragua, provides protein and nonhaem iron, but inhibitors such as phytate may prevent absorption of iron and zinc by the consumer. Warehouses in Nicaragua do not have controlled atmospheres, so beans are exposed to high temperatures and humidities that may accelerate quality loss. To evaluate the impact of 6 months of storage on quality, four national accessions of common bean were submitted to two treatments, a conventional warehouse with uncontrolled temperature and humidity, and accelerated ageing at 40 °C and 75% RH. Iron content was 61–81 mg/kg of which 3–4% was bioavailable, and zinc content was 21–25 mg/kg, of which 10–12% was bioavailable. Bioavailability generally increased in storage, significantly so in year-old INTA Linea 628 in accelerated ageing. The concentration of phytate was 8.6–9.6 mg/g and it contained 54–63% of the total phosphorus. Improvement in bioavailability of divalent cations is needed.  相似文献   

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