测定小麦与面粉中灰分含量的作用

<正> 小麦粉的定等基础是加工精度,而加工精度是以粉色麸星来表示的。粉色就是小麦粉的颜色,麸星是指小麦粉中含有的粉状麸皮。一般粉色的深浅主要取决于麸星含量的多少,而麸星含量的多少又取决于加工精度。加工精度高,麸星含量少,粉色就较白。加工精度低,麸星含量多,粉色就较暗或偏低。又因为麸皮含有较高的灰分,在6.5％左右,因此,可以从测定成品粮的灰分含量来看加工精度和品质情况。小麦籽粒内所含矿物元素和无机盐,经灼烧后所得白色粉末称为灰分。灰分在小麦籽粒内的分布是极不均匀的,胚乳灰分含量     

制粉工艺中控制粉色麸星的关键点

为了解决小麦粉生产出现频率较高的粉色差、麸星多的问题,结合工作经验总结出了小麦粉生产工艺中控制粉色、麸星的关键点:原料、清理、工艺、添加剂.介绍了各个关键控制点的内容及注意事项.     

加工精度测定仪在面粉行业的应用

中国的面食消费与其它国家有很大不同,大多数面制品消费都是以蒸煮类为主,对面制品的色泽要求,白度高、麸星少,因此对面粉的加工精度要求自然也就高了。所以中国的小麦粉国家标准GB1355--1986中规定：小麦粉按照加工精度分为特一粉、特二粉、标准粉,执行和落实办法是与国家小麦粉实物标准样对比,检验粉色和麸星。也就是说,粉色越高、麸星越少的面粉加工精度就越高,面粉的价格也就越高。     

控制小麦粉粉色与麸星的技术探讨

为解决小麦制粉过程中出现较高频率的粉色差、麸星重等具体问题,结合生产实践,指出小麦制粉过程中粉色、麸星的关键控制点,提出在小麦选择、小麦清理、着水润麦、制粉工艺等环节控制小麦粉粉色与麸星的方法。     

小麦粉粉色与麸星检测方法研究

通过对133个不同加工精度的小麦粉样品数字图像特性进行分析研究,建立了小麦粉粉色与麸星的检测方法.对18个备选国家小麦粉加工精度实物标准样验证检测,结果表明：粉色测定值标准偏差为0.029%～0.113%,平均值0.070%,变异系数平均值0.09%,与F457兰光白度计测定值的偏差为-1.22%～＋0.96%,偏差绝对值平均0.36%;麸星测定值标准偏差为0.083%～0.327%,平均值0.071%,变异系数为1.81%～9.43%,平均为5.90%,与Branscan 2000 Mk2型麸星仪测定值显著相关,R=0.9910.     

制粉工艺中控制粉色麸星的关键点

为了解决小麦粉生产出现频率较高的粉色差、麸星多的问题，结合工作经验总结出了小麦粉生产工艺中控制粉色、麸星的关键点，介绍其内容及注意事项。第一控制点是原料状况，包括原粮的品种、储存时间、等级；第二控制点是清理。包括毛麦的清理、水分和润麦、入磨净麦状况；[第一段]     

小麦粉加工精度结果判定的探讨

以库存检查收集到的小麦制成的小麦粉为研究对象,统计分析小麦粉粉色、麸星对照实物标准样品的分等情况,进一步研究小麦粉等级判别、加工精度同粉色、出粉率的关系。结果表明:241份小麦的平均出粉率61.4%,最大值68.9%,最小值50.1%;平均白度值为76.9。出粉率与白度值不完全呈负相关关系,说明粉色与小麦品种有较大关系。     

小麦粉加工精度测定仪在实物标样研制中的应用

基于图像处理技术的小麦粉加工精度测定仪能够快速、客观、直接测定粉色、麸星,测定结果与感官检验一致,能够准确反映小麦粉的加工精度。在小麦粉加工精度实物标样的研制中,多年的应用表明该仪器是指导小麦粉生产,研究小麦粉品质的一种科学、方便的检测工具。     

小麦粉麸星的量化检测与分析

对制粉生产中不同制粉系统的42个小麦粉样品以及不同类型的实验磨磨制的20个小麦粉样品分别进行麸星及灰分含量测试.测试结果表明,麸星仪可以敏锐地感应出制粉生产线不同系统小麦粉中麸星含量及麸星斑点的细微变化,并通过数据和图像显示出来.不同制粉系统小麦粉的麸星含量与灰分含量呈正相关,其相关系数达0.8097,但不同实验磨粉机磨制的小麦粉样品,二者的相关系数变幅较大.麸星仪对白麦麦皮的感应相对较差.     

小麦粉麸星的量化检测与分析

对制粉生产中不同制粉系统的42个小麦粉样品以及不同类型的实验磨磨制的20个小麦粉样品分别进行麸星及灰分含量测试。测试结果表明。麸星仪可以敏锐地感应出制粉生产线不同系统小麦粉中麸星含量及麸星斑点的细微变化，并通过数据和图像显示出来。不同制粉系统小麦粉的麸星含量与灰分含量呈正相关，其相关系数达0．8097，但不同实验磨粉机磨制的小麦粉样品，二者的相关系数变幅较大。麸星仪对白麦麦皮的感应相对较差。     

面粉麸星的计算机检测

传统的面粉麸星检测都是靠人工感官方式，由于麸星的数量多而面积小，靠人工感官检测方式只能对麸星的多少进行定性分析难以给出具体数量。本文着重介绍以计算机模式识别方式精确计算面粉单位面积的麸星个数、单个麸星的面积大小、麸星的总面积、麸星的总面积占面粉单位面积的百分比等量化值。     

彩色小麦麸皮的营养分析

彩色小麦麸皮作为小麦加工的主要副产物未被深度利用,通过对彩色小麦与普通小麦麸皮粉的蛋白质含量、氨基酸组成、矿物质元素含量的比较,展现了彩色小麦麸皮独特的营养价值。通过设计合理的工艺条件提取彩色小麦麸皮的糊粉层粉作为具有特色食品的营养添加物具有非常好的市场前景。     

Image analysis for detecting insect fragments in semolina

Semolina is used for the manufacture of pasta (long goods and short goods) and couscous and any contrasting colored specks adversely affect the appearance of the finished product. The specks result from wheat bran, diseased wheat, ergot or weed seeds. However, there is also the possibility that insect fragments will appear as specks. Specks are currently mostly determined by a manual process or by a speck counter in milling units. We compared the speck counts from an electronic speck counter (SPX Maztech Micrco Vision), acid hydrolysis and flotation (AOAC method 993.26), and near-infrared (NIR) hyperspectral imaging in semolina seeded with insect fragments (50-300 fragments/50 g) of Tribolium castaneum (Coleoptera: Tenebrionidae). There was a significant positive correlation between the number of insect fragments added and detected by all three methods. These results underline the importance of controlling insects in flour mills producing semolina, and also in plants producing pasta and couscous, to reduce speck counts in the finished products.     

麦麸超微粉对面团特性及制品品质的影响

对超微粉碎麦麸粉面团的流变学特性进行研究,分别将超微粉碎麦麸(添加质量分数分别为0%、5%、10%、15%、20%)添加到面粉中并调制成面团,测定并记录其粉质特性和拉伸特性等。结果表明：麦麸超微粉的添加会使面粉的吸水率增大,面团形成时间、弱化度均有所增加,面团的稳定时间呈下降趋势;从粉质特性总体来看,超微麦麸粉的添加能改善面粉的粉质特性。在麦麸超微粉添加量在10% 时,麦麸超微粉馒头样品模糊综合评价结果为良好,其色泽、气味、组织结构、口感都可以被人接受。     

Determination of Deoxynivalenol in Wheat Bran and Whole-Wheat Flour by Fluorescence Polarization Immunoassay

A rapid and accurate fluorescence polarization (FP) immunoassay has been optimized for the determination of deoxynivalenol (DON) in wheat bran and whole-wheat flour. A preliminary treatment with activated charcoal was used to eliminate the strong matrix effect due to highly colored interfering compounds present in raw wheat bran extracts. In particular, matrix effect was removed by adding activated charcoal to the wheat bran extract (3.5 mg/mL) and mixing for 3 min of incubation time prior to the FP immunoassay analysis. No preliminary treatment was necessary for whole-wheat flour. Average recoveries from samples spiked with DON at levels of 500, 1,000, and 1,500 μg/kg were 95 % for wheat bran and 94 % for whole-wheat flour, with relative standard deviation generally lower than 13 %. Limits of quantification of the optimized FP immunoassay were 120 μg/kg for both matrices. The overall time of analysis was lower than 15 min for wheat bran and 10 min for whole-wheat flour. Good correlations (r?>?0.971) were observed between DON contents obtained by both FP immunoassay and high-performance liquid chromatography with immunoaffinity cleanup for 37 and 23 samples of naturally contaminated wheat bran and whole-wheat flour, respectively. These results show that the FP immunoassay is suitable for high-throughput screening as well as for quantitative determination of DON in wheat bran and whole-wheat flour.     

热处理对麦麸及全麦制品品质改善研究进展

热处理是常用的改善小麦麸皮品质的方法，适当热处理可显著改善麦麸的贮藏稳定性、营养品质和功能特性；麦麸经适当热处理后，所制得的全麦制品的营养品质和感官品质也得到了提升。本文首先概括了干热、湿热、过热蒸汽、微波、挤压、蒸汽爆破六种目前常用的用于麦麸改性的热处理方法，然后总结了麦麸经热处理后在酶活性、色泽、植酸盐含量、膳食纤维含量与组成、抗氧化能力等方面的变化，并对比并分析了热处理后全麦面条、全麦馒头、全麦面包及全麦饼干等全麦制品的质构、感官、营养等品质的变化，以期为麦麸及面全麦制品品质改善的更深入研究和应用提供参考。     

Effect of adding wheat bran and germ fractions on the chemical composition of high-fiber toast bread

The effect of the type of bran, level of addition, particle size and addition of wheat germ on the chemical composition of high-fiber toast bread was investigated. The bran and germ fractions were found to be high in ash, protein, fat and total dietary fiber contents. The wheat germ had a protein content of 27.88% compared with 11.35, 12.69 and 15.76% for white flour, whole wheat flour and red fine bran, respectively. The chemical composition of high-fiber breads, in terms of minerals, protein, fat and dietary fiber contents, was found to be far superior than that of the whole wheat flour (control) bread sample. Considering these results, it can be concluded that high-fiber toast bread, with lighter crumb color and improved sensory and nutritional qualities than the whole wheat flour bread, can be produced using white flour, and equal proportions of coarse and fine bran at 20%, germ at 7.5%, and sodium stearoyl-2-lactylate at 0.5% levels.     

麦麸对酥性饼干物理性质和淀粉消化性的影响

目的 研究麦麸对酥性饼干颜色、物理性质以及淀粉消化性的影响。方法 将麦麸按0～50%比例添加到面粉中制作饼干,测定混合粉的溶剂保持力,测定饼干颜色、延展度、硬度以及淀粉消化性。结果 添加麦麸导致混合粉的水和碳酸钠溶剂保持力值增加,乳酸溶剂保持力值和面筋性能指数降低(4.71%～33.20%和25.73%～34.11%),饼干颜色变暗。当麦麸添加量大于20%时,饼干的延展度和硬度增大(53.54%～64.31%和135.98%～408.53%)。此外,麦麸的添加在一定程度上降低了饼干淀粉消化性。麦麸添加量与饼干物理性质呈强正相关性,与消化终点葡萄糖含量呈负相关。通过主成分分析,提取了2个主成分,累计方差贡献率为85.3%。结论 适量添加麦麸有效改善了饼干酥脆性,并在一定程度上抑制了饼干淀粉的消化,增加了饼干的功能性质,可以为麦麸产品的进一步开发提供参考。