Protein characteristics and peroxidase activities of different Indian wheat varieties and their relationship to chapati-making quality

Different wheat varieties grown at a single geographical location were evaluated for protein quantity and quality, rheological properties, and activities of peroxidase as well as polyphenol oxidase. The protein content in these varieties ranged from 11.6 to 14.6%, farinograph water absorption ranged from 70 to 76%, and the damaged starch content varied from 12.3 to 16.3%. The total protein content of whole wheat flours significantly correlated to stiffness (R/E values) of the dough (r=0.73, p<0.05); however, it did not influence any of the quality parameters of chapati. However, the protein quality parameter, Glu-1 score, which reflects the high molecular weight (HMW) glutenin subunit composition, correlated significantly to the cutting force, which indicates the texture of chapati (r=0.78, p<0.05). The quantity of low molecular weight protein fraction having molecular weight of 20 kDa showed significant correlation to over all quality scores of chapati (r=0.78, p<0.05). The color of chapatis was significantly correlated to color of dough (r=0.76, p<0.05), which became darker on resting. Peroxidase activity greatly influenced the color of chapatis (r=0.81, p<0.05).     

Influence of size distribution of proteins,thiol and disulfide content in whole wheat flour on rheological and chapati texture of Indian wheat varieties

The influence of protein composition, as measured by size-exclusion high performance liquid chromatography (SE-HPLC), on rheological properties and chapati texture was investigated in the whole wheat flours of eight Indian wheat cultivars grown at a single location. Proteins were extracted using two-step procedure: extraction with buffer containing 0.5% SDS (SDS buffer), followed by sonication. The results showed that SDS buffer extracted 72–90% of the total flour protein in different varieties and 7–11% protein was extracted from the remaining residues by sonication. The proteins extracted were fractionated by SE-HPLC into large polymeric proteins (>130 kDa), small polymeric proteins (80–130 kDa) and monomeric proteins (10–80 kDa). Total polymeric protein content in the flour protein showed a significant positive correlation with dough hardness (r = 0.71, p < 0.05) and positive correlation with chapati texture (r = 0.58, p < 0.05). Of the SDS extractable polymeric proteins, large polymeric protein in flour protein had significant positive correlation to dough hardness (r = 0.89, p < 0.05) and chapati cutting force, which reflects the chapati texture (r = 0.70, p < 0.05). Protein disulfide content showed positive correlation to dough hardness (r = 0.66, p < 0.05) and texture of chapati (r = 0.58, p < 0.05) while protein thiol content showed significant negative correlation to chapati texture (r = −0.77, p < 0.05). Thus, the results indicate that high proportion of SDS extractable large polymeric protein in flour protein increases the toughness of chapati texture while flours having high thiol content decrease the toughness of chapati.     

High‐molecular‐weight glutenin subunit composition of Pakistani hard white spring wheats grown at three locations for 2 years and its relationship with end‐use quality characteristics

Eleven Pakistani hard white spring wheat cultivars, along with one durum wheat and two hard white American‐grown wheat cultivars, were evaluated for their high‐molecular‐weight (HMW) glutenin subunit composition via sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE). The relationships among different quality characteristics and between these characteristics and HMW glutenin subunits were computed. Three to six HMW glutenin subunits were observed in Pakistani bread wheat cultivars. The presence of HMW glutenin subunits was not affected by growth locations or crop years. However, variations in intensities were observed. Correlations were noticed between certain HMW glutenin subunits and some quality attributes, such as protein, farinograph dough development time, farinograph water absorption, loaf volume and mixograph peak height. The presence of HMW glutenin subunit 20 in the older wheat cultivars C591 and C273, known for excellent chapati quality, indicated a possible relationship between this band and chapati quality. This observation will need to be confirmed by testing a larger number of wheat samples known to have characteristics for both good and poor chapati quality. © 2000 Society of Chemical Industry     

Relationship between glutenin subunit composition and gluten strength measurements in durum wheat

Durum breeders use a range of techniques in the development of new cultivars. An important selection criterion is the rheological properties of semolina dough and durum wheat breeders use this criterion in the development of new cultivars using a range of techniques. Because of the need to process large numbers of genotypes encountered in breeding programs, methods that are inexpensive, rapid, require small amounts of sample and that correlate with semolina quality are desirable. Using breeding material, this study investigated the relationship between the glutenin subunit composition and two traditional tests of gluten strength, gluten index (GI) and mixograph. Two sample sets of durum wheat breeding lines and cultivars, one grown in Canada (n = 229) and the other grown in Australia (n = 139) were analysed for GI, mixograph and both high molecular weight (HMW) and low molecular weight (LMW) glutenin subunits by SDS‐PAGE. Nine different HMW and 14 different LMW allelic combinations were found. In the Canadian set, the most frequent LMW alleles were aaa, bba, caa and cfa while in the Australian set, caa was predominant. For the HMW subunits, the most common allelic groups were Glu‐A1c/Glu‐B1d (null, 6 + 8) and Glu‐A1c/Glu‐B1b (null, 7 + 8) with fewer numbers of Glu‐A1c/Glu‐B1e (null, 20) in both sample sets. LMW subunits were more important contributors to gluten strength than HMW subunits with the rank for higher GI according to the LMW allele (Canadian set) being caa = aaa > bba and aaa > cfa while HMW subunits 6 + 8 = 7 + 8 > 20. Similarly, using the mixograph, strength ranking for the LMW alleles was aaa > cfa = bba and HMW subunit 20 gave poorer rheological properties. For some samples with a good LMW allelic group a low GI was observed and vice versa. Further characterisation of the protein composition in these samples showed the GI results could be explained by polymeric/monomeric (P/M), glutenin/gliadin (Glu/Gli) and HMW/LMW ratios or the proportion of unextractable polymeric protein. © Crown in the right of the State of New South Wales, Australia; and for the Department of Agriculture and Agri‐Food, Government of Canada, © Minister of Public Works and Government Services Canada 2005. Published for SCI by John Wiley & Sons, Ltd.     

Anti‐glycative and anti‐inflammatory effects of caffeic acid and ellagic acid in kidney of diabetic mice

Protective effects of caffeic acid (CA) and ellagic acid (EA) in kidney of diabetic mice were examined. CA or EA at 2.5 and 5% was mixed in diet and supplied to diabetic mice for 12 wk. Results showed that the intake of CA or EA increased renal content of these compounds, alleviated body weight loss, decreased urine output, increased plasma insulin and decreased blood glucose levels at weeks 6 and 12 (p<0.05). The intake of these compounds dose dependently reduced plasma blood urea nitrogen and elevated creatinine clearance (p<0.05). CA or EA at 5% significantly decreased the levels of plasma HbA1c, urinary glycated albumin, renal carboxymethyllysine, pentosidine, sorbitol and fructose (p<0.05), and significantly diminished renal activity of aldose reductase and sorbitol dehydrogenase, as well as suppressed renal aldose reductase mRNA expression (p<0.05). CA or EA dose dependently lowered renal levels of IL‐6, IL‐1β, tumor necrosis factor (TNF)‐α and monocyte chemoattractant protein 1 (MCP‐1) (p<0.05). Furthermore, CA or EA dose dependently down‐regulated tumor necrosis factor‐α and monocyte chemoattractant protein‐1 mRNA expression in kidney (p<0.05). Based on the observed anti‐glycative and anti‐inflammatory effects, the supplement of CA or EA might be helpful for the prevention or attenuation of diabetic kidney diseases.     

Improving wheat for bread and tortilla production by manipulating glutenin‐to‐gliadin ratio

Gluten, starch, water soluble material, and glutenin‐rich and gliadin‐rich proteins were extracted from three Canadian wheat cultivars representing the Canada Western Red Spring (CWRS) (cv Roblin), Canada Western Extra Strong (CWES) (cv Glenlea) and Canada Prairie Spring (CPS) (cv AC Crystal) classes having glutenin‐to‐gliadin (Glu:Gli) ratios of 0.70, 0.75 and 0.85 respectively, all giving the same high‐molecular‐weight glutenin subunit score (Glu‐1 score) of 10. The resulting fractions were reconstituted to produce 18 mixtures of flour components, representing all combinations of Glu:Gli ratio and protein content observed in the original three flours. Dough rheological properties and baking (bread and tortilla) performance were determined using small‐scale techniques. Within any of the cultivars, increasing the Glu:Gli ratio in a reconstituted dough system had significant effects on dough and end‐use properties, causing increases in mixograph development time (MDT), maximum resistance (Rmax), pan bread loaf volume, tortilla dough maximum resistance and cooked tortilla puncture force. The CWRS wheat Roblin, proved to be best suited for pan bread at higher protein content and higher Glu:Gli ratio, and also produced a high protein tortilla of large diameter at a Glu:Gli ratio of 0.70. The CPS flour, AC Crystal, was good for making tortillas at protein contents of 110–130 g kg⁻¹ and at its original ratio of 0.85. The CWES wheat Glenlea, did not perform as well in bread or tortilla‐making but in its role as a blending wheat, altering the Glu:Gli ratio of Glenlea to 0.70 may have an advantage by lowering mixing time without compromising baking properties. Manipulating the Glu:Gli ratio may make a wheat cultivar suitable for a particular end‐product. For the Department of Agriculture and Agri‐Food, Government of Canada, © Minister of Public Works and Government Services Canada 2005. Published for SCI by John Wiley & Sons, Ltd.     

The influence of 1B/1R chromosome translocation on gluten protein composition and technological properties of bread wheat

The Austrian bread wheat Amadeus without and with 1BL/1RS translocation and three further translocation genotypes with known HMW subunit compositions were grown under the same environmental conditions. Their flours were characterised by the determination of crude protein content and, partly, by the determination of glutathione and cysteine. Furthermore, the qualitative and quantitative composition of gluten protein types was analysed by a combined extraction and reversed phase HPLC procedure. Dough development time, maximum resistance and extensibility of dough and gluten, and bread volume were determined by means of microscale methods. Protein, glutathione and cysteine contents of flours were only slightly influenced by translocation. The HPLC patterns of gliadins and glutenin subunits showed that translocation caused characteristic changes concerning ω‐gliadins, γ‐gliadins and LMW subunits of glutenin. The amount of ω 1,2‐gliadins was significantly increased and that of LMW subunits decreased. The effect of translocation on the rheological properties of dough and gluten was characterised by a strongly reduced dough development time, reduced maximum resistance and increased extensibility. Bread volume was decreased by about 10%. The amount of glutenin subunits was correlated with dough development time, resistance of dough and gluten, and bread volume to a higher extent (r = 0.79–0.91) than the amount of gliadins (r = 0.52–0.80). Correlation coefficients for LMW subunits were higher (r = 0.82–0.88) than those for HMW subunits (r = 0.35–0.61) when all five wheats were included. Instead, when only translocation lines were considered, HMW subunits (r = 0.89–0.98) were more important than LMW subunits (r = 0.64–0.86). Altogether, the results demonstrate that translocation causes important quantitative as well as qualitative changes in gluten protein composition which can be efficiently determined by reversed phase HPLC. © 2000 Society of Chemical Industry     

Sensory quality of ethylene‐exposed carrots (Daucus carota L,cv ‘Yukon’) related to the contents of 6‐methoxymellein,terpenes and sugars

Carrots were analysed for taste and odour and for contents of terpenes, 6‐methoxymellein and sugars during 3 weeks storage at 15 °C in an atmosphere containing ethylene (1 µl l⁻¹). The ethylene treatment caused an increase in 6‐methoxymellein and the conversion of higher amounts of sucrose to fructose and glucose compared to control carrots stored in air. This corresponded to higher sensory scores for bitterness and terpene flavour and a lower score for sweetness, as measured by an expert taste panel. Principal component analysis showed a more expressed bitter taste, earthy flavour, green flavour, terpene flavour and aftertaste in the ethylene‐treated carrots. Correlations were found between sweet taste and the content of sucrose (r = 0.91, p < 0.005) and between the contents of various terpenes (particularly γ‐terpinene, limonene and caryophyllene) and terpene flavour, green flavour, aftertaste and bitter taste (r ≥ 0.72, p < 0.05). In the air‐stored carrots these off‐flavours seemed to be masked by a high sucrose content. © 2000 Society of Chemical Industry     

Relationships Between Some Physicochemical Properties of Starches from Maize Cultivars Grown in East China

Granule size, amylose content, degree of crystallinity, thermal, pasting, and gel textural properties of starches separated from thirty seven maize cultivars grown in East China were studied with a laser particle size analyzer, spectrophotometer, X‐ray diffractometer, differential scanning calorimeter, Rapid Visco Analyser, and texture analyzer. Various correlations between the physicochemical properties were observed. The correlation coefficient between T_o and T_p, between T_o and T_c, and between T_p and T_c were 0.967, 0.879, and 0.941 (p<0.01), respectively. Amylose content was correlated negatively with T_c (r=‐0.640, p<0.01). Pasting temperature was positively correlated to T_p (r=0.738, p<0.01). Significantly positive correlations were observed between amylose content and final viscosity, between amylose content and setback (r=0.665 and 0.735, respectively, p<0.01) and between peak viscosity and breakdown (r=0.893, p<0.01). Trough viscosity was positively correlated to final viscosity and setback (r=0.851 and 0.704, respectively, p<0.01). Significant correlations existed between final viscosity and setback, and hardness (r=0.972 and 0.615, respectively, p<0.01). There was a significant interrelationship between setback and hardness (r=0.655, p<0.01).     

Charakterisierung von Weizensorten durch SDS-Polyacrylamidgel-Elektrophorese (SDS-PAGE) und zweidimensionale Elektrophorese (2D-PAGE) der Glutenine

Zusammenfassung Vierundzwanzig Weizensorten wurden durch SDS-PAGE und 2D-PAGE in horizontalen, ultradünnen Gelsystemen mit Silberfärbung auf Glutenin-Untereinheiten analysiert. Das Auftreten der hochmolekularen Untereinheiten 2 (codiert auf Weizenchromosom Glu-1A) bzw. 3 und 10 (Glu-1D) sowie 5 und 9 (G1u1B) ist mit guten Backeigenschaften (A-Qualität) der Mehle korreliert. Zwischen den hochmolekularen Untereinheiten (Gruppe A, HMW-Untereinheiten,M _r = 90000–125000) und den niedermolukularen Gluteninen (Gruppe B, LMW-Untereinheiten;M _r = 43 500–56 000) tritt eine bisher wenig beachtete Gruppe mit mittleren Molekulargewichten (Gruppe AB, MMW-Untereinheiten;M _r = 56 500–80 000) auf, die ebenfalls sortenspezifische Unterschiede zeigt.In der zweidimensionalen Elektrophorese zeigt sich neben der ladungsbedingten Heterogenität der einzelnen Untereinheiten bei einigen Sorten eine weitere, anscheinend eigenständige Gruppe BC mit niederem Molekulargewicht (M _r = 40 500–43 500). Die Proteine dieser Gruppe besitzen, im Gegensatz zu den umgebenden basischen Gruppen B und C, deutlich niedrigere isoelektrische Punkte.

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Characterization of glutenins in wheat varieties by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis (2D-PAGE)

Summary Twenty-four wheat varieties were analysed for glutenin subunits by SDS polyacrylamide gel electrophoresis (PAGE) and two-dimensional (2D)-PAGE using horizontal ultrathin pore-gradient gels and silver staining. The following high-molecular-weight (HMW) subunits correlated well with good baking quality (Grade A varieties): 2 (coded in wheat chromosome Glu-1A), 3 and 10 (Glu-1D) and 5 and 9 (Glu-1 B). Some other grade A varieties showed the HMW subunits 2, 4, 8, and 11, which are typical for grade B and C varieties.Between the HMW subunits (group A subunits,M _r = 90000–125 000) and the low-molecular-weight (LMW) subunits (group B subunits,M _r = 43 500–56 000), the electropheretograms exhibited a group of sharp protein bands with intermediate molecular weights (MMW-subunits,M _r = 56 500–80 000). The pattern of this group, which has up to now been practically unnoticed, is also dependent on the wheat variety.In addition to the charge-dependent heterogeneity of the subunits, the 2D-electropheretograms of some varieties showed an additional protein group, denoted BC, which has a low molecular weight (M _r = 40 500–43 500). In contrast to the adjacent basic groups B and C, these BC proteins have significantly lower isoelectric points.

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Gefördert von der Arbeitsgemeinschaft Industrieller Forschungsvereinigungen (AIF) über den Forschungskreis der Ernährungsindustrie e. V.     

Flaxseed oil reduces the growth of human breast tumors (MCF‐7) at high levels of circulating estrogen

Flaxseed (FS) has been shown to attenuate mammary tumorigenesis, possibly due to its high α‐linolenic acid (ALA)‐rich oil (FSO) content. This study determined the effect of FSO on the growth of estrogen receptor‐positive human breast tumors (MCF‐7) in ovariectomized athymic mice at high premenopausal‐like estrogen (E2) levels. Mice with established MCF‐7 tumors were fed basal diet (control) or basal diet supplemented with FSO (40 g/kg) for 8 wks. Compared with control, FSO reduced tumor size (33%, p<0.05) and tumor cell proliferation (38%, p<0.05) and increased apoptosis (110%, p<0.001). FSO also reduced human epidermal growth factor receptor‐2 (79%, p<0.05) and epidermal growth factor receptor (57%, p=0.057) expression, which then may have led to a reduction in Akt (54%, p<0.05) and phosphorylation of mitogen‐activated protein kinase (MAPK) to phosphorylated MAPK (pMAPK, 28%, p<0.05). Insulin‐like growth factor‐1 receptor, vascular endothelial growth factor receptor, MAPK and phosphorylated Akt were not affected. FSO increased (p<0.001) serum ALA, eicosapentaenoic acid and docosahexaenoic acid and, in vitro, ALA reduced MCF‐7 cell proliferation (33%, p<0.001). Thus, FSO regressed estrogen receptor‐positive human breast tumorigenesis at high E2 levels via downregulation of the growth factor mediated pathway, likely through its ALA content, and may explain the anti‐tumorigenicity of FS.     

Fibre‐optic method for estimation of bovine fat quality

Spectroscopy using remote surface, contact, insertion and transmission fibre‐optic probes and a sensor at wavelengths of 400 to 1100 nm was used for rapid estimation of the physio‐chemical characteristics of bovine fat. Surface reflectance of the adipose tissue was negatively correlated with the bovine fat colour score at many wavelengths and positively correlated with the contents of the polyunsaturated fatty acids at 400 to 650 nm (P < 0.05). Internal reflectance using an insertion probe at 445 to 1100 nm was positively correlated with melting point and negatively correlated with refractive index (P < 0.05). Internal reflectance using a contact probe tended to be related to saturated and monounsaturated fatty acid contents. Transmittance at almost all wavelengths was positively correlated with refractive index (P < 0.05). Internal reflectance of the intermuscular fat from 34 animals measured at a meat market was correlated (P < 0.01) with saturated fatty acid content (r = 0.72 at 650 nm) and with monounsaturated fatty acid content (r = ?0.69 at 650 nm). These results indicated the possibility of using fibre‐optic measurements, requiring 1 s in bovine adipose tissue, to evaluate the quality of depot fat and that the various types of probe can be used to evaluate different physiochemical characteristics of fat. Copyright © 2003 Society of Chemical Industry     

Functional and multiple end‐use characterisation of Canadian wheat using a reconstituted dough system

Three Canadian wheat cultivars representing the Canada Western Red Spring, Canada Western Extra Strong and Canada Prairie Spring classes, varying in protein content yet containing similar high‐molecular‐weight glutenin subunits, were evaluated for dough functionality and multiple end‐use properties. The effect of protein content on dough properties and end‐product quality was also studied. Gluten, starch and water‐soluble components were extracted from the flours and reconstituted to make up three samples for each variety to match the protein content of the three parent flours. Empirical and dynamic dough rheological properties, baking (bread and tortilla) performance and noodle‐making properties of the flours were determined using small‐scale techniques. Results indicated that protein content had a significant effect on rheological and end‐use quality of wheat flours. Increase in protein content (of the reconstituted dough) increased mixograph peak height (r = 0.761), peak width, maximum resistance to extension and end‐product quality characteristics such as loaf volume (r = 0.906), noodle firmness and cutting force and decreased storage and loss moduli. Reconstituted flours from the three varieties at the same protein content also showed significant differences in mixing time, mixograph peak height, maximum resistance to extension, composite fineness of pan bread, tortilla diameter, cooked noodle hardness, gumminess and dynamic viscosity of dough. This study indicates that a simple reconstituted dough system can provide an unambiguous assignment of the quantitative and qualitative effects of dough components on dough properties. It has the advantages that any aspect of flour composition can be manipulated and details of the relation between composition and functional behaviour can be obtained for any end‐product. Copyright © 2003 Crown in the right of Canada. Published by Society of Chemical Industry     

Effects of amounts of HMW glutenin subunits determined by capillary electrophoresis on technological properties in wheat doubled haploids

BACKGROUND: Knowledge of the types and amounts of individual HMW glutenin subunits (HMW-GS) is important for predicting technological quality. In this study, 228 wheat doubled haploids were compared in respect of HMW-GS composition, seed protein content, flour yield, rheological properties of dough, and loaf properties. The quantitative and qualitative composition of particular HMW-GS was determined by CE. The relative amounts of x-type and y-type subunits encoded by individual Glu-1 loci were considered. RESULTS: The results show that the amounts of some pairs x + y of HMW-GS are correlated with technological properties. The importance of quantities of particular pairs of HMW-GS for technological values depends on allele compositions in all the Glu-1 loci. Positive correlation was found between the amount of subunits Ax1, Ax2*, Bx7 + By8 or Dx5 + Dy10 and loaf volume (r = 0.215–0.618, P < 0.05). The influence of an increasing amount of Ax1 was positively correlated with dough softening (r = 0.451, P < 0.01) and negatively with dough development time (r = − 0.209, P < 0.05) and stability (r = − 0.351, P < 0.01), whereas for subunit Ax2* these associations were opposite. CONCLUSION: The results confirm the occurrence of epistatic interactions between alleles of Glu-1 loci. The effects of amounts of HMW subunits on bread-making quality should be considered only within glutenin subunit compositions. Copyright © 2008 Society of Chemical Industry     

Relationship between proteolytic changes and tenderness in prerigor lactic acid marinated beef

A meat tenderising procedure involving injection of a lactic acid solution into prerigor muscle was investigated using beef M pectoralis profundus. The distribution of lysosomal enzymes in subcellular fractions, densities of myofibrillar protein bands after SDS‐PAGE and shear force were measured in non‐injected, 0.5 M and 1.0 M lactic‐acid‐injected samples during a 21 days ageing period. The activities of cathepsin B + L and β‐glucuronidase in the soluble fraction increased with level of lactic acid and with time post‐mortem (P < 0.001). Lactic acid and storage decreased densities of SDS‐PAGE bands migrating at the position of myosin heavy chain (MHC) and α‐actinin and increased densities of a 150 kDa band (P < 0.01). SDS‐PAGE of isolated perimysium cleaved with CNBr showed proteolytic cleavage of collagen after prolonged storage. Lactic acid injection significantly reduced shear force (P < 0.001). The cathepsin B + L activity in the soluble fraction correlated to shear force (r = −0.8), the degradation of MHC and α‐actinin (r = −0.88 and −0.90) and the generation of the 150 kDa fragment (r = 0.90) but not to the generation of a 31 kDa fragment (r = 0.05). A major part of the tenderness improvement after lactic acid injection was complete at 24 h post‐mortem, and was therefore due to a rapid process, eg pH‐induced swelling of the muscle structure. The data on enzyme activities and protein degradation, however, suggested that the action of lysosomal cathepsins also contributed to textural changes. © 1999 Society of Chemical Industry     

Nutritionally Important Starch Fractions of Rice Cultivars Grown in Southern United States

Abstract: Dietary starches can be classified into 3 major fractions according to in vitro digestibility as rapidly digestible (RDS), slowly digestible (SDS), and resistant starch (RS). Literature indicates that SDS and/or RS have significant implications on human health, particularly glucose metabolism, diabetes management, colon cancer prevention, mental performance, and satiety. In this study, the nutritionally important starch fractions (RDS, SDS, and RS) in cooked rice were assayed in vitro, making use of 16 cultivars grown in 5 southern U.S. rice growing locations (Arkansas, Louisiana, Mississippi, Missouri, and Texas). RDS, SDS, and RS were 52.4% to 69.4%, 10.3% to 26.6%, and 1.2% to 9.0%, respectively, of cooked rice dry weight. Cultivar, location, and cultivar-by-location interaction contributed to the variations in RDS, SDS, and RS contents. Means pooled across locations indicated that SDS was higher for the Louisiana samples than those from Texas, whereas RS was higher for the Texas samples than those from Arkansas, Louisiana, and Mississippi. Some cultivars were identified to possess high levels of RS (for example, Bowman and Rondo) or SDS (for example, Dixiebelle and Tesanai-2) and were also stable across growing locations. Apparent amylose content correlated positively with RS (n = 80, r = 0.54, P ≤ 0.001), negatively with RDS (n = 80, r =−0.29, P ≤ 0.05), and insignificantly with SDS (n = 80, r = 0.21, P > 0.05). RS and SDS were not collinear (n = 80, r =−0.18, P > 0.05); it does not follow that a cultivar high in RS will also be high in SDS, and vice versa. The observed differences in RDS, SDS, and RS among the samples are indicative of wide genetic diversity in rice.     

Quantitative and Qualitative Assessment of Wheat Gluten Proteins and their Contribution to Instant Noodle Quality

This study was carried out to examine the effect of quantity and quality of wheat gluten proteins on the quality attributes of instant fried noodles. Dough development time, dough stability, SDS sedimentation volume, gluten index and Resistance to extension/Extensibility (R/E) ratio were found to be positively correlated with glutenin content, whereas negatively associated with the quantity of gliadin sub-fractions. Medium strong flours were found most suitable for noodle preparation. The weaker flours from cultivars HW 2004 and C 306 having HMW-GS composition of Null, 2+12 and 20 alleles expressed at Glu-A1, B1 and D1, respectively could not withstand sheeting, resulted in rough surface and high breakage of noodles. The best noodle cultivars DBW 16 and WH 542 had 5+10 glutenin subunits at Glu-D1, however, differed in subunits expressed at Glu-A1 and Glu-B1 loci. Oil uptake and cooking time of noodles varied considerably from 15.4 to 22.7% and 2.0 to 4.0 min, respectively. Oil uptake in noodles was positively correlated with dough softening, however, all the parameters related to gluten quality and strength were negatively associated with the oil uptake. Cooking time of instant noodles was found to be highly associated with protein content (R² = 0.778) of flour, gluten quality and strength. Hardness or firmness of cooked noodles was found to be significantly linked with SDS sedimentation volume (R² = 0.725), gluten index (R² = 0.610), glutenin content (R² = 0.619), gliadin content (R² = ?0.567), R/E ratio (R² = 0.532) and gliadins/glutenins (R² = ?0.605) ratio.     

Effects of cultivar and culture conditions on γ‐aminobutyric acid accumulation in germinated fava beans (Vicia faba L.)

BACKGROUND: High levels of γ‐aminobutyric acid (GABA) accumulate in plant tissues under various stresses. GABA accumulation is also influenced by cultivar. This aim of this study was to select the most promising cultivar of fava bean for GABA accumulation and to optimise the culture conditions for GABA production in germinated fava beans by response surface methodology based on central composite design (CCD). RESULTS: GABA content and glutamate decarboxylase activity in germinated seeds of cultivar S2 were significantly higher than those in other cultivars (P < 0.05). A significant negative correlation (r = −0.765, P < 0.05) between germination percentage and 1000‐kernel weight was observed. There was a linear relationship between GABA content and sprout length (R² = 0.816). The regression model fitted to the experimental data of CCD was valid in predicting GABA production in germinated fava beans. Temperature and pH value of the culture solution had significant effects on GABA content in germinated fava beans. Under optimal culture conditions (33.6 °C, pH 3.19 and an air flow rate of 1.19 L min⁻¹), GABA content reached up to 2.41 g kg⁻¹ dry weight, about 48 times that in raw seeds. CONCLUSION: Germinated fava bean is a good resource of GABA‐rich food. Both cultivar and culture conditions have significant effects on GABA production. Copyright © 2009 Society of Chemical Industry     

Characteristics of yellow alkaline noodles prepared from Korean wheat cultivar

Physicochemical properties of Korean wheat flours were evaluated to determine the effect of flour characteristics on yellow alkaline noodles by comparing commercial and imported wheat flours. Optimum water absorption, thickness, and color of noodle dough significantly correlated with protein content-related parameters of flour. Korean waxy wheats showed shorter cooking time (8 min) and softer texture of cooked noodles than other Korean wheats. Cooking time significantly correlated with protein content, optimum water absorption, and thickness of noodle dough. Hardness of cooked noodles positively correlated with protein content (r=0.614, p<0.01) and protein content related parameters. Cohesiveness of cooked noodles positively correlated with SDS-sedimentation based on a constant protein weight (r=0.437, p<0.05). Several Korean wheat cultivars showed comparable noodle making properties to commercial flour for yellow alkaline noodles despite of dark noodle color. Wheat cvs. Baekjoong, Jeokjoong, and Ol had softer and more elastic texture than other Korean wheats.     

高分子量谷蛋白亚基近等基因系面粉品质及其流变学特性的研究

分析了高分子量谷蛋白亚基近等基因系的高分子量谷蛋白亚基组成，并对该近等基因系进行了品质性状的分析，结果表明：Glu-D1位点的变化比Glu-B1位点的变化对面粉品质和流变学特性影响大；并且同时具有Glu-B1 14 15和Glu-D1 5 10的近等基因系2号无论是面粉品质还是流变学特性都优于其它两个近等基因系8号(null，7 9，5 10)和近等基因系13号(null，14 15，10)；而8号又优于13号，即Glu-B1 14 15的存在没有弥补Glu-D1 5亚基的缺失。