Iron,zinc and phytic acid content of selected rice varieties from China

Rice is the major Chinese staple food (per capita approx 250 g day^?1) and, as such, is an important source of essential minerals. However, due to a number of factors the bio‐availability of these minerals is limited. In this study, the variation of phytic acid (PA), iron (Fe) and zinc (Zn) levels in 56 varieties of Chinese rice was investigated. The samples included in this study were collected in proportion to the importance of the rice‐growing regions in China. Fe levels showed the biggest variation (9–45 mg kg^?1) and were not related with PA content or grain shape although growing locations were identified yielding higher (25.2 mg kg^?1) and lower (14.2 mg kg^?1) Fe levels. Zn showed a moderate variability (13–39 mg kg^?1), which was narrower than for Fe, while broader than for PA (7.2–11.9 g kg^?1). Zn content is correlated (R² = 0.5; P < 0.01) with PA content, and shows a relation with growing region and kernel shape. Variation of PA content is the least among the three components. Molar ratios of PA to Fe and Zn ranged from 15 to 105 and 27 to 67, respectively. The results of the mineral contents and PA content can be interpreted in terms of expected bio‐availability. This study shows that the mineral bio‐availability of Chinese rice varieties will be <4%. Despite the variation in mineral contents, in all cases the PA present is expected to render most mineral present unavailable. We conclude that there is scope for optimisation of mineral contents of rice by matching suitable varieties and growing regions, and that rice products require processing that retains minerals but results in thorough dephytinisation. Copyright © 2006 Society of Chemical Industry     

植酸钙的提取及固定化细胞植酸酶酶解

本文重点研究了以麦麸为原料提取植酸钙的工艺条件,最佳工艺条件为60℃水浴浸泡6h,通过浸泡方式的改进,以二次浸泡和动态摇床浸泡两种方式进行实验,结果发现这两种方式均使植酸钙得率提高。另外,利用在细胞壁表面产植酸酶的克鲁维假丝酵母,采用细胞固定化技术,进行植酸酶酶解。细胞固定化和酶解反应的方法都比较简单,而且多次反应后酶解率损失较低。此法为肌醇、磷酸肌醇的酶法制取提供了可行性方案。     

Changes in mineral absorption inhibitors consequent to fermentation of Ethiopian injera: implications for predicted iron bioavailability and bioaccessibility

Possible changes in mineral bioavailability during processing of different types of injera sampled in Ethiopian households were assessed using different methods: phytic acid/mineral molar ratio, absorption prediction algorithm and in vitro availability measurements. Most foods analysed were rich in iron, but most of the iron likely resulted from soil contamination. The highest iron, zinc and calcium contents were found in teff–white sorghum (TwS) injera and flour. The lowest phytic acid/Fe and phytic acid/Zn molar ratios were found in barley–wheat (BW) and wheat–red sorghum (WrS) injeras. Although ideal phytic acid/Fe molar ratios (<0.4) were found in BW and WrS injeras, no significant difference between in vitro iron bioaccessibility and algorithm predicted absorption was observed. In injera, phytic acid degradation alone is unlikely to improve iron bioavailability, suggesting interactions with other absorption inhibitors. The use of phytic acid/Fe molar ratios to predict bioavailability may thus be less appropriate for iron‐contaminated foods.     

Dephytinisation of Sangak and Barbari bread made from different extraction rate flours increases iron and zinc bioaccessibility in Caco‐2 cells

Bread is a staple food in many countries and an important source of iron and zinc. The bioavailability of these minerals is generally low because of the content of phytic acid. Traditional Iranian breads were prepared with flours of different extraction rates, Sangak at 93% and Barbari at 82%. Breads were dephytinised by addition of Aspergillus niger phytase during in vitro digestion. The effect upon iron and zinc bioaccessibility in the Caco‐2 cell model was investigated. The cellular uptake of iron and zinc was lower from Sangak, compared to Barbari, despite higher mineral content in Sangak. Dephytinisation of both breads increased iron uptake in the Caco‐2 cells (0.65 vs. 1.64 in Sangak and 0.77 vs. 1.97 ng mg^?1 protein in Barbari). Zinc uptake increased from 0.98 to 2.8 in Sangak and from 1.4 to 2.9 ng mg^?1 protein in Barbari. Thus, dephytinisation substantially improves iron and zinc bioaccessibility.     

2019年安徽省市售鸡产品中铜、锌含量分析

目的 研究安徽省市售4类鸡产品鸡肉、鸡蛋、鸡胗、鸡肝中铜、锌元素的含量,并分析铜、锌元素在不同鸡产品中分布特征,为人群合理膳食和补充微量元素铜、锌提供参考。方法 采集16个地级市市售的4类鸡产品,依据GB 5009.268—2016《食品安全国家标准食品中多元素的测定》对4类鸡产品中铜、锌含量进行分析,采用SPSS17.0对数据进行统计分析。结果 237份样本中鸡肉、鸡蛋、鸡胗和鸡肝中铜含量的平均值分别为0.41、0.59、0.85、3.68 mg/kg,锌含量的平均值分别为12.50、12.95、27.14、39.66 mg/kg,鸡肉、鸡肝、鸡胗和鸡蛋中铜、锌含量的分布相同,都为鸡肝>鸡胗>鸡蛋>鸡肉,且4类鸡产品中铜、锌含量有显著性差异,且P<0.05。不同地区（皖南、皖北、皖中）4类样本中,部分含量差异有统计学意义。结论 对于本地区人群来说4类鸡产品可作为人体摄入铜、锌主要来源之一,鸡肝和鸡胗因铜锌含量较高不易长期过量摄入,但当机体铜、锌缺乏时,鸡肝和鸡胗可作为营养补充的重要来源。     

Electrophoretic identification of hard white spring wheats grown at different locations in Pakistan in different years

Pakistani wheats were identified via acid polyacrylamide gel electrophoresis (A‐PAGE) of gliadin proteins. Gliadin electrophoretograms of wheat cultivars were qualitatively independent of growth locations and years. The Pakistani wheat Faisalabad 83 and the American wheat KS84HW196 contained an intense gliadin band in the region of the relative mobility 50 band of Marquis. That band was readily distinguishable and was followed by distinct intense double bands in the same position as those of Marquis, and can be used as a reference for mobility assignments in wheat cultivar identification work. Minor differences in band intensities across locations and years were noticed. Identification tables based on band mobilities relative to Marquis and relative intensities were established. © 2000 Society of Chemical Industry     

铜、铁、锌、锰添加水平对蛋青鸡生长性能及养分利用的影响

525只1日龄罗曼褐壳蛋鸡随机分为5处理,每处理7重复,每重复15只鸡。所有处理使用一种基础日粮,统一添加碘和硒。铜、铁、锌、锰四种微量元素添加方案如下,A组不额外添加;B组按50%NRC标准直接添加;C组和D组将日粮铜、铁、锌、锰总量补齐到2倍和3倍NRC水平;E组以基础日粮铁含量与NRC标准比值为基准,将其余微量元素校正到同样倍数。铜、铁、锌、锰添加形式均为硫酸盐。结果表明,1~18周龄生长蛋鸡典型基础日粮中添加铜、铁、锌、锰不影响采食量(P>0.05)、期末体重和能量表观代谢率(P>0.05),过量添加降低日增重和饲料转化率(P<0.05),但提高蛋白质表观代谢率(P<0.05)。随日粮微量元素水平增加,排泄物铜、锌、锰含量线性增加(P<0.05),铜、锌、锰表观代谢率呈先增加后降低二次曲线变化(P<0.05)。西北地区典型蛋青鸡基础日粮中铜、铁,锌、锰已满足需要,无需额外添加。     

Impact of durum wheat milling on deoxynivalenol distribution in the outcoming fractions

The milling behaviour of two naturally infected samples of durum wheat grain with contrasting levels of mycotoxins was studied. Although the two samples showed a similar milling behaviour, an increase of ～20% in deoxynivalenol (DON) levels was found in semolina from the sample containing the higher level of mycotoxin. However, even if the highest concentration of DON was found in fractions originating from the grain outer layers, the mycotoxin contamination in semolina and flours were not related to the amount of two compounds (ash or phytic acid) used to monitor these external tissues. The presence of the trichothecene-producing fungi in the inner-most semolina fraction was also shown using specific DNA primers and PCR amplification. Comparison of DON concentrations in the feed stock and corresponding output at each milling step or grinding of semolina fractions followed by sizing showed that concentration of mycotoxin occurs in the finest particles at the first processing steps. Therefore, DON contamination of milling fractions is not simply due to the presence of peripheral grain tissues.     

Antioxidant properties of commercial soft and hard winter wheats (Triticum aestivum L.) and their milling fractions

The total phenolic content (TPC), total antioxidant activity (TAA), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging capacity, inhibition of coupled oxidation in a β‐carotene–linoleate model system, iron(II) chelation activity and inhibition of copper‐induced oxidation of human low‐density lipoprotein (hLDL) cholesterol of 80% ethanolic extracts of soft and hard winter wheat samples and their milling fractions, namely flour, germ, bran and shorts, were investigated. Soft wheat extracts examined demonstrated higher TPC and TAA compared to those of hard wheat extracts. The germ fraction possessed the highest TPC, followed by bran, shorts, whole grain and flour for both wheat types examined. The TAA of both wheat types showed similar results except that shorts performed better than bran in this assay. Free radical scavenging properties of whole grain and milling fractions of both soft and hard wheat samples were examined against DPPH radical. The germ and flour fractions demonstrated the highest and lowest DPPH radical scavenging activity, respectively, among wheat fractions. Wheat extracts were also efficient in preventing bleaching of β‐carotene, which is also known to be free radical mediated. In the iron(II) chelation assay the flour extracts demonstrated excellent activity, while the germ extracts showed a weak activity. The trends were similar in both soft and hard wheat for the iron(II) chelation assay. Wheat extracts also inhibited copper‐induced oxidation of hLDL. In LDL oxidation assay, wheat extracts performed better than the reference antioxidant, ferulic acid. Thus wheat phenolics may serve as effective antioxidative components as measured by in vitro techniques. Copyright © 2005 Society of Chemical Industry     

Minerals,phytic acid,tannin and rutin in buckwheat seed milling fractions

The composition of common buckwheat (Fagopyrum esculentum Moench) seed milling fractions depends upon the relative abundance of various seed tissues in each. Fancy (light) flour contains mainly central endosperm, while the bran milling fraction has seed coat and some embryo tissues. Phytate, found in protein bodies of embryo and aleurone cells, is the major storage form of phosphorus, potassium, magnesium and some microelements in seeds. Phytic acid (35–38 g kg^?1) and minerals are concentrated in bran, a milling fraction with high concentrations of phytate‐rich tissues. Polyphenolics, including condensed tannins (proanthocyanidins), are also concentrated in bran (11–15 g kg^?1). Rutin is concentrated in the hull of common buckwheat (0.8–4.4 g kg^?1). Rutin concentration is low (0.2–0.3 g kg^?1) in groats of common buckwheat but higher (0.7–0.8 g kg^?1) in bran containing hull fragments. Rutin is 300‐fold more concentrated (81 g kg^?1) in groats of tartary buckwheat (Fagopyrum tataricum (L) Gaertn) than in groats of common buckwheat. Only small amounts of quercetin were detected. Bran is a concentrated source of phytic acid and tannins, a consideration in consumption of large amounts of buckwheat bran for nutritional or medicinal purposes. © 2001 Society of Chemical Industry     

发芽时间对不同系统小麦粉品质的影响

将豫农035小麦按不同时间梯度发芽后,进行常规水分调节并研磨制粉,探讨小麦发芽程度对不同系统小麦粉品质的影响。实验结果表明,虽然发芽6h后各系统小麦粉的降落数值均明显下降,并随发芽时间的增加而逐渐下降,不同系统小麦粉品质指标的变化有相近的规律,却也不尽相同。随着发芽时间的增加,不同系统小麦粉的出粉率、湿面筋含量、面筋指数、峰值黏度、回生值、衰减值、最终黏度均呈现不同程度的下降,而当发芽时间为24~48h时,降幅显著;不同系统小麦粉的水溶物、灰分、损伤淀粉含量有所增加,但不同系统及发芽时间段的变幅不同,其中1M、2M粉的水溶物增幅较大;而发芽48h后,各系统小麦粉损伤淀粉含量均显著增加。     

Comparative compositional and functional characterisation of rye varieties and novel industrial milling fractions

This work aimed to collect and study all milling fractions generated during an industrial rye milling technology and to select nutritionally promising subfractions for further investigations (chemical composition and rheological behaviour) also considering their yield. To investigate the varietal effect, four rye samples were examined and applied in the milling experiments. The results showed great variability of technological properties (mainly in viscous behaviour) among rye samples. Generally, subfractions had higher protein, lipid, total and soluble dietary fibre content than white flours, and several subfractions provided higher values even than wholemeal flours. Significant differences were found between the fractions in the mixing and viscous behaviour, which could be explained principally by the variable dietary fibre content and composition, however, the effect of protein content was found also prominent. The results pointed out that alternative milling products with favourable composition and technological properties can be produced by collecting appropriate subfractions.     

Protein content of grains of different size fractions in malting barley

The negative relationship between grain size (percentage >2.5 mm) and protein content usually observed in barley grain samples is attributed to the presence of thin grains. The objective of this study was to determine whether, in grain samples from a given environment, thin grains had a different protein content than plump grains. Grain samples from field experiments were analysed for grain yield, size and protein content of the whole sample and of four size fractions within each sample. Grain yield ranged from 1.5 to 6.5 mg ha^?1 and grain protein (whole sample) ranged from 6.8 to 13.4 %. Most of the variation observed in protein content was explained by the ratio of nitrogen availability to grain yield. Within a grain sample, thin grains had more protein than plump grains (>2.5 mm) only when the protein content of the whole sample was high, that is, when the grain sample came from an environment with a high relative abundance of nitrogen. The fact that grain samples with low grain size tend to have high protein content is not due to the presence of a high proportion of thin grains, because thin grains do not always have more protein than plump grains. Copyright © 2014 The Institute of Brewing & Distilling     

Sourdough fermentation of wheat fractions rich in fibres before their use in processed food

Fibre‐rich fractions of wheat are an important source of minerals but also contain considerable amounts of phytic acid, known to impair mineral absorption. This study explores the efficiency of wheat bran sourdough fermentation on phytate hydrolysis and mineral solubility, in comparison with whole‐wheat flour. In vitro trials were performed to assess the consequences of the addition of calcium carbonate (CaCO₃), an alkalinising salt, on phytic acid breakdown and mineral bioavailability during sourdough fermentation. Sourdough fermentation was found effective for solubilising minerals in whole‐wheat flours but was less effective with bran. In addition, sourdough acidity was blunted by the addition of CaCO₃, whereas degradation of phytic acid remained effective. Despite extensive breakdown of phytic acid (almost 70%), the addition of calcium exerted a very negative effect on zinc solubility. In conclusion, a pre‐fermentation process of whole cereals or bran, in suitable conditions of hydration, allows degradation of the major part of phytic acid and optimal mineral bioavailability. Copyright © 2007 Society of Chemical Industry     

Distribution of some essential trace elements in commercial flour-mill streams

The iron, copper, zinc, manganese, chromium, nickel, selenium, protein and ash contents of two different bread grists and flour samples from the first to fourth break and A to J reduction systems of a commercial flour mill were determined. Iron, zinc, manganese and selenium levels followed the trend of ash and protein with the lowest from the A, B and C rolls and highest from either the fourth break or J roll. Copper and chromium levels were relatively homogeneous among the grist and mill streams while for nickel there was only a slight increase through the break and reduction systems.     

Historical shifts in the seed mineral micronutrient concentration of US hard red winter wheat germplasm

The yield of wheat (Triticum aestivum L. em. Thell) has greatly improved through breeding, but it is not known how this has affected seed micronutrient content. In the present study, the iron (Fe), zinc (Zn), copper (Cu), and selenium (Se) content of seed of 14 US hard red winter wheat varieties from production eras spanning more than a century was measured. The seed that was analyzed was obtained from a replicated field trial conducted at two locations in Kansas. The Fe, Zn, and Cu content was obtained by inductively coupled plasma emission spectroscopy (ICPES) and Se content was obtained by hydride‐generated atomic absorption spectrometry (HG‐AAS). Significant effects of location on micronutrient content of seed were observed. Similarly, depending on the micronutrient, significant differences in seed micronutrient content between varieties were detected at one or both locations. A significant negative regression of seed Zn content on both yield and variety release date was observed at both locations, while seed Fe content exhibited a significant negative regression on yield and variety release date at one location. Regression of seed Se content on variety release date was significant and negative at one location. These results suggest that genetic gains in the yield of US hard red winter wheat have tended to reduce seed Fe, Zn, and Se concentrations. However, the extent to which this effect manifests itself is influenced by environmental effects. Published in 2006 by John Wiley & Sons, Ltd     

Distribution of aflatoxins and fumonisins in dry-milled maize fractions

The aim was to evaluate the distribution of aflatoxins and fumonisins in fractions derived from the dry-milling of contaminated maize. Two maize lots with different contamination levels were processed and sampled: the first (maize 1) had aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) levels of 3.6 and 5379 µg kg^?1, respectively; the second (maize 2) had corresponding levels of 91.1 and 8841 µg kg^?1, respectively. The cleaning step reduced AFB₁ and FB₁ levels by 8 and 11% in maize 1 and by 57 and 34% in maize 2. The subsequent removal of bran and germ led to a further decrease in contamination levels in the products destined for human consumption. In the latter, AFB₁ was uniformly distributed, while FB₁ was concentrated in the finer size fractions. Contamination of raw maize 1 (3.6 µg kg^?1) was below the European Union AFB₁ limit of 5 µg kg^?1 for unprocessed maize, but among the final products only coarse flour (1.7 µg kg^?1) was within the European Union limit of 2 µg kg^?1, while grits and fine flour showed higher levels (2.7 and 2.5 µg kg^?1, respectively). As regards cleaned maize, a different distribution of the two toxins was observed in the kernels: AFB₁ contamination was more superficial and concentrated in germ, while FB₁ contamination affected the inner layers of the kernels.     

Impacts of phosphorus and zinc levels on phosphorus and zinc nutrition and phytic acid concentration in wheat (Triticum aestivum L.)

BACKGROUND: Zinc (Zn) and phytic acid content in grain crops are directly related to their nutritional quality and therefore human health. To investigate the nutritional influences of phosphorus (P) and Zn levels on wheat (Triticum aestivum L.), plants were grown hydroponically to maturity in chelator‐buffered solutions. RESULTS: Appropriate amounts of P, coupled with sufficient Zn, increased P and Zn concentrations in wheat grain. The Zn supply decreased both phytic acid and the molar ratios of phytic acid to Zn in wheat grain with respect to the Zn₀ treatment. Furthermore, proportions of Zn and P content in the grain relative to that of the whole plant were improved. With increasing P, the proportion of Zn and P content in the grain relative to the whole plant decreased. P and Zn acted antagonistically in roots. Excess P inhibited Zn uptake in roots, while Zn decreased the transfer of P from roots to shoots. For P that had been transported to the shoots, supplemental Zn facilitated its transfer to the grain. CONCLUSION: Excess P decreased the distribution of Zn in grain, while Zn enhanced the uptake of Zn and P in grain, The combined application of Zn fertilizer with the extensive use of P fertilizer can effectively increase the P and Zn concentration and Zn bioavailability of wheat grain, and hence Zn nutritional quality. Copyright © 2011 Society of Chemical Industry     

Effects of pH and phosphate status of a silty clay loam on manganese,zinc and copper concentrations in soil fractions and in clover

The field pH of a silty clay loam soil affected manganese, zinc and copper concentrations in the fraction extracted by DTPA; lower pH soils had higher metal concentrations. The soil pH also affected manganese and zinc but not copper concentrations in the soil solution, and in shoots of clover grown in pots. Metal concentrations in soil fractions were not affected by soil phosphate status, but zinc and copper concentrations in clover shoots were significantly lower when plants were grown on soils of high phosphate status. Manganese and zinc levels in shoots were predicted slightly more accurately by using soil solution data than by using concentrations extracted by DTPA.     

The prevalence of deoxynivalenol and its derivatives in the spring wheat grain from different agricultural production systems in Lithuania

Deoxynivalenol (DON) together with two acetylated derivatives, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) occurs in cereal grains and their products. Co-occurrence of DON and acetylated derivatives in cereal grain is detected worldwide. Until now, DON and its derivatives have been considered equally toxic by health authorities. In this study, we analysed 103 samples of spring wheat grain, originating from the fields of different production systems in Lithuania, for the co-occurrence of type-B trichothecenes (DON, 3-ADON, 15-ADON). The samples were classified according to the production system—organic, sustainable and intensive. Mycotoxin levels in the spring wheat grain samples were determined by the HPLC method with UV detection. The type-B trichothecenes were found to be present at higher concentrations in the grain from the intensive production system. Eighty-one percent of the spring wheat grain samples from the intensive production system were co-contaminated with a combination of DON+3-ADON+15-ADON, 1% with DON+3-ADON. Additionally, DON+15-ADON and DON were found in 5% and 10% of the tested samples, respectively. Two percent of the samples were free from mycotoxins. In the grain samples from the sustainable production system, DON and a combination of DON+3-ADON showed a higher incidence – 47% and 23%, respectively. The samples with a combination of DON+3-ADON+15-ADON accounted for 18%. Completely different results were obtained from the analyses of organic grain samples. A large number of the organic spring wheat grain samples were contaminated with DON+3-ADON (55%) or DON (36%). The combination of DON+3-ADON+15-ADON was not present, while DON+15-ADON was present in 9% of the samples tested. The production systems did not lead to significant differences in mycotoxin levels, although a trend toward higher incidence and higher contamination was observed for the samples from the intensive and sustainable production systems.