Determination of Bran Contamination in Wheat Flours Using Ash Content,Color, and Bran Speck Counts

A fast new method based on image analysis, ScanPro Speck Expert (SPX), to determine the bran contamination in wheat flour was studied and compared with existing methods (air-oven, ash, and color measurements) using an Agtron color meter and a Minolta chromameter. Twenty-one hard red winter wheat flour samples with ash contents of 0.30–0.58% were collected from the Kansas State University pilot mill and used for this study. Intrinsic variability in the flour sample because of randomness of bran speck orientation and distribution in the sample holder could result in variation in the speck count. Simple and multiple linear regression analyses showed that estimation of flour ash content from the SPX results (R² = 0.91) would be more accurate than the results from color measurements (R² = 0.66 [Agtron color meter] and 0.74 [L*]). The added capability of SPX image analyzer to not only count the number of bran specks but also to measure their areas probably increases the accuracy of determining the bran contamination in wheat flour by image processing.     

An Automated System for the Continuous Measurement of Time-Dependent Changes in Noodle Color

Fresh noodles may develop a gray discoloration over time during storage. This characteristic is related to polyphenoloxidase activity and is partly a varietal characteristic of the wheat flour; it is also influenced by processing conditions and is regarded as a major negative factor in noodle quality. Screening of wheat genotypes by measuring color at a fixed-time interval (commonly 24 hr) after manufacture is not informative about time-dependent color development. We developed a computer-controlled automated sample platform attached to a reflectance spectrophotometer to simultaneously monitor color changes (L*, a*, b*) over time in up to 12 noodle samples. Application of the unit to monitor color changes in white-salted and yellow-alkaline noodles is described.     

Automated Color Classification of Single Wheat Kernels Using Visible and Near-Infrared Reflectance

Modification of an existing single kernel wheat characterization system allowed collection of visible and near-infrared (NIR) reflectance spectra (450–1,688 nm) at a rate of 1 kernel/4 sec. The spectral information was used to classify red and white wheats in an attempt to remove subjectivity from class determinations. Calibration, validation, and prediction results showed that calibrations using partial least squares regression and derived from the full wavelength profile correctly classed more kernels than either the visible region (450–700 nm) or the NIR region (700–1,688 nm). Most results showed >99% correct classification for single kernels when using the visible and NIR regions. Averaging of single kernel classifications resulted in 100% correct classification of bulk samples.     

用遗传神经网络方法进行苹果颜色自动检测的研究

该文通过计算机视觉技术获取苹果的色度直方图并提取其表面颜色特征，采用先进的遗传算法建立了一个多层前馈神经网络系统，从而实现了苹果成熟度的自动判别。实测表明，该方法准确率较高，并具有鲁棒性、灵活性和高速度。     

基于遗传神经网络的玉米叶色的自动测定研究

利用计算机图像处理技术和遗传神经网络技术,建立了一个多层前馈神经网络,实现了大田玉米和背景图像的正确识别,并且通过获取玉米叶的色度直方图提取了玉米叶表面颜色特征,进而求得了玉米叶色的测定值。实验结果表明,玉米叶色值自动测定系统,识别玉米的准确率可达91.6%,可以有效地测定玉米的叶色。该研究为实现大田玉米的化肥精确施用提供了理论依据。     

Measurement of Fertilizer Leaching from the Root Zone Using an Automated Infiltration Soil Water Sampler in an Unsaturated Sandy Field

In sandy fields with vegetable cultivation, fertilizer leaching may occur and it should be well-controlled. The development of a direct soil water sampler is necessary to examine solute transport and fertilizer leaching in the vadose zone, since soil water reflects timely monitoring of data more accurately than groundwater. We developed a Suction-Controlled Flux Sampler to collect infiltration soil water in a sandy soil. In the present study, we monitored fertilizer leaching in an unsaturated sandy field during the rainy season, while evaluating the sampling performance of SCFS for the sampling of infiltration water. SCFS directly collected the infiltration water effectively over a period of several months in the sandy field and recorded the Water-Collecting Efficiency from 92 to 115% under various infiltration conditions during a period of 50 d. WCE was affected by the rainfall intensity as well as by previous rainfall, which enhanced WCE. The results obtained from the use of SCFS and several sensors demonstrated that the amount of leached water remained low as long as irrigation was applied according to the cultivation manual. However, an unexpected heavy rainfall event led to fertilizer leaching. The fertilizer leaching trend was effectively monitored by several sensors inserted into the soils, while detailed analysis of the components was performed after collection by using SCFS. Direct access to infiltration water enabled to examine the infiltration process and detailed variations in the amounts of discharged anions. The sensor-equipped monitoring system together with SCFS is suitable for precise management of fertilizer and irrigation application.     

Observation and Measurement of Residual Bran on Milled Rice Using Hyperspectral Imaging

Residual bran on milled rice is directly related to its quality. This study proposes a method to measure the residual bran patterns on a single rice grain by using hyperspectral imaging (HSI). HSI is a sensing technique that combines both spatial and spectral information and may be used for chemical compound identification and quantification. In this study, HSI was applied to assess rice bran residue nondestructively. In the experiment, rice samples were milled and scanned with an HSI system. Afterward, the rice samples were dyed to enable the residual bran to be identified with optical microscopy and image processing algorithms. Classifiers were then developed to predict the rice bran residue by using the HSI measurements as inputs. The predicted images were compared with the micrograph images for classifier performance evaluation. The proposed approach can estimate the residual bran distribution on milled rice surface with an accuracy of 93.5%.     

Measurement of Wheat Starch Granule Size Distribution Using Image Analysis and Laser Diffraction Technology

Starch was isolated from flour of four wheats representing hard red winter (Karl), hard red spring (Gunner), durum (Belfield 3), and spelt (WK 86035‐8) wheat classes. Digital image analysis (IA) coupled with light microscopy was used to determine starch size distributions where the volume of granules was calculated as spherical particles or oblate spheroids. Starch granules were classified into three size ranges: A‐type granules (> 15 μm), B‐type granules (5–15 μm), and C‐type granules (<5 μm). An error was noted in using digital image analysis because the perimeter of some granules touch the edge (PTE) of the field being analyzed. To correct for this error, the PTE granules were manually replaced into the field by measuring their diameters and entering them into the database. The results showed differences in the starch size distributions between the classes of wheat evaluated, as well as the method of analysis. Four laser diffraction sizing (LDS) instruments were used to measure granule distributions of the four classes of wheat. LDS compared with IA resulted in a ≈40% underestimation of the A‐type granule diameter and a ≈50% underestimation of the B‐type granule diameter. A correction factor (adjustment) was developed from IA data to correct LDS analysis. LDS data correlations before adjustments to IA data were R² = 0.02^ns to 0.55***. After adjustment, these correlations improved to R² = 0.81*** to 0.93*** depending on the class of wheat starch evaluated.     

Effect of Starch Granule Size Distribution and Elevated Amylose Content on Durum Dough Rheology and Spaghetti Cooking Quality

To obtain an indication of the effect of increasing the starch amylose content above normal levels (27–74%) and increasing the percentage of B‐type starch granules (11–60%) on durum dough properties and the quality of the spaghetti derived from these doughs, the reconstitution approach was used. Reconstituted flours were prepared from a common Wollaroi gluten, solubles and tailings fraction combined with starches containing varying B‐granule contents, or with starches from maize with varying amylose content. An increased B‐granule content increased farinograph water absorption. Cooked spaghetti firmness was highest with B‐type granules at 32–44% (volume percentage basis), which is ≈10–15% higher than normally found in durum starch. Increasing the amylose content in the starch caused the dough to be more extensible, increased spaghetti firmness, and decreased water absorption with optimum quality of amylose at 32–44%. The information indicates there would be benefit in producing durum wheats with slightly elevated B‐granule and amylose contents.     

Quantitative Modeling of Photoassimilate Flow in an Intact Plant Using the Positron Emitting Tracer Imaging System (PETIS)

The photoassimilate flow in an intact plant stem was imaged in real-time and its dynamics was quantitatively described using the Positron Emitting Tracer Imaging System (PETIS). Radioactive ¹¹CO₂ was fed to a leaf of an intact broad bean ( Vicia faba L.) plant, together with air containing an ambient concentration of non-radioactive carrier CO₂ gas. Movies of flow of the ¹¹C-labeled photoassimilates in the plant body were captured with PETIS. Here we demonstrate that the average flow speeds and the distribution ratios of photoassimilates in the respective nodes and internodes of the observed stem can be estimated by the transfer function analysis, one of the mathematical modeling methods. We also estimated the changes in the spatial distribution of the average flow speeds in the same stem when the fed leaf was exposed to enriched carrier CO₂ gas.     

Effect of Heat Treatments on Starch Pasting,Particle Size,and Color of Whole‐Grain Barley

Barley β‐glucan has cholesterol‐lowering properties and can be positively affected by heat treatments. The aim of this study was to examine the effects of heat treatments of whole‐grain barley on starch pasting, particle size, and color. Three heat treatments (micronization, roasting, and conditioning) were performed on three cultivars of barley (CDC Rattan, CDC McGwire, and CDC Fibar). All three heat treatments increased peak, breakdown, setback, and final viscosity of CDC Rattan and CDC Fibar. However, they had little effect on the starch‐pasting profile of CDC McGwire. Roasting and conditioning reduced the mean particle size compared with untreated particles, whereas micronization had minimal effect. Heat treatments reduced L* and increased a* and b* compared with no treatment. Overall, this research shows that heat treatments can change other properties of barley that may affect its function in food applications.     

C‐Glycosylflavone and Lignan Diglucoside Contents of Commercial,Regular, and Whole‐Wheat Spaghetti

Consumption of whole‐wheat products, including whole‐wheat spaghetti, is associated with beneficial health effects. Flavonoids and lignans are antioxidant phytochemicals that have received much attention from researchers. Investigations were conducted on the content of flavonoid glycosides, lignan diglucoside, and secoisolariciresinol diglucoside (SDG) as contributors to the health‐promoting properties of whole‐wheat spaghetti. Flavonoid glycosides present in regular and whole‐wheat spaghetti samples were identified as 6‐C‐glucosyl‐8‐C‐arabinosyl apigenin and the sinapic acid ester of apigenin‐C‐diglycoside while, in a previous study, the sinapic acid ester of apigenin‐C‐diglycoside was found only in wheat germ tissues. The content of these compounds was significantly higher in whole‐wheat spaghetti (17.0 and 15.1 μg of apigenin equivalent/g) compared to the regular brands (9.5 and 5.8 μg apigenin equivalent/g). SDG content was also significantly higher in whole‐wheat spaghetti (41.8 μg/g) compared to the regular brands (12.9 μg/g). These findings lend further support to the notion that phenolic compounds, along with dietary fiber, are concentrated in the bran layers of the wheat kernel; hence, consumption of whole grain products is strongly recommended to obtain significant levels of health‐promoting phytochemicals.     

Measurement of Color,Gloss, and Translucency of White Salted Noodles: Effects of Water Addition and Vacuum Mixing

Sensory evaluation showed panelists could detect small differences in gloss and translucency in boiled white salted noodles (WSN) but sensory evaluation requires significant resources. Methods for the measurement of noodle gloss and translucency in boiled WSN were developed and the effects of hardness, protein, water addition, and vacuum mixing on these visual sensory characteristics and color (as measured by CIE L*, a*, and b*) were investigated. Noodles derived from hard wheats at low flour protein contents were more translucent than noodles from soft wheat flour at low protein. This trend changed at the highest flour protein contents observed. Translucency of the soft wheat noodles increased to levels equal to or exceeding the translucency of high protein hard wheat noodles. Translucency of all noodle varieties increased as flour protein increased. CIE L* decreased, a* increased, and b* increased when water addition to dough increased from 30 to 35%, but there was no further effect on color when water addition was increased to >35% for raw soft and hard WSN. Boiled noodle translucency was significantly increased when water addition to the dough was increased from 35 to 38% and when noodles made from soft wheat flour were mixed under vacuum. Vacuum mixing significantly increased gloss of boiled noodles made from soft wheat flours.     

Variability in a Starch Isolation Method and Automated Digital Image Analysis System Used for the Study of Starch Size Distributions in Wheat Flour

A starch isolation method and digital image analysis system were developed to accurately measure size distributions of the starch populations in wheat. The image analysis system was coupled directly to a light microscope equipped with computer controlled step stage and automatic focus. Automation of data acquisition and processing eliminated some of the labor intensive steps previously required for analyzing starch granule size distributions. This system was used to standardize starch isolation methods and compare variation and precision of the system. Operational variations were determined and statistically assessed. The number of fields of view required for low standard errors and acceptable speed of analysis was determined to be fifty. A major advantage of the system has been the increased resolution. The use of higher magnifications and stage automation allowed the analysis of starch granules as small as 0.84 μm in diameter while analyzing thousands of starch granules per sample.     

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.     

In Vitro Starch Digestibility of Gluten‐Free Spaghetti Based on Maize,Chickpea, and Unripe Plantain Flours

Gluten‐free and high indigestible carbohydrate food development is a topic that deserves investigation because of an increased focus on gluten intolerance and celiac disease and on metabolic disorders caused by overweight and obesity. Here, chickpea and maize flours were used as sources of protein and carbohydrate (because of the level used in the mixture) and unripe plantain as an indigestible carbohydrate source in composite gluten‐free spaghetti elaboration. The mixture of unripe plantain, chickpea, and maize was used at different levels to prepare spaghetti (samples S15Pla and S25Pla); control pasta was made of 100% semolina (S100Sem), and a 100% unripe plantain flour (S100Pla) pasta was also evaluated. In vitro amylolysis rate of fresh and stored (three and five days) spaghetti was assessed. The spaghetti with 100% unripe plantain (S100Pla) had higher resistant starch (RS) content than the control sample and the two cooked composite gluten‐free spaghettis (S15Pla, S25Pla), and RS further increased with the storage time. The plantain spaghetti (S100Pla) also had the highest rapidly digestible starch and the lowest slowly digestible starch contents; this pattern agrees with the hydrolysis rate, especially after cold storage. The stored S25Pla spaghetti showed the lowest hydrolysis rate and predicted glycemic index. Blending chickpea, maize, and unripe plantain flours represents a way to obtain gluten‐free spaghetti with high nondigestible carbohydrate content and slow digestion properties.     

运用乙炔抑制-静态土柱培养法测定旱地土壤氮素反硝化损失

介绍了测定土壤反硝化作用的乙炔抑制 -静态土柱培养法 ,并就其应用中的一些条件进行了说明 ,内容包括土柱的取样深度、土柱取样量、土柱培养方式及基本操作程序等。最后阐述了这一方法在北京郊区土壤上的使用情况。     

自动化监测系统在水土流失观测中的引进与应用

由于土壤侵蚀使土壤退化及土地生产力下降,甚至威胁人类生产生活的生态环境.多年来土壤侵蚀规律研究一直是自然科学领域研究的关键性技术.20世纪50年代初,黄委会在黄土丘陵沟壑区第1副区设立了小流域土壤侵蚀不同类型的因子观测站网、径流小区等,采集获得60 a多的原始观测资料.长期以来一直为人工观测,成果资料多为降雨-径流-泥沙的特征点源数据,而每次降雨侵蚀是一个连续的自然过程,人工监测由于其因子对位性、监测数据的连续性和系统性较差,造成研究成果只局限于土壤侵蚀影响的单因子或部分因子研究成果,严重影响该区水土流失系统模型的开发.为了进一步提升水土流失规律研究的水平,寻找土壤侵蚀客观真实的自然数据规律,加快该区水土流失模型开发,在该区引进了现代自动化的水土流失监测系统,经过2 a的监测实践和成果数据的比测分析,不仅节约了大量的人、才物资源,而且获取得了客观真实、精度较高和连续动态的水土流失过程数据,对该区水土流失规律研究将起到积极的推动作用.     

Comparison of Water Absorption Patterns in Two Barley Cultivars,Using Magnetic Resonance Imaging

Two barley cultivars, Excel and Prisma (six-row and two-row types, respectively), were obtained from the 1993 harvest at Crookston, MN. Magnetic resonance imaging (MRI) was used to follow water imbibition in single, large seeds of Excel and Prisma barley. A comparison of moisture distribution on longitudinal sections of Prisma and Excel barley during early hours of steeping was then made. MRI analysis revealed that the majority of water initially entered the kernel through the kernel surfaces and into the endosperm tissues. Water was observed under the surface of the hull tissues and appeared to be migrating into the aleurone and endosperm tissues. Then water was detected moving from the embryo to the scutellum and then into the crushed cell layers. Aleurone and embryo tissue showed more rapid water uptake and distribution than did scutellar tissue. Some transient water distribution was observed in the scutellum, ventral furrow, and vascular tissues. This indicates that the hydration of surface tissues and crushed cell layers may be significant during the early hours of steeping. During the late hours of steeping, the crushed cell and endosperm cavity region appears to become remarkably active in water transport. Water was distributed throughout the endosperm tissue of the Prisma cultivar more efficiently than in that of the Excel cultivar, although Excel absorbed more water initially.