Effects of Sprouting on Texture of Cooked Buckwheat (Fagopyrum esculentum Moench) Noodles

Abstract

The firmness of buckwheat noodles plays an important role in its palatability. We investigated the effects of artificial sprouting after harvest and preharvest sprouting in the field of buckwheat grains on the firmness of cooked buckwheat noodles by measuring the force required to compress the cooked noodles. Sprouting significantly decreased the peak force and peak strain to compress cooked noodles, suggesting that sprouting lowers the palatability of cooked buckwheat noodles. Sprouting significantly decreased the force needed to compress cooked noodles largely, suggesting that the cooked noodles made from sprouting grains lead to the perception of less resistance to completely cut off by mastication.     

Evaluation of Cultivar Differences in Preharvest Sprouting of Common Buckwheat (Fagopyrum esculentum Moench)

Abstract

Preharvest sprouting of buckwheat (Fagopyrum esculentum Moench) is an important problem, but cultivar differences in preharvest sprouting and their causes have not been investigated. We detected cultivar differences under natural field conditions. Preharvest sprouting of three cultivars was significantly lower than that of the current main cultivar. Seeds collected before rainfall were threshed and incubated on a wet filter paper in a petri dish for 10 days at 10, 20, 30 and 40ºC in the dark, or at an alternating light and temperature condition of 8 h light at 30ºC and 16 h darkness at 20ºC. Germination was promoted by a higher temperature except for 40ºC, suggesting that the risk of preharvest sprouting in buckwheat is higher at a relatively higher temperature. The risk of preharvest sprouting in the field was highly correlated with germination at 20ºC (r = 0.98***) and 30ºC (r = 0.99***) in the dark, suggesting that germination test can be used to predict preharvest sprouting in the field. Preharvest sprouting was significantly correlated (r = ?0.77**) with main stem length, suggesting that ecotype is partly responsible for this phenomenon.     

Hagberg Falling Number and Rheological Properties of Wheat Cultivars in Wet and Dry Preharvest Periods

Abstract

The effects of dry and wet preharvest periods on Hagberg falling number (HFN), a parameter of α-amylase activity, and rheological properties including farinograph dough development time (FDT), farinograph absorption (FA), resistance to extension (RE), loaf volume (LV) and baking score (BS) were examined in 30 hexaploid wheat (Triticum aestivum L.) cultivars originating from 19 countries. The cultivars were grown in the field in 2000 – 2010 and HFN and rheological properties were analyzed for three replicates. The cultivars were divided into three groups according to HFN in the wet preharvest period: HFN below 150 s (group H-1), HFN from 250 to 350 s (group H-2), and HFN over 400 s (group H-3). The cultivars in group H-3 were superior to those in either group H-1 or H-2 in all rheological properties except RE. In the dry preharvest periods, HFN was not correlated with rheological properties, while in the wet preharvest period HFN showed a highly significant positive correlation with FDT and BS. The canonical variate analysis for assessment of the general performance of all cultivars with HFN as the main factor and the other rheological properties as subfactors, indicated that the cultivars Stepnaja 30, Garazinko, Kirac, Klein Forten and ?itarka showed the highest potential regardless of preharvest rainfall amounts. In conclusion, differential genetic expression of resistance to preharvest sprouting, maintenance of low α amylase level, high HFN values, maintenance of rheological properties, and baking performance can be reliably detected and measured under wet preharvest conditions.     

The Rapid Visco Analyzer (RVA) as a tool for differentiating potato cultivars on the basis of flour pasting properties

Potatoes of two cultivars representing extremes in potato texture, Russet Burbank (mealy) and IdaRose (waxy), were lyophilized, ground into flour, and analyzed with a Rapid Visco Analyzer (RVA) to identify flour pasting characteristics unique to each cultivar. A factorial experiment, which included multiple levels of heating rate, peak temperature, and flour concentration, was employed to assess RVA run parameter association with flour pasting behaviors and the potential to differentiate cultivars according to the responses. Pasting profiles of the potato flour provided a unique functional finger-print for each cultivar flour, which embodies structural and molecular components of the native potato tissue. Pasting profile viscosity attributes were influenced by variable levels of heating rate, peak temperature, and flour concentration. At increasing flour concentrations, RVA viscosity attributes increased in magnitude, but possessed similar pasting curves. A variable heating rate primarily affected events occurring early within the pasting profile (time to gelatinization, time to peak viscosity, peak viscosity), while changes in peak temperature influenced viscosity attributes (trough viscosity, breakdown, final viscosity, total setback) associated with the latter portion of the viscosity curve. A high peak temperature generally resulted in increased breakdown and total setback and decreased trough and final viscosities. RVA viscosity attributes, time to gelatinization, peak viscosity, breakdown, and final viscosity were identified as potential characteristics for cultivar differentiation. Discrimination of the cultivar extremes was affected by RVA run parameters, and was maximized at moderate heating rates (4 to 6 C min^-1), moderate to high levels of peak temperature (85 to 90 C), and intermediate flour concentrations.     

Impact of proteins on pasting and cooking properties of waxy and non-waxy rice

Changes of RVA viscosity and texture properties of waxy rice (n=9) and non-waxy rice (n=10) were analyzed through protein removal or disulfide bond disruption. Protease or DTT had similar effects on the pasting behavior of the waxy rice, but affected differently that of non-waxy rice. For all waxy rice flour treated with DTT or protease, the peak, breakdown and consistency viscosity values all significantly decreased, and the viscosity curves barely rose from the baseline. Pre-incubation of flours with a protease increased RVA pasting temperatures, decreased viscosities along all the points of the curves and the slopes of the linear parts of the curves for all non-waxy cultivars. DTT decreased RVA pasting temperatures and peak viscosities of all non-waxy flour, but increased breakdown viscosities in six non-waxy rice cultivars. With DTT-added cooking water, the hardness of cooked waxy and non-waxy rice, as determined by Instron, generally decreased. With DTT-added cooking water, the adhesiveness of all cooked waxy rice significantly decreased, while it increased significantly or remained the same in all cooked non-waxy rice. The above results indicated that the protein agent of a network linked by disulfide bonds increased the RVA gelatinized paste rigidity, the hardness and adhesiveness of cooked rice of all waxy cultivars, while in non-waxy cultivars, both the network and the increase of the gelatinized paste concentrations resulting from protein hydration contributed to the enhancements of the RVA paste rigidity and the cooked rice hardness.     

Seasonal conditions influence dormancy and preharvest sprouting tolerance of wheat (Triticum aestivum L.) in the field

Preharvest sprouting occurs following rainfall after maturity and reduces grain quality and value. Dormancy at maturity is a trait frequently used by wheat breeders to improve tolerance to sprouting. To determine the environmental influence on the predicative relationship between dormancy at maturity and improved preharvest sprouting tolerance, dormancy (germination index) at maturity and grain quality (falling number) at maturity and then, after rainfall, was measured over three seasons. Based on the results it was possible to draw three main conclusions. Firstly, genotypes with strong dormancy (germination index <0.20) which have the embryo and seed coat component of dormancy maintained a falling number >300 s at all sites and seasons for the 2-month period after maturity despite receiving up to 122 mm of rain. Adequate preharvest sprouting tolerance also occurred in dormant genotypes, with just the embryo component; in all but the most severe conditions. Secondly, though the effect of environment and interaction of genotype and environment was significant, the G by E interaction did not account for a large proportion of the variation (<6%) in sprouting tolerance (measured by falling number after rainfall) or change the relative rankings of preharvest sprouting tolerance. Finally, other defects associated with rainfall during grain filling such as black point and fungal staining may slightly reduce dormancy estimates and preharvest sprouting tolerance. For this reason grain defects need to be improved in parallel with preharvest sprouting tolerance. In conclusion, strong dormancy provides a reliable source of preharvest sprouting tolerance in the field.     

Differences of Physicochemical Properties Between Chalky and Translucent Parts of Rice Grains

Rice grain chalkiness is an important characteristic, but the difference between chalky and translucent parts in grains is still unclear. Here, we investigated the differences of flour made from the chalky or translucent part of rice grains in three indica and three japonica rice varieties. The chalky flour had significantly lower amylose and protein contents and looser starch granule morphology, and starches in the chalky flour had higher relative crystallinity, higher short chain content but lower long chain content than those in the translucent flour. The water states, determined with nuclear magnetic resonance, differed between the chalky and translucent flour after soaking, cooking and retrograding, and the chalky flour had more bound and free water but less constructural water than the translucent flour. Mostly, the chalky flour had lower viscosity and shorter gel consistency, but higher onset temperature and gelatinization enthalpy than the translucent flour. The results indicated that starch granule morphology would be more indicative than other attributions on pasting and gelatinization properties of chalky and translucent parts of rice grains.     

Inheritance of flour paste viscosity is associated with a rice Waxy gene exon 10 SNP marker

Apparent amylose content is a key element for characterizing a rice (Oryza sativa L.) cultivar for cooking quality. However, cultivars with similar apparent amylose content can have widely varying quality attributes, including major parameters of flour paste viscosity. It has been postulated that the presence of a rice Waxy gene single nucleotide polymorphism (SNP) marker is associated with elevated Rapid Visco Analyser (RVA) properties in specific high amylose rice cultivars. A mapping population derived from a cross between two varieties, Cocodrie and Dixiebelle, having similar high apparent amylose contents, but with different paste viscosity properties and Waxy gene markers was analyzed for the genetic segregation of various pasting properties, measured with RVA instrumentation. Marker inheritance analyses revealed that the Waxy exon 10 SNP marker was associated with the proportion of soluble to insoluble apparent amylose and most RVA pasting measurements. Waxy gene markers can be used to efficiently improve the selection of rice with desirable characteristics, particularly for superior parboiling and canning quality.     

Properties of field-sprouted sorghum and its performance in ethanol production

The objective of this research was to investigate physicochemical and biochemical characteristics of field-sprouted grain sorghum and its fermentation performance in ethanol production. Five field-sprouted grain sorghum varieties, which received abnormally high rainfall during harvest, were used in this study. Enzyme activities, microstructure, flour pasting properties, kernel hardness, kernel weight, kernel size, flour size and particle distribution of field-sprouted grain sorghum were analyzed. The effect of germination (i.e., sprouting) on conversion of grain sorghum to ethanol was determined by using a laboratory dry-grind ethanol fermentation procedure. Sprouted sorghum had increased α-amylase activity; degraded starch granules and endosperm cell walls; decreased kernel hardness, kernel weight, kernel size, and particle size; and decreased pasting temperature and peak and final viscosities compared with non-sprouted grain sorghum. The major finding is that the time required for sprouted sorghum to complete fermentation was only about half that of non-sprouted sorghum. Also, ethanol yield from sprouted sorghum was higher (416–423 L/ton) than that from non-sprouted sorghum (409 L/ton) on a 14% moisture basis.     

Quality and antioxidant properties of instant noodles enhanced with common buckwheat flour

The objective of this study was to investigate the feasibility of incorporating common buckwheat (Fagopyrum esculentum Moench) into instant noodle formulations. Australian Soft (AS) and Baker's flours were used to evaluate the effects of varying buckwheat contents (0–40%) on noodle quality. The results of texture analysis indicate that noodles made using AS flour produced softer texture whereas there was minimal effect for Baker's flour when buckwheat was incorporated. The colour, measured by L* values, decreased with increased addition of buckwheat for both flours. Fat uptake for noodle samples made from AS flour was only marginally affected, but increased for Baker's flour, when higher levels of buckwheat flour were added. The antioxidant rutin was detected in noodles made from both wheat flours, generally increasing with % buckwheat flour added. These findings indicate that the incorporation of 20% buckwheat into the formulation can be used to enhance the quality of instant noodles.     

Breaking Strength of Pedicel and Grain Shattering Habit in Two Species of Buckwheat (Fagopyrum spp.)

Abstract

The grain shattering habit was examined in nine common buckwheat cultivars/strains (Fagopyrum esculentum Moench.) and four tartary buckwheat strains (F. tataricum Gaertner). As indices of grain shattering habit, the breaking bending strength and breaking tensile strength of the pedicel and the pedicel diameter were measured. Thin longitudinal pedicel sections were also observed. The breaking strength showed significant differences among cultivars, but the stage of seed maturity influenced the grain shattering habit. The two breaking strengths were larger in common buckwheat than in tartary buckwheat, and these differences may be explained by the pedicel diameter. The abscission layer was not observed in the pedicel tissue of the buckwheat cultivars.     

Protein digestibility (in vitro) of chickpea and blackgram seeds as affected by domestic processing and cooking

Protein digestibility (in vitro) of grains of chickpea (Cicer arietinum) and blackgram (Vigna mungo) cultivars varied from 48 to 53% and 52 to 58%, respectively. Soaking, cooking (both of unsoaked and soaked seeds), autoclaving and sprouting improved significantly the protein digestibility of all the cultivars of chickpea and blackgram. Autoclaving was found to be most effective followed by cooking and sprouting; cooking of sprouts had only marginal effect. Protein digestibility was higher when soaked instead of unsoaked grains were cooked.     

Breaking Strength of Pedicel as an Index of Grain-Shattering Habit in Autotetraploid and Diploid Buckwheat (Fagopyrum esculentum Moench.) Cultivars

Abstract

The grain-shattering habit was compared among diploid and autotetraploid cultivars of common buckwheat (Fagopyrum esculentum Moench.). In the first experiment, one diploid and one autotetraploid cultivar were grown in the field, and the number of grains shed naturally by wind or rain, and the number of grains detached by threshing the plants (by dropping from 1 m height onto a concrete floor, five times) were measured to evaluate grain shattering. The number of the naturally shed grains in the field was higher in the diploid than in the autotetraploid cultivar, although the number of grains detached by threshing was not different between the two cultivars. In another set of experiments, breaking bending strength and breaking tensile strength of pedicels were measured as indices of grain-shattering habit to examine the difference in shattering among two autotetraploid and four diploid cultivars (two summer types and two autumn types). They were grown in summer and autumn seasons to examine the environmental effect on grain shattering. Both breaking strengths were about two times higher in the autotetraploid cultivars than in the diploid cultivars. The breaking strength was well correlated with the diameter of pedicels. The values of grain-shattering resistance traits obtained in the autumn cropping season were higher than those obtained in the summer cropping season.     

郑麦1860品质特性及面条加工适用性分析

为明确郑麦1860的品质及加工适用性,对2020-2021年河南省29个地点收获的郑麦1860的籽粒性状、磨粉品质、面团流变学特性、淀粉糊化特性和面条加工品质指标进行了测定与分析。结果表明,郑麦1860为优质中强筋面条小麦品种,特点是籽粒大、容重高、出粉率高,面条弹性好、色泽白亮、褐变较轻。在不同地点间郑麦1860的多数品质性状变异程度小,品质表现较稳定;相比较而言,其粉质参数、拉伸参数变异程度较大,淀粉糊化特性和面筋特性变异程度次之,籽粒品质性状、磨粉品质和面条加工参数变异程度较小。籽粒硬度、粒径、容重与出粉率呈显著正相关;容重、籽粒蛋白质含量、面粉灰分含量与面条总评分呈显著负相关;面粉色泽L^*值、吸水率、峰值黏度、低谷黏度、终值黏度、回生值与面条总评分呈显著正相关。综上所述,籽粒蛋白质含量、面粉色泽和淀粉糊化特性是影响郑麦1860面条品质的主要因素。郑麦1860制作的面条感官评分高、品质稳定,在豫北、豫东和豫南等区域种植均适合制作优质面条。     

Immunological analysis of serum for buckwheat fed celiac patients

Buckwheat (Fagopyrum esculentum, Moench), a herbaceous plant of the Polygonaceae family, does not have any affinity for the Gramineae family. It is commercially rated as a cereal, which has led to some misunderstanding concerning its use in gluten induced enteropathy or celiac disease. The effect of buckwheat flour ingestion by celiac patients was evaluated through the indirect immunofluorescence technique. Samples of serum were collected 30 days after the flour ingestion. Cryostat performed cuts of wheat and buckwheat grains were accomplished in order to compare the reactivity of their proteins and serum of celiac and normal patients. The assay revealed that the buckwheat flour presents no toxicity for the celiac patient and no anti-protein antibodies formation in the grain was observed for serum dilutions of 1:2 up to 1:32 with 0.15 M NaCl solution in 0.01 M phosphate buffer, pH 7.2 throughout the 30 day assay period. The results of the immunological assays showed that the buckwheat flour does not present toxic prolamines to celiac disease patients.     

Field studies on abscisic acid and embryonic germinability in winter wheat

Wheat (Triticum aestivum L.) cultivars differ in resistance to preharvest sprouting, which can occur when rains precede harvest. The objective of this study was to determine of sprouting resistance was related to endogenous levels of embryonic abscisic acid (ABA) and/or to the degree of embryonic sensitivity (capability of ABA to block embryonic germination) to exogenously applied ABA. Embryonic ABA levels and sensitivity were compared during the grain development period in 1983 and 1984 in a sprouting-resistant cultivar, ‘Brevor’, and a susceptible cultivar, ‘Greer’. The ABA levels were influenced by environment and year but not by cultivar, except at the soft-dough/ hard-dough transition stage of development in both years and at hard-dough stage in 1983. At those stages, Brevor had higher levels of free ABA than Greer. Embryonic ABA level and rate of germination of dissected embryos in water were not related, but the rate of germination was reduced by exogenous ABA (5×10⁻⁵M), and was reduced more in Brevor than in Greer. Differences in embryonic sensitivity to ABA, modulated by environmental conditions during the grain-filling period, may contribute to cultivar differences in resistance to preharvest sprouting.     

小麦籽粒淀粉合成动态及糊化特性的基因型差异

为了明确不同基因型小麦品种籽粒灌浆过程中的淀粉合成动态,为小麦的高产优质栽培提供参考信息,对6个不同基因型小麦籽粒形成过程中淀粉组分的变化及淀粉糊化特性进行了分析。结果表明,非糯性小麦的直链淀粉含量随着花后天数的增加呈上升的趋势,糯性小麦则呈先上升后下降的趋势,所有品种的支链淀粉含量均呈上升的趋势;不同基因型小麦直链、支链淀粉积累速率均呈单峰曲线图,不同品种直链淀粉最大积累速率出现的时间不同,而支链淀粉最大积累速率出现的时间均在花后21d;不同小麦品种的峰值粘度、低谷粘度、最终粘度均随着花后天数的增加而上升;不同品种淀粉糊化特性不同:糯性小麦之间在糊化时间、反弹值上无差异,而在峰值粘度、低谷粘度、最终粘度、稀懈值上的差异达显著水平;对于非糯性小麦,豫麦50和其他品种的多数糊化参数差异达显著水平;糯小麦和非糯小麦在糊化参数上的差异达1%显著水平。     

Evaluation of roller milling potential of amaranth grains

In the present study roller milling potential of amaranth grains was evaluated. The conditioning moisture influenced the millability of the amaranth grain. The results showed that the coarse seed coat (CSC) fraction increased from 12.91 to 38.33% with increase in conditioning moisture of the grains from 11 to 18.5%. The nutrients were more concentrated in the CSC fraction, while flour (FL) fraction showed low protein, ash, fat and dietary fiber contents. As the grain moisture content was increased from 11.0 to 15.5%, the yield of flour decreased with improvement in the brightness values. CSC showed higher values for redness and yellowness and lower values for brightness compared to other milled fractions. CSC had the highest water and oil holding capacities with the values of 410 g/100 g and 215 g/100 g respectively. The swelling power was also higher for CSC and fine seed coat (FSC) fractions. Among milled fractions, highest pasting temperature of 75.9 °C and peak viscosity of 212 BU was recorded for CSC and FL fractions respectively. These results showed that the roller mill can be used for milling amaranth grains to produce fractions rich in nutrients with unique functional properties.     

茶叶粉对小麦面粉流变学及糊化特性的影响

为进一步提高茶叶在食品工业中的应用范围,以小麦西农538(中筋)为供试材料,分别添加0、2%、4%、6%、8%和10%的绿茶、红茶和黑茶3类茶叶粉于面粉中,并对其进行面团流变学特性及糊化特性分析。结果表明,3类茶叶粉均可显著改善面团的流变学特性及糊化特性。随着茶叶粉添加量的增加,面团吸水率均显著增大;添加2%~10%的绿茶粉及6%~10%的黑茶粉,面团的形成时间和稳定时间均显著提高,弱化度均显著降低。添加6%的绿茶粉时,面团的拉伸能量和最大拉伸阻力增幅均达到最大值,延伸度出现小幅度升高的拐点;添加4%的红茶粉,面团的拉伸面积显著增大,继续增加添加量则变化不明显;黑茶和红茶粉添加量分别大于4%和6%时,面团延伸度均显著降低。面粉中添加适量的茶叶粉可改善面粉的品质,绿茶粉的添加对面团网络结构形成速度和面团筋力的改良效果大于红茶粉和黑茶粉。面粉糊化的峰值黏度、低谷黏度、最终黏度、峰值时间、回生值随着茶叶粉添加量的增大均呈不同幅度的降低趋势;3类茶叶粉对面粉糊化的热稳定性具有不同程度的改善作用。     

Cultivar and processing effects on the pasting characteristics,tannin content and protein quality and digestibility of cowpea (Vigna unguiculata)

Four popular West African local cultivars of cowpea (Vigna unguiculata), with distinctly different seed coat colors, were evaluated for their relative amylograph pasting characteristics, condensed tannin content, in vitro protein digestibility and Tetrahymena protein efficiency ratio (t-PER). The effects of roasting and dehulling on these properties were also determined. There were wide variations in the hot paste viscosity characteristics of the different cultivars studied. The raw cowpea flour samples exhibited maximum paste viscosities ranging between 260 Brabender Units (BU) for the Mottled cultivar and 460 BU for the cream-colored Blackeye cultivar. Cowpea cultivars with the greatest peak viscosities showed low stabilities to extended cooking. Roasting depressed paste viscosity properties of all the cowpea cultivars studied. Tannin concentrations were 0.3–6.9 and 7.2–116 mg CE/g flour from whole cowpea seeds and seed coats respectively, increasing with intensity of seed color. Although dehulling removed 98% of the tannin content of raw cowpeas, improvement in protein quality as a result of dehulling was observed for only the highly-pigmented Maroon-red variety. Roasting significantly improved digestibility and more than doubled the t-PER of all cowpea cultivars studied. Roasted cowpeas possess adequate nutritional and functional qualities as protein supplements in cereal-based weaning foods. However, it appears that dehulling is necessary to enhance the nutritional quality of the highly pigmented cultivars of cowpea.