富硒小麦籽粒中硒分布规律的研究

为了探索富硒小麦中硒的赋存形态及分布规律,采用原子吸收分光光度法分别测定小麦籽粒中各主要成分中硒的含量。结果表明,富硒小麦籽粒中硒主要以有机态存在,占总硒的83．34％;小麦籽粒中硒主要赋存形态为多糖和蛋白质结合硒,其中蛋白质结合硒占总硒的43．08％;在蛋白质结合硒中,谷蛋白中硒含量较高,占总硒的22．6％。     

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     

基于高光谱成像技术小麦籽粒霉变鉴别方法研究

小麦霉变籽粒是小麦不完善粒一种,鉴别小麦霉变粒是粮食霉变程度的重要参考。为了更精确地鉴别小麦霉变籽粒,本文利用高光谱成像技术采集不同品种小麦霉变籽粒及非霉变籽粒的光谱信息,建立小麦霉变籽粒的鉴别预测模型,实现小麦霉变籽粒快速、无损、有效、稳定的鉴别。首先收集了100粒霉变和100粒正常非霉变籽粒400-1000 nm范围的高光谱图谱,通过不同的光谱预处理方法进行处理,选出最优光谱信息预处理方法。接着,采用连续投影算法(SPA)和竞争性自适应重加权采样(CARS)提取特征波长,分别比较通过全波长范围和特征波长下建立的偏最小二乘判别分析(PLS-DA)和支持向量机(SVM)模型并进行比较。结果表明,淮麦22和宁麦13的最优预测模型分别为全波长-OSC-SVM和SPA-OSC-SVM模型,对应的R分别为0.9963和0.9998,RMSEP分别为0.0309和0.0064,R分别为0.9975和0.9995,RMSECV分别为0.0247和0.0111。     

小麦籽粒硬度特性及其研究进展

该文系统介绍软、硬小麦品质和加工特点,籽粒硬度测定方法及对小麦制粉影响;从生化 和遗传学角度,分析小麦硬度形成及变化机理。     

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。     

主要食品对小麦籽粒品质的要求

随着人民生活水平的提高和食品工业的发展,食品加工业除了改进加工工艺和设备以外,更加注重加工原料的质量标准和产品的稳定性,以及加工原料与其制作的食品的适应性。 一、面包对小麦籽粒品质的要求 以面包作为主要传统食品的欧洲、美洲、大洋洲的食品科学家已经对面包的品质分析与评价方法进行了长时间的研究,对面包品质与小麦籽粒的品质关系也了解得比较清楚,育种工作者已经基本掌握了制作面包的小麦品种的选育方法。一般认为:制作面包的小麦籽粒为硬质,淀粉酶活性适中,有较高的容重和蛋白质含量。     

小麦籽粒在制麦过程中碳水化合物降解趋势的研究

以小麦品种扬麦13和皖麦38为研究对象,以啤酒大麦为对照,通过微型制麦工艺(断水浸麦方式、降温式发芽、低温干燥绿麦芽),较为系统的分析了制麦过程中小麦籽粒淀粉降解的趋势,讨论小麦品种的制麦特性以及淀粉降解的机理.结果表明,制麦过程中淀粉含量和直链淀粉含量下降较为缓慢;还原糖的含量变化总体为上升趋势;β-葡聚糖含量下降速度较快,且在发芽结束后小麦样品的β-葡聚糖含量小于啤酒大麦;戊聚糖含量在发芽的前3天内呈下降趋势,但发芽第4天有较大程度的增长,发芽结束后小麦样品中的戊聚糖含量小于啤酒大麦;浸出物在发芽初期以较高速度增加,在发芽后期上升较为缓慢;黏度在制麦中变化幅度较小,呈逐渐下降趋势;通过电子扫描电镜观察淀粉颗粒在制麦过程中的变化发现,小麦麦芽的胚乳结构越来越疏松,在发芽前期只要是蛋白质和大颗粒淀粉的降解,在发芽后期小颗粒淀粉的降解速度较快.由结果可知,小麦和啤酒大麦在制麦过程中碳水化合物的变化有较大差异;小麦发芽结束后除β-葡聚糖含量、戊聚糖含量小于啤酒大麦,其他指标均高于啤酒大麦;β-葡聚糖和戊聚糖含量不是造成小麦麦芽汁具有较高黏度的主要原因.     

淮麦20号小麦籽粒压缩特性的研究

使用Brookfield质构仪对淮麦20号籽粒进行了各种压缩特性的试验,计算出淮麦20号籽粒的各项特性参数;通过研究含水率参数在压缩特性中的作用,得到其含水率与压缩破坏力的函数模型。结果表明:淮麦20号小麦籽粒的破坏力和含水率的函数关系为线性关系,破坏应变增大时,破坏能却减小。     

基于高光谱成像技术的小麦籽粒品种鉴别方法研究

为了更精确地鉴别小麦品种,实现小麦品种快速、无损、有效、稳定的鉴别.利用高光谱成像系统采集6个小麦品种籽粒光谱和图像信息,提取小麦籽粒胚、胚乳、胚和胚乳混合部位的光谱,采用不同的预处理方法对原始光谱进行处理,利用竞争性自适应重加权算法(CARS)和连续投影算法(SPA)提取特征波长,基于全波长和特征波长建立线性判别分析...     

浅谈小麦籽粒的结构与制粉工艺的关系

浅谈小麦籽粒的结构与制粉工艺的关系安徽农业大学食品系（２３００３６）周裔彬１前言小麦籽粒的结构，往往是制粉工艺设计者所易忽视的枝节，也是生产操作者所不重视的方面。本文就小麦的结构性质与制粉工艺的关系谈谈自已浅显的看法，以供同行参考。小麦籽粒的皮层含量...     

小麦粮堆中热量传递特性研究

采用人工加热的方法在小麦粮堆中形成明显的温度梯度,通过观察加热阶段和加热结束后粮堆内部的温度变化,探究小麦粮堆中热量传递特性。结果表明:加热过程整体粮温呈线性上升,距热源越近的位置温度上升速率越快,热量逐层传递,各层粮温变化成显著正相关,粮堆内部原"热皮冷芯"的现象被打破。全地板通风下不同横向距离处粮温变化不显著,不同纵向距离的粮温变化极显著(Ρ0.01),热量平均传递速率约为0.087m/h。停止加热后平均粮温基本保持不变,但粮堆内部热量从高温区向低温区扩散,热量传递速率由(0.1~0.16)m/d逐渐降至(0.02~0.04)m/d并保持稳定。整个过程中中上层及上层粮温出现先下降再上升的趋势,表现出一定的滞后性。表面粮层受外界环境影响较大,变化较剧烈,同时粮堆水分变化不大,水分在温度梯度和热应力的作用下有向上扩散和渗透的趋势,但传递速率远小于热量的传递。     

便携式近红外谷物分析仪快速测定小麦蛋白质的研究

收集中国小麦各个主产区不同品种样品104份,研究采用国产便携式近红外谷物分析仪快速测定小麦蛋白质含量,用化学计量方法建立了小麦蛋白质含量的近红外分析模型,并对模型进行了预测准确性评价。在建模过程中,分别探讨光谱散射和数学导数处理等优化对定标模型的影响。结果表明:采用偏最小二乘法(PLS)建立模型,光谱预处理最佳条件为:Savitzky-Golay平滑、Savitzky-Golay一阶导数、基线校正、均值中心化、主因子数为12。所建模型的定标标准偏差(SEC)和定标相关系数(RC)分别为0.177和0.988;外部验证的标准偏差(SEP)和相关系数(RP)分别为0.188和0.961。标准方法测定值与NIRS方法预测值之间的T检验结果为T=0.304(P<0.05),表明两种测定方法测定值之间无显著性差异,说明定标模型具有很好的预测准确性,可应用于优质小麦收购中蛋白质含量的快速测定。     

Discrimination of wheat grain varieties using image analysis: morphological features

This paper presents the results of a study on the discrimination of 11 wheat grain varieties in three successive years of cultivation and at the grain humidity of 12, 14 and 16%. Each grain was described with the use of 54 geometric variables which, after reduction of variables, left 20 for use in the main analysis. Variables calculated from linear dimensions had the greatest share in the group of discriminating variables, with shape-related indexes being of lesser importance. Seven methods of variables selection based on genetic algorithms (the Class Ranker and Class RankersSearch methods) were used in the study. The final discriminant analysis was performed with the use of stepwise progressive analysis and Meta MultiClass Classifier. The proposed statistical model classified varieties with 90–100% accuracy, depending on the experimental group. Grain images were acquired with a flat scanner, and grains were arranged with a specially designed matrix which enabled arranging 552 grains in rows and columns within several minutes; this makes the method usable in the cereal industry.     

Rheological parameters determination using Near Infrared technology in whole wheat grain

Rheological properties of dough are important for wheat quality characterisation. This research sought to obtain prediction models for rheological characteristics and to characterise the breadmaking quality of whole wheat using NIRS (Near Infrared Reflectance Spectroscopy) technology, in order to offer a rapid tool to the farmers to know the quality of their product at the harvest moment. Tenacity (P), extensibility (L), deformation energy (W) and ratio P/L of dough were measured using traditional methods. NIR spectra were acquired from these samples. Models to predict the values from these parameters were developed. The SEC achieved for the extensibility, deformation energy and tenacity of dough and the ratio between the two latter parameters were 5.27 mm, 9.97 × 10⁻⁴ J, 3.98 mm and 0.025, respectively. The four models were validated by cross-validation, and by independent validation. The precision obtained in these models was enough for being applied in harvesters or at delivering moment.     

Biochemical characteristics of trypsin inhibitor from wheat grain, beta variety

A homogenous trypsin inhibitor from wheat grain has been characterized. It is a protein of molecular weight 9105 Da and isoelectric point pI = 9.5. It belongs to arginine type inhibitors. The isolated inhibitor does neither inhibit native proteinases from wheat grain nor alpha-chymotrypsin, papein and pepsin. However, it inhibits some proteinases from microorganisms and moulds. It is susceptible to the action of hydrogen peroxide. The inhibitory protein consists of all amino acid residues with the largest amount of glutamic acid, proline and arginine, and the lowest of histidine and tyrosine, respectively.     

Associations between grain characteristics and alcohol yield among soft wheat varieties

Samples of ten winter wheat varieties, grown at four locations on the eastern side of the UK were assessed for alcohol yield. There was a strong negative association between alcohol yield and grain nitrogen content, but this was strongly influenced by differences between the sites, with a range of alcohol yields observed at given nitrogen levels. Inclusion of grain size parameters, thousand grain weight and grain length:width ratio, along with nitrogen, in a multiple regression, enabled more accurate prediction of alcohol yield for most of the varieties, indicating that grain size would be a useful parameter for selecting the best samples within varieties. A small‐scale measurement of hot water extract, along with grain nitrogen content, gave a reasonable prediction of alcohol yield, but the regression equation was not consistent across seasons. Starch content and turbidity (a measure of the ease of starch release) were both shown to be significantly influenced by variety, but not to give significant correlations with alcohol yield over a range of samples. Positive expression of these characters appeared, however, to contribute to improved alcohol yield in certain of the varieties. It was concluded that different genetic mechanisms influence alcohol yield and that improved breeding lines could be developed by combining positive alcohol yield attributes from complementary parents. Copyright © 2007 Society of Chemical Industry     

提高麦麸可食用性的研究

小麦麸皮是小麦制粉工艺流程的副产品 ,它的纤维含量及营养成分是人们希望从天然食品中得到的物质。本实验以麦麸纤维面包为例 ,研究提高麦麸可食用性的技术方法     

高效液相色谱法测定粮食中的脱氧雪腐镰刀菌烯醇

本文建立了一种使用岛津超高效液相色谱仪LC-30A快速测定粮食中脱氧雪腐镰刀菌烯醇的方法。玉米样品经磨碎后用水匀浆提取,提取液经过免疫亲和柱净化,超高效液相色谱LC-30A紫外检测器检测。试验结果表明：线性范围0.05~10.00μg/mL,相关系数大于0.999 9;标准样品的仪器检出限为0.016μg/mL,仪器定量限为0.05μg/mL;3个浓度标样的保留时间和峰面积相对标准偏差分别在0.041%~0.043%和0.11%~1.57%之间;玉米样品3个浓度加标回收率在81.2%~90.0%之间。该方法简便快速,且易操作。     

面粉中戊聚糖含量测定方法的探讨

对测定面粉中戊聚糖含量的地衣酚 -盐酸法进行了研究 ,得到如下结论 :面粉中存在的己糖干扰可通过双波长 (670、580 nm)下吸光度的差值消除 ;利用酵母发酵去除葡萄糖会带来更多干扰 ;对地衣酚 -盐酸法和间苯三酚法进行了比较 ,二者所得可溶性戊聚糖含量相似 ,但后种方法测得总戊聚糖含量略低。     

Immunochromatography for the rapid determination of cadmium concentrations in wheat grain and eggplant

BACKGROUND: A simple and quick on‐site test for trace levels of cadmium (Cd) in food is needed because of the human toxicity of this heavy metal. We developed an immunochromatography kit which uses the antigen‐antibody complex reaction between the Cd–ethylenediaminetetraacetic acid (Cd–EDTA) complex and an anti‐Cd–EDTA antibody. We previously reported the successful use of this kit to determine Cd concentrations in brown rice with respect to the international standard: 0.4 mg kg^?1. Here, we measured, using this immunochromatography kit, Cd concentrations in crops with lower international standards than rice. RESULTS: Cadmium extracted with 0.1 mol L^?1 HCl from wheat grain and fresh eggplant was purified sufficiently using an ion‐exchange column treatment. Appropriate HCl extraction rates and dilution rates for the column eluate were selected; Cd concentrations in wheat grain and fresh eggplant were determined successfully by immunochromatography with respect to the international standards of 0.2 mg kg^?1 and 0.05 mg kg^?1 fresh weight, respectively. CONCLUSION: Approximate Cd concentrations in wheat grain and fresh eggplant can be monitored easily and quickly by this method at locations where facilities for acid digestion and precision analysis are not available. Copyright © 2011 Society of Chemical Industry