Total Polymeric Protein Research Articles

Determining factors of durum wheat bread loaf volume and alveograph characteristics under optimal, drought and heat stress conditions

Durum wheat is an important crop, especially in Mediterrannean countries; around 25% of durum wheat world-wide, and 70–90% in the Middle East, is used for bread making. Climate change is causing increased periods of drought stress and higher temperatures which are affecting wheat quality. Alveograph extensibility is important for durum wheat loaf volume (LFV), as is the relationship between dough tenacity and extensibility. This study was done to identify the factors determining LFV and alveograph properties under optimal and stress conditions. Six durum wheat cultivars with the same glutenin composition were grown for two seasons under optimal, drought and heat stress conditions. Good LFV was consistently related with higher dough extensibility, irrespective of production conditions. A number of the LMW glutenin fractions, and the γ-gliadins were significantly reduced and β-gliadins were increased under both heat and drought stress. The large and total unextractable polymeric proteins and unextractable HMW glutenins were significantly reduced by heat stress. In a multiple regression of LFV (without alveograph values), solvent retention capacity and sodium dodecyl sulphate sedimentation were the best predictors of LFV under all conditions. Size-exclusion high-performance liquid chromatography fractions combined with flour protein content were good predictors of LFV only under optimal conditions.

Diverse wheat lines to mitigate the effect of drought on end-use quality

Global climate change is causing an increasing number of drought events, which might impact the stability of wheat breadmaking quality. In this study, 73 spring wheat lines with diverse genetic backgrounds (modern, old, and wheat–rye introgression) were drought treated, and the grains were analyzed by high-performance liquid chromatography for protein composition traits related to breadmaking quality. The amount of total sodium dodecyl sulfate-extractable and -unextractable proteins (TOTE, which correlates to grain protein content) increased significantly under late drought, while no effect of early drought was found on the analyzed protein composition traits. Under control treatment, genotypes with 3R showed significantly higher TOTE than genotypes with 1R, 1RS, and 2R, indicating the potential role of 3R in increasing grain protein concentration. The lower percentage of sodium dodecyl sulfate-unextractable polymeric protein in the total polymeric protein (%UPP) found in 1R and 1RS genotypes as compared to modern and old genotypes suggested a gluten strength reduction induced by 1R and 1RS. Despite the negative yield–protein correlation found in this study, lines 252 (3R), 253 (3R), and 258 (2R) displayed the presence of germplasm with both high yield and protein concentration. The %UPP was found to be positively correlated to spike-size-related traits (grains per spike, grain weight per spike, and spike length) across all three treatments. Additionally, high and stable TOTE was mainly obtained in genotypes with 3R, while old genotypes showed dominant performance in %UPP. Thus, genes responsible for high and stable protein concentration and gluten strength should be explicitly searched among introgression lines with chromosome 3R and old Swedish cultivars, respectively.

Protein network assessment and sensory characteristics of durum wheat fresh pasta fortified with artichoke bracts and tomato powders

Fresh pasta samples fortified with artichoke bracts and tomato powders (added as a treated-mush (TM) and lio-powder (LP)) obtained through the application of an innovative, non-thermal and non-invasive physical technology (Patent n°001426984) were studied in this work. Results of the raw and cooked pasta samples indicated how the addition of the artichoke bracts had a remarkable influence on the gluten network arrangement than tomato, for both the tested formulations, even if the technological properties were found to be good, when compared to the control sample (100% semolina pasta). Chemical and SDS-PAGE analyses allowed us to confirm these results, highlighting the lower protein cooking loss of the pasta samples fortified with tomato, for both the tested formulations, due to a gluten protein network characterized by a high percentage of total unextractable polymeric proteins (%UPP) and a high ratio (SS/SH). The addition of the vegetables also affected the sensory characteristics of the samples, highlighting how the addition of the LPs more affected consumer acceptability.

Drought and heat stress effects on gluten protein composition and its relation to bread-making quality in wheat

Wheat grain proteins are largely affected by environmental conditions, with drought and heat stress causing considerable changes to gluten composition, resulting in variations in bread-making quality. Size-exclusion high-performance liquid chromatography (SE-HPLC) was used to assess the effects of moderate and severe drought and heat stress on variation in gluten proteins in bread wheat cultivars. Extractable gliadin (exGLi), mixing time (MixT) and total polymeric proteins (TPP) were largely genetically determined, while flour protein content (FPC) and extractable albumins/globulins (exAG) were significantly affected by treatment. The two levels of both heat and drought stress caused differential expression of gluten proteins. The unextractable polymeric proteins were reduced under severe heat stress, while both extractable and unextractable low molecular weight glutenin fractions were increased, leading to a weakening of the dough and deterioration of quality. Severe drought caused increased values of all bread-making related characteristics and loaf volume (LV), coupled with significant increases in unextractable polymeric and monomeric proteins and exGLi. Moderate heat stress caused increases in extractable HMW glutenin, which negatively affected bread-making characteristics. The large and total polymeric proteins were consistently correlated with LV for all treatments, although extractable HMW glutenins were generally negatively correlated with baking characteristics under all treatments.

Effects of Quinoa Flour on Wheat Dough Quality, Baking Quality, and in vitro Starch Digestibility of the Crispy Biscuits.

Quinoa is a pseudo-cereal which has excellent nutritional and functional properties due to its high content of nutrients, such as polyphenols and flavonoids, and therefore quinoa serves as an excellent supplement to make healthy and functional foods. The present study was aimed to evaluate the quality characteristics of wheat doughs and crispy biscuits supplemented with different amount of quinoa flour. The results showed that when more wheat flour was substituted by quinoa flour, proportion of unextractable polymeric protein to the total polymeric protein (UPP%) of the reconstituted doughs decreased and the gluten network structure was destroyed at a certain substitution level. The content of B-type starch and the gelatinization temperature of the reconstituted flours increased. The storage modulus, loss modulus, development time, and stability time of the dough increased as well. Moreover, hardness and toughness of the formulated crispy biscuits significantly decreased. Analyses suggested that starch digestibility was reduced and resistant starch content increased significantly. Taken together, quinoa flour improved dough rheological properties, enhanced the textural properties, and increased resistant starch content in crispy biscuits, thus adding to high nutritional value.

Influence of low soil nitrogen and phosphorus on gluten polymeric and monomeric protein distribution in two high quality spring wheat cultivars

The effect of low levels of nitrogen, phosphorus and a combination of the two on the distribution of polymeric and monomeric proteins in two high quality spring bread wheat cultivars was investigated for two consecutive seasons. Size exclusion-high performance liquid chromatography (SE-HPLC) was used to determine the quantity and relationships of monomeric and polymeric proteins, and their relationship with flour protein content (FPC) and SDS sedimentation volume (SDSS). The low nitrogen and combined low nitrogen and low phosphorus treatments had a much larger effect on the protein fractions than the low phosphorus treatment alone. The SDS-soluble large monomeric protein fraction and the percentage SDS-insoluble monomeric proteins, were significantly increased under low nitrogen and a combination of low nitrogen and low phosphorus treatments. The percentage SDS-insoluble large and total polymeric proteins was significantly reduced under low nitrogen and a combination of low nitrogen and phosphorus treatments. The SDS-soluble and -insoluble small polymeric proteins were significantly increased under both low nitrogen and a combination of low nitrogen and low phosphorus treatments. The low nitrogen treatment consistently caused the lowest FPC and SDSS values. Under low nitrogen conditions, there was a significant positive correlation between the SDS-soluble gliadins and SDSS, and FPC.

Can nitrogen fertilization be used to modulate yield, protein content and bread-making quality in Uruguayan wheat?

Genotype and environment jointly determine yield and bread-making quality of bread wheat, being possible modulators for these characters. Eleven cultivars were grown at three different nitrogen regimes combining quantity and timing of nitrogen availability for two years; yield, grain protein concentration and Alveograph parameters were determined. Amount and size distribution of proteins were measured using Size Exclusion-High Performance Liquid Chromatography. The results showed year to be the most important determinant of percentage of unextractable polymeric protein in total polymeric protein (%UPP) and yield, while nitrogen regime determined grain protein concentration, the total amount of SDS-extractable and -unextractable proteins, Alveograph W and L. High nitrogen regime generated three types of responses among the cultivars; i) an increase of yield and grain protein concentration, ii) an increase in grain protein concentration but a reduction in %UPP, and iii) an increase in %UPP. For group ii, a low nitrogen regime at early stages but high at later stages was preferential, while for other groups, a high nitrogen regime during the whole season was the most beneficial. This study showed that it is possible to modulate yield and quality in bread wheat by the nitrogen regime, although an understanding of genotype-environmental relationships is necessary.

Influence of durum wheat-faba bean intercrop on specific quality traits of organic durum wheat

To identify agronomic practices able to increase the nitrogen (N) availability for durum wheat under organic farming, the temporary intercropping with faba bean (Vicia faba L. var. minor Beck.) was tested in a multiyear experimental trial. The accumulation of total protein and specific protein fractions in the grain of eight Italian durum wheat cultivars grown as sole crop (SC) or intercropped with legume until durum wheat shooting were compared. Gluten quality was also examined. Analysis of variance indicated that gluten quality, total protein concentration, and monomeric and polymeric protein amounts were significantly higher in intercrops than in SCs whereas the grain yield was significantly higher in the SC. Significant cultivar × treatment interactions were observed for most of the tested parameters. PCA allowed the visualization of the genotypes able to use the higher N availability coming from the temporary intercropping to achieve the grain protein concentration of 14.1% dry matter, the threshold considered suitable by the industry for producing high quality pasta. In addition, one such genotypes also showed good grain yield, with the highest values in the temporary intercrop. The results suggested that the durum wheat-faba bean temporary intercropping could be an agronomic strategy for improving the grain quality of the cereal under organic management and, as a consequence, it may be expected to have a positive impact on the durum wheat end-product quality.

Governing plant development in barley (Hordeum vulgare L.): relation to protein composition and breakdown rates of protein polymers during malting

AbstractBACKGROUNDThis study aimed at investigating opportunities to manipulate development rhythms of barley (Hordeum vulgare L.) and to relate such rhythms to protein concentration, composition and breakdown during malting. The spring malting barley cultivar Tipple was grown in daylight chambers at various sowing dates, nitrogen application timings and temperature levels to govern the development rhythms.RESULTSExtensive options were shown to be available for manipulating the plant development rhythm of spring malting barley. Individually, sowing times, N application timings and temperature levels were negatively correlated with the development time. The combination of early sowing and 100% N application at sowing/low temperature during the grain maturation period (GMP) resulted in a long development time before and after anthesis. The combination of late sowing and 50% N at sowing/high temperature during GMP led to short development time before and after anthesis. The highest protein concentration and lowest percentage of sodium dodecyl sulfate‐unextractable polymeric proteins in total polymeric proteins were found to be associated with short development time. Extensive degradation of proteins during malting was the result of short development time as compared to long development time.CONCLUSIONThe development rhythm of barley affects protein concentration, composition and breakdown and might thus not only influence the end‐use quality of barley but also the next generation of plants. © 2013 Society of Chemical Industry

Comparison of Protein and Starch Content of Substituted and Complete Triticales (X Triticosecale Wittmack): Contribution to Functional Properties

The starch and protein content of substituted and complete triticales were quantitated and evaluated for their contribution to the functional properties of flours by means of the amylograph, farinograph, and the breadmaking test. Although no clear differences were observed in the starch and protein contents of the two triticale genotypes, a detailed analysis of their components revealed compositional differences between them. The amylose content was lower in the substituted triticales Duron S and Alamos 83 than in the complete types Tarasca 87 and Brumby II (P ≤ 0.05). Among the protein fractions, only the albumin and the total polymeric protein, although with an opposite effect, significantly contributed to the rheological properties of triticale doughs evaluated with the farinograph and in the breadmaking test. The SDS-PAGE test showed that the substituted triticales contained an additional HMW-GS band that was not observed in the complete triticales. Amylograph peak temperatures and maximum viscosities, farinograph development times, and loaf volumes of triticale doughs were higher in substituted triticale flours than those of the complete ones. This study demonstrated that the triticale genotypes can be differentiated not only by quantitating their starch and protein composition, but also by testing their functional dough properties.

Amount and Size Distribution of Monomeric and Polymeric Proteins in the Grain of Organically Produced Wheat

ABSTRACTIn the present study, we evaluated 444 organically grown wheat genotypes for the amount and size distribution of polymeric proteins by size‐exclusion HPLC. The investigated genotypes were divided into six genotype groups—selection, spelt, old cultivar, primitive, landrace, and cultivar—and these were grown in four different locations, namely, Alnarp, Bohuslän, Gotland, and Uppsala in Sweden. The results showed that the percentage of unextractable polymeric proteins in total polymeric proteins (%UPP) and percentage of large unextractable polymeric proteins in total polymeric proteins were higher in the cultivar group as compared with the rest of the investigated genotype groups. The amounts of total extractable polymeric proteins (TOTE) and total unextractable polymeric proteins were low in cultivars and selections, respectively. Spring wheat grain was found to have a significantly higher amount of all protein fractions as compared with winter wheat. The genotype Kenya was found to belong to both groups of the 20 genotypes with the highest TOTE and %UPP. Thus, the genotype Kenya might be of relevance for consumption and future breeding to improve the breadmaking quality of organically produced wheat.

Towards the understanding of bread-making quality in organically grown wheat: Dough mixing behaviour, protein polymerisation and structural properties

Achieving high quality of organic bread is a major objective of organic wheat production. The aim of the present study was to understand the mechanisms related to bread-making quality in organically grown wheat genotypes from a diverse background. Fifty one organically grown winter and spring wheat genotypes were evaluated for percentage of unextractable polymeric proteins in total polymeric proteins (%UPP) in flour and dough, mixing behaviour and structural properties. The results showed a large variation in genotypes for %UPP in flour, changes in %UPP at mixing, mixing parameters and structural properties. Genotypes with high %UPP in flour and low change in %UPP at optimum mixing were; Agron, Hjelmqvist 6357 blå and Effrada. The light microscopy (LM) and confocal laser scanning microscopy (CLSM) results confirmed that genotypes with high %UPP in flour and a low change at optimal mixing resulted in a more extended protein network (continuous and interconnected) at mixing as compared to the other genotypes. Genotypes with good mixing properties as to the mixograph analyses were; Diamant ax, Lantvete Gotland 4496 spelt, Erbe brun and Jacoby 59. The present study shows the presence of opportunities to select genotypes suitable for cultivation and breeding of bread wheat for organic production.

Individual and interactive effects of genetic background and environmental conditions on amount and size distribution of polymeric proteins in wheat grain

Bread-making quality of wheat flour is influenced by wheat storage proteins. The percentage of sodium dodecyl sulphate (SDS)-unextracted polymeric proteins in total polymeric proteins (% UPP), as one important factors determining bread-making quality, is largely influenced by the individual and interactive effect of genetical background and environmental conditions. Four spring wheat cultivars were grown in green house. Two of the cultivars have high molecular weight glutenin subunits 5+10 while the other two have 2+12. Four different nitrogen regimes and two different temperature levels (distinguished as low and high temperature) were used. The results highlighted the importance of interactive influence of cultivars, nitrogen regimes and temperature levels for creating differences in the amount of % UPP during grain maturation period (GMP) and at maturity. The shift to end up with either high or low % UPP at maturity happened early during GMP (around 12 days after anthesis). Influences of cultivars on % UPP was found early during the GMP while influences of temperature and nitrogen regimes were seen much later during the GMP. The results will help in understanding the relationship between quality parameters of wheat flour and how these are influenced by different environmental and genetic factors.

Individual and interactive effects of cultivar maturation time, nitrogen regime and temperature level on accumulation of wheat grain proteins

Background and reasons for differences in wheat grain protein accumulation and polymerization are not fully understood. This study investigated individual and interactive effects of genetic and environmental factors on wheat grain protein accumulation and amount and size distribution of polymeric proteins (ASPP). Individual factors, e.g. maturation time of a cultivar, nitrogen regime and temperature level, influenced grain protein accumulation and ASPP, although interaction of these factors had a greater influence. Early maturation time and long grain maturation period (GMP) in a cultivar resulted in high amounts of sodium dodecyl sulphate (SDS)-extractable proteins (TOTE) and low percentage of SDS-unextractable polymeric proteins in total polymeric proteins (%UPP). Cultivars with late maturation time and short GMP resulted in low TOTE and high %UPP. Late versus early nitrogen application regime resulted in low %UPP versus low TOTE and high %UPP, respectively. High versus low temperature resulted in high %UPP and low %UPP, respectively. Differences in ASPP at maturity started as changes in protein accumulation from 12 days after anthesis. Length of GMP, especially in relation to length until maturity, governs gluten strength (%UPP) and grain protein concentration (TOTE). Length of GMP is determined by cultivar, temperature during GMP and late nitrogen availability.

Effect of split applications of urea on protein size distribution, physical dough properties, and baking performance of five experimental bread wheat lines

Five experimental bread wheat lines (BWL) were grown at the Yaqui Valley Experimental Station in Sonora, México during two consecutive growing cycles. The effect of five nitrogen fertilization (NF) treatments on protein size distribution (PSD), physical dough properties (PDP), and baking performance of the BWL was evaluated. Polymeric and monomeric proteins were evalu-ated by SE-HPLC. PDP were carried out by the National Mixograph and the TA-XT2 Texture Analyzer. Baking performance was evaluated using the straight dough method. Protein content (PC), main protein fractions (glutenins, gliadins, albumins-globulins), and mixograph development time (MDT) were significantly influenced by NF treatment and BWL but not by their interaction. On the other hand, PDP measured by the Kieffer rig, and baking performance were significantly influenced by the main factors (NF and BWL) and their interaction. The amount and timing of fertilizer applied to the BWL modified the PC, PSD, PDP, and bread loaf volume. PDP exhibited a larger variation in comparison to the PSD of glutenins. The split application of 150 kg of urea/ha (50-50-50) to all BWL showed a better loaf volume response than the same amount of urea applied at sowing (150-0-0). The application of 300 kg of urea/ha to all BWL, either at sowing or at three split applications of 100 kg of urea/ha each, resulted in higher flour unextractable polymeric protein (FUPP). On the other hand, the split application of 100-100-100 kg of urea/ha to three of the BWL represented the higher total unextractable polymeric protein (TUPP). Differences on PC and PSD were reflected on differences on PDP and bread loaf volume observed among the BWL.

Effect of Allelic Variation and Expression Quantity at Glu-1 Loci on Size Distribution of Glutenin Polymer in Common Wheat

Two sets of common wheat ( Triticum aestivum L.) lines were used in this study, including 23 spring wheat genotypes in Trial I and 21 winter wheat genotypes in Trial II. The size distribution of glutenin polymers was significantly affected by allelic variation and expression quantity of Glu-1 loci based on flour protein content, especially on total expression quantity of high-molecular-weight glutenin subunits (HMW-GS). In Trail I, when the expression of HMW-GS was in a low level, significantly ( P < 0.01) additive effects were observed at Glu-B1 and Glu-D1 loci on content of SDS-unextractable polymeric protein (UPP) and percent SDS-unextractable polymeric protein in total polymeric protein (%UPP). The contribution of individual glutenin subunit ranked as 7 OE+8* > 7+9 > 17+18 > 7+8 at Glu-B1 and 5+10 > 2+12 at Glu-D1. The %UPP in genotype with subunit combination of 5+10 was higher than that with subunit combination of 2+12. The quantity of HMW-GS was positively correlated with UPP ( r = 0.79–0.93, P < 0.01). In Trial II, when expression of HMW-GS was in a high level, significantly additive effect on %UPP was only observed at Glu-D1 ( P < 0.05). The contribution to %UPP of individual glutenin subunit was ranked as 5+10 > 2+12 or 4+12 at Glu-D1. The size distribution of polymers was not significantly different among subunit combinations. The quantity of HMW-GS was positively correlated with UPP ( r = 0.42–0.86, P < 0.05 or 0.01). In conclusion, gluten strength and end-use quality can be improved by selection of high quality subunits in combination with high expression in breeding programs.

Changes in durum wheat kernel and pasta proteins induced by toasting and drying processes

Durum wheat kernels were subjected to a toasting process and the proteins characterised by size exclusion-high performance liquid chromatography (SE-HPLC) and sodium dodecyl sulphate–polyacrylamide gel electrophoresis. With this physical process, albumins and globulins, as well as glutenins and gliadins, polymerised as seen by a shift of the SE-HPLC profile to lower elution times. The polymerisation seemed to happen mainly through disulphide bonds, even though the participation of ω-gliadins to the aggregation suggested the involvement of other kinds of interactions. It led to the revelation of a new peak originated by thermal aggregation of small polymeric proteins. The changes in the chromatographic profile were accompanied by increasing amounts of total unextractable polymeric proteins. The replacement of semolina with toasted durum wheat flour (5%, 10%, 15%, 20% and 30%) for the production of pasta in the shape of spaghetti significantly (p < 0.001) affected the molecular size distribution of the polymeric proteins, even though the replacement of semolina with 5% and 10% of toasted durum wheat flour (TDWF) did not significantly (p > 0.05) change the unextractable polymeric proteins (UPP) when compared with spaghetti made with 100% durum semolina. On the other hand, the replacements of semolina with 15–30% TDWF showed significant (p < 0.001) increase in UPP when compared with 100% durum semolina spaghetti.

A Novel Pair of HMW Glutenin Subunits from Aegilops searsii Improves Quality of Hexaploid Wheat

ABSTRACTThis study involved screening of wild species of wheat in search of functionally useful seed storage proteins for improvement of breadmaking quality of wheat (Triticum aestivum). After screening of 177 disomic addition lines (DALs) of wheat belonging to different wild species, Aegilops searsii DALs were selected and studied in detail. These DALs of Ae. searsii were from chromosome 1Ss to 7Ss in the background of cultivated wheat cv. Chinese Spring (CS). By analyzing these addition lines, genetic loci of actively expressed genes for the high molecular weight glutenin subunits (HMW‐GS) and gliadin were found on the chromosome 1Ss for the first time and have been designated as Glu‐Ss1 and Gli‐Ss1, respectively. Disomic addition line of chromosome 1Ss (DAL1Ss) showed improved dough strength in different generations compared with CS. SDS sedimentation value and specific sedimentation of DAL1Ss were higher than CS. Mixograph peak height and band width were higher, with no difference in mixing peak time from CS. All these factors indicate a positive effect of quantity as well as quality of gluten proteins of Ae. searsii. This was further supported by increased polymer formation in DAL1Ss because the ratio of unextractable polymeric protein to total polymeric protein (UPP/TPP%) of DAL1Ss was significantly higher than CS. Genes for HMW‐GS (major determinant of end‐product quality in wheat) of Ae. searsii were cloned and sequenced from the DAL1Ss. Phylogenetic analysis of deduced amino acid sequences showed that both x and y HMW‐GS were more similar to that of D genome rather than B genome of wheat. Although S genome is structurally more similar to B genome of wheat, functionally it is more similar to the D genome of wheat and possesses good quality HMW‐GS required for improvement of breadmaking quality of wheat.

Association Between % SDS‐Unextractable Polymeric Protein (%UPP) and End‐Use Quality in Chinese Bread Wheat Cultivars

ABSTRACTTrial I, with 33 spring cultivars, and trial II, with 21 winter cultivars, sown in four environments in the northwestern China spring wheat region and northern winter wheat region, respectively, were used to study the effect of genotype and environment on the size distribution of polymeric proteins. Association between quantity and size distribution of polymeric protein and dough properties (both trials) and northern‐style Chinese steamed‐bread (CSB) (trial I) and pan bread (trial II) qualities were also investigated. In trial I, all protein attributes, such as flour protein content, SDS‐extractable polymeric protein in the flour (EPP), SDS‐unextractable polymeric protein in the flour (UPP), and percent UPP in total polymeric protein (%UPP), were largely determined by environment, whereas variation in dough strength resulted from variation in UPP and %UPP across environments. In trial II, EPP was largely determined by environment, and UPP and %UPP were largely determined by genotype. These differences might result from different levels of protein content and dough strength in the two trials. The EPP was positively correlated with dough extensibility and was generally negatively correlated with dough stability and maximum resistance in both trials. However, %UPP was significantly positively correlated with dough stability and maximum resistance and end‐use quality in both trials. In trial I, correlation coefficients between %UPP and maximum resistance and CSB score were r = 0.90 and 0.71, respectively, whereas in trial II, the correlation coefficients between %UPP and maximum resistance and pan bread score were 0.96 and 0.87, respectively. Therefore, selection for high %UPP together with high‐quality glutenin subunits should lead to improved dough strength and end‐use quality in Chinese wheats.

Relationship between SDS-Unextractable Glutenin Polymeric Protein and Mixograph Parameters

Improvement of end-use quality has become a major breeding objective in China. In order to further improve gluten quality, effective selection parameter in early generation is necessary in wheat quality breeding program. In total, 108 wheat (Triticum aestivum L.) varieties and advanced lines were used to test kernel hardness, protein content, sedimentation value, mixogragh parameters, glutenin polymeric protein content by biuretium protein fraction procedure, and the amount and ratio of gluten protein fractions by size-exclusion high-performance liquid chromatography method (SE-HPLC). The relationship between flour protein content, sedimentation volume, and mixograph parameters and gluten protein fractions in quantity were investigated. The results showed that broad variations for quality traits and quantitativedata for protein fractions were observed in this set of germplasm. The range of mixograph peak time was 1.12–7.19 min, and the range of SDS-unextractable polymeric protein was very broader than that of SDS-extractable polymeric protein. There were less correlation between grain hardness, flour protein content, whole meal sedimentation value, and mixograph peak time with r of 0.24–0.49. The amount of gliadin was not signifi- cantly correlated with mixograph parameters, while the ratio of gliadin to glutenin (Gli/Glu) was crucial in determining mixograph parameters [r = (–0.52)– (–0.61), P0.001], which was independent of flour protein content. The strong associations between percent SDS-unextractable fraction in total polymeric protein (%UPP) and mixograph parameters were observed with r of0.70–0.85 (P0.001). %UPP and Gli/Glu tested by SE-HPLC can be used as effective parameters for early generation selection to improve wheat gluten strength due to their automatic micro-analyzing method.