Benzoxazinoid and alkylresorcinol content,and their antioxidant potential,in a grain of spring and winter wheat cultivated under different production systems

The health-promoting properties of the grains of common wheat (Triticum aestivum L.) are associated with the presence of unique phytochemicals. This study determines the profile of alkylresorcinols (ARs) and benzoxazinoids (BXs) in T. aestivum spring and winter cultivars grown in Poland under the two different production systems: conventional and organic. Wheat grain extracts were subjected to qualitative and quantitative UPLC-UV-MS/MS analyses. The ARs profile consisted of five 5-n-alkylresorcinol derivatives, among which 5-n-heneicosylresorcinol (C21:0) and 5-n-nonadecanylresorcinol (C19:0) predominated; while six different BXs were determined in hydrothermally treated grains. Our research shows significant differences in the contents of ARs and BXs among wheat cultivars, as well as the two production systems used. Organically grown varieties had their total contents of ARs and BXs significantly higher than those grown conventionally. Another aim of the study was to determine the antioxidant capacity of alkylresorcinol extracts from tested wheat cultivars. The quantitative TLC-DPPH• method for determining the antiradical capacity of wheat ARs extracts was developed. We observed a positive relationship between the free radical scavenging activity of extracts and the total amount of ARs. The biological activity research is important for developing value-added wheat cultivars, having an improved profile and composition of nutritional substances.     

Breeding for increased grain protein and micronutrient content in wheat: Ten years of the GPC-B1 gene

To provide food and nutrition security for a growing world population, continued improvements in the yield and nutritional quality of agricultural crops will be required. Wheat is an important source of calories, protein and micronutrients and is thus a priority to breed for improvements in these traits. The GRAIN PROTEIN CONTENT-B1 (GPC-B1) gene is a positive regulator of nutrient translocation which increases protein, iron and zinc concentration in the wheat grain. In the ten years since it was cloned, the impacts of GPC-B1 allelic variation on quality and yield traits have been extensively analyzed in diverse genetic backgrounds in field studies spanning forty environments and seven countries. In this review, we compile data from twenty-five studies to summarize the impact of GPC-B1 allelic variation on fifty different traits. Taken together, the results demonstrate that the functional copy of the GPC-B1 gene is associated with consistent positive effects on grain protein, Fe and Zn content with only marginally negative impacts on yield. We conclude that the GPC-B1 gene has the potential to increase nutritional and end use quality in a wide range of modern cultivars and environments and discuss the possibilities for its application in wheat breeding.     

GlutoPeak parameters of whole wheat flours for gluten quality evaluation in soft wheat breeding programs

In soft wheat breeding programs, the gluten strength of flours from specific genotypes is determined by various chemical and rheological tests. Based on such tests, the experimental wheat lines with very weak flour gluten are typically selected for the production of soft-dough biscuits, while the lines with medium gluten strength and extensibility are reserved for hard-dough biscuits. Often, the genotypes having high gluten strength are removed from such breeding programs. In the present study, the usability of the GlutoPeak tester on whole wheat flour samples was investigated for assessing the gluten strength of soft wheat breeding materials. In the study, 25 soft wheat genotypes, grown in seven locations for three years, were categorized by commonly used gluten-quality-related parameters. Based on the results of the study GlutoPeak whole wheat flour PMT values ranging from 30.0 to 50.0 s and AM values from 15.0 to 20.0 GPU were found to be suitable for soft-dough biscuit products, whereas the values between 40.0 and 60.0 s and 20.0 and 23.0 GPU were appropriate for hard-dough biscuit products. The genotypes exhibiting AM values > 24.0 GPU and PMT values > 60.0 s were judged to have too-strong gluten, and thus eliminated from the breeding program. The gluten aggregation energy (AGGEN), and the torque after the maximum torque (PM) values were only useful and applicable to flours for soft-dough products. The maximum torque (BEM) values were not effective in discriminating against the genotypes. The results of this study demonstrated that the GlutoPeak whole wheat PMT and AM parameters can be recommended as quick and accurate parameters especially for early generation screening with small-scale tests in soft wheat improvement programs.     

Responses of glutamine synthetase activity and gene expression to nitrogen levels in winter wheat cultivars with different grain protein content

Glutamine synthetase (GS) plays a central role in plant nitrogen (N) metabolism, which improves crops grain protein content. A pot experiment in field condition was carried out to evaluate GS expression and activity, and grain protein content in high (Wanmai16) and low grain protein (Loumai24) wheat cultivars under two N levels (0.05 and 0.15 g N kg⁻¹ soil). High nitrogen (HN) resulted in significant increases in GS1 and GS2 expression at 10 days after anthesis (DAA), and higher GS activity during the entire grain filling stage. HN also significantly increased yield, grain protein content and protein fraction (except for glutenin of Luomai24) in two wheat cultivars, which indicated that it increased grain yield and protein content by improving nitrogen metabolism. Wanmai16 showed higher grain protein content, gliadin and glutenin content, and had higher expression level of GS2 both in flag leaves and grains at early grain filling stage. However, Luomai24 had greater yield and higher expression level of GS1. The difference expression of GS2 and GS1 genes indicates they had various contributions to the accumulation of protein and starch in wheat grains, respectively. The results suggest that GS2 would be serving as a potential breeding target for improving wheat quality.     

Genome-wide association mapping of starch granule size distribution in common wheat

Starch is a crucial component in wheat endosperm and plays an important role in processing quality. Endosperm of matured wheat grains contains two distinct starch granules (SG), referred to as larger A- and smaller B-granules. In the present study, 166 Chinese bread wheat cultivars planted in four environments were characterized for variation in SG size. A genome-wide association study (GWAS) using the 90 K SNP assay identified 23 loci for percentage volumes of A- and B-granules, and 25 loci for the ratio of A-/B-granules volumes, distributing on 15 chromosomes. Fifteen MTAs were associated with both the percentage volumes of A-, B-granules and the ratio of A-/B-granules volumes. MTAs IWB34623 and IWA3693 on chromosome 7A and IWB22624 and IWA4574 on chromosome 7B associated with the percentage volumes of A- and B-granules consistently identified in multiple environments were considered to be stable. Linear regression analysis showed a significantly negative correlation of the number of favorable alleles with the percentage volumes of A-granules and a significantly positive correlation between the number of favorable alleles and the percentage volumes of B-granules, respectively. The loci identified in this study and associated markers could provide basis for manipulating SG size to obtain superior noodle quality in wheat.     

The impact of Septoria tritici blotch in bread making quality among argentinean wheat cultivars

Septoria tritici blotch (STB), caused by Zymoseptoria tritici is a relevant foliar wheat disease worldwide. Several reports show the importance of STB on grain yield, their components and grain protein while little is known about its effect on the rheological properties of the wheat flour. The scarce literature found, only mentions the effect of the complex of foliar diseases on wheat quality, without individualizing the effect of the different pathogens separately. This study analyze the influence of increasing doses of inoculum of Zymoseptoria tritici, on the bread making quality of ten Argentinean wheat cultivars and its possible variation according to their quality group. The increase of inoculum concentration augmented the area under disease progress curve, decreased green flag leaf area duration and green leaf area duration. Cultivars K. Flecha and B.75 Aniversario had the lowest green flag leaf area duration causing higher reduction in grain filling period and higher reductions in P, indicating a lower gliadin/glutenin ratio. STB decreased P/L and E while L, W, D, SV and bread volume increased. Cultivars differed in rheological parameters according to their quality group. Gluten/protein relationship was significant in quality group 1 and non-significant in cultivars belonging to quality group 2 and 3.     

Combined mutations in five wheat STARCH BRANCHING ENZYME II genes improve resistant starch but affect grain yield and bread-making quality

Increases in the proportion of amylose in the starch of wheat grains result in higher levels of resistant starch, a fermentable dietary fiber associated with human health benefits. The objective of this study was to assess the effect of combined mutations in five STARCH BRANCHING ENZYME II (SBEII) genes on starch composition, grain yield and bread-making quality in two hexaploid wheat varieties. Significantly higher amylose (∼60%) and resistant starch content (10-fold) was detected in the SBEII mutants than in the wild-type controls. Mutant lines showed a significant decrease in total starch (6%), kernel weight (3%) and total grain yield (6%). Effects of the mutations in bread-making quality included increases in grain hardness, starch damage, water absorption and flour protein content; and reductions in flour extraction, farinograph development and stability times, starch viscosity, and loaf volume. Several traits showed significant interactions between genotypes, varieties, and environments, suggesting that some of the negative impacts of the combined SBEII mutations can be ameliorated by adequate selection of genetic background and growing location. The deployment of wheat varieties with increased resistant starch will likely require economic incentives to compensate growers and millers for the significant reductions detected in grain and flour yields.     

Impact of pre-germination on amylopectin molecular structures,crystallinity, and thermal properties of pre-germinated brown rice starches

Ungerminated brown rice (UGBR) and pre-germinated brown rice (PGBR) obtained from different pre-germination durations were studied to investigate the changes in total starch contents of flour, amylopectin molecular structures, crystallinity, and thermal properties of starches as affected by pre-germination. Each paddy of three rice cultivars with different amylose contents (RD6, waxy; KDML105, low amylose; and RD31, high amylose) was soaked in water at 30°C for 12 h and incubated over different periods until the three stages of embryonic growth length (EGL) were achieved. The total starch contents of three-stage PGBR flour from all rice cultivars decreased when pre-germination durations were increased. The three-stage PGBR starches from the three rice cultivars had lower weight-average molecular weight (Mw) and number-average molecular weight (Mn) than UGBR starches. All starches from the three rice cultivars displayed an A-type X-ray diffraction pattern (XRD). Isolated UGBR starch from RD6 had the highest (31.33%) relative crystallinity (RC), while RD31 showed the lowest RC (26.79%). The slight increases in the RC of three-stage PGBR starches from three rice cultivars were found after pre-germination. Isolated PGBR starches from the three rice cultivars had higher gelatinization temperatures and enthalpy, but lower retrogradation enthalpy and %retrogradation than UGBR starches.     

Genotypic variations in zinc accumulation and bioaccessibility among wheat (Triticum aestivum L.) genotypes under two different field conditions

Zinc (Zn) is an essential micronutrient for human health. Breeding zinc-rich crop genotypes is considered as potential solution to Zn deficiency. In this study, variation of Zn uptake, accumulation, distribution and the estimated bioaccessibility among 30 wheat genotypes across two locations were investigated with field experiments. A significant difference in grain Zn concentrations occurred across the two locations, with the corresponding values of 55.24 and 57.14 mg kg⁻¹. Grain Zn concentration was significantly and positively correlated with grain Mn concentration (0.698**, 0.617** for two locations). The estimated grain Zn bioaccessibility also showed a significant difference, a trend similar to grain Zn concentrations but with lower values (13.87 and 13.49 mg Zn d⁻¹ for two locations). These results indicate that the interaction of locations * genotypes may play an important role in grain Zn concentrations and Zn bioaccessibility.     

Polymerisation of gluten proteins in developing wheat grain as affected by desiccation

The breadmaking quality of wheat is affected by the composition of gluten proteins and the polymerisation of subunits that are synthesised and accumulated in developing wheat grain. The biological mechanisms and time course of these events during grain development are documented, but not widely confirmed. Therefore, the aim of this study was to monitor the accumulation of gluten protein subunits and the size distribution of protein aggregates during grain development. The effect of desiccation on the polymerisation of gluten proteins and the functional properties of gluten were also studied. The results showed that the size of glutenin polymers remained consistently low until yellow ripeness (YR), while it increased during grain desiccation after YR. Hence, this polymerisation process was presumed to be initiated by desiccation. A similar polymerisation event was also observed when premature grains were dried artificially. The composition of gluten proteins, the ratios of glutenin to gliadin and high molecular weight-glutenin subunits to low molecular weight-glutenin subunits, in premature grain after artificial desiccation showed close association with the size of glutenin polymers in artificially dried grain. Functional properties of gluten in these samples were also associated with polymer size after artificial desiccation.     

Prediction of bread wheat baking quality using an optimized GlutoPeak®-Test method

The GlutoPeak^®-Test (GPT) as a rapid small-scale technique was optimized to evaluate the gluten aggregation properties and to predict the loaf volume, on the basis of a multiyear and multilocation analysis of wheat samples, using different solvents. 5 % lactic acid and 1 % sodium chloride displayed significant GPT responses. Relationships between protein content, sedimentation value, GPT parameters and loaf volume were investigated. With 1 % sodium chloride, the torque 15 s before maximum torque (AM) presented the highest correlation with loaf volume of samples from 2013 to 2014 (r = 0.77, r = 0.63, p < 0.001, respectively). A multiple regression analysis indicated that the best prediction of loaf volume was a linear function of protein content and AM, explaining the variation in loaf volume by 63 % and providing an uncertainty of ±39 ml. The accuracy of the validation of the linear function leads to 64 % correct and to 36 % incorrect predictions of the loaf volume. This emphasizes that the application of the linear function of protein content and AM cannot replace the actual measurement of loaf volume, but it could be a useful rapid screening test in breeding for improved baking quality in bread wheat.     

Low temperature increased the biosynthesis of 2-AP,cooked rice elongation percentage and amylose content percentage in rice

Rice fragrance, cooked rice elongation and amylose content are some of the traits used in determining rice grain quality. 2-acetyl-1-pyrroline (2-AP) is the major compound that is responsible for fragrance in rice.This experiment was conducted with two indica rice cultivars: Meixiangzhan 2 and Xiangyaxiangzhan. Three temperature-controlled chambers: High (32 °C from 06:00 to 17:59 and 26 °C from 18:00 to 05:59), medium (27 °C from 06:00 to 17:59 and 21 °C from 18:00 to 05:59) and low (22 °C from 06:00 to 17:59 and 16 °C from 18:00 to 05:59) were used for the study. At the onset of heading, both cultivars were transferred to the three temperature-controlled chambers. Our results showed that in both cultivars, low temperature growth had the highest 2-AP content, while high temperature growth recorded the lowest 2-AP content. Principal component analysis showed remarkable differences in the metabolomes of rice grown in high, medium and low regimes. In the grains of both cultivars, we observed significant reduction in 2-AP content after 6 and 9 months of storage, however; 2-AP retention differed greatly in both cultivars. We also reported that low temperature growth increased cooked rice elongation percentage and the biosynthesis of amylose in rice. In conclusion, our findings will provide more information to breeders working on the improvement of rice grain quality.     

Immunomodulatory activities of non-prolamin proteins in wheat germ and gluten

Albumin (Alb), globulin (Glo), glutelin (Gll) and glutenin (Gln) were separately extracted from wheat germ and wheat gluten. Amino acisd composition, molecular weight distribution, solubility, in vitro digestibility, and immunomodulatory activities were all analyzed. Gll and Gln have similar molecular weight distributions, which differed from those of Alb and Glo. Alb showed the highest solubility at various pH values (except pH 4.0), whereas Glo showed the highest in vitro digestibility. Glo and Gll have the highest proportion of essential to total amino acids, while Alb and Gll have the highest protein digestibility-corrected amino acid scores. Gll had the strongest immunomodulatory effects in terms of stimulation of RAW 264.7 cells to produce IL-6, TNF-α, and IL-10, and good stimulatory effects on splenocyte proliferation, production of IL-2, phagocytosis, and secretion of nitric oxide in RAW 264.7 cells. Gll can be considered a good protein source for use in health foods.     

Linear relationships between agronomic and nutritional traits in transgenic genotypes of maize

The aims of this study were to assess the linear relationships between agronomic and nutritional traits and identify promising traits for indirect selection in transgenic genotypes of maize. Eighteen transgenic maize genotypes were assessed in randomized blocks with three replications. The agronomic (number of days from sowing until male flowering, number of days from sowing until female flowering, plant height, ear insertion height and grain yield) and nutritional (crude protein, ether extract, crude fiber, starch and amylose) traits were measured. Analysis of variance was run for each of the 10 traits and phenotypic and genotypic correlation coefficient matrices estimated. Ridge path analysis were performed the nutritional traits were treated as main variable (dependent) and agronomic traits as explanatory variables (independents). The number of days from sowing until female flowering has a positive linear relationship to crude protein, ether extract and starch. Plant height has a positive linear relationship to crude fiber. Ear height has a positive linear relationship to amylose. Grain yield has a positive linear relationship to starch. The number of days from sowing until male flowering, plant height, ear height and grain yield can be used indirect selection in maize.     

Effect of high temperature stress during ripening on the accumulation of key storage compounds among Japanese highly palatable rice cultivars

High temperature stress during ripening increases the frequency of chalky grains, resulting in a lower market value for rice (Oryza sativa L.). Changes in starch properties and the accumulation pattern of storage proteins are proposed to be related to the occurrence of chalky grains. This study investigated changes in the accumulation of key storage compounds in the grains of Japanese highly palatable rice cultivars, subjected to high temperature stress when grown in a growth chamber and the field. The 13 kDa prolamin content was significantly reduced in a highly heat-sensitive cultivar, Tsukushiroman, whereas the 13 kDa prolamin content was not affected in a heat-tolerant cultivar, Genkitsukushi, even in a high temperature chamber condition (31/26 °C day/night), when compared with the control chamber condition (26/21 °C day/night) for both genotypes. In addition, grains grown in field conditions revealed that severely chalky grains had less 13 kDa prolamin than perfect grains in all five genotypes. Changes in amylose content and the distribution of amylopectin chain lengths did not explain the difference in grain appearance both for chamber and field experiments. These results strongly suggest that physiological processes linked with the synthesis of 13 kDa prolamin are associated with grain appearance in Japanese highly palatable under high temperature stress.     

A new lean no time test baking method with improved discriminating power

In response to customer concerns related to gluten strength in commercial baking, the Canadian Grain Commission assessed whether the Canadian Short Process (CSP) test bake method was generating useful data related to intrinsic strength of wheat varieties. Assessment of CSP loaf volume data for Canadian variety trials spanning 2003 to 2013 showed very little correlation with dough strength parameters as measured by farinograph and extensigraph. A lean no time (LNT) test baking method was developed that can better discriminate genotypes and provide objective indicators of the effect of intrinsic dough strength on baking quality. From early method development, through method validation and verification using diverse sets of samples targeting different Canadian wheat classes and grown in three different crop years, results showed the LNT method to be more discriminating and easily adopted by other laboratories. In 2015, the LNT method was adopted as the method of choice in future Canadian variety registration trials. The LNT method is fast, simple and well-suited to high throughput test baking conditions encountered in the evaluation of large numbers of breeder lines. A new objective parameter, loaf top ratio, was also introduced and found to correlate well with dough strength and dough handling properties.     

A new lean no time test baking method with improved discriminating power

In response to customer concerns related to gluten strength in commercial baking, the Canadian Grain Commission assessed whether the Canadian Short Process (CSP) test bake method was generating useful data related to intrinsic strength of wheat varieties. Assessment of CSP loaf volume data for Canadian variety trials spanning 2003 to 2013 showed very little correlation with dough strength parameters as measured by farinograph and extensigraph. A lean no time (LNT) test baking method was developed that can better discriminate genotypes and provide objective indicators of the effect of intrinsic dough strength on baking quality. From early method development, through method validation and verification using diverse sets of samples targeting different Canadian wheat classes and grown in three different crop years, results showed the LNT method to be more discriminating and easily adopted by other laboratories. In 2015, the LNT method was adopted as the method of choice in future Canadian variety registration trials. The LNT method is fast, simple and well-suited to high throughput test baking conditions encountered in the evaluation of large numbers of breeder lines. A new objective parameter, loaf top ratio, was also introduced and found to correlate well with dough strength and dough handling properties.     

Impact of ethanol,succinic acid,and the combination thereof at levels produced during sponge fermentation on hard wheat,soft wheat,and durum wheat farinograph rheology

The sponge and dough mixing process is one of the most common in the world, yet the mechanistic understanding of this process has yet to be sufficiently explored. In this study, aqueous solutions of ethanol, succinic acid, and their combination were prepared at concentrations intended to replicate fermentation times of 3, 4 and 6 h. These solutions were added to a farinograph mixer to make dough using hard wheat, soft wheat, and durum wheat flour. The results indicate that these yeast metabolites (ethanol, succinic acid) impact the mixing resistance, peak mixing value, and dough mixing stability in each of the flour types, likely primarily affected by the ratios of gliadin to glutenin and LMW glutenin in each flour type. Results suggest a stabilizing non-covalent interaction imparted by gliadin at peak mixing time, a stabilizing effect of HMW glutenin during break down, and synergistic effects of ethanol and succinic acid that leads to a faster rate of breakdown in later stages of mixing. It also suggests an increase in mixing resistance when acidulants are added to durum wheat dough. Taken together, this study adds new insights on the sponge and dough mixing process in a way that has not previously been conducted.     

Use of fermented milling by-products as functional ingredient to develop a low-glycaemic index bread

Selected Lactobacillus plantarum DSM 32248 and Lactobacillus rossiae DSM 32249, isolated and identified from wheat germ, were used to ferment a milling by-products mixture. Lactic acid bacteria metabolisms improved the functional properties of wheat bran and germ, which are considered important sources of functional compounds. Wheat breads were manufactured using 15% (w/w) of fermented (and unfermented) milling by-products, and compared to baker’s yeast wheat bread manufactured without the addition of milling by-products. The use of the fermented ingredient improved the biochemical, functional, nutritional, textural, and sensory features of wheat bread, showing better performances compared to the solely use of wheat flour. Protein digestibility, nutritional indexes, and the rate of starch hydrolysis markedly improved using fermented milling by-products as ingredient. Enriched bread was also characterized by high content of dietary fibre and low glycaemic index determined in vivo.This study exploited the potential of fermented milling by products as functional ingredient. According to the Regulations the bread made under this study conditions can be defined as “high fibre content” and “low glycaemic index”. A number of advantages encouraged the manufacture of novel and healthy and functional leavened baked goods.     

Effects of wheat tempering and stone rotational speed on particle size,dough rheology and bread characteristics for a stone-milled weak flour

The poor technological performance of weak wheat flours means that they are usually considered difficult to be transformed into satisfactory bread. During milling, there are several settings that can affect flour characteristics. In this study, we tested two operative parameters that have the potential to affect flour quality – stone rotational speed and wheat tempering. Tempering moistures were set at 11%, 13%, 15%, and 17%, while stone rotational speeds were set at 173, 260, and 346 rpm. Both factors were found to affect operative milling parameters, notably flour yield, process productivity and specific energy consumption. Grain moisture had a significant effect on both dough rheology and bread characteristics (dough stability, tenacity, and extensibility). Dough stability was maximum at 13% moisture. Dough tenacity decreased as moisture increased, while extensibility increased as moisture increased. Bread specific volume and crumb specific volume were improved at 13% and 15% moisture. In conclusion, wheat tempering can be used to improve the potential of a weak flour and bread characteristics, while stone rotational speed affects operative parameters and white flour yield.