Relationships Between Small-Scale Wheat Quality Assays and Commercial Test Bakes

Typical commercial bakeries in the United States are highly mechanized, mass-production facilities. U.S. hard wheat breeding programs use small-scale physical dough testing and pup loaf bake procedures to identify and select improved quality genotypes. The accuracy of such approaches in the prediction of commercial-scale quality performance is poorly understood. Samples from six hard red winter wheat cultivars grown in 11 locations over three harvest years were used to correlate grain hardness, small-scale test bakes, mixograph variables, and various measures of flour protein composition with quality assessments from commercial test laboratories. Samples were milled on both pilot- and small-scale mills. Protein content and 100-g pup loaf volume were more often significantly correlated with commercial test bake variables than all other small-scale variables. Stepwise multiple regression models explained, on average, ≈40% of the variation in commercial test bake procedures. Mixograph properties, pup loaf volumes and absorption, and flour protein content were the most frequent variables identified in model development. Pup loaf bake results on pilot- and small-scale milled flours were highly correlated. Differences in milling technology do not appear to be a significant source of error in relating small-scale test bakes to commercial quality.     

黄土塬区小麦茎流速率变化及其与环境的关系

利用Dynamax茎流测量系统和自动气象站分别对黄土塬区小麦(陕麦150)拔节期和开花期的液流变化及其周围气象环境因子变化进行了监测。结果表明:(1)两个时期小麦茎流速率日变化趋势基本相同,为单峰型;液流启动时间分别为早晨7:00—8:00和6:00—7:00,在中午12:00—14:00左右达到各自峰值,其值大小分别为1.90和2.66g/h(4月24日和25日,晴天,拔节期),3.39和2.96g/h(5月18日和19日,晴天,开花期),21:00左右降到最低,夜间无明显液流;晴天茎流速率明显大于阴天。(2)不同时期茎流速率日变化与环境因子日变化紧密相关。相关分析显示,影响小麦茎流变化的主要因子是光合有效辐射、大气温度、湿度和风速等;其中,湿度与茎流速率负相关。     

降水因子与小麦产量最优回归模型的探讨

通过对陕西省关中及延安地区５８个县（区）的１４个降水因子和小麦产量进行相关和多元逐步回归分析，结果表明：就秦岭以北、榆林地区以南的降雨场而言，小麦生育期间的各月降水，除２月份以外，均与小麦产量成显著正相关；而休闲期间的６，７，８三月降水与小麦产量成显著负相关。得到了由１月、４月、８月降水和干燥度４个降水因子与小麦产量构成的最优回归模型。最后揭示了降水并不是在延安北部、关中东部和西部旱塬及秦岭北坡沿     

Molecular Structure and Organization of Starch Granules from Developing Wheat Endosperm

Wheat starches isolated from seeds harvested between 7 and 49 days after anthesis (DAA) were fractionated into large (>8 μm) and small (<8 μm) granules and studied for starch structure and architecture. Starch granules at 7 DAA possessed unimodal size distribution, whereas it was bimodal at later maturity stages. The apparent amylose fraction of starch granules at early maturity (7 and 14 DAA) consisted of intermediate‐type materials, whereas starch at later maturity stages (28 and 49 DAA) contained branched amylose. Wide‐angle X‐ray scattering (WAXS) revealed a well‐developed polymorphic structure already at 7 DAA. Although the presence of a small proportion of B‐type crystallites mixed with A‐type crystallites was observed in the X‐ray diffractogram of starches at early maturation (7 and 14 DAA), it was masked by the A‐type crystallites at later maturity stages. However, the large granules had a higher proportion of B‐type crystallites and lower relative crystallinity (RC) than their small‐granule counterpart. The iodine absorption properties of the starch granules demonstrated different levels of mobility of the starch polymers at different stages of maturity and the mobility of more glucan polymers in the large granule population compared with the small granules at the same maturity stage. Iodine did not change the characteristic A‐type crystalline pattern of starch, but it increased RC. Changes in peak width at half height based on WAXS data further suggested the possible interaction of iodine with amylopectin intercluster chain segments and branch chains in formation of inclusion complexes.     

Relationship Between NIR Spectra and RVA Parameters During Wheat Germination

The process of germination in six different wheat cultivars was monitored using NIR spectroscopy and the Rapid Visco Analyser (RVA) method. Near‐infrared spectra provided insight into both chemical and physical changes that occur in the seed, in particular mobilization processes involving carbohydrates. RVA curves also contain physical and chemical information and can be interpreted as physicochemical spectra. The process of germination was followed sensitively through the RVA curves and some rheological parameters (peak viscosity, trough, breakdown, final viscosity, and setback) were highly correlated (R = 0.95–0.98) with predicted values calculated from NIR spectra. Viscosity data calculated from RVA curves collected at 200–480 sec showed the most characteristic changes during the early heat treatment stage of the pasting procedure. Strong intercorrelations were found between viscosity data and NIR spectra from the beginning of the swelling and gelatinization processes in germinating seed. The NIR and RVA methods were sensitive tools for the rapid investigation of the germination process, which is important both from a physiological and technological point of view.     

攀枝花泥石流发育的环境条件及其分布特征

攀枝花市大部分地区属泥石流重度危险区,所辖区县历史上多次受泥石流危害,现在仍有许多城镇、工矿、电站和交通设施受泥石流威胁。本区具有地质构造复杂、岩体破碎、新构造运动活跃、地震频繁的地质条件,坡陡谷深、谷盆交错分布的地形特征,降水集中、气温日较差大、干燥少雨的气候特点,再加上人类不合理的开发活动为泥石流的发育创造了良好的条件。受其影响,泥石流与断裂构造、地震活动、地层岩性、岩石风化程度、暴雨强度及人类活动具有空间分布上一致性。这不仅揭示了泥石流与其发育环境的关系,也为区域泥石流防灾减灾提供了依据。     

高产与中产麦田小麦产量和光能及氮素利用效率的差异

研究高产与中产麦田小麦产量、光能和氮素利用效率的差异,为缩小产量和资源利用率差,实现小麦高产高效生产提供理论依据。选取高产田和中产田2块麦田,常年小麦产量水平分别为9 000,7 500 kg/hm²。以小麦品种烟农1212为供试材料,分析不同产量水平麦田光能利用和氮素利用的差异。结果表明,高产田植株拔节期、开花期和成熟期氮素积累量较中产田提高6.65%~11.25%,开花前氮素向籽粒中的转运量较中产田提高11.60 kg/hm²,开花后氮素同化量较中产田提高21.99 kg/hm²。开花后14~28天旗叶氮代谢酶活性均表现为高产田显著高于中产田。高产田土壤氮素表观盈亏量较中产田减少48.61%。高产田开花期和开花后7~28天叶面积指数和旗叶SPAD值较中产田分别提高6.89%~34.56%和8.45%~27.32%;开花期和开花后7~28天高产田冠层光能有效辐射截获率和截获量较中产田提高3.92%~7.70%和3.97%~7.85%。高产田籽粒产量较中产田提高26.71%,光能利用率和氮素利用率分别提高17.39%和19.50%。综上所述,高产田小麦开花后冠层光能有效辐射截获率和营养器官贮存氮素向籽粒的转运量高,提高小麦成熟期籽粒中氮素的积累量,进而提高产量、光能利用率和氮素利用率,同时减少土壤氮素表观盈亏量,减少氮素损失。     

旱地麦田水肥关系及对产量的影响试验研究

用微区隔离遮雨棚法研究结果分析回归得出，氮肥用量、磷肥用量、供水量与冬小麦产量之间关系。固定肥料用量，在试验供水范围内水分和小麦产量呈近似直线关系；固定供水量，施肥量和小麦产量呈抛物线关系。氮肥用量和供水量之间有明显的正交互作用，磷肥用量与供水量之间交互作用不明显。大田不同降雨年份试验结果表明，施肥增产效果是降雨多＞降雨中＞降雨少的年份，在蓄墒期、生育期降雨量为355、411和523 mm的低、中、高降雨年份，冬小麦达最高产量时的氮、磷肥用量分别为每hm²施N 64.5 kg、P₂O₅52.5 kg；N 27.5 kg、P₂O₅105.0 kg和N 192.0 kg、P₂O₅157.5 kg。     

小麦液流及蒸腾速率测定方法初探

为寻求一种无伤测定小麦植物茎内汁液物质流量进而估算农田植物蒸腾速率的生物电子测试方法，作者改良了一种基于热量平衡原理的新型探测器。该探测器由微型加热片和热电偶组成，热电偶产生的信号用２１Ｘ型微电脑数据记录器采集处理；在春小麦上进行了茎秆热量平衡法测定值与称重法测定值对比。结果表明两者之间误差不超过１．４ｇ／ｈ·株。     

Relationship Between Objective and Subjective Wheat Flour Tortilla Quality Evaluation Methods

Accurate determination of tortilla quality is imperative because of the growing market. This calls for quality tests that are replicable. However, current tortilla quality testing relies heavily on subjective tests with unknown reliability. This study aimed to determine the relationship between subjective tortilla quality testing and available objective methods, and assess whether the latter can potentially replace the former. Correlation and regression analyses were done using data on subjective opacity and rollability, and objective L* value and texture parameters based on 114 wheat samples. Opacity scores and L* values were significantly correlated, but this relationship was affected by evaluator experience; in a controlled setting, experienced evaluators scores were more reliable (SEM = ±0.25 – 3.8, r = 0.96) than less experienced evaluators (SEM = ±0.25 – 7.3, r = 0.92). Tortilla rollability, which approximates shelf stability, correlated most strongly with the rupture distance from two‐dimensional extensibility test (r = 0.77). Subjective rollability at day 16 of storage was predicted by rupture distance (day 0) and work (day 4) (R² = 0.69). Adding rupture force to the model slightly improves the R² to 0.72. Objective color and texture parameter measurements have a potential to replace the subjective tests as primary methods for tortilla quality.     

柑橘地土壤大孔隙与优先流的关系研究

以重庆市江津区10和20a林龄的柑橘地为研究对象,应用优先流染色法和室内图像提取技术,土壤水分穿透曲线及Poiseulle方程综合分析土壤大孔隙与优先流的关系。结果表明,大孔隙使染色区的水分渗透速率较非染色区提高了1.48倍以上。柑橘地大孔隙孔径范围在0.3～1.7mm,半径大于0.7mm的土壤大孔隙是形成优先流路径的主要孔径范围。     

娃娃沟流域泥石流活动与植被关系探讨

娃娃沟位于九龙县境内,属川西南高植被覆盖山区.2006年7月16日该流域暴发大规模泥石流灾害,此次泥石流容重高,粗大颗粒比重大,表现出黏性泥石流的特征.通过解译TM遥感影像发现流域内植被覆盖度高达80%,森林覆盖率超过50%,以针阔叶混交林和针叶林为主.分析发现该流域植被与泥石流活动间存在以下关系:流域植被对泥石流的抑制作用是有限的,当泥石流暴发时沟道两侧的部分植被也随失稳土体一起滑人沟道,成为泥石流固体物质的一部分;不同植被类型对泥石流活动控制作用有差异,该区以针阔叶混交林和针叶林为主的植被类型对泥石流活动的控制作用不强.     

Relationship Between Protein Characteristics and Instant Noodle Making Quality of Wheat Flour

We investigated the relationship between the protein content and quality of wheat flours and characteristics of noodle dough and instant noodles using 14 hard and soft wheat flours with various protein contents and three commercial flours for making noodles. Protein content of wheat flours exhibited negative relationships with the optimum water absorption of noodle dough and lightness (L*) of the instant noodle dough sheet. Protein quality, as determined by SDS sedimentation volume and proportion of alcohol‐ and salt‐soluble protein of flour, also influenced optimum water absorption and yellow‐blueness (b*) of the noodle dough sheet. Wheat flours with high protein content (>13.6%) produced instant noodles with lower fat absorption, higher L*, lower b*, and firmer and more elastic texture than wheat flours with low protein content (<12.2%). L* and free lipid content of instant noodles were >76.8 and <20.8% in hard wheat flours of high SDS sedimentation volume (>36 mL) and low proportion of salt‐soluble protein (<12.5%), and <75.7 and >21.5% in soft wheat flours with low SDS sedimentation volume (<35 mL) and a high proportion of salt‐soluble protein (>15.0%). L* of instant noodles positively correlated with SDS sedimentation volume and negatively correlated with proportion of alcohol‐ and salt‐soluble protein of flour. These protein quality parameters also exhibited a significant relationship with b* of instant noodles. SDS sedimentation volume and proportion of salt‐soluble protein of flours also exhibited a significant relationship with free lipid content of instant noodles (P < 0.01 and P < 0.001, respectively). Protein quality parameters of wheat flour, as well as protein content, showed significant relationship with texture properties of cooked instant noodles.     

干旱与冬小麦和玉米产量关系的分析

对庆阳地区前一年伏期和秋季、当年春季和春末夏初大气干旱指数与冬小麦和玉米气候产量进行了对比分析和相关分析。结果表明，冬小麦产量与上年秋旱关系最为密切，其次为春旱、春末夏初旱和上年伏旱；玉米产量与当年伏旱关系最为密切，其次为秋旱、春和春末夏初旱。     

Relationship Between Grain,Semolina, and Whole Wheat Flour Properties and the Physical and Cooking Qualities of Whole Wheat Spaghetti

Durum breeding programs need to identify raw material traits capable of predicting whole wheat spaghetti quality. Nineteen durum wheat (Triticum turgidum L. var. durum ) cultivars and 17 breeding lines were collected from 19 different environments in North Dakota and were evaluated for physical and cooking qualities of whole wheat spaghetti. Raw material traits evaluated included grain, semolina, and whole wheat flour characteristics. Similar to traditional spaghetti, grain protein content had a significant positive correlation with cooking quality of whole wheat spaghetti. Stepwise multiple regressions showed grain protein content, mixogram break time, and wet gluten were the predominant characteristics in predicting cooked firmness of whole wheat spaghetti.     

Theoretical and Empirical Relationships Between Oat Test Weight and Groat Proportion

Test weight and groat proportion are two very important quality characteristics of oat grain. In this study, we pose the hypothesis that these two characteristics are related through characteristics of grain density. Test weight is defined as the product of kernel density and packing proportion. Groat proportion, in theory, is the ratio of the groat mass to the kernel mass. We present two theoretical constructions expressing test weight in terms of groat proportion, packing proportion and kernel density components. To test these, we have applied measurements of test weight, groat proportion, kernel density components, and packing proportion of 18 oat cultivars grown at six environments. Whereas the groat proportion alone accounted for only 34% of the variation in test weight, our theoretical constructions that included groat proportion could account for ≤82% of variation in test weight. Also, we present previously undescribed variation in oat kernel density components across genotypes and environments. Although the kernel density alone could account for most of the variation in test weight across genotypes, packing proportion appeared to be more important in describing variation in test weight of a genotype across different environments. We observed significant variation in both groat and hull density which, together with groat proportion, described most of the variation in kernel density.     

Interaction Between Plant Roots and Soil Water Flow in Response to Preferential Flow Paths in Northern China

Preferential flow is expected to provide preferential channels for plant root growth and variations in soil water flow, but few studies were conducted to imply the impacts of these changes, particularly for preferential flow in stony soils. This study aimed to characterize soil water flow and plant root distribution in response to preferential flow paths and quantitatively describe the relation between plant root distribution and soil water flow. Field dye‐tracing experiments centered on experimental plants were conducted to determine the root length density and soil water flow process. Laboratory analyses were performed to characterize changes in the relative concentration of the accumulated effluent and the degree of interaction between plant roots and soil water flow. The amount of fine plant roots with preferential flow paths decreased with increasing soil depth for all experimental plots. The largest plant roots were recorded in the upper soil layers to a depth of 20 cm. The relative concentration of the accumulated effluent increased with time and decreased with soil depth under saturated soil conditions, whereas a distinct early turning point for the relative concentration of the accumulated effluent was observed in the 0–20‐cm soil columns, and the relative concentration of the accumulated effluent initially decreased and then increased with time under unsaturated soil conditions. This study provides quantitative information with which to characterize the interaction between plant roots and soil water flow in response to preferential flow paths in soil–plant–water systems. Copyright © 2016 John Wiley & Sons, Ltd.     

Production of Starch with Very Low Protein Content from Soft and Hard Wheat Flours by Jet Milling and Air Classification

Jet milling is a fluid energy impact‐milling technique generally used for the ultrafine reduction of higher value materials. The efficiency of jet milling combined with air classification appears very efficient to separate starch from other wheat flour aggregate components and to produce wheat starch with very low residual protein content. Indeed, residual protein content of the starch‐rich fraction can be reduced to <2% db with a series of successive grinding and air classification operations. Lipid and pentosan contents were also reduced in the starch‐rich fraction. Nevertheless, jet milling cannot eliminate grinding differences observed between different types of wheat. Wheat hardness continues to have an effect on milling and classification yields and on the composition of air classification fractions. To obtain starch‐rich fraction with only 2% protein content, hard wheat flour required a series of at least five grinding steps, whereas only three steps are necessary for soft wheat flour. Under these conditions, hard wheat flours give 24% mass yield with 12% starch damage compared with 39% yield and a low starch damage content (6.4%) for soft wheat flour. These results highlight new prospects for the development of cereal flours, especially soft wheat flours.     

Relationship Between Soft Wheat Flour Physicochemical Composition and Cookie‐Making Performance

Nowadays in Argentina, cookies, crackers, and cakes are made of flour obtained from bread wheat with additives or enzymes that decrease the gluten strength but increase production costs. The present research work aims to study the relationship between flour physicochemical composition (particle size average [PSA], protein, damaged starch [DS], water soluble pentosans [WSP], total pentosans [TP], and gluten), alkaline water retention capacities behavior, solvent retention capacities profile (SRC) and cookie‐making performance in a set of 51 adapted soft wheat lines with diverse origin to identify better flour parameters for predicting cookie quality. Cookie factor (CF) values were 5.06–7.56. High and significant negative correlations between sucrose SRC (–0.68), water SRC (–0.65), carbonate SRC (–0.59), and CF were found, followed by lactic SRC that presented a low negative but significant correlation (r = –0.35). The flour components DS (r = –0.67), WSP (r = –0.49), and TP (r = –0.4) were negatively associated to CF. PSA showed a negative correlation with CF (r = –0.43). Protein and gluten were the flour components that affected cookie hardness, but no significant correlation were found with pentosan or DS content. A prediction equation for CF was developed. Sucrose SRC, PSA, and DS could be used to predict 68% of the variation in cookie diameter. The cluster analysis was conducted to assess differences in flour quality parameters among genotypes based on CF. Clusters 1 and 4 were typified by lower CF (5.70 and 5.23, respectively), higher DS, pentosan content, and SRC values. Cluster 2 with a relative good CF (6.47) and Cluster 3 with the best cookie quality, high CF (7.32) and low firmness, and the lowest DS, TP, WSP content, and sucrose SRC values.     

Relationship Between Single Wheat Kernel Particle-Size Distribution and Perten SKCS 4100 Hardness Index

The Perten Single Kernel Characterization system is the current reference method for determination of single wheat kernel texture. However, the SKCS 4100 calibration method is based on bulk samples. The objective of this research was to develop a single-kernel hardness reference based on single-kernel particle-size distributions (PSD). A total of 473 kernels, drawn from eight different classes, was studied. Material from single kernels that had been crushed on the SKCS 4100 system was collected, milled, then the PSD of each ground single kernel was measured. Wheat kernels from soft and hard classes with similar SKCS hardness indices (HI 40–60) typically had a PSD that was expected from their genetic class. That is, soft kernels tended to have more particles at <21 μm than hard kernels after milling. As such, a combination of HI and PSD gives better discrimination between genetically hard and soft classes than either parameter measured independently. Additionally, the use of SKCS-predicted PSD, combined with other low level SKCS parameters, appears to reduce classification errors into genetic hardness classes by ≈50% over what is currently accomplished with HI alone.