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1.
A review of literature on wheat minerals is presented. Varietal and environmental differences are discussed. Mineral content differences in some wheat products are reported. The factors which affect the binding capacity of minerals to fiber are discussed. This review describes the agronomic factors which affect the mineral content of wheat. 相似文献
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《American Journal of Potato Research》1959,36(10):380-380
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《Field Crops Research》1999,60(1-2):143-163
Of all the elements, the most important to consider in terms of food-chain contamination are arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb) and selenium (Se). Where soils are enriched in these elements, it is usually through the agricultural, industrial or urban activities of man, except for Se where high concentrations in soil are often derived from high-Se parent rock materials. The propensity for plants to accumulate and translocate these contaminants to edible and harvested parts depends largely on soil and climatic factors, plant genotype and agronomic management. Elevated As intake, especially of inorganic As, is most likely to arise from high-As drinking water than from ingestion of food. Cadmium and Se are of the greatest concern in terms of terrestrial food-chain contamination, with the former element receiving most attention. Worldwide, the probability of insufficient Se in the human diet exceeds that of toxicity, with deficiency usually associated with monotonous vegetarian diets in areas with Se-deficient soils. Excessive human intake of Cd is of concern as this element accumulates over a lifetime in the body, with impairment of kidney function being the main adverse effect. Cadmium inputs to soil in fertilizer, biosolids, soil amendments and atmospheric deposition often exceed outputs in crops and drainage waters, so that Cd concentrations in many agricultural soils are slowly increasing. However, evidence for increases in Cd concentrations in crops over time is contentious, as is the evidence for human health problems due to low-level Cd contamination of the food chain. Adverse health effects due to Cd intake have been manifest only in situations of gross soil contamination, with a predominantly rice-based diet, where soil–plant and plant–human transfer of Cd would have been enhanced. Human feeding studies have indicated that food Cd bioavailability is dependent on Fe nutrition, and animal studies have indicated that Zn, Ca, P and other elements and food constituents (e.g. fiber, phytate) affect Cd bioavailability. While plant breeding and agronomic management can minimize soil–plant transfer of Cd, and maximize concentrations of antagonists to Cd assimilation in humans, it remains important that inputs of this metal to soil be minimized. 相似文献
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Despite much research, bread crumb firming during storage and amylase anti-staling properties are still ill understood. We present a coherent view on the topic based on literature, experimental data, and food polymer science-related concepts. During bread storage, the gelatinised starch (amylopectin) network, present in soft, fresh bread, is gradually transformed into an extensive, partially crystalline, permanent amylopectin network, with amylopectin crystallites acting as junction zones. This network increasingly accounts for the bulk rheological behaviour of aging bread crumb. Furthermore, as amylopectin retrogradation proceeds, moisture migration within the crumb structure occurs, and more and more water is immobilised within amylopectin crystallites. The crystalline hydrate water can no longer plasticise the different networks, which goes hand in hand with increased crumb firmness and decreased crumb resilience, due to a less flexible gluten network. The efficiency of anti-staling amylases can be related to the extent they limit the formation and the strength of the permanent amylopectin network, and the water immobilisation. Conventional alpha-amylases weaken the amylopectin network by cutting the long polymer chains connecting the crystalline regions, but have little effect on amylopectin recrystallisation. In contrast, maltogenic alpha-amylase primarily shortens the amylopectin side chains, thus hindering amylopectin recrystallisation, and the concomitant network formation and water immobilisation. 相似文献
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Studies were carried out to determine the changes in glycosaminnoglycan (GAG)metabolism in rats fed cassava with varying cyanoglucoside levels and two levels of protein. Results indicated that there was an enhancement in the level of total and individual GAG with a corresponding reduction in the activity of enzymes involved in the degradation of glycosaminoglycan. These changes were significant for rats given a cassava diet (raw and boiled cassava) and low protein. The changes in total and individual GAG and the decrease in the activity of degrading enzymes was more for high cyanide (raw cassava) groups compared with other groups showing that consumption of untreated cassava is an additive factor for the promotion of mucopolysaccharidosis. 相似文献
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This review provides an overview on the most common rice weed species of the world. It shows that a few generalists have established in rice independent from sites, crop management systems, and local climatic conditions. Cosmopolitan weeds are even constant elements where rice cultivation started just a century ago. Local differences may be explained by cultivation methods, growing seasons, or special weed management. Some general changes in weed spectra have been observed globally in recent years. Weedy rice (Oryza sativa L.) and herbicide resistance have become general global problems within the last decades. Some global key weed genera such as Echinochloa, Cyperus, Scirpus, or Fimbristylis species are, however, still dominating rice fields despite the decade long use of well performing herbicides. On the other side, general species shifts as a result of resistance have not been observed yet. Leptochloa species started to become major problems in Asia in the end of the last century and now in Europe also. Several modern herbicides allow the control of perennial weeds, such as Cyperus rotundus L. or Eleocharis kuroguwai Ohwi which makes them no longer serious threats. Some genera in rice such as Echinochloa and Oryza (weedy rice) are characterized by an enormous germplasm variability which makes species definitions difficult. The fact that weeds in rice have to adapt to wet or aquatic conditions reduces the biodiversity range in comparison to other arable crops. Water management has a considerable impact on weed spectra. The increase of rice acreages with reduced irrigation may end up in higher weed infestations. Long term results of weed surveys in rice as they exist for other crops are, however, not available. This makes predictions on biodiversity changes in this crop quite difficult. 相似文献
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The nucleus of the cell serves to maintain, regulate, and replicate the critical genetic information encoded by the genome. Genomic DNA is highly associated with proteins that enable simple nuclear structures such as nucleosomes to form higher-order organisation such as chromatin fibres. The temporal association of regulatory proteins with DNA creates a dynamic environment capable of quickly responding to cellular requirements and distress. The response is often mediated through alterations in the chromatin structure, resulting in changed accessibility of specific DNA sequences that are then recognized by specific proteins. Anti-cancer drugs that target cellular DNA have been used clinically for over four decades, but it is only recently that nuclease specific drugs have been developed to not only target the DNA but also other components of the nuclear structure and its regulation. In this review, we discuss some of the new drugs aimed at primary DNA sequences, DNA secondary structures, and associated proteins, keeping in mind that these agents are not only important from a clinical perspective but also as tools for understanding the nuclear environment in normal and cancer cells. 相似文献
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Cereal grains contain many phytochemicals, some of which significantly influence the grain colour. Anthocyanins are accumulated in the aleurone or pericarp layer and give blue, purple or combination of these colours. Flavonoids, such as yellow C-glycosides of flavones, flavonols, flavanonols, proanthocyanidins and reddish-coloured phlobaphenes are mainly present in the outer layer of grains while carotenoids that are responsible for yellow grain are in the endosperm. Therefore, accumulation of these pigments in the grain can represent an important target in breeding programmes aimed at increasing the concentrations of bioactive components in grain and products. This review therefore summarises our current knowledge of anthocyanin and carotenoid pigments, their genetic control and variation in levels in different wheat lines. 相似文献
11.
Dale Every Lidia MotoiShiva P. Rao Stephen C. ShorterLyall D. Simmons 《Journal of Cereal Science》2008
Genotype and environment sets of wheat cultivars and breeding lines were tested for bread making, dough mixing, dough rheology, protein composition and thiol/disulphide composition to find methods that could identify wheat with high baking quality (high-BQ) and moderate work input (moderate-WI) requirement using the mechanical dough development system. Wheat with these properties generally had a high baking response to ascorbic acid (AA) and a GluD1a (HMW-GS 2 + 12) allelic composition. Strong wheat with high WI and high-BQ generally had low baking response to AA and a GluD1d (HMW-GS 5 + 10) allelic composition. Using protein composition data to identify wheat of high-BQ (with AA) and moderate-WI, it was best to select wheat with as high as possible percent of SDS-unextractable polymeric protein (%UPP) in flour and as low as possible %UPP in total polymeric protein. Using a dough extension test for identifying wheat of high-BQ (with AA) and moderate-WI, it was best to select wheat with intermediate values for maximum resistance to extension (Rmax) and for values of extension at Rmax as high as possible within the intermediate Rmax range. Cysteine content of protein fractions and glutathione content of flour gave mostly poor to weak correlations with all baking and mixing properties. 相似文献
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Frank Havemann Michael Heinz Hildrun Kretschmer 《Journal of Biomedical Discovery and Collaboration》2006,1(1):6
Background
The hypothesis that distance matters but that in recent years geographical proximity has become less important for research collaboration was tested. We have chosen a sample–authors at German immunological institutes–that is relatively homogeneous with regard to research field, language and culture, which beside distance are other possible factors influencing the willingness to co-operate. We analyse yearly distributions of co-authorship links between institutes and compare them with the yearly distributions of distances of all institutes producing papers in journals indexed in the Science Citation Index, editions 1992 till 2002. We weight both types of distributions properly with paper numbers.Results
One interesting result is that place matters but if a researcher has to leave the home town to find a collaborator distance does not matter any longer. This result holds for all years considered, but is statistically most significant in 2002. The tendency to leave the own town for collaborators has slightly increased in the sample. In addition, yearly productivity distributions of institutes have been found to be lognormal.Conclusion
The Internet did not change much the collaboration patterns between German immunological institutes.13.
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Gaffa T Jideani IA Nkama I 《Plant foods for human nutrition (Dordrecht, Netherlands)》2002,57(1):73-81
A survey of the production, consumption and storage ofKunu was carried out. Some of the information included consumption rate, processing techniques andequipment, producer's status and grains used. About73% consume Kunu daily, 26% occasionally; 1% knowit is produced but may or may not be consuming it. Millet (Pennisetum typhoideum), sorghum (Sorghum vulgare), maize (Zea mays), rice (Oryza sativa) and acha (Digitalis exilis) wereused in its production in decreasing order ofpreference. The grains were used singly or combined;sorghum/millet was the most common combination in aratio of 1:2 (w/w). Steeping was done in ordinary water for 12–72 h, depending on the grain type, in localclay pots, plastic buckets, calabashes or basins or5–7 h in warm water (60–70 °C). The grainswere dry or wet milled with or without spices such asginger, red pepper, black pepper, clove and garlic.Other ingredients introduced included: sweet potatoes,malted rice, malted sorghum and Cadaba farinosacrude extract. Both dry and wet milling was done withgrinding mills, mill stones or mortar and pestle,depending on locality. The product was then cookedinto a thin free flowing gruel. The various types ofkunu were: Kunun zaki, Kunun gyada, Kunun akamu, Kununtsamiya, Kunun baule, Kunun jiko, Amshau and Kunungayamba. Kunun zaki was the most commonly consumed. Production and consumption cut across all socialclasses of the society. 相似文献
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Iwe MO van Zuilichem DJ Ngoddy PO 《Plant foods for human nutrition (Dordrecht, Netherlands)》2000,55(2):159-168
Blends of defatted soy flour and sweet potato flour were extruded in asingle-screw extruder run at varying pre-set rotational speeds. Diediameter of the extruder was also varied. A central composite, rotatablenearly orthogonal response surface design was used in studying theinteractive effects of extrusion variables on color of the extrudates.Color of raw and processed samples was determined on a DRLANGE TricolorLFM3 instrument. Measurements were made in duplicates to obtain the CIELABL* a* b* values. Results showed that whiteness (L*)decreased with increase in sweet potato in the blends during extrusion.Reduction in whiteness (darkening) evidenced in decreased L* valuesof samples was only affected by increase in sweet potatoes in the blends.Redness (*) significantly increased as sweet potatoes contentincreased, which confirmed the decrease in whiteness. Yellowness(*) also increased considerably, but as a result of the diediameter. 相似文献
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The Cool Farm Tool – Potato (CFT-Potato) is a spreadsheet programme that allows the calculation of the amount of CO2 equivalents that it costs to produce 1 t of potato. The spreadsheet was adapted from an original generic version of the tool,
and completed for potato production in diverse production areas in the world applying different levels of technology. The
CO2 embedded in chemicals during their production and released from the soil after nitrogen fertilization in the CFT-Potato has
been updated to consider more recent products and production methods. Energy costs of the operations in the original version
taken from generic data provided by the American Society of Agricultural and Biological Engineers Standard, however, were
altered (usually increased) where there was evidence from practical sources that the original figures did not apply. For example,
the figure of around 16 l of diesel per ha for potato harvesting in the original version was corrected to 60 l of diesel per
ha based on observational data. Figures for typical potato operations such as windrowing were supplied. Irrigation with pumps
powered by diesel or electricity from the grid, with a centre pivot, a rain gun, drip irrigation and flooding and energy cost
for extracting water from deeper sources were also added. We added data for grading, washing, store loading and unloading,
the application of a sprout suppressant and storage with ventilation of ambient air or forced refrigeration. The CFT-Potato
can be used by growers to calculate the actual costs of 1 t of potato in terms of kilograms CO2 and explore the repercussion of altered management options. Here the comparison of four potato production systems in the
Netherlands is shown: seed potatoes (115 kg CO2/t), table potatoes (77 kg CO2/t), starch potatoes (71 kg CO2/t) and organic potato (82 kg CO2/t). Based on potato dry matter, however, starch potato has the lowest footprint mainly due to the extensive use of pig slurry
of which the production and transport CO2 costs are attributed to the pig production chain. 相似文献
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During breadmaking, wheat gluten proteins form a continuous network which is stabilized by disulfide bonds and modified by thiol/disulfide interchange reactions. This gluten network results in visco-elastic dough that holds together the other dough components and assists in retaining carbon dioxide. Wheat flour contains several components, enzyme co-factors and enzymes which can affect the formation and properties of the gluten network and, hence, the dough and bread characteristics. We present a brief overview of our current knowledge of the fate of gluten proteins during breadmaking, and how they are affected by endogenous wheat components (e.g. glutathione, cysteine and NAD(P)(H)) and enzyme systems (e.g. tyrosinase, peroxidase, the NADP-dependent thioredoxin and glutathione enzyme systems, protein disulfide isomerase, lipoxygenase, catalase and dehydrogenases). 相似文献
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Hęś Marzanna Dziedzic Krzysztof Górecka Danuta Jędrusek-Golińska Anna Gujska Elżbieta 《Plant foods for human nutrition (Dordrecht, Netherlands)》2019,74(3):255-265
Plant Foods for Human Nutrition - Many studies have proved that bioactive components of Aloe vera have an anti-inflammatory effect and support lipid and carbohydrate metabolism, helping to maintain... 相似文献