The influence of fermentation processes and cereal grains in wholegrain bread on reducing phytate content

Wholegrain bread is generally thought of as being more healthy than white bread due to it having a higher content of dietary fibre, vitamins (especially vitamin B and E) and many important minerals. However, wholegrain bread also contains high levels of phytate (myo-inositolhexakisphosphate, InsP-6) which may bind desirable nutrients, preventing their absorption in the gut and thereby reducing the nutritional value of the end product. In order to evaluate factors influencing phytate levels, the effects of fermentation and selected wholemeal flours from rye, oats and wheat were investigated. Phytate levels were assessed using a spectrophotometric assay based on the measurement of iron with 2,2′-bipyridine. Phytate decreased in freshly ground wholegrain flour dough during the fermentation process with time of fermentation being the most important factor. Fermentation temperature was found to make only a small difference to the process of phytate reduction. Since the potential benefits of wholemeal breads incorporating various grains (e.g. oats and rye) are increasingly evident, this research has important implications for human health.     

Phytate and mineral elements concentration in a collection of Italian durum wheat cultivars

Mineral deficiencies are prevalent in human populations and the improvement of the mineral content in cereal products represents a possible strategy to increase the human mineral intake. Nevertheless, most of the inorganic phosphorus (P_i) present in mature cereal seeds (40–80%) is stored as phytate, an anti-nutritional factor that forms complexes with minerals such as Ca, Mg, Zn and Fe reducing their bioavailability. The present study was undertaken: (i) to determine the variation in phytate and mineral concentrations in the whole grains of 84 Italian durum wheat (Triticum durum Desf.) cultivars representative of old and modern germplasm; (ii) to estimate the magnitude of genotype × environment interaction effects; and (iii) to examine the interrelationships among mineral concentrations in durum wheat with the final aim to identify superior durum wheat cultivars that possess low phytate content and high concentration of mineral elements in their whole-wheat flour. The cultivars were grown in field trials during 2004–2005 at Foggia, Italy and during 2005–2006 at Foggia and Fiorenzuola d’Arda—Southern and Northern Italy. The phytate content was estimated indirectly by using a microtitre plate assay evaluating the P_i absorbance at 820 nm, while the Cu, Fe, Mn, Ca, K, Mg, Na and Zn mineral contents were determined by ICP/OES. The contents of Zn and Fe across years and locations ranged from 28.5 to 46.3 mg/kg for Zn with an average of 37.4 mg/kg and from 33.6 to 65.6 mg/kg for Fe with an average of 49.6 mg/kg. P_i grain content was between 0.46 and 0.76 mg/g showing a positive correlation with all minerals except Cu and Zn. Although breeding activity for Fe and Zn would be difficult because G × E interaction is prevalent, multi-location evaluation of germplasm collection help to identify superior genotypes to achieve this objective. The results here reported open the possibility of designing a specific breeding program for improving the nutritional value of durum wheat through the identification of parental lines with low-P_i and high minerals concentration in whole grains.     

Effect of extrusion processing on the soluble and insoluble fiber,and phytic acid contents of cereal brans

The health benefits associated with dietary fiber have resulted in it now being used in virtually all food product categories, including many products which are manufactured using extrusion processing. The objective of the present study was to determine if extrusion processing affected phytic acid, and soluble and insoluble fiber contents. The effect of screw speeds of 50, 70, and 100% of maximum rotations per minute (% MRPM) on these components was investigated. A BI-EX Model DNDG-62/20D co-rotating intermeshing self-cleaning twin-screw extruder, manufactured by Bühlerag, CH-9240, Uzwil, Switzerland, was used to process wheat, oat and rice brans. It was found that extrusion did not affect the insoluble fiber content of wheat bran; however, a decrease in this component was observed in rice and oat brans. The effect on rice bran insoluble fiber was greatest at screw speeds of 50 and 70% MRPM. This occurred in oat bran at 50% MRPM. Soluble fiber content increased in all brans after extrusion, except ER₁₀₀. For oat and rice bran soluble fibers, the greatest increase occurred at 50 and 70% MRPM, while for wheat bran this occurred at 70 and 100% MRPM. Extrusion did not affect the phytate content of the cereal brans.     

Grain concentrations of protein and mineral nutrients in a large collection of spelt wheat grown under different environments

A large number of spelt wheat genotypes (ranging from 373 to 772) were evaluated for grain concentrations of protein and mineral nutrients under 6 different environments. There was a substantial genotypic variation for the concentration of mineral nutrients in grain and also for the total amount of nutrients per grain (e.g., content). Zinc (Zn) showed the largest genotypic variation both in concentration (ranging from 19 to 145 mg kg⁻¹) and content (ranging from 0.4 to 4.1 μg per grain). The environment effect was the most important source of variation for grain protein concentration (GPC) and for many mineral nutrients, explaining between 37 and 69% of the total sums of squares. Genotype by environment (G × E) interaction accounted for between 17 and 58% of the total variation across the minerals. GPC and sulfur correlated very significantly with iron (Fe) and Zn. Various spelt genotypes have been identified containing very high grain concentrations of Zn (up to 70 mg kg⁻¹), Fe (up to 60 mg kg⁻¹) and protein (up to 30%) and showing high stability across various environments. The results indicated that spelt is a highly promising source of genetic diversity for grain protein and mineral nutrients, particularly for Zn and Fe.     

Increased grain yield and micronutrient concentration in transgenic winter wheat by ectopic expression of a barley sucrose transporter

Optimising assimilate partitioning to spikes is important to increase wheat yield potential. Novel winter wheat lines (HOSUT), ectopically expressing barley sucrose transporter HvSUT1 controlled by the barley Hordein B1 promoter were used to evaluate the potential of improved sucrose uptake capacity on grain yield and quality under field-like conditions. Three independent HOSUT lines were grown over three years in micro-plots. Grain yield per plot was significantly increased by 28%, together with higher protein yield per plot and higher iron and zinc concentration when compared to the non-transformed control wheat Certo. Thousand grain weight was enhanced, indicating that expression of HvSUT1 increases individual grain sink strength. HOSUT grains are larger, display increased grain width and to a lesser extent grain length, indicating transgene effects at a stage when grains grow under filial control. Grain number per spike was decreased by 15% and protein contents by 5%, on average, especially that of glutenins. Overall, despite some compensating effects on grain number per spike and protein contents, HOSUT lines generate a significant yield advantage. The findings can contribute to understanding determinants of grain size and number and its relationship to grain sink strength and might identify limitations of wheat yield potential.     

茶叶企业的人力资源管理探讨

在经济全球化和信息时代，在激烈的市场竞争中．人们逐渐认识到．现代企业的竞争优势与“人”的因素联系得越发紧密：现代企业的竞争，主要是科学技术的竞争．智力的竞争，归根到底是人力资源开发及利用的竞争。因此,人们对人力资源的管理日益重视．许多茶叶企业也在积极探索和提高人力资源管理水平。     

Fertilizer effects on yield,mineral and amino acid composition,dietary fibre content and nutritive value of leeks

In pot experiments with greatly differing rates of N, P, S, K and Ca, dry matter (DM) yields of leek stems varied from 25 to 164 g/pot. Total-N and NO₃-N concentrations varied from 1.18 to 3.56% and from 10 to 1515 ppm in DM, respectively. Both N applications and P and K deficiency greatly increased total-N and NO₃-N content. S applications increased total-S content from 0.047 to 0.359% in DM, of which between approximately 100 to 25% were found in methionine+cystine. Total-N/total-S ratios decreased from 57 to 6 with the highest S level. P and K applications increased their respective content in DM two- and threefold. Severe Ca deficiency reduced Ca content from 0.495 to 0.045%. Iron, zinc, manganese and copper contents varied from 33–69, 14–26, 11–34 and 3.1–5.7 ppm in DM, respectively. Increasing N contents, whether due to N applications or P or K deficiency, decreased the content of all essential and some other amino acids in crude protein. Both S and severe P deficiency had a pronounced negative effect on amino acid composition and chemical score. Only glutamic acid (glutamine) and arginine were increased by increasing N contents. However, expressed as g/kg DM the concentrations of all amino acids were positively correlated with protein content. S and P deficiency reduced total dietary fibre (TDF) content of DM from 28.3 to 18.6% and 17.4%, respectively, of which between 53 and 60% were insoluble dietary fibre (IDF). Digestible energy (DE) was positively correlated with protein content (r=0.90**). In N-balance trials with rats, increasing protein concentrations (50% of total protein given as casein and supplemented with 1% methionine) raised the true digestibility (TD) of the protein from 44 to 72%. The biological value (BV) of protein was generally high, with a mean of 91.7 N deficiency tended to increase and S deficiency tended to decrease the BV.     

Reducing the incidence of cereal head infection and mycotoxins in small grain cereal species

Reducing the level of infection of cereal heads caused by Fusarium and associated mycotoxin accumulation in grains is of a high priority in order to secure the yield, agronomic performance, and food and feed safety from field to table. Strategies to tackle the problem have been proposed at many levels, including greater knowledge of the biology of toxigenic fungi and of plant–pathogen interactions, monitoring activities which extend from the field to the end-products, pre-breeding, breeding and transgenesis to develop new resistant plant varieties, crop protection based on synthetic or natural molecules, biocontrol of fungal populations, the development and use of models that take into account the climatic conditions, and the adoption of technological protocols for reducing or inactivating mycotoxins. This review article highlights that the problem is very complex but that the scientific community continues to produce important knowledge and potential solutions.     

A tropical grass resource for pasture improvement and landscape management: Themeda triandra Forssk

Themeda triandra Forssk. is one of the most widespread grasses in the dry to mesic prairie ecosystems of Africa, Asia and Australia. It is of particular interest due to its high value as a forage species for wildlife and livestock, and its potential use in landscaping practices. In this review we have collated information from the many studies that have been devoted to this species since the 1960s to provide information about the species' distribution, taxonomy, morphology, ploidy and reproduction, and to describe its vegetation and germination and their relationship with the most important ecological aspects of its preferred habitats. Agronomic aspects are considered in detail, with particular focus on the role of T. triandra as a forage species and the relative importance of grazing, fire and rainfall regimes for its management. We also explore how this species can help with the rehabilitation of degraded areas, soil and water conservation, countering exotic species invasion and landscaping in general. We conclude with a brief discussion of the as yet unresolved taxonomic relationship between the African species T. triandra and the Australian species Themeda australis.     

Translating and applying a simulation model to enhance understanding of grassland management

Each new generation of grassland managers could benefit from an improved understanding of how modification of nitrogen application and harvest dates in response to different weather and soil conditions will affect grass yields and quality. The purpose of this study was to develop a freely available grass yield simulation model, validated for England and Wales, and to examine its strengths and weaknesses as a teaching tool for improving grass management. The model, called LINGRA-N-Plus, was implemented in a Microsoft Excel spreadsheet and iteratively evaluated by students and practitioners (farmers, consultants, and researchers) in a series of workshops across the UK over 2 years. The iterative feedback led to the addition of new algorithms, an improved user interface, and the development of a teaching guide. The students and practitioners identified the ease of use and the capacity to understand, visualize and evaluate how decisions, such as variation of cutting intervals, affect grass yields as strengths of the model. We propose that an effective teaching tool must achieve an appropriate balance between being sufficiently detailed to demonstrate the major relationships (e.g., the effect of nitrogen on grass yields) whilst not becoming so complex that the relationships become incomprehensible. We observed that improving the user-interface allowed us to extend the scope of the model without reducing the level of comprehension. The students appeared to be interested in the explanatory nature of the model whilst the practitioners were more interested in the application of a validated model to enhance their decision making.     

Improving the protein content and composition of cereal grain

Cereals are important sources of protein for human nutrition but have low quality due to limitations in the amounts of essential amino acids, notably lysine. These deficiencies result from the low levels of these amino acids in the prolamin storage proteins and hence are exacerbated when high levels of nitrogen fertiliser are used to increase yield and total protein content.Genetic and genetic engineering strategies to increase both total protein content and the composition of essential amino acids have been employed. These include the exploitation of mutant high lysine genes and the use of transformation to either express additional proteins which are rich in lysine and/or methionine or to increase the free pools of these amino acids.     

转植酸酶基因玉米的获得及其后代的初步鉴定

构建了仅含有启动子序列、植酸酶基因和终止子序列的线性基因转化元件(UPN)及其两端分别带有T-DNA边界序列(T-UPN)和一段载体序列(V-UPN)的不同线性转化元件,不含选择性标记基因和载体骨架序列,采用花粉管通道法对选定的玉米自交系进行转化,对728株T1代转化玉米PCR检测。结果表明,UPN、T-UPN、V-UPN 3个转化元件的阳性率分别为0.44%、2.2%和1.8%,平均转化率为1.5%。检测时,以种子在果穗上的不同位置分别播种、检测。结果表明,PCR阳性株都是来源于第5～9圈的种子,这个部位的阳性率达到3.57%,说明花粉管通道法转化玉米的成功率与种子结实的位置有关。植酸酶比活结果说明外源基因在转化玉米植株内实现了蛋白质水平的表达。     

Implications of grazing by sows for nitrate leaching from grassland and the succeeding cereal crop

Outdoor pig production may have benefits in terms of animal welfare but could be undesirable in terms of nutrient losses. In paddocks on sandy soil grazed by lactating sows, nitrate leaching was determined using the suction cup technique from the start of grazing in October to after the following barley/pea wholecrop with perennial ryegrass. The inorganic N concentration in soil was uneven after sow grazing, with the highest values found near the feeding area. In contrast to low nitrate leaching in the year of grazing (25–30 kg of N ha^–1), losses were considerable in the following autumn and winter. Throughout the measuring period of 18 months, nitrate leaching inside paddocks was on average 320 kg of N ha^–1 with the major part near the feeding area. Ten metres from the feeding area, leaching losses were 500 kg of N ha^–1 and, at 16 m distance, losses were 330 kg of N ha^–1. At 22 and 28 m distance from the feeding area, about 200 kg of N ha^–1 was leached and outside paddocks about 100 kg of N ha^–1. The combination of a sandy soil with high winter rainfall leads to a large proportion of the N surplus being lost by nitrate leaching near the feeding area. To reduce nitrate leaching, stocking density and the level of dietary nutrient input must be adjusted, and more uniform distribution might be achieved by manipulating the excretory behaviour of the sows.     

Comparative studies on the nutritional and toxic composition of three varieties of Lesianthera africana

The research presents analytical data on three varieties of a commonly consumed vegetable, Lesianthera africana, in southern Nigeria. The Etoi (bitter) variety seemed to possess the best (p0.01) nutritional value (highest lipid, protein, calories, iron, calcium, phosphorus, least fiber) but highest toxic components (mg/100 g: 1.62 HCN; 17.6 oxalate; 1630 glucosinolates), which are far below toxic limits. The Ikot Abasi (riverine) variety was found to be highly (p0.01) fibrous (18.1 mg/100 g dry matter) but low in micronutrient minerals. The Etinan (flavorful) variety was found to be moderately nutritious. The findings are discussed in relation to nutrient interactions and recommendations are made regarding dietetic use.     

Replicate and die for your own good: Endoreduplication and cell death in the cereal endosperm

Development of the cereal endosperm involves different stages that include cell proliferation, endoreduplication, the biosynthesis and accumulation of storage compounds, and programmed cell death (PCD). During endoreduplication, repeated genome duplications without mitosis or cytokinesis result in large polyploidy nuclei. Endoreduplication is affected by genetic, epigenetic, hormonal and environmental factors, as well as by several cell cycle-controlling genes. Although endoreduplication is strongly correlated with an increase in cell size, the accumulation of storage reserves, and high metabolic rates, its exact role(s) in endosperm development has not been demonstrated.     

引黄灌区水肥一体模式下春玉米磷素吸收特征与磷肥适宜用量研究

以玉米品种宁吉198为试验材料,设6个磷肥量级,对玉米磷素吸收特性、磷肥利用率和玉米产量等相关指标进行测定分析,所有处理N、K₂O用量一致,确定银川平原引黄灌区水肥一体化模式下最佳磷肥施用量。玉米生育期内取样测定,分析不同磷肥处理对玉米叶面积指数、磷素积累量、磷肥利用率、灌浆速率和产量等指标的影响。结果表明,施用磷肥180 kg/hm²表现最佳,与其他处理相比植株磷素积累量和干物质积累量最高,对子粒贡献率上升8.57%～26.28%,干物质积累量显著增加5.71%～11.44%,产量增加4.9%～17.7%。滴灌水肥一体模式下磷肥施用量180 kg/hm²可以提高玉米叶面积指数、干物质积累量、植株磷素积累转运量和肥料利用率,产量最高可达14 492.13 kg/hm²。通过一元二次方程将2年产量数据进行拟合,得出最高产量下对应磷肥施用量为175.43 kg/hm²,是银川平原引黄灌区磷肥最佳施用量。     

DNA-based methods for identification and quantification of small grain cereal mixtures and fingerprinting of varieties

The composition of cereal-based foods is a key factor in determining the quality and safety of the final product while the reliable identification of cereal species and cultivars are essential for the handling, marketing and processing of grain and for the protection of plant breeders' rights. Analytical methods have therefore been developed and applied to identify and quantify cereal species in food products and also to fingerprint and identify grain at the genotype and variety levels. DNA-based methods for the detection and quantification of mixtures of small grain cereals are reviewed, together with the recent development of molecular markers for varietal fingerprinting.     

磷肥不同施用方法对郑单958产量及养分吸收的影响

玉米苗期低温会降低玉米对磷养分吸收能力,导致后期减产。改进玉米磷肥施肥方法将会提高玉米的产量。通过对玉米品种郑单958磷肥5种不同施肥方法的比较研究,表明种肥条施能促进玉米对磷的吸收,进而增加产量。促根剂促进玉米根系生长,增加了对磷吸收和产量的提高。     

有机肥磷替代化肥磷对春玉米干物质积累和磷素吸收的影响

2008～2009年在吉林省公主岭黑土上研究有机肥磷部分替代化肥磷对春玉米干物质积累、产量、养分吸收和利用的影响。结果表明,有机肥磷替代化肥磷增加苗期或拔节期土壤速效磷含量;与100%化肥磷处理相比,用30%有机肥磷替代化肥磷对玉米干物质积累、子粒产量和磷素吸收没有显著影响,但显著增加营养体磷素的再分配率和对子粒的贡献率,提高了磷素的农学效率。