小麦品种单籽粒性状的研究

小麦单籽粒鉴定法（ＳＫＣＳ）的发明使得小麦品种间和品种内单籽粒性状的研究成为可能,从而为小麦育种目标性状的制定,品种鉴定及品质评价带来了新的认识和信息,通过对１３个小麦品种（品系）单籽粒性状的研究认为,品种内单籽粒含量存在着较大的变化,单籽粒重量的变幅较为突出,且品种内的变化大于品种间的变化;个别品种籽粒宽度的变异系数较高;关中地区的小麦品种绝大多数为硬质麦,个别品种存在着籽粒质地不纯的现象,籽粒     

EFFECT OF HEAT TREATMENT ON THE INDUSTRIAL QUALITY OF TWO VARIETIES OF MEXICAN WHEAT

Two Mexican wheat varieties conditioned to three initial moisture levels (17, 25 and 37% dry basis) were dried with air at 40, 60, 80 and 100°C for 60 min periods in a laboratory scale fluidised bed system. Drying kinetics and activation energy was determined. Weight per hectolitre, wheat hardness, total protein content, dough mixing time and loaf volume were analysed. The results showed that the initial moisture content and drying velocity lowered the activation energy necessary to extract water from the grain. The effect of temperature and moisture content in the grain were the most important factors to control damage during drying. The hard wheat variety was less susceptible to heat damage than the soft variety, probably due to its higher protein content and harder texture. Weight per hectolitre, wheat hardness and drying did not considerably modify total protein content. Conversely, mixing time and loaf volume showed changes directly related to heat treatment severity. Fluidised bed drying at 40 and 60°C of both varieties at 17% initial moisture content showed an improving effect on loaf volume.     

Wheat Hardness: Time Required to Grind Wheat with the Brabender Automatic. Micro Hardness Tester

The Brabender automatic micro hardness tester was used to measure the time required to grind 4g of wheat. Effects of temperature and moisture were determined. Increasing temperature from 15 to 40°C generally decreased grinding time, but differentiation among samples was better at 15°C than at higher temperatures. Increasing moisture content increased the grinding time of soft wheat much more than it increased the grinding time of hard wheat. The tester can detect differences related to milling properties of hard wheats, hardness among some wheat classes and among some varieties representing a single class of wheat. The instrument can also be used to evaluate hardness of plant-breeders' samples, so that selections with extreme hardness or softness can be discarded, and to distinguish between hard and soft wheats in marketing channels.     

Repeatability of Mice Consumption Discrimination of Wheat (Triticum aestivum L.) Varieties across Field Experiments and Mouse Cohorts

Whole grain wheat (Triticum aestivum L.) foods can provide critical nutrients for health and nutrition in the human diet. Potential flavor differences among varieties can be examined using consumption discrimination of the house mouse (Mus musculus L.) as a model system. This study examines consistency and repeatability of the mouse model and potentially, wheat grain flavor. A single elimination tournament design was used to measure relative consumption preference for hard red spring and hard white spring varieties across all 3 experiments in combination with 2 mouse cohorts. Fifteen replicate mice were used in 24‐h trials to examine differences in preference among paired wheat varieties until an overall “winner” was established as the most highly preferred variety of wheat. In all 3 experiment–cohort combinations, the same varieties were preferred as the “winner” of both the hard red spring and hard white spring wheat varieties, Hollis and BR 7030, respectively. Despite the consistent preference for these varieties across experiments, the degree (magnitude) to which the mice preferred these varieties varied across experiments. For the hard white spring wheat varieties, the small number of varieties and confounding effects of experiment and cohort limited our ability to accurately gauge repeatability. Conversely, for the hard red spring wheat varieties, consumption preferences were consistent across experiments and mice cohorts. The single‐elimination tournament model was effective in providing repeatable results in an effort to more fully understand the mouse model system and possible flavor differences among wheat varieties.     

Equilibrium moisture content and sorption isosteric heats of five wheat varieties in China

The moisture sorption isotherm data of five Chinese wheat varieties were investigated via the gravimetric static method at five different temperatures (10, 20, 25, 30, and 35 °C) and relative humidity ranging from 11.3 to 96.0%. The sorption data of wheat decreased with an increase in temperature at a constant relative humidity (r.h.). The hysteresis effect was observed between adsorption and desorption isotherms. The width and span of the hysteresis loop decreased with increased temperature, but was not influenced by the hardness of wheat varieties. Six models, namely the Chen-Clayton (CCE), Modified BET (BET), Modified-Chung-Pfost (MCPE), Modified-Henderson (MHE), Modified-Oswin (MOE) and Strohman-Yoerger (SYE), were employed to describe the experimental data. The BET, MCPE and MOE models were selected to best describe the sorption isotherms of wheat in the ranges of 11.3-49.9, 11.3-96.0 and 11.3-96.0% r.h., respectively. The hygroscopic property difference between hard wheat (cv. ‘Longyuan’ and ‘Nanduan’) and soft wheat (cv. ‘Zhaozhuang’ and ‘Lumai’) was very small. The sorption isosteric heat of wheat decreased with an increase in moisture content until the dry bulb moisture content (m.c.) of 20% was reached, and then decreased smoothly with increasing moisture content. A big difference was found between adsorption and desorption isosteric heats of wheat below 20% m.c., but the sorption isosteric heat difference between hard and soft wheat isotherms was small.     

Physical and stress-strain properties of wheat (Triticum aestivum) kernel

BACKGROUND: Two hard wheat varieties and one soft variety grown under the same agroecological conditions were analyzed for their physical and uniaxial stress–strain compression properties. RESULTS: The physical properties of wheat kernel were determined at a moisture content of 0.13 kg kg^?1 (wet basis), whereas the stress–strain compression test was conducted at a kernel moisture content from 0.082 to 0.433 kg kg^?1. Mean kernel lengths were 5.46 (5.37 and 5.38) mm, widths were 2.56 (2.47 and 2.62) mm and thicknesses were 2.12 (2.18 and 2.43) mm for Simonida, Dragana and NS 40S cultivars, respectively. Bulk densities were 791.34 (Simonida), 788.51 (Dragana) and 731.77 kg m^?3 (NS 40S). The force at the yield point was 241.46 N for Dragana (moisture content 0.133 kg kg^?1), 244.30 N for Simonida (0.136 kg kg^?1) and 164.90 N for NS 40S (0.433 kg kg^?1). CONCLUSION: The width and thickness of the analyzed kernels were small compared with the length, and bulk densities were also moderate. The yield point force values of the two hard varieties were 2.2 times higher than the values of the soft variety, at a moisture content of 0.136 kg kg^?1 for Simonida, 0.133 kg kg^?1 for Dragana and 0.141 kg kg^?1 for NS 40S. Copyright © 2011 Society of Chemical Industry     

小麦籽粒硬度与胚乳显微结构关系研究

本文选用了8个籽粒角质率不同的小麦品种(系)进行籽粒硬度和胚乳横断面显微结构关系的研究。结果表明籽粒硬度不同的小麦品种其胚乳结构存在差异：硬度值较大的硬质品种胚乳蛋白质较多。淀粉粒与蛋白质结合紧密；而硬度值较小的软质小麦品种胚乳蛋白质较少。淀粉粒与蛋白质结合松散。     

小麦入磨水分和硬度对研磨特性的影响

在间歇式实验制粉系统上研究了硬度和水分调节对小麦研磨特性的影响。皮磨系统对入磨水分的变化敏感，随着水分的增加，小粒度麦渣心的提取率基本保持不变，而大粒度麦渣心的提取率显著降低；皮磨系统面粉出率增加，面粉灰分也降低；细麸皮的出率基本保持不变，而粗麸皮的出率显著增加。用硬麦获得的麦渣、麦心的数量显著高于软麦的，特别是大粒度麦渣心的数量，小粒度麦渣心的数量基本一样；硬麦在皮磨系统面粉的出率低于软麦，而总出粉率高于软麦；硬麦的细麸皮和次粉的出率和软麦基本一致，而粗麸皮的出率显著低干软麦。水分调节和硬度对小麦研磨特性的影响相似。     

A mean moisture content-equilibrium relative humidity relationship for nine varieties of wheat

A mean moisture content-equilibrium relative humidity relationship for nine varieties of wheat at 25°C is presented, for which the curves were fitted by eye. The mean safe storage moisture content in equilibrium with 70% relative humidity (r.h.) for all the wheat varieties adsorbing moisture was 14.7% (wet weight basis) but if varietal differences and errors in measurement are taken into account, the moisture content of stored wheat may need to be as low as 13% to be safe from attack by mites. The hysteresis between adsorption and desorption reached a maximum of 0.7% moisture content at 40–50% r.h. Hysteresis was found to be statistically significant up to 75% r.h. Equilibrium moisture contents were calculated from data transformed using the Chung and Pfost equation and compared with the measured moisture contents.     

Arabinoxylan content and characterisation throughout the bread‐baking process

End‐use quality of wheat (Triticum aestivum L.) is influenced in a variety of ways by nonstarch polysaccharides, especially arabinoxylan (AX). The objective of this study was to track total and water‐extractable AX (TAX and WEAX, respectively) throughout the bread‐baking process, using wholemeal and refined flour. The TAX and WEAX content and the ratio of arabinose: xylose were assessed in flour, mixed dough, proofed dough and the bread loaf, which was separated into crumb, upper crust and bottom crust. Changes in TAX during the baking process differed between the refined flour and wholemeal samples, suggesting a change in the TAX availability which we ascribe to molecular interactions and heat treatment. WEAX content dramatically decreased during baking, suggesting that oxidative cross‐linkages rendered it unextractable. Higher levels of WEAX and lower levels of arabinose substitution were correlated with higher loaf volumes for refined flour among the hard wheat varieties. Having a better understanding of the importance of both WEAX content and arabinose substitution allows for directed breeding efforts towards improved hard wheat varieties for optimum bread baking.     

Detection of External and Internal Insect Infestation in Wheat by Near-Infrared Reflectance Spectroscopy

Near-infrared spectroscopy (NIR) in the reflectance mode was investigated for the rapid, automatic and non-destructive detection of insect stored-grain pests external or internal to wheat kernels. Convincing calibration performance was obtained for external adult Oryzaephilus surinamensis (L) (saw-toothed grain beetle) in unmilled samples including varieties Beaver (soft wheat) and Mercia (hard wheat) at two moisture contents. With this large substrate variability, the method could differentiate between uninfested samples and samples with approximately 270 insects kg⁻¹ or more. Milling made no improvement. Large spectral differences were observed between uninfested kernels and kernels infested internally with Sitophilus granarius (L) (grain weevil) larvae or pupae, arising from both a changed chemical composition and physical structure. Single uninfested and infested kernels were discriminated by their second derivative (d²) spectra. For both external and internal infestation there was substantial evidence that insect protein and/or chitin and moisture were being detected. NIR should be useful as a rapid method of detection.     

PHYSICAL-CHEMICAL AND SENSORY QUALITY EVALUATION OF POTATO VARIETIES (SOLANUM TUBEROSUM L.)

Seven table potato varieties were studied for pH, soluble solids content, moisture, firmness, color, external appearance of raw tubers and flavor and texture of the fried and boiled product. Monalisa was the most appreciated variety regarding external appearance, Bartina was preferred for the flavor of the fried product while Victoria and Desiree were the best for flavor and texture of boiled potatoes. The different scores by variety depending on frying or boiling suggest a specific use for each variety. Soluble solids content, pH, and moisture determinations showed minimal differences between varieties. Firmness was highest in the two varieties with the least moisture (Desiree and Victoria) and lowest in varieties with a high degree of moisture (Bartina and Caesar); fresh potato firmness had a positive correlation with these sensorial parameters when the product was boiled. All colorimetric parameters were useful to discriminate red skin from yellow‐white skin varieties.     

Historical shifts in the seed mineral micronutrient concentration of US hard red winter wheat germplasm

The yield of wheat (Triticum aestivum L. em. Thell) has greatly improved through breeding, but it is not known how this has affected seed micronutrient content. In the present study, the iron (Fe), zinc (Zn), copper (Cu), and selenium (Se) content of seed of 14 US hard red winter wheat varieties from production eras spanning more than a century was measured. The seed that was analyzed was obtained from a replicated field trial conducted at two locations in Kansas. The Fe, Zn, and Cu content was obtained by inductively coupled plasma emission spectroscopy (ICPES) and Se content was obtained by hydride‐generated atomic absorption spectrometry (HG‐AAS). Significant effects of location on micronutrient content of seed were observed. Similarly, depending on the micronutrient, significant differences in seed micronutrient content between varieties were detected at one or both locations. A significant negative regression of seed Zn content on both yield and variety release date was observed at both locations, while seed Fe content exhibited a significant negative regression on yield and variety release date at one location. Regression of seed Se content on variety release date was significant and negative at one location. These results suggest that genetic gains in the yield of US hard red winter wheat have tended to reduce seed Fe, Zn, and Se concentrations. However, the extent to which this effect manifests itself is influenced by environmental effects. Published in 2006 by John Wiley & Sons, Ltd     

Selected Geometric and Mechanical Properties of Barley (Hordeum Vulgare L.) Grain

The properties of grain of Mauritia and Prestige barley varieties were determined for moisture content of 12.5 and 15.5% wet basis. Broad variations were observed in the relationship between the moisture content of grain, its variety, and the geometric properties of barley. Most of the geometric properties of barley were dependent on both the cultivar studied and the moisture content of grain, while selected characteristics were dependent on moisture content of grain or barley cultivar only. The values of displacement, force and energy required for kernel rapture were lower for Mauritia variety than Prestige variety and were not dependent on the moisture content of grain.     

Identification of characteristic starch properties of wheat varieties used to commercially produce dried noodles

The starch physicochemical properties of wheat varieties used to commercially produce dried noodles were studied. Scanning electron microscopy and laser microparticle size analyser were used to observe the starch particles; the polymorphism of the waxy (Wx) protein of each wheat variety was also studied. The correlation analysis among commonalities of the starch physicochemical properties and noodle textural properties was performed. Results indicated that the amylose contents of the noodle wheat varieties ranged from 17.8% to 21.7%. There was a significant, positive correlation between the thermodynamic temperature of starch and the volume distribution of particle size. The correlation between the volume distribution of B-type starch granules and noodle springiness was significant, which means that volume distribution of starch particle size could be used as one of the indicators to evaluate the springiness of noodles. Molecular polymorphism identification of Wx protein was also useful to select desirable noodle wheat variety. The results of this study provide useful information for wheat breeding works and wheat variety selection of noodle-making company.     

A systemic approach to qualitative changes in the stored-wheat ecosystem: Prediction of deterioration risks in unsafe storage conditions in relation to relative humidity level, infestation by Sitophilus oryzae (L.), and wheat variety

A multidimensional laboratory trial was carried out to identify the primary causes of changes in quality traits in the stored-grain ecosystem to reveal critical storage condition boundaries that may endanger grain quality retention. Qualitative criteria were followed on grain batches from 3 wheat varieties which were stored for 160 d at temperature of 22-23 °C, at two different relative humidities, and with or without infestation by the rice weevil Sitophilus oryzae, to build a multivariate data matrix. The interactions between biotic deteriorative factors and qualitative trait changes were explored through a principal component analysis (PCA). From the Pearson’s product moment correlation matrix, it was observed that the variables that correlated significantly with insect and fungal species dynamics were: moisture content, hL mass, seed viability, and fat acidity of extracted whole flour. Four factors explained the major part of the variance: storage duration, moisture content, hidden insect infestation density, and fungal contamination level. The rate of increase of the insect population was significantly different between varieties. PCA revealed that the significant difference in qualitative deterioration pattern observed between the three varieties was not related to their hardness but rather to a different relationship between the grain and relative humidity. Germination rate was the first quality factor to decline during the storage period. The technological properties of flour extracted from each variety were not affected before insect population density exceeded 1000 adult insects per kg. The rate of qualitative changes induced by the biotic deterioration factors was processed into a “biodeterioration susceptibility index” (BSI) according to the safe storage time assessed in the present study. This index may be used in IPM approaches to predict the susceptibility of a particular wheat variety to insect and fungal damage during long-term storage.     

新收获小麦后熟过程中蛋白质和氨基酸含量的变化

分析了储存在4℃和室温条件下新收获的软麦和硬麦在后熟过程中的生理生化变化。新收获小麦在20℃的发芽率超过80%,在收获后3~4个月中呼吸有2次高峰,尤其第1个呼吸峰非常明显,室温条件较4℃提高第1个呼吸峰值。当呼吸速率趋于不变时,软麦硬度增大在第4个月,硬麦在第5个月。水溶蛋白、盐溶蛋白及谷蛋白各有2次合成高峰。硬麦醇溶蛋白在第60天有一个积累高峰,软麦至少有2个积累高峰,分别在第30天和60天。谷蛋白合成最高峰在第90天,与水溶蛋白类似,而醇溶蛋白合成最高峰在第60天,与盐溶蛋白类似。随着醇溶蛋白和游离巯基含量减少,谷蛋白迅速积累。常温条件下谷蛋白的氧化聚合较低温条件下迅速,积累量大。软麦谷蛋白氧化聚合过程较硬麦早。谷蛋白积累之前,绝大部分氨基酸急剧积累,在室温条件较4℃下积累明显。半胱氨酸含量在90~120天时增加到最大,之后迅速减少。     

小麦籽粒品质与馒头品质关系的研究

馒头是我国主要食品之一，消费量和面条相当，且南方的消费量还在逐年增长。21世纪以前，国内学者对制做馒头小麦粉品质的要求，馒头品质的评价方法，馒头品质与小麦品种籽粒品质的关系所能提供的研究资料十分有限。国外学者从70年代起就一直注意跟踪和研究这些问题。由于馒头的地域种类较多，不同人群对馒头的喜好不同，评价馒头品质指标的标准化程度不够，使不同结果之间有一定的差异，或完全相反。作者通过对小麦品种籽粒品质的分析，制作馒头面团发酵特性和油炸结果测定，馒头品质的评价认为：馒头对小麦粉品质的要求范围较大，从中筋到弱筋小麦品种都可以制作馒头；筋力愈高，面团的发酵时间愈长，馒头的弹性愈高；小麦品种小偃107制作的馒头色白，体积较大；小偃107的发酵面团在油炸过程中体积增加，有可能表现出吸油率低的特点。     

The House Mouse (Mus musculus L.) Exerts Strong Differential Grain Consumption Preferences among Hard Red and White Spring Wheat (Triticum aestivum L.) Varieties in a Single‐Elimination Tournament Design

Wheat (Triticum aestivum L.) plays a central role in the health and nutrition of humans. Yet, little is known about possible flavor differences among different varieties. We have developed a model system using the house mouse (Mus musculus L.) to determine feeding preferences as a prelude to extending results to human sensory analysis. Here, we examine the application of a single‐elimination tournament design to the analysis of consumption preferences of a set of hard red and hard white spring wheat varieties. A single‐elimination tournament design in this case pairs 2 wheat varieties and only 1 of the 2 is advanced to further tests. Preferred varieties were advanced until an overall “winner” was identified; conversely, less desirable varieties were advanced such that an overall “loser” was identified. Hollis and IDO702 were the winner and loser, respectively, for the hard red varieties, and Clear White 515 and WA8123 were the winner and loser, respectively, for the hard white varieties. When using the more powerful protocol of 14 mice and a 4?d trial, differences in mean daily consumption preferences of 2 varieties were separated at P‐values as small as 2 × 10^?8. The single‐elimination tournament design is an efficient means of identifying the most and least desirable varieties among a larger set of samples. One application for identifying the 2 extremes in preference within a group of varieties would be to use them as parents of a population to identify quantitative trait loci for preference.     

Effects of Processing on Wheat Tortilla Quality: Benefits of Hard White Wheat

Hard white wheat was established as a new wheat class by Grain Inspection, Packers and Stockyards Administra- tion in 1990. Originally supplying a domestic niche market, several states, Kansas in particular, have steadily increased production and investme…