小麦面筋吸水量检测的影响因素分析

面筋吸水量是判定小麦储存品质的重要指标,实际工作中受实验条件和检验人员操作技能的影响,容易出现实验误差较大的情况。通过对面筋吸水量影响因素的试验分析,研究探讨降低面筋吸水量检验误差的办法。     

太阳光照是怎样影响小麦品质的?

小麦籽粒的蛋白质含量与小麦抽穗到蜡熟期的日照时数的关系极为密切。经过多次反复试验研究证实 ,小麦要形成良好的品质 ,需要较强的太阳辐射。为了分析研究太阳光照对于小麦品质的影响程度 ,有人曾进行过如下试验 :采用人工降雨机对春小麦进行人工降水试验 ,白天因人工降水的细小水滴使进入作物群体的太阳辐射大大减弱 ,而夜间进行人工降水的春小麦由于白天受到较强的阳光照射 ,其蛋白质含量要比白天人工降水处理的明显多 ,面筋含量也多 ,其产量也增加。综上所述 ,太阳光照对小麦品质的影响主要是影响小麦蛋白质和面筋的含量以及影响到小麦…     

赤霉病粒对小麦真菌毒素及加工品质的影响

本文通过研究不同赤霉病粒含量对小麦真菌毒素及加工品质的影响,进一步了解小麦的食品卫生指标如呕吐毒素、玉米赤霉烯酮,加工品质指标如小麦粉湿面筋含量、面筋吸水率、降落数值等随赤霉病粒含量的变化规律,为指导小麦收购、储藏及加工提供理论依据。结果表明,随着赤霉病粒含量的增加,小麦的加工品质特性均发生劣变,同时呕吐毒素和玉米赤霉烯酮含量明显增加。     

关于小麦面筋吸水量检验过程中有关问题的探讨

根据GB／T20571-2006《小麦储存品质判定规则》的规定，小麦储存品质控制指标包括色泽、气味、面筋吸水量和品尝评分值三项，并根据上述三项检验结果将储存小麦划分为宜存、轻度不宜存和重度不宜存。由此可以看出，面筋吸水量是判定小麦是否宜存的一项重要品质指标。它的变化速度反映了小麦随着储存时间的延长，其食用品质下降的情况。因此，测定和研究小麦的面筋含量和面筋吸水量，对小麦储存品质和小麦粉质量具有重要的意义。     

浅谈人为因素对小麦面筋吸水量测定的影响

小麦面筋吸水量,是判断小麦储藏品质的重要指标,实际检测中发现人为因素对检测结果影响很大,本试验通过不同人对同一样品进行检测,分析人为因素对检测结果的影响.     

小麦化学组成与馒头品质之间的关系

小麦粉是生产馒头的主要原料，小麦品质对馒头质量有很大影响，尤其是小麦面筋蛋白对馒头制作起着决定性的作用。适于做优质馒头的小麦蛋白质合量在12％一13％，湿面筋含量在30％—33％以上，面筋强度中等；支链淀粉／直接淀粉比值高的面粉可蒸制优质馒头。     

面筋吸水量实验误差可控范围的探讨

面筋吸水量是判定小麦储存品质的重要指标,研究采用标准方法对新收获的3个等级的小麦进行面筋吸水量的测定和分析。结果表明:通过控制湿面筋和干面筋测定偏差,可将面筋吸水量双实验误差控制在5%左右。     

面筋蛋白对馒头加工品质影响的研究进展

本文介绍了小麦蛋白中面筋蛋白——醇溶蛋白和谷蛋白的研究现状,重点综述了这两种蛋白及其比例对馒头加工品质的影响,旨在探析面筋蛋白对馒头加工品质的影响机理,为更好地提高馒头加工品质提供理论基础。     

不同储藏方式对小麦品质的影响

研究了在实仓储藏条件下,充氮气调、准低温、常规储藏3种储藏方式对小麦储藏品质的影响。检测指标包含水分、发芽率、降落数值、干面筋含量和湿面筋含量等,检测方法采用国家标准检测法。结果表明:随着储藏时间的延长,小麦的品质都发生了不同程度的劣变,充氮气调储藏和准低温储藏各项指标的变化较常规储藏慢,能更好地保持粮食品质。     

优质强筋小麦高产栽培技术

优质强筋小麦(即面包、面条小麦)的栽培技术要求在保证强筋小麦品质物性的基础上,提高产量和效益,达到高产优质高效的目的。强筋小麦的栽培技术对品质的要求是保证小麦籽粒蛋白质含量高,温面筋含量高,面团稳定时间长,容量高,出粉率高等等,每一项栽培技术措施都应该围绕达到上述品质指标和高产高效的要求来制定。1选用优质高效的小麦良种:小麦的品质性和产量特性是其遗传基因决定的,栽培措施对它的影响处于第二位,当然也是很重要的。要生产高质量的强筋小麦,首先要选用优质高产的强筋小麦品种。近几年来,我国主要产麦省已选育出一批优良强筋…     

不同试验磨对小麦制粉品质和小麦粉品质特性的影响

对目前我国常用的15台由5个不同厂家生产的试验磨所制得的小麦粉品质状况进行了初步研究。结果表明:不同性能试验磨制粉对小麦的制粉品质和面团流变学特性都会产生一定的影响,尤其是对破损淀粉和小麦粉颗粒度以及表征面团筋力强弱的粉质稳定性参数和吹泡特征参数的影响较大;破损淀粉含量与粉质吸水率和稳定性都有极显著的正相关关系,与馒头品质评分相关性显著,有可能成为小麦试验制粉品质的评价指标之一,用于对试验制粉操作进行评定,但是具体评价方法尚需要深入研究。     

基于文献计量法的强筋小麦研究现状分析

近些年随着强筋小麦在国民生活中的作用不断凸显,国家对强筋小麦的发展越来越重视。为了解我国强筋小麦研究现状并促进我国强筋小麦研究的进一步发展,本文以中国知网(CNKI)作为数据源,选取"强筋小麦"为检索词进行检索,采用文献计量法对强筋小麦相关文献的年份分布、作者、关键词、基金来源、载文期刊进行统计分析,结果表明近十年是我国强筋小麦研究的主要时期,研究多集中在强筋小麦的品质和产量两个方面。     

A Note on the Market Valuation of Grain Quality Characteristics

The issue addressed in this paper is whether the grain quality factors used by the Federal Grain Inspection Service in determining the quality grades of wheat exported by the United States including test weight, dockage, moisture content, percentage of foreign material, percentage of shrunken and broken kernels, and protein content are characteristics that influence the price of wheat for export. Using shiplot data on the transactions price for hard red winter wheat, hard red spring wheat, and soft white wheat and the associated quality characteristics covering the period January 1990 through October 1991 and exported to 63 countries, the results suggest that only the test weight and the protein content are characteristics consistently valued by the market.     

黄淮海平原农业结构的系统分析及其优化展望

黄淮海平原为我国重要的农产品生产基地和最大的农产品消费市场。该平原为我国小麦、玉米、棉花、油料以及肉牛、肉羊优势产区。文中应用主成分分析、区位熵、灰色关联分析等方法剖析了该平原经济综合实力在全国的地位与农业结构的特点,指出了农业结构优化的方向,提出了大力发展强筋小麦、专用玉米、优质棉花等对策。     

Is Wheat a Homogeneous Product?

A hedonic approach is used to test for two kinds of product differentiation for wheat. It is shown that wheat is differentiated by end use and by country of origin. This simply recognizes the fact that buyers purchasing wheat for different purposes put different weights on quality criteria and that country-specific factors such as weather as well as grading and inspection systems matter. The results suggest that between 1980 and 1988, wheat protein content had a significant influence on price. This influence varies over time and across wheat categories.     

Identifying Strategies to Mitigate Handling Risks in the Canadian Grain Supply Chain

The introduction of new generation agricultural products has generated an increased need for efficient and accurate product segregation across a number of Canadian agricultural sectors. As a key component of wheat handling in the Canadian grain industry, grading of wheat for value‐added blending has historically been accomplished by visual identification. As of 2008 in Canada, visual identification was eliminated for all primary classes of wheat and replaced by an alternative system of wheat declaration. Given the high costs of testing each truck and railcar for quality assurance, the declaration system must rely on incentives and trust as there is now considerable potential for accidental or opportunistic misrepresentation throughout the grain supply chain. This research attempts to identify cost‐effective handling strategies and policies so as to maintain the integrity of the supply chain under the new declaration system. An agent‐based simulation model is developed to capture the effects of individual heterogeneity as well as behavioral adaption to the declaration system within the modern wheat supply chain. The simulated results are used to identify superior testing strategies for handlers, along with the relative risks and costs associated with each of the testing strategies.     

Protein and the demand for hard wheats*

Wheat protein is one of the most important specifications used in domestic and import purchase contracts and is used partly as a proxy for functional quality. The purpose of this article is to analyse the demand for wheat delineated by protein class. A choice‐based econometric model is specified and estimated using a novel dataset of pooled wheat shipments to individual importing countries. Buyers are importing countries that make purchase decisions among different protein levels. The model frames the choice in terms of attributes of the choice and of the importing countries. Results indicate that there have been shifts over time, and purchase probabilities are highly price elastic and vary across importing regions. Functional characteristics including wet gluten content and extraction rates have significant impacts on purchase probabilities. These results have implications for breeders as it clearly illustrates the role of protein and functional characteristics on demand. The results also have implications for analysts modelling wheat trade in that there are many factors impacting market segments that would not be captured in conventional demand specifications.     

小麦中脱氧雪腐镰刀菌烯醇残留检测研究进展

由镰刀菌引起的小麦赤霉病是中国最主要的小麦病害之一,能造成小麦严重减产,品质下降,而且镰刀菌还能产生多种真菌毒素,进一步危害小麦及其制品的质量安全。其中,脱氧雪腐镰刀菌烯醇是小麦中检出率最高、危害最严重的真菌毒素之一,严重威胁着人类和动物健康。文章综述了近年来应用于小麦中脱氧雪腐镰刀菌烯醇残留检测的主要方法的研究进展,包括薄层色谱法、免疫化学分析方法、色谱法和色谱质谱联用法等,并展望其发展趋势,以期为小麦中脱氧雪腐镰刀菌烯醇的残留检测提供参考。     

基于ACRM模型不同时期冬小麦LAI和叶绿素反演研究

通过冬小麦4个生育期不同长势冠层光谱观测数据,模拟HJ小卫星多光谱等效反射率;然后使用双层冠层反射率模型(ACRM)反演各生育期冬小麦LAI和叶绿素含量,分析HJ小卫星多光谱数据定量反演LAI和叶绿素含量的应用潜力以及ACRM模型在不同冬小麦生育期的LAI和叶绿素含量反演误差。将模型反演值与实测值对比分析发现:(1)LAI和叶绿素含量反演值与地面实测值有很高的相关性,应用HJ小卫星多光谱数据定量反演LAI和叶绿素有很大的应用潜力;(2)ACRM模型在不同生育期的冬小麦LAI和叶绿素含量反演误差存在差异。     

Residual demand measures of market power of Russian wheat exporters

Traditionally, the international wheat market has been considered a good example of a market with perfect competition. Yet, several articles provide evidence of imperfect competition and price discrimination in the wheat trade. However, these studies focused on traditional high‐quality wheat exporters such as Canada and the United States. In contrast, this article investigates whether Russian wheat exporters exercise market power in eight selected importing countries using the residual demand elasticity (RDE) model. The article makes two major contributions. First, it focuses on a nontraditional exporter, who exports mainly wheat of mediocre quality to low‐ and middle‐income countries. Second, the RDE model is estimated for the first time using a nonlinear estimator, the instrumental variable Poisson pseudo‐maximum likelihood estimator. This is important because the double logarithmic functional form can provide biased results in the presence of heteroskedasticity. The results indicate that Russian wheat exporters can exercise market power in only a few markets, while they are price takers in the majority of importing countries.