Influence of storage conditions and packaging of fortified wheat flour on microbial load and stability of folate and vitamin B12

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Fortified flours were stored for 6 months at controlled temperature and humidity.

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Well-packaged flours were stable up to 6 months whatever the storage conditions.

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Vitamins B9 and B12 were mostly affected by the permeability of the packaging.

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In low-quality packaging, vitamins were affected by relative humidity variations.

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In low-quality packaging, flour microbial quality was impacted when stored at 85% RH.

Flour fortification with folic acid (FA) is implemented in many countries, and the fortification of flour with vitamin B12 has been planned. However, vitamins losses can occur during storage. In this study, fortified wheat flour was packaged either in paper bags or multilayer aluminum/PET bags, and stored in controlled conditions of temperature (25 °C or 40 °C) and relative humidity (65% or 85% RH) for 6 months. FA content, cyanocobalamin content, and microbial quality were regularly assessed. In flours packed in multilayer bags (non-permeable to oxygen and humidity), no significant FA and cyanocobalamin losses were observed, irrespective of temperature and RH. In flours packed in permeable paper bags, the microbial quality deteriorated in flours stored at 85% RH, FA loss reached 22–53% after 6 months at 85% RH, whereas cyanocobalamin loss reached 49–63% after 6 months at 65% RH. This shows that, depending on environmental conditions, packaging choice is of critical importance.

Barley production in Spain and Italy: Environmental comparison between different cultivation practices

In Europe, around 12 million ha are cultivated with barley and Spain and Italy are two important producers' countries. This study aims to compare the cultivation of barley of two different contexts, Spain and Italy, evaluating the related environmental performances; this is carried out considering the similar latitude and climatic conditions of the two countries, but taking into account the different average mechanisation solutions that differentiate considerably the two production frameworks. Inventory data about barley cultivation were gathered mainly by questionnaires with farmers and technical expert interviews. To quantify the environmental performances of barley production in the two Countries, the Life Cycle Assessment approach was applied and 1 ton of grain at the commercial moisture was selected as reference unit and 12 impact categories were evaluated. The outcomes of the impact assessment highlight how for 7 of the 12 evaluated impact categories, barley production in Spain shows a higher impact respect to the Italian production (from +7% for photochemical oxidant formation to +120% for freshwater ecotoxicity) mainly due to the lower grain yield and to the higher consumption of mineral fertilisers. For the other evaluated environmental effects, the Spanish production performs better than the Italian one, mostly because of the lower emissions of ammonia into the air. Yield is the main driver of the environmental effects. Additionally, due to mechanisation of field operations and to fertilisations, wide differences on the environmental side emerge from the comparison. There is a trade-off between the Spanish production, where the use of mineral fertilisers reduces all the environmental effects related to ammonia volatilisation, and the Italian barley cultivation, where the use of animal slurry improves the results on the impact categories affected by the fertiliser production but worsens those affected by the nitrogen emissions.

Selenium toxicity in upland field-grown rice: Seed physiology responses and nutrient distribution using the μ-XRF technique

Selenium (Se) is an essential element for human and animal, although considered beneficial to higher plants. Selenium application at high concentration to plants can cause toxicity decreasing the physiological quality of seeds. This study aimed to characterize the Se toxicity on upland rice yield, seed physiology and the localization of Se in seeds using X-ray fluorescence microanalysis (μ-XRF). In the flowering stage, foliar application of Se (0, 250, 500, 1000, 1500, 2000 g ha^-1) as sodium selenate was performed. A decrease in rice yield and an increase in seed Se concentrations were observed from 250 g Se ha^-1. The storage proteins in the seeds showed different responses with Se application (decrease in albumin, increase in prolamin and glutelin). There was a reduction in the concentrations of total sugars and sucrose with the application of 250 and 500 g Se ha^-1. The highest intensities Kα counts of Se were detected mainly in the endosperm and aleurone/pericarp. μ-XRF revealed the spatial distribution of sulfur, calcium, and potassium in the seed embryos. The seed germination decreased, and the electrical conductivity increased in response to high Se application rates showing clearly an abrupt decrease of physiological quality of rice seeds. This study provides information for a better understanding of the effects of Se toxicity on rice, revealing that in addition to the negative effects on yield, there are changes in the physiological and biochemical quality of seeds.

Standard substances free quantification makes LC/ESI/MS non-targeted screening of pesticides in cereals comparable between labs

LC/ESI/MS is the technique of choice for qualitative and quantitative food monitoring; however, analysis of a large number of compounds is challenged by the availability of standard substances. The impediment of detection of food contaminants has been overcome by the suspect and non-targeted screening. Still, the results from one laboratory cannot be compared with the results of another laboratory as quantitative results are required for this purpose. Here we show that the results of the suspect and non-targeted screening for pesticides can be made quantitative with the aid of in silico predicted electrospray ionization efficiencies and this allows direct comparison of the results obtained in two different laboratories. For this purpose, six cereal matrices were spiked with 134 pesticides and analysed in two independent labs; a high correlation for the results with the R² of 0.85.

Whole grain and high-fibre grain foods: How do knowledge, perceptions and attitudes affect food choice?

The health benefits of whole grains and dietary fibre are well established, however intakes of both remain low across the globe. Innovative added-fibre refined grain products may present a solution to increase fibre intakes given potential sensory barriers to whole grain intake. However, to consider the efficacy of such products, or potential alternative measures, an awareness of consumer knowledge, perceptions and attitudes towards both whole grain and added-fibre grain foods is needed. Focus groups (with adults with no formal nutrition education) were conducted to explore factors affecting consumer grain choice. Discussions were transcribed verbatim and analysed using inductive thematic analysis. Nine focus groups composed of 52 participants (23 men; 29 women) were conducted. Participants tended to report choosing 'grainy' bread but few other whole grain foods. Most participants were unaware of the long-term health benefits of whole grains, recommended whole grain intakes, or how to identify foods that were high in whole grains, thereby limiting motivation to increase intake. Additionally, scepticism surrounding the health value of carbohydrate-based foods appeared to hinder grain intakes in general. These findings suggest that further public education and promotion of whole grain benefits, with a focus on food-based targets and messaging, may be important in efforts to increase whole grain and subsequently fibre intakes. Added-fibre grain products may be a useful addition, specifically for avid whole grain-avoiders who are unlikely to accept whole grain sensory properties. However, as most participants were open to whole grain consumption, industry innovation should also focus efforts on increasing availability and variety of products high in whole grains.

Nanobody-alkaline phosphatase fusion-mediated phosphate-triggered fluorescence immunoassay for ochratoxin a detection

Ochratoxin A (OTA) is a kind of mycotoxin that seriously harms the health of humans and animals. In this study, a nanobody-alkaline phosphatase fusion-mediated phosphate-triggered fluorescence immunoassay (Nb-AP-mediated PT-FIA) was developed for detecting OTA. Based on the constructed phosphate-triggered fluorescence sensing system for Nb-AP and the optimal working conditions, the Nb-AP-mediated PT-FIA has a half maximal inhibition concentration (IC₅₀) of 0.46 ng/mL, a limit of detection (IC₁₀) of 0.12 ng/mL, and a linear range (IC_20-80) of 0.2-1.26 ng/mL, respectively. The recovery experiment indicated acceptable accuracy and precision of the Nb-AP-mediated PT-FIA, and the results were validated by high performance liquid chromatography with fluorescence detector. Thus this proposed method is applicable to sensitive, rapid, and low-cost detection of OTA and other toxic analytes with low molecular weight in food and environment.

Cadmium allocation to grains in durum wheat exposed to low Cd concentrations in hydroponics

This study aims to characterize the response of durum wheat to different concentrations of Cd found in agricultural soils. One French durum wheat cultivar (i.e. Sculptur) was exposed to low concentrations of Cd (5 nM or 100 nM) in hydroponics. After anthesis, the plants were fed with a solution enriched with the stable isotope ¹¹¹Cd to trace the newly absorbed Cd. Plants were sampled at anthesis and grain maturity to assess how plant growth, Cd uptake and partitioning among organs, as well as Cd remobilization, differed between the two Cd exposure levels. Durum wheat did not show any visual symptoms of Cd toxicity, regardless of which Cd treatment was applied. However, post-anthesis durum wheat growth was 14% penalized at 100 nM due to the large transpiration-based accumulation of Cd in leaves at this stage. The allocation of Cd to the grains was not restricted but enhanced at 100 nM compared to 5 nM. Both the root-to-shoot Cd translocation and the fraction of aboveground Cd allocated to grains were higher in plants exposed to 100 nM. Cadmium was remobilized exclusively from roots and stems, and remobilized Cd contributed on average to 40-45% of the Cd accumulated in mature grains, regardless of which Cd treatment was applied. The relevance of these results to decreasing the concentration of Cd in durum wheat grains is discussed.

Surface glycan-binding proteins are essential for cereal beta-glucan utilization by the human gut symbiont Bacteroides ovatus

The human gut microbiota, which underpins nutrition and systemic health, is compositionally sensitive to the availability of complex carbohydrates in the diet. The Bacteroidetes comprise a dominant phylum in the human gut microbiota whose members thrive on dietary and endogenous glycans by employing a diversity of highly specific, multi-gene polysaccharide utilization loci (PUL), which encode a variety of carbohydrases, transporters, and sensor/regulators. PULs invariably also encode surface glycan-binding proteins (SGBPs) that play a central role in saccharide capture at the outer membrane. Here, we present combined biophysical, structural, and in vivo characterization of the two SGBPs encoded by the Bacteroides ovatus mixed-linkage β-glucan utilization locus (MLGUL), thereby elucidating their key roles in the metabolism of this ubiquitous dietary cereal polysaccharide. In particular, molecular insight gained through several crystallographic complexes of SGBP-A and SGBP-B with oligosaccharides reveals that unique shape complementarity of binding platforms underpins specificity for the kinked MLG backbone vis-à-vis linear β-glucans. Reverse-genetic analysis revealed that both the presence and binding ability of the SusD homolog BoSGBPMLG-A are essential for growth on MLG, whereas the divergent, multi-domain BoSGBPMLG-B is dispensable but may assist in oligosaccharide scavenging from the environment. The synthesis of these data illuminates the critical role SGBPs play in concert with other MLGUL components, reveals new structure-function relationships among SGBPs, and provides fundamental knowledge to inform future (meta)genomic, biochemical, and microbiological analyses of the human gut microbiota.

Selenium Content and/or T-2 Toxin Contamination of Cereals, Soil, and Children's Hair in Some Areas of Heilongjiang and Gansu Provinces, China

It has been strongly suggested that selenium deficiency and T-2 contamination in cereals are responsible for the development of Kashin-Beck disease (KBD). In order to assess these risk factors of KBD in the internal and external environments, our team undertook a two-stage survey in some areas of Heilongjiang and Gansu Provinces, China. The selenium content in children's hair (293), cereal (192), and soil (46) samples were determined using the 2, 3-diamino-naphthalene fluorometric assay technique. The T-2 toxin contamination level in the cereal samples (704) was assayed using an ELISA kit. There were no clinical KBD cases identified in this survey. The selenium statuses of the children in all the investigated regions during the first phase were at the medium selenium nutrition level. During the second phase, the selenium status of the children in Weiyuan County, Ning County, and Shangzhi City was at the medium selenium nutrition level, at the edge of selenium deficiency, and selenium deficient, respectively. Furthermore, the selenium contents in the cereal and soil samples were low. During the first phase, the average T-2 toxin contamination level in the family staple food samples for all the investigated regions was about 10 ng/g. However, the T-2 toxin contamination levels in eight homegrown corn samples were higher than 100 ng/g. During the second phase, all the average T-2 toxin contamination levels in the flour and corn samples from the three investigated regions were less than 10 ng/g. Risk factors that affect the prevalence of KBD still remain in the internal and external environments of some areas in Heilongjiang and Gansu Provinces.

Whole-Genome Bisulfite Sequencing and Epigenetic Variation in Cereal Methylomes

Whole-genome bisulfite sequencing (WGBS) is a technique used for the analysis of genome-wide DNA methylation patterns (DNA methylomes) at a single-base resolution. Here, I describe a simple DNA extraction method from rice endosperm and the universal protocol of WGBS, MethylC-sequencing library preparation. The use of benzyl chloride allows for the extraction of high-quality genomic DNA from starchy endosperm, while sodium bisulfite converts unmethylated cytosine to uracil, whereas methylated cytosine is unchanged. The bisulfite conversion of whole genome sequencing libraries before the final amplification step allows for the discrimination of methylated from unmethylated cytosines in a genome-wide manner.

Updating and interaction of polycomb repressive complex 2 components in maize (Zea mays)

The information on core components in maize polycomb repressive complex 2 (PRC2) are updated at a genome-wide scale, and the protein-protein interaction networks of PRC2 components are further provided in maize. The evolutionarily conserved polycomb group (PcG) proteins form multi-subunits polycomb repressive complexes (PRCs) that repress gene expression via chromatin condensation. In Arabidopsis, three distinct PRC2s have been identified, each determining a specific developmental program with partly functional redundancy. However, the core components and biological functions of PRC2 in cereals remain obscure. Here, we updated the information on maize PRC2 components at a genome-wide scale. Maize PRC2 subunits are highly duplicated, with five MSI1, three E(z), two ESC and two Su(z)12 homologs. ZmFIE1 is preferentially expressed in the endosperm, whereas the remaining are broadly expressed in many tissues. ZmCLF/MEZ1 and ZmFIE1 are maternally expressed imprinted genes, in contrast to the paternal-dominantly expression of ZmFIE2 in the endosperm. In maize, E(z) members likely provide a scaffold for assembling PRC2 complexes, whereas Su(z)12 and p55/MSI1-like proteins together reinforce the complex; ESC members probably determine its specificity: FIE1-PRC2 regulates endosperm cell development, whereas FIE2-PRC2 controls other cell types. The duplicated Brassicaceae-specific MEA and FIS2 also directly interact with maize PRC2 members. Together, this study establishes a roadmap for protein-protein interactions of maize PRC2 components, providing new insights into their functions in the growth and development of cereals.

Development of a biotin-streptavidin-amplified nanobody-based ELISA for ochratoxin A in cereal

A biotin-streptavidin-amplified enzyme-linked immunosorbent assay using a biotinylated nanobody (BA-Nb ELISA) was developed to detect ochratoxin A (OTA) in cereal. The limit of detection (LOD) of the BA-Nb ELISA, which equals to 10% maximal inhibitory concentration, was 0.011 ng/mL for OTA in buffer, and the sensitivity was approximately improved by one order of magnitude compared with the traditional Nb ELISA (LOD = 0.112 ng/mL). Under optimal conditions, the developed assay could be accomplished in 40 min with maximal inhibitory concentration of 0.138 ng/mL and the linear detection range of 0.034-0.460 ng/mL. The average recovery rate of the BA-Nb ELISA ranged from 92.8% to 114%, and the relative standard deviation was in the range of 2.04-9.85%. The developed BA-Nb ELISA was validated by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the results indicated the reliability of BA-Nb ELISA for the detection of OTA in cereal.

Mouse model of human poisonings with tetramethylenedisulfotetramine: Characterization of the effect of exposure route on syndrome outcomes

Tetramethylenedisulfotetramine (TMDT) is a synthetic neurotoxic rodenticide and potential chemical threat agent. Signs of TMDT poisoning include convulsions which can progress into status epilepticus and death. Although clinical reports clearly show that poisoning via food and drink is the main route of exposure, experimental studies have primarily utilized parenteral routes. Here we used two different modes of oral administration of TMDT and compared the toxic outcomes with two different parenteral routes. Adult male mice were given various doses of TMDT either perorally in peanut butter or cereal pellets, or injected intraperitoneally (i.p.) or subcutaneously (s.c.). All routes produced the complete TMDT syndrome including twitches, clonic and tonic-clonic seizures and death. However potencies varied with the following rank order: i.p. > s.c. > oral (cereal)>>oral (peanut butter). Our data clearly show that ingestion of TMDT with peanut butter markedly reduces the overall syndrome severity relative to oral exposure via cereals. No significant differences were observed by substituting peanut oil for water as a vehicle for i.p. administered TMDT. In conclusion, high vs low fat food can differentially affect TMDT onset of action, probably due to differences in availability from the gastrointestinal tract. These results should be considered when searching for effective treatments for TMDT poisoning.

Regulation of a novel Fusarium cytokinin in Fusarium pseudograminearum

Fusarium pseudograminearum is an agronomically important fungus, which infects many crop plants, including wheat, where it causes Fusarium crown rot. Like many other fungi, the Fusarium genus produces a wide range of secondary metabolites of which only few have been characterized. Recently a novel gene cluster was discovered in F. pseudograminearum, which encodes production of cytokinin-like metabolites collectively named Fusarium cytokinins. They are structurally similar to plant cytokinins and can activate cytokinin signalling in vitro and in planta. Here, the regulation of Fusarium cytokinin production was analysed in vitro. This revealed that, similar to deoxynivalenol (DON) production in Fusariumgraminearum, cytokinin production can be induced in vitro by specific nitrogen sources in a pH-dependent manner. DON production was also induced in both F. graminearum and F. pseudograminearum in cytokinin-inducing conditions. In addition, microscopic analyses of wheat seedlings infected with a F. pseudograminearum cytokinin reporter strain showed that the fungus specifically induces its cytokinin production in hyphae, which are in close association with the plant, suggestive of a function of Fusarium cytokinins during infection.

Towards an understanding of the Cd isotope fractionation during transfer from the soil to the cereal grain

Cd in soils might be taken up by plants, enter the food chain and endanger human health. This study investigates the isotopic fractionation of major processes during the Cd transfer from soils to cereal grains. Thereto, soil, soil solution, wheat and barley plants (roots, straw and grains) were sampled in the field at three study sites during two vegetation periods. Cd concentrations and δ^114/110Cd values were determined in all samples. The composition of the soil solution was analyzed and the speciation of the dissolved Cd was modelled. Isotopic fractionation between soils and soil solutions (Δ^114/110Cd_{20-50cm-soil solution} = -0.61 to -0.68‰) was nearly constant among the three soils. Cd isotope compositions in plants were heavier than in soils (Δ^114/110Cd_{0-20cm-plants} = -0.55 to -0.31‰) but lighter than in soil solutions (Δ^114/110Cd_{soil solution-plants} = 0.06-0.36‰) and these differences correlated with Cd plant-uptake rates. In a conceptual model, desorption from soil, soil solution speciation, adsorption on root surfaces, diffusion, and plant uptake were identified as the responsible processes for the Cd isotope fractionation between soil, soil solution and plants whereas the first two processes dominated over the last three processes. Within plants, compartments with lower Cd concentrations were enriched in light isotopes which might be a consequence of Cd retention mechanisms, following a Rayleigh fractionation, in which barley cultivars were more efficient than wheat cultivars.

Virus-Induced Gene Silencing (VIGS) for Functional Characterization of Disease Resistance Genes in Barley Seedlings

With the recent advances in sequencing technologies, many studies are generating lists of candidate genes associated with specific traits. The major bottleneck in functional genomics is the validation of gene function. This is achieved by analyzing the effect of either gene silencing or overexpression on a specific phenotypic or biochemical trait. This usually requires the generation of stable transgenic plants and this can take considerable time. Therefore any technique that expedites the validation of gene function is of particular benefit in cereals, including barley. One such technique is Virus-Induced Gene Silencing (VIGS), which evokes a natural antiviral defense mechanism in plants. VIGS can be used to downregulate gene expression in a transient manner, but long enough to determine its effects on a specific phenotype. It is particularly useful for screening candidate genes and selecting those with potential for disease control. VIGS based on Barley Stripe Mosaic Virus (BSMV) is a powerful and efficient tool for the analysis of gene function in cereals. Here we present a BSMV VIGS protocol for simple and robust gene silencing in barley and describe it to evaluate the role of the hormone receptor BRI1 (Brassinosteroid Insensitive 1) in barley leaf resistance to Fusarium infection.

Mycotoxins' evaluation in wheat flours used in Brazilian bakeries

Abstract

The aim of this study was to evaluate the mycotoxicological quality of wheat flours used by bakeries from the North Region in Rio Grande do Sul state, Brazil, regarding the presence of mycotoxins. On collecting type-1 refined wheat flour, a conglomerate sampling from 13 cities and 3 bakeries per city (n = 39), selected from the defined region was performed. The mycotoxins analysis was using QuEChERS method and UPLC-MS/MS analysis. As a result, 100% of samples presented contamination by DON, with concentrations ranging from 76.7 to 3630.2 µg kg^-1 and ZON was found in one sample (26.7 µg kg^-1), which represented 2.6% of the analyzed wheat flours. Other mycotoxins (AFB1, AFB2, AFG1, AFG2, DAS, HT-2 toxin, OTA, FB1 and FB2) were not detected in the analyzed samples.

Graphical abstract

Structure and biosynthesis of benzoxazinoids: Plant defence metabolites with potential as antimicrobial scaffolds

Benzoxazinoids, comprising the classes of benzoxazinones and benzoxazolinones, are a set of specialised metabolites produced by the plant family Poaceae (formerly Gramineae), and some dicots. The family Poaceae in particular contains several important crops like maize and wheat. Benzoxazinoids play a role in allelopathy and as defence compounds against (micro)biological threats. The effectivity of benzoxazinones in these functionalities is largely imposed by the subclasses (determined by N substituent). In this review, we provide an overview of all currently known natural benzoxazinoids and a summary of the current state of knowledge of their biosynthesis. We also evaluated their antimicrobial activity based on minimum inhibitory concentration (MIC) values reported in literature. Monomeric natural benzoxazinoids seem to lack potency as antimicrobial agents. The 1,4-benzoxazin-3-one backbone, however, has been shown to be a potential scaffold for designing new antimicrobial compounds. This has been demonstrated by a number of studies that report potent activity of synthetic derivatives of 1,4-benzoxazin-3-one, which possess MIC values down to 6.25 μg mL^-1 against pathogenic fungi (e.g. C. albicans) and 16 μg mL^-1 against bacteria (e.g. S. aureus and E. coli). Observations on the structural requirements for allelopathy, insecticidal, and antimicrobial activity suggest that they are not necessarily conferred by similar mechanisms.

Microbiological and chemical properties of wet tarhana produced by different dairy products

This study investigated the use of kefir, yogurt and their combination in the production of wet tarhana with an aim to increase the nutritional value of the end product. Along with microbiological and chemical properties, the volatile compound composition of wet tarhana was also evaluated. Wet tarhana revealed an increase in the lactic acid bacteria count (LAB) with the addition of kefir. After fermentation, counts of total yeast, LAB, and total mesophilic aerobic bacteria were 7.57, 8.26 and 7.64 log CFU/g, respectively. The values of pH and titratable acidity were measured as 4.78 and 4.68% in terms of lactic acid, respectively, at the end of fermentation. Lactic acid content increased from 3.31 to 10.82 g/kg throughout fermentation. A total of 72 volatile compounds were recorded during fermentation and 44 of these were identified by GC-MS. The most abundant compounds identified in the tarhana samples were hexadecanoic acid and 9,12-octadecadienoic acid. Moreover, ABTS antioxidant activity results of all formulations were measured in the range of 15.86 and 19.31 µmol TE/g at the end of fermentation and it was independent of the fermentation period.

In vitro investigation of bioactivities of solid-state fermented lupin, quinoa and wheat using Lactobacillus spp

This study is an in-vitro investigation of the health-promoting properties of fermented whole-grain lupin, quinoa and wheat, using 72 h solid-state fermentation by Lactobacillus reuteri K777 and Lb. plantarum K779. Antiproliferative activity against Caco-2 and MCF-7 cancer cell lines (tumour cell lines of intestinal and mammary origin, respectively) was investigated, as well as α-amylase and α-glucosidase inhibition, antihypertensive, antioxidant and proteolytic activities. ABTS antioxidant activities of fermented lupin (FL, 55% w/v), quinoa (FQ, 55% w/v) and wheat (FW, 55% w/v) ranged from ∼12.0% to 55.0%, ∼17.6% to 73.0%, and ∼29.0% to 26.0%, respectively. Lupin, quinoa and wheat fermented by L. plantarum had pronounced antihypertensive activities (∼85%). The α-glucosidase inhibition in FL was higher than that of FQ and FW. The magnitude of the antiproliferative activities of FL was markedly greater (p < 0.05) than of FQ and FW by approximately three-fold and two-folds against Caco-2 and MCF-7 cell lines, respectively.

A low-cost method to rapidly and accurately screen for transpiration efficiency in wheat

BACKGROUND

Wheat (Triticum aestivum L.) productivity is commonly limited by the availability of water. Increasing transpiration efficiency (biomass produced per unit of water used, TE) can potentially lead to increased grain yield in water-limited environments ('more crop per drop'). Currently, the ability to screen large populations for TE is limited by slow, low-throughput and/or expensive screening procedures. Here, we propose a low-cost, low-technology, rapid, and scalable method to screen for TE. The method uses a Pot-in-Bucket system that allows continuous watering of the pots and frequent monitoring of water use. To investigate the robustness of the method across environments, and to determine the shortest trial duration required to get accurate and repeatable TE estimates in wheat, plants from 11 genotypes varying in phenology were sown at three dates and grown for different durations in a polyhouse with partial environmental control.

RESULTS

The method revealed significant genotypic variations in TE among the 11 studied wheat genotypes. Genotype rankings for TE were consistent when plants were harvested the same day, at the flag-leaf stage or later. For these harvests, genotype rankings were consistent across experiments despite changes in environmental conditions, such as evaporative demand.

CONCLUSIONS

These results indicate that (1) the Pot-In-Bucket system is suitable to screen TE for breeding purposes in populations with varying phenology, (2) multiple short trials can be carried out within a season to allow increased throughput of genotypes for TE screening, and (3) root biomass measurement is not required to screen for TE, as whole-plant TE and shoot-only TE are highly correlated, at least in wheat. The method is particularly relevant in developing countries where low-cost and relatively high labour input may be most applicable.

Accumulation and distribution of PAHs in winter wheat from areas influenced by coal combustion in China

In order to investigate level and potential sources of polycyclic aromatic hydrocarbons (PAHs) in wheat fields affected by coal combustion in Henan and Shaanxi Provinces and to investigate distribution and transfer of PAHs in winter wheat grown in the areas, various tissues of the crop and the corresponding rhizosphere soils were collected during the harvest season of winter wheat. The mean concentrations of USEPA 15 priority PAHs (sum of the three- to six-ring PAHs) ranged from 486 to 1117 μg kg^-1 in the rhizosphere soils, indicating serious PAH contamination. Based on both the isomeric ratios of PAHs and a principal component analysis (PCA), the main sources of PAHs in the agricultural soils were from combustion of biomass, coal and petroleum, and petroleum. ∑₁₅PAHs were significantly (p < 0.001) higher in the roots (287-432 μg kg^-1) than those in aerial tissues (221-310 μg kg^-1). There were two decreasing gradients of PAH concentrations, one from roots, stems to leaves, and the other from glumes to grains. Regardless of sampling sites, most PAHs detected in the roots and in the aerial tissues were three-ring PAHs (acenaphthene, acenaphthylene, fluorene, phenanthrene, and anthracene) and the percentages of three-ring PAHs were much higher in the aerial tissues (72.5-82.7%) than in the roots (49.5-74.0%) and in the rhizosphere soils (36.3-65.7%). The distribution of PAHs with different ring numbers in the stems, leaves, and glumes was quite similar to each other but was significantly different from that of the roots and rhizosphere soils. Combined with significant results from partial correlation and linear regression models, the present study suggested that partial three- to four-ring PAHs in the aerial tissues are derived from root-soil uptake and that six-ring PAHs may come from the air-to-leaf pathway, although the quantity contribution of foliar uptake and root uptake was yet to be further studied.

Effect of Two Oat-based Cereals on Subjective Ratings of Appetite

Viscosity generated by oat β-glucan induces gastrointestinal mechanisms that influence appetite. Two oat-based ready-to-eat cereals (RTEC) with similar amounts of β-glucan but differing in their protein and sugar content were compared for their effects on appetite. Forty-seven healthy individuals, ≥18 years old, enrolled in a crossover trial consumed RTEC1 or RTEC2 in random order at least a week apart. Breakfasts contained 250kcals cereal and 105kcals fat-free milk. Subjective ratings of appetite were completed at baseline, and at 30, 60, 120, 180 and 240 minutes after consumption of the breakfast meals. Responses were analyzed as area under the curve (AUC) and per time-point. Significance was set at α=0.05. Fullness (p=0.01) and stomach fullness (p=0.02) were greater with RTEC 1 compared to RTEC 2 at 240 minutes. Stomach fullness (p=0.01) was greater at 30 minutes, and desire to eat (p=0.04) was reduced at 120 minutes with RTEC2 compared to RTEC1. There was no difference in the AUC for hunger, fullness, stomach fullness, desire to eat, or prospective intake. Ready-to-eat cereals containing similar amounts of oat β-glucan differed in the timing of significant differences in fullness or desire to eat, but appetite ratings over a four hour period did not differ.

Soya bean meal increases litter moisture and foot pad dermatitis in maize and wheat based diets for turkeys but maize and non-soya diets lower body weight

1. A 2 × 2 factorial experiment was conducted to compare the effects of wheat or maize based diets differing in dietary electrolyte balance (DEB) on litter moisture and foot pad dermatitis (FPD) at 4, 8 and 12 weeks of age in heavy-medium turkeys. A second objective was to investigate the effects on foot pad dermatitis of the interaction between dietary composition and artificially increasing litter moisture by adding water to the litter. 2. High DEB diets contained soya as the main protein source whereas low DEB diets did not contain soya bean meal. Diets were formulated to be iso-caloric and iso-nitrogenous in each of 3 successive 4-week phases following recommended dietary compositions. DEB concentrations were 330, 290 and 250 mEq/kg in high DEB diets and 230, 200 and 180 mEq/kg in low DEB diets. 3. Litter moisture and mean FPD score were higher in turkeys fed on high DEB diets compared with low DEB diets whereas there was no difference between maize and wheat. 4. Food intake was similar and body weight was lower after litter moisture was artificially raised in the wet compared with the dry litter treatment and there was no interaction with dietary composition. 5. Mean body weight and feed intake were higher in turkeys fed on wheat compared with maize and in high DEB compared with low DEB diets at 12 weeks of age. 6. Lowering dietary DEB for turkeys may improve litter moisture and lower the prevalence of FPD in commercial turkey flocks.

Residuals, bioaccessibility and health risk assessment of PAHs in winter wheat grains from areas influenced by coal combustion in China

Polycyclic aromatic hydrocarbons (PAHs) contamination in atmospheric and soil was serious, which is mainly due to high level of emission of PAHs in China resulted from the predominating use of coal in energy consumption and continuous development of economy and society for years. However, the status of PAHs in winter wheat grains from the areas influenced by coal combustion in China was still not clear. During harvest season, the winter wheat grains were collected from agricultural fields surrounding coal-fired power plants located in Shaanxi and Henan Provinces. This study found that the mean concentrations of 15 priority PAHs ranged from 69.58 to 557.0μgkg^-1. Three-ring PAHs (acenaphthene, acenaphthylene, fluorene, phenanthrene and anthracene) were dominant in the grains, accounting for approximately 70-81% of the total PAHs. The bioaccessibility of low molecular weight (LMW, 2-3 ring) PAHs (51.1-52.8%), high molecular weight (HMW, 4-6 ring) PAHs (19.8-27.6%) and total PAHs (40.9-48.0%) in the intestinal condition was significantly (p<0.001) higher than that (37.4-38.6%; 15.6-22.5%; 30.7-35.5%) in the gastric condition, respectively. Based on total PAHs, the values of incremental lifetime cancer risk (ILCR) for children, adolescents, adults and seniors were all higher than the baseline value (10^-6) and some even fell in the range of 10^-5-10^-4, which indicated that most grains from the areas affected by coal combustion possessed considerable cancer risk. The present study also indicated that the children were the age group most sensitive to PAHs contamination. The pilot research provided relevant information for the regulation of PAHs in the winter wheat grains and for the safety of the agro-products growing in the PAHs-contaminated areas.