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1.
OBJECTIVE: To evaluate the efficacy of a community-based dietary intervention to reduce risk of micronutrient inadequacies in high-phytate maize-based Malawian diets. DESIGN: Quasi-experimental post-test design with a non-equivalent control group. SETTING: Four villages in Mangochi District, Southern Malawi. PARTICIPANTS: Households with children aged 3-7 years in two intervention (n = 200) and two control (n = 81) villages participated in a 6-month intervention employing dietary diversification, changes in food selection patterns, and modifications to food processing to reduce the phytate content of maize-based diets. Baseline comparability between the groups was confirmed via assessment of sociodemographic characteristics, anthropometry, knowledge and practices, morbidity, haemoglobin and hair zinc. After 12 months, knowledge and practices and dietary intakes were assessed by interactive 24-hour recalls, one during the food plenty and a second during the food shortage season. Nutrient adequacy for the two groups was compared via dietary quality indicators and predicted prevalence of inadequate intakes using the probability approach. RESULTS: Intervention children had diets that were significantly more diverse and of a higher quality than those of controls. Median daily intakes of protein, calcium, zinc (total and available), haem iron, vitamin B12 and animal foods (grams; % of total energy) were higher (P < 0.05) whereas phytate intakes, phytate/zinc and phytate/iron molar ratios were lower (P < 0.01) in the intervention group; some spread of knowledge and practices to controls occurred. CONCLUSIONS: Our community-based dietary strategies reduced the predicted prevalence of inadequate intakes of protein, calcium, zinc and vitamin B12, but not iron, in children from Malawian households with very limited resources.  相似文献   

2.
The consumption of foods made from soybeans is increasing because of their desirable nutritional value. However, some soy foods contain high concentrations of oxalate and/or phytate. Oxalate is a component of calcium oxalate kidney stones, whereas phytate is an inhibitor of calcium kidney stone formation. Thirty tested commercial soy foods exhibited ranges of 0.02-2.06 mg oxalate/g and 0.80-18.79 mg phytate/g. Commercial soy foods contained 2-58 mg of total oxalate per serving and 76-528 mg phytate per serving. Eighteen of 19 tofu brands and two soymilk brands contained less than 10 mg oxalate per serving, defined as a low oxalate food. Soy flour, textured vegetable soy protein, vegetable soybeans, soy nuts, tempeh, and soynut butter exhibited greater than 10 mg per serving. The correlation between oxalate and phytate in the soy foods was significant (r = 0.71, P < 0.001) indicating that oxalate-rich soy foods also contain higher concentrations of phytate. There also was a significant correlation, based on molar basis, between the divalent ion binding potential of oxalate plus phytate and calcium plus magnesium (r = 0.90, P < 0.001) in soy foods. Soy foods containing small concentrations of oxalate and moderate concentrations of phytate may be advantageous for kidney stone patients or persons with a high risk of kidney stones.  相似文献   

3.
The kinetics, depletion/repletion of zinc, and effects of dietary ligands/food matrices on (65)Zn uptake was studied in Caco-2 cells. The uptake of zinc showed a saturable and nonsaturable component, depending upon the media zinc concentrations. Intracellular depletion increased zinc uptake, whereas zinc loading did not. Phytic acid and histidine inhibited zinc uptake, while tannic acid, tartaric acid, arginine, and methionine increased zinc uptake. Tannic acid at a 1:50 molar ratio promoted zinc uptake from wheat- and rice-based food matrices. Further, Caco-2 cells responded similarly with zinc and iron uptake when fed Indian bread prepared from low- and high-extraction wheat flour, representing low and high phytate content. However, inclusion of tea extract or red grape juice as a source of polyphenols enhanced the uptake of zinc while decreasing that of iron. These results suggest that the Caco-2 cells predict the correct direction of response to dietary ligands even from complex foods.  相似文献   

4.
OBJECTIVE: To assess the prevalence of zinc inadequacy based on dietary intakes and plasma zinc concentrations and, simultaneously, the prevalence of inadequate intakes of energy, protein, calcium and iron. DESIGN: A cross-sectional study of a convenience sample of subsistence farming households in Sidama, Southern Ethiopia. SUBJECTS: Dietary intakes were calculated from 1-day weighed food records and 40 repeats from 99 pregnant women in the third trimester using analysed values of major staple foods for zinc, iron, calcium and phytate. The distribution of observed intakes was adjusted for usual intakes and the prevalence of inadequacy estimated using the estimated average requirement (EAR) cutpoint method. Prevalence of inadequacy for zinc, protein and iron intakes were compared with those based on biochemical measures. RESULTS: Prevalence of zinc inadequacy was very high: 99% for US FNB EAR and 100% for IZiNCG EAR compared to 72% based on low plasma zinc concentrations. Corresponding prevalence estimates for iron were much lower: 4% for inadequate intakes based on US FNB EAR vs. 8.7% for iron deficiency anaemia (haemoglobin < 110 g l-1; ferritin < 12 microg l-1) and 32.3% for low storage iron. Prevalence of inadequacy for protein was 100% for adjusted intakes and 91% for serum albumin < 32 g l-1. For calcium, 74% were at risk for inadequate intakes. CONCLUSION: The high prevalence of inadequate intakes of zinc and protein was reasonably consistent with those based on biochemical measures. Such dietary deficits could be overcome by regular consumption of cellular animal protein. In contrast, both dietary and biochemical measures of iron inadequacy were low.  相似文献   

5.
Ma G  Li Y  Jin Y  Du S  Kok FJ  Yang X 《Public health nutrition》2007,10(8):848-854
OBJECTIVES: To assess the intake inadequacy and food sources of zinc of people in China. DESIGN AND SUBJECTS: Diets of 68 962 subjects aged 2-101 years (urban 21 103, rural 47,859) in the 2002 China National Nutrition and Health Survey were analysed. Dietary intake was assessed using 24-hour recall for three consecutive days. Zinc intake inadequacy was calculated based on values suggested by the World Health Organization. RESULTS: The median zinc intake ranged from 4.9 mg day- 1 (urban girls, 2-3 years) to 11.9 mg day-1 (rural males, 19+ years). The zinc density of urban residents (2-3 to 19+ years) was 5.0-5.3 mg day-1 (1000 kcal)-1, significantly higher than that of their rural counterparts (4.7-4.8 mg day-1 (1000 kcal)-1). Differences in food sources of zinc from cereal grains (27.4-45.1 vs. 51.6-63.2%) and animal foods (28.4-54.8 vs. 16.8-30.6%) were found between urban and rural residents. Zinc from vegetables and fruits (8.2-13.8 vs. 9.7-12.4%) and legumes (1.3-3.3 vs. 2.5-3.4%) was comparable between urban and rural residents. The proportion of zinc intake inadequacy ranged between 2.8% (urban females, 19+ years) and 29.4% (rural lactating women). Rural residents had higher proportions of zinc intake inadequacy than their urban counterparts. Significantly higher proportions of zinc inadequacy were found in the category of phytate/zinc molar ratio >15 for both rural and urban residents. CONCLUSIONS: About 20% of rural children are at risk of inadequate zinc intake, with phytate as a potential important inhibitor. Moreover, lactating women are also considered a vulnerable group.  相似文献   

6.
In 2002, Brazil issued a regulation requiring that corn and wheat flours be fortified by the addition of folic acid and iron. The aim of the present work was to evaluate the levels of folic acid, iron, and zinc in macaroni, pizza, and bread prepared with fortified flour. The methodologies used for the mineral (FAAS) and vitamin (HPLC) determinations were validated and considered adequate. For macaroni, the folic acid content range was 50.0–182.4 μg/100 g. The iron and zinc levels were 1.6–5.4 mg/100 g and 0.7–1.0 mg/100 g, respectively. The pizza and bread samples contained 14.8–271.3 μg/100 g and 47.4–481.4 μg/100 g of folic acid, respectively. The iron and zinc levels were 2.6–7.3 mg/100 g and 0.4–0.9 mg/100 g, respectively, for pizza, and 3.0–12.4 mg/100 g and 0.4–0.8 mg/100 g for bread. The results indicated that the distribution of folic acid and iron in the majority of the samples tested was heterogeneous. This study could be of use to governmental authorities in their food fortification evaluation programs. Moreover, the average iron contents observed in the products could result in problems with zinc absorption, and it is important to consider that iron can induce oxidative stress in cells.  相似文献   

7.
This study analyzed soybean seeds from 116 cultivars for total, insoluble, and soluble oxalate (Ox), phytate (InsP6), calcium (Ca), and magnesium (Mg) because of their potential beneficial or harmful effects on human nutrition. These cultivars were divided into four groups (A-D) on the basis of the year and geographic location where they were grown. Oxalate concentration ranged from about 82 to 285 mg/100 g of dry seed. The InsP6 concentration ranged from 0.22 to 2.22 g/100 g of dry seed. There was no correlation between Ox and InsP6 within or among the four groups of cultivars. There was a significant correlation between total Ox and Ca, but not Mg, in group D cultivars (r = 0.3705; p < 0.0005). No significant relationship was found in the group A-C cultivars. Eleven group D cultivars had InsP6 less than 500 mg/100 g, but all had total Ox of 130 mg/100 g or greater. Five cultivars from groups A-C had relatively low InsP6 (group B; < or =1.01 g/100 g) and low Ox (<140 mg/100 g). These cultivars could be useful for producing soy foods beneficial to populations at risk for kidney stones and for improved mineral bioavailability. The Ox and InsP6 concentrations of the cultivars indicate that choosing specific parents could generate seeds in succeeding generations with desirable Ox and InsP6 concentrations.  相似文献   

8.
Consumption of soybeans and food products made from them is increasing because of their desirable nutritional value. However, the oxalate content of seeds from 11 cultivars of soybean showed relatively high levels of total oxalate from 0.67 to 3.5 g/100 g of dry weight. Oxalate primarily was found as calcium oxalate crystals. Thirteen tested commercial soyfoods contained between 16 and 638 mg of total oxalate per serving. These values compare to those of three other legume foods, peanut butter, refried beans, and lentils, which contained 197, 193, and 100 mg of total oxalate per serving, respectively. After oxalate has been absorbed from the diet, it cannot be metabolized and is excreted by the kidney into urine, where it binds to calcium forming an insoluble salt that may precipitate to form kidney stones. The amounts of total oxalate in soybean seeds, soy foods, and other common legume foods exceed current recommendations for oxalate consumption by individuals who have a history of calcium oxalate kidney/urinary stones. This study serves as the basis to find soybean cultivars lower in oxalate, which will have lower risk for kidney stone formation after human consumption.  相似文献   

9.
The objectives of this research were to study the bioavailable calcium from widely used cereals and millets by an in vitro method and to provide data on the role of calcium inhibitors. The average total calcium content of the analyzed raw cereals and millets ranged from 10.2 to 324.6 mg/100 g (the lowest and highest values correspond to maize and finger millet, respectively), whereas the rest of the raw cereals and millets had calcium content in the range of 26.3–50.4 mg/100 g, except for rice samples (10.4 mg/100 g). Soluble percentage of calcium is the highest in maize (45.1%), and dialyzable calcium percentage is the highest in wheat (34.9%). The cooking process did not significantly affect calcium bioavailability and the contents of phytate and tannin. However, cooking reduced the oxalate content, and in the case of dietary fiber significant increase was observed. The order of oxalate content in the cereals and millets studied was found to be pearl millet > finger millet > wheat > maize > sorghum > rice. Multiple regression analysis carried out to explain the influence of oxalate, phytate, tannin, and dietary fiber on calcium bioavailability showed greater inhibitory effect of oxalate.  相似文献   

10.
A modified version of the Haug and Lantzsch method for rapid photometrical phytate determination was applied for the analysis of phytate in soybean, wheat, and maize meals. In comparison to the original protocol, the amount of the toxic reagent thioglycolic acid is reduced substantially to minimize potential health risks for laboratory personnel. Different extraction conditions for soybean meal were tested, and boiling for at least 30 min was found to be necessary to remove an interfering compound in soybean meal extracts. Phytate contents determined according to the modified Haug and Lantzsch method did not differ from those obtained by measuring total precipitated phosphorus or by sensitive and specific high-performance ion chromatography. Applicability and accuracy of the modified method for phytate analysis in major feed substrates, including soy-based textured vegetable protein, were demonstrated.  相似文献   

11.
OBJECTIVE: To determine the nutrient composition of complementary foods consumed by 6-12-month-old South African infants. DESIGN: Nutrient intake was determined for infants who were recruited to participate in a randomised controlled trial using a single 24-hour dietary recall. SETTING/SUBJECTS: Infants aged 6-12 months (n=475) residing in The Valley of a Thousand Hills, a rural area in KwaZulu-Natal, South Africa. RESULTS: Energy and protein intakes from complementary foods were adequate. Infants who consumed infant products (commercially available fortified infant cereals/ready-to-eat canned baby foods/formula milk powder) had significantly higher intakes of calcium, iron, zinc, vitamin A, thiamine, riboflavin, niacin, vitamin B6, vitamin B12 and vitamin C than infants who did not consume any infant products. For infants who consumed infant cereals (n=142), these cereals provided 51% of total iron intake. Infant cereals provided more than 25% of total intake for magnesium, thiamine, niacin and vitamin B12. For infants consuming ready-to-eat canned baby foods (n=77), these products contributed less than 15% of total intake for all the micronutrients. The nutrient density of the complementary diet was less than half the desired density for calcium, iron and zinc. Animal products were consumed by 17% of infants, 26% consumed dairy products and 18% consumed vitamin-A-rich fruit and vegetables during the 24-hour recall period. CONCLUSION: The nutrient composition of complementary foods among rural South African infants was inadequate, especially for iron, zinc and calcium. Strategies should be developed to improve the nutritional quality of their diets.  相似文献   

12.
A pot experiment was done to study the effect of zinc (Zn) application on the reproductive development and quality of wheat (Triticum aestivum L. cv. SP 343) seeds. The soil was low in diethylenetriaminepentaacetate (DTPA)–extractable Zn and was fortified with a mixture of nitrogen, phosphorus, and potassium (NPK) as basal fertilizers. Four treatments included a control (no Zn), 5 mg Zn, 10 mg Zn, and 10 mg Zn kg?1 soil with urea instead of ammonium nitrate. Zinc addition improved the pollen-producing capacity of anthers, pollen viability, and seed yield with an increase in seed Zn, phytate, and starch contents but decreased the phytate/zinc molar ratio at 5 mg Zn kg?1 and increased it at 10 mg Zn kg?1. Application of urea increased the seed protein content at 10 mg Zn kg?1 but was ineffective in lowering the phytate/Zn ratio, which was still less than the alarming level.  相似文献   

13.
Seventy-six farmers' varieties of sorghum from Benin were distinguished by amplified fragment length polymorphism (AFLP) and clustered into 45 distinct genotypes. The genotype clusters were evaluated for their Fe, Zn, and phytate concentrations to assess the impact of genetic and environmental effects on the composition of the grains and to identify farmers' varieties with high potential Fe and Zn availability. The Fe concentration of the grains ranged from 30 to 113 mg/kg with an average of 58 mg/kg. The Zn concentration ranged from 11 to 44 mg/kg with an average of 25 mg/kg. The phytate concentration of the grain ranged from 0.4 to 3.5% with a mean of 1.2%. The grain-Fe and grain-Zn did not show consistent linkage to genetic variation, but varied significantly across field locations, suggesting a predominant environmental impact. The phytate concentration of the grains appeared to be environmentally as well as genetically determined. No varieties provide adequate Zn to meet nutritional requirements of sorghum consumers. The most promising varieties for Fe supply were tokogbessenou, mahi swan, biodahu, sa? ma?, mare dobi, sakarabokuru, and chabicouma, as they showed a [phytate]/[Fe] ratio of <14, which is the critical value above which Fe availability is strongly impaired. These varieties could therefore be recommended for the preparation of food products such as dibou, in which processing methods have only a slight diminishing effect on phytate levels. Further research is needed to test these varieties for the stability of [phytate]/[Fe] molar ratio across various environmental conditions.  相似文献   

14.
青鳞鱼骨粉的食用营养价值及应用研究   总被引：7，自引：1，他引：7  
研究了青鳞鱼骨粉的食用营养价值及其在玉米粥、马蹄粉和鸡精中的应用。结果表明：(1)青鳞鱼骨粉是一种蛋白质含量为27.0%、脂肪含量为2.0%的典型的高营养低热能食品；它具有独特的补钙生物学功能的关键因素和优势。(2)青鳞鱼鱼骨粉钙磷比为2.32∶1，钙和铁易于被人体吸收和利用。(3)青鳞鱼骨粉氨基酸总量为24.36 mg/100g，其中必需氨基酸为5.23 mg/100g，占氨基酸总量的21.49%；蛋白质质量优越于猪骨粉，具有更大的利用价值。(4)以10%的比例将超微鱼骨粉分别添加到策友牌玉米粥，互润牌桂花马蹄粉和美极牌鲜鸡精中，可以提高产品的感官质量，达到强化蛋白质和钙磷铁等矿物质元素、改善食品的钙磷比例等目的。  相似文献   

15.
The amount of coagulant added to soy milk is a critical factor for tofu-making; particularly it affects the textural properties of tofu. Earlier research indicated that the critical point of coagulant concentration (CPCC) is a characteristic parameter of soy milk and could be used as an effective indicator of optimal coagulant concentration (OCC) for making filled tofu. The objective of this study was to investigate the possible correlations between CPCC and the characteristics of soy milk made from various soybean samples and the effect of soy milk cooking and dilution conditions on CPCC. CPCC was determined by a titration method. Calcium chloride and magnesium chloride were used as coagulants. Soy milk characteristics including solid, protein, phytate, pH, titratable acidity, mineral content, and 11S/7S protein and these characteristics as affected by heating rate, heating time, and sequence of dilution and heating were studied. The results showed that the CPCC was significantly (p < 0.05) positively correlated with phytate content (grams per gram of protein), pH, and 7S protein content but negatively correlated with protein content, 11S protein content, 11S/7S ratio, titratable acidity, and original calcium content. Within the same soybean material, more proteins required more coagulant, but higher protein concentration during cooking resulted in less coagulant required by each gram of protein during coagulation. The CPCC decreased with increasing soy milk heating time or decreasing heating rate. The sequence of heating and diluting for preparing soy milk also had an effect on CPCC.  相似文献   

16.
The method described for determining NO3- in dried foods is based on extraction of NO3- from the sample with subsequent nitration of benzene. The nitrobenzene is extracted with ethyl acetate, analyzed by using a gas chromatograph-thermal energy analyzer (GC-TEA), and quantitated against a nitrobenzene standard. Sensitivity is 100-200 micrograms/kg. Coefficients of variation for analyses of dried foods were 3-13%. Recovery of NO3- from nonfat dry milk spiked at 10 mg/kg averaged 100%.  相似文献   

17.
宠物干粮食品辐照杀菌工艺参数的确定   总被引：4，自引：1，他引：3  
依照国内外学者的研究结果和国际辐照饲料工艺规范的规定,研究了宠物干粮食品辐照杀菌工艺,确定了各项技术指标,并就主要技术指标的确定依据进行了阐述。该技术规定：辐照前宠物干粮食品细菌总数≤5×104 MPN/100g,霉菌≤4.5×104 CFU/g,沙门氏菌≤1×103 CFU/25g,辐照后细菌总数≤1000 CFU/g,大肠菌群≤30 MPN/100g,霉菌≤25 CFU/g,沙门氏菌不得检出,宠物干粮食品辐照杀菌的最低有效剂量为4.0 kGy,最高耐受剂量为15.0 kGy。辐照产品箱中最小吸收剂量应不小于最低有效剂量,最大吸收剂量应不大于产品的最高耐受剂量。  相似文献   

18.
The nutritional bioavailability of zinc from cooked milled, undermilled, and brown Philippine rice (variety PSB Rc14) was evaluated in rats, comparing results based on weight gain, tibia zinc incorporation (slope ratio analyses), and zinc radiotracer retention. Milling reduced the phytic acid and mineral content of the rice, resulting in zinc concentrations of 16.5, 19.4, and 27.2 microg/g and phytate/zinc molar ratios of 4, 20, and 28 for milled, undermilled, and brown rice, respectively. Measured zinc bioavailability was similar whether using growth, bone zinc, or radioisotope retention as criteria, at approximately 92, 86, and 77% of zinc sulfate, for milled, undermilled, and brown rice, respectively. However, the higher percent bioavailability of the zinc after milling was insufficient to compensate for the lower zinc content. With respect to zinc, the nutritional value was inversely related to milling, providing approximately 15, 17, and 21 microg bioavailable zinc/g rice, respectively, for milled, undermilled and brown rice of this variety.  相似文献   

19.
Simulations of gastro-intestinal digestion, used to estimate in vitro iron and zinc availability, were performed on two kinds of samples: (i) samples with decreased phytate contents from whole pearl millet flour and (ii) nondephytinized or dephytinized samples from two pearl millet grain fractions, a decorticated fraction with low fiber and tannin contents and a bran fraction with high fiber and tannin contents. Iron and zinc in vitro availabilities of whole pearl millet flour were significantly improved by phytate degradation, even if the IP6 were not all degraded. Total dephytinization of decorticated fraction led to a marked increase in iron and zinc in vitro availabilities, but that of bran fraction had no effect on either iron or zinc in vitro availability. Even if phytates are involved in reducing in vitro iron and zinc availability in pearl millet flour, fibers and tannins play an important role by chelating a high proportion of iron and zinc in grain hulls.  相似文献   

20.
Problems associated with measuring phytate in infant cereals   总被引：1，自引：0，他引：1  
The inositol hexaphosphate (IP6) content of commercially available dried infant cereals was measured by ion pair high-pressure liquid chromatography (ion pair HPLC) and ion exchange high-pressure liquid chromatography (ion exchange HPLC). Large differences between methods were apparent: ion pair HPLC gave values 14 to 190-fold lower than the values from ion exchange HPLC. Poor recoveries of added IP6 (25 to 60%) by ion pair HPLC suggested that some component of the infant cereal was responsible for the difference. Further experimentation suggested that an excess of minerals (approximately 11 mg/g calcium and 0.3 mg/g iron) in these samples sequestered the endogenously low phytate content. This problem may be unique to samples with low IP6 and high mineral content as wheat bran was not problematic. These results suggest that ion exchange HPLC is the method of choice for measuring inositol phosphates in infant cereals.  相似文献   

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