创新工艺与设备可行性论证（三）——撞击与研磨工艺效果对比分析

撞击与研磨的剥刮率、取粉率、灰分、面粉粗细度、面粉白度、破损淀粉含量和面筋质含量及品质等项工艺效果的对比分析结果是判断撞击磨粉机是否能用和好用及是否能取代辊式磨粉机的关键因素。理论分析和已有测试数据显示,与辊式磨粉机相比撞击磨粉机在多数项目对比上占明显优势。撞击磨粉机进一步大面积推广应用的前景广阔。     

创新工艺与设备可行性论证(三)——撞击与研磨工艺效果对比分析

撞击与研磨的剥刮率、取粉率、灰分、面粉粗细度、面粉白度、破损淀粉含量和面筋质含量及品质等项工艺效果的对比分析结果是判断撞击磨粉机是否能用和好用及是否能取代辊式磨粉机的关键因素。理论分析和已有测试数据显示,与辊式磨粉机相比撞击磨粉机在多数项目对比上占明显优势。撞击磨粉机进一步大面积推广应用的前景广阔。     

2007年小麦最低收购价格确定

2007年小麦的最低收购价以国标三等小麦为标准品，白麦每市斤0．72元，红麦、混合麦每市斤0．69元。白麦是指种皮为白色或黄白色的麦粒不低于90％的小麦（白硬麦角质率不低于70％，白软麦粉质率不低于70%）；红麦是指种皮为深红色或红褐色的麦粒不低于90％的小麦（红硬麦角质率不低于70％，红软麦粉质率不低于70％）；不符合以上要求的为混合麦。标准品的具体质量标准为：     

不同润麦水分对全麦粉及馒头品质的影响

以2种不同小麦为原料，采用直接粉碎法对小麦进行微粉碎处理至粒度为100～120目，研究不同润麦水分对全麦粉及馒头品质的影响。结果表明：随着润麦水分增加，2种小麦全麦粉的出粉率和白度值均增大，麸星个数和破损淀粉含量均降低，水分含量和降落数值均升高。全麦粉的峰值黏度、谷值黏度和最终黏度在润麦水分为16%时最大。随着润麦水分增加，全麦粉的吸水率均降低，平度中筋小麦全麦粉和加拿大西红春麦全麦粉分别在润麦水分为12%和16%时，稳定时间和粉质质量指数最高，弱化度最低。随着润麦水分增加，加拿大西红春麦全麦粉馒头的硬度、咀嚼性和胶着性均降低，馒头品质变好，平度中筋小麦全麦粉馒头则相反，2种全麦粉馒头的L*值均随着润麦水分的升高而增加，a*值和b*值均随着润麦水分的升高而降低，从而表明增加润麦水分对不同品种小麦全麦粉品质及全麦粉馒头品质的影响不同。     

不同润麦水分对面粉品质的影响

研究了不同润麦水分对面粉品质的影响。分别采用15%、16%、17%、18%、19%的润麦水分梯度处理小麦并研磨得到面粉,然后对面粉相关组分的物化指标进行测定。结果表明:随着润麦水分的增加,面粉的破损淀粉含量、湿面筋含量、干面筋含量、蛋白质含量均呈下降趋势;面筋指数、面粉白度、A淀粉得率呈上升趋势。面粉的糊化特性研究表明,随着润麦水分的增加,相同工艺处理的面粉的峰值黏度、谷值黏度以及破损值均呈先增后减的趋势,A淀粉的破损淀粉含量呈无规律变化。该研究为面粉生产提供了一定的理论基础。     

研磨与撞击对小麦加工在制品颗粒的粒度及相关品质的影响

通过磨粉机与撞击机对小麦加工在制品颗粒的粉碎实验,探索粉碎方式的改变对粉碎后颗粒的粒度、粒度分布状态以及相关品质的影响规律.实验表明:不同粉碎方式制得的小麦粉激光粒度曲线均呈现三峰形态,其峰值高度随被测颗粒的粒度而变化.随着被测颗粒粒度的减小,11～50 μm粒度区间的峰值明显增大.撞击粉碎比光辊研磨后颗粒的粒径稍粗一些,破损淀粉含量相对较低,但对麸屑的破碎作用较强,使用时应尽量减少入机物料的麸屑含量.对齿辊与光辊研磨后穿过同一筛网的物料进行粒度分析表明,齿辊研磨后大于50μm的颗粒体积百分比相对较高,平均粒径相对较粗,破损淀粉含量相对较低.     

小麦硬度影响制粉

绝大多数粉厂打算加工硬麦或加工软麦,很少数厂轮流交替加工硬、软两种小麦。指定用于既研磨极软又研磨极硬两种小麦的粉厂,在设计中总含有折中成分,这不但影响粉质而且影响产量,甚至两者都影响。用同一制粉机组研磨硬度范围很广的小麦,在世界上许多地区都认为不经济。杜仑麦通常在指定专门用于这种极硬小麦的机组上研磨,有例外但很少。 典型的硬麦（非杜仑麦）制粉机组可以研磨从中硬麦到硬麦,如美国硬红冬麦及硬红春麦。典型的软麦制粉机组可以加工从软麦到中硬麦,如美国软红冬麦、低蛋白硬红冬麦、硬白麦和西部白麦。 硬麦的胚乳需要有较大的挤压力才会破碎。反之,软麦的胚乳很容易用极少的挤压力破碎。但这个简单的解释留下许多难以回答的问题。谁来确定     

挤压膨化藜麦粉工艺优化及品质分析

为丰富藜麦产品多样性,开发即食型藜麦产品,采用挤压膨化工艺加工藜麦粉,通过响应面法确定最佳工艺参数,并对挤压膨化藜麦粉的营养成分、体外抗氧化活性与淀粉体外消化性进行了评价,同时研究了挤压膨化加工对藜麦粉品质的影响。结果表明:最佳挤压参数为水分含量16.61%,模口直径4.00 mm,挤压温度140.00℃,螺杆转速160.00 r/min,综合评分为88.17分。在此条件下,挤压膨化藜麦粉蛋白质含量为12.44 g/100 g DW(干重),含17种氨基酸,总脂肪含量为6.32 g/100 g DW,亚油酸、亚麻酸含量分别占总脂肪的55.38%、8.07%,含有较高的矿物质钙、铁和锌含量;总酚含量为2.45 mg GAE/g DW,总黄酮含量为0.29 mg CE/g DW,其DPPH自由基清除力、ABTS+自由基清除力和Fe3+还原力分别为2.80、3.34、8.45 μmol TE/g DW;淀粉消化性良好且体外血糖生成指数为84.69。经挤压膨化加工后,藜麦粉部分营养成分存在一定程度损失,总酚、总黄酮含量下降,抗氧化活性减弱,但淀粉体外消化性明显提高且产品食用体验更佳。     

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。     

有关小麦粉中破损淀粉值测定方法及影响因素的研究

采用SDmatic破损淀粉仪法和GB/T 9826—2008《粮油检验小麦粉破损淀粉测定α-淀粉酶法》对小麦粉中的破损淀粉值进行了测定,通过相关性分析可知,SDmatic法测定破损淀粉数据可靠性高,R2为0.937,且具有耗时短、人为误差小、试剂消耗少等优点。分析了小麦粉加工过程中,破损淀粉的影响因素,其中小麦品种为主要影响因素,角质粒小麦破损淀粉值高,粉质粒小麦破损淀粉值低;同一原料研磨,研磨产生的颗粒越细,破损淀粉值越高;灰分较低的前路心粉比中路粉破损淀粉值高,但又比灰分高、麸星重的后路基粉低。     

The rapid non-enzymic determination of damaged starch in flour

A rapid non-enzymic method for the measurement of damaged starch in wheat flour is described. The method is based on the iodometric determination of extractable amylose. A comparison with damaged starch values obtained using an enzymic method showed that the correlation between the non-enzymic and enzymic methods was better for flours milled from soft wheats than for flours milled from hard wheats. The relationship between starch damage values obtained by the two methods and flour particle size is examined, the results suggesting that the two methods differ in their sensitivity to the type of damage suffered by hard wheats during milling.     

制粉工艺对小麦粉粉质特性和糊化特性的影响

使用快速粘度分析仪(RVA)测定了采用脱皮制粉工艺和传统制粉工艺生产得到的小麦粉的糊化特性,并通过测定小麦粉的损伤淀粉含量等,考察了两种工艺条件下,小麦粉糊化特性和粉质特性间的关系。结果显示,脱皮工艺小麦粉的损伤淀粉含量减少,淀粉平均粒度大,而α-淀粉酶含量减少。制粉工艺对中筋的南阳白麦和高筋的8901特二粉的影响最为明显,脱皮工艺小麦粉的峰值粘度和最终粘度明显增加,而其他样品基本不变;同时,这两种样品的衰减度较大,而其他样品的衰减度则有所减小。脱皮制粉得到的所有样品的低谷粘度均高于采用传统工艺的同等小麦粉,但回生值较低。     

糯小麦粉配粉对小麦加工品质的影响(Ⅰ)对理化特性的影响

通过对2种糯小麦和3种非糯小麦理化特性进行比较研究,并利用其中1种糯小麦与非糯小麦配粉,研究其对配粉理化特性的影响。结果表明:糯小麦制粉过程中产生的破损淀粉含量更高,具有极高的吸水能力;在RVA糊化过程中具有较短的峰值时间,低的回生值和低谷黏度,以及较高的衰减值;在DSC测试中还表现出较高的热力学转变温度和糊化焓。糯小麦粉的添加对配粉理化特性的影响因基础粉的不同而有较大差异。配粉的RVA曲线表现为双峰,回生值显著降低;一定比例的添加能够提高峰值黏度低的基础粉的峰值黏度;添加糯小麦粉对弱筋小麦粉的筋力影响较小,其粉力甚至因为面团延伸性的改善而得到增强;对于筋力较强的小麦粉,超过15%的添加量则会使稳定时间降低,但是对粉力的影响不大;添加韧性和延伸性都较低的糯小麦粉,能够提高配粉的吹泡延伸性而不降低其韧性,其原因有待于进一步研究。     

Carbohydrate Digestibility and Resistant Starch of Steamed Bread

Sixteen Australian hard and soft wheats and two U.S. hard wheats were milled into flours (break and reduction) for preparation of steamed breads. Chemical composition and rheological properties of the flour were determined. Steamed breads were analyzed for carbohydrate digestibility and resistant starch. There was no relationship between flour type, protein content and specific volume of steamed breads. Carbohydrate digestibility of steamed breads from soft wheat flour was higher than that of breads from hard wheat flour. Reduction flours produced steamed breads with higher carbohydrate digestibility than break flours. Resistant starch was higher in steamed breads from soft wheat flours than in those from hard wheat flours. Reduction flour produced higher resistant starch levels than break flours. Commercial white bread had resistant starch levels similar to those of steamed breads from soft wheat flour and hard wheat reduction flour.     

调质对小麦粉粒度及组分的影响

调质是小麦研磨前不可缺少的工序之一,可有效改善制粉效果和小麦粉品质。本文通过改变调质水分（14.5%、15.5%、16.5%）、调质温度（25、35、45 ℃）及调质方式（真空调质、常规调质）,探究调质对小麦粉粒度及其组分的影响。结果表明,随着调质水分增加,小麦粉颗粒度先变细后变粗,出粉率、灰分、总蛋白、麦谷蛋白和破损淀粉呈降低趋势,L*与醇溶蛋白增大,总淀粉先降低后升高。提高调质温度后小麦粉颗粒度、总淀粉与支链淀粉逐渐增大,总蛋白、麦谷蛋白和破损淀粉逐渐减小。与常规调质相比,真空调质后小麦粉整体粒径较大,醇溶蛋白和破损淀粉含量较低,麦谷蛋白和支链淀粉含量较高。不同调质条件对小麦制粉品质有显著差异,在调质水分为15.5%、调质温度25 ℃时,小麦粉最细、出粉率较高、灰分较低,小麦制粉品质较好。     

Quality variations in flours used for pretzel manufacturing

Research on the flour properties and their influence on pretzel characteristics is scarce. In the first part of the study, flour protein quantity and quality, flour pasting properties and solvent retention properties of 108 flour samples were investigated to help profile the flour properties used by the pretzel industry. Four different flours with a wider protein range than what was revealed in the flour evaluation were selected to produce pretzels and to determine the relationship between flour properties and the final product quality. Pretzel hardness, colour and pasting properties were used as a measure of pretzel quality. Results indicated that hard wheat flour would produce a harder pretzel but would not affect the surface colour of final product. However, soft wheat flour with a lower damaged starch, low water absorption levels and lower water binding powers during operations is desired for making hard pretzel.     

Effect of the milling process on quality characteristics of rye flour

BACKGROUND: Most of rye flour is obtained by a gradual reduction system using roller flour mills, which generate different flour streams. The study of the different flour streams composition is necessary since it determines the flour quality and the flour uses. Four break streams and nine reduction streams were analysed for moisture, ash, starch, protein, damaged starch, falling number, amylose/amylopectin ratio, β‐glucans and colour. Mixing and pasting properties were also determined with a doughLAB and a Rapid Visco Analyser respectively. RESULTS: As the milling process advanced, moisture and starch content decreased but protein, ash, β‐glucans and damaged starch increased. The differences in composition are probably related to the effect of the roller mills and the increase in the contamination with bran. The absorption, development time, and pasting viscosity increased as the milling proceeded, in detriment of the peak time. The β‐glucan content was positively correlated to absorption, mixing tolerance index and pasting viscosity, and negatively correlated to peak time. CONCLUSION: Differences in composition, above all, in bran, showed different mixing and pasting properties in rye streams. The most different streams corresponded to the last streams in the break process, in the sizings and in the middlings. Copyright © 2008 Society of Chemical Industry     

Influence of damaged starch on cookie and bread-making quality

In this study two wheat and one triticale cultivars were milled in a disc mill to obtain different levels of damaged starch. The effects of the damaged starch content on physicochemical flour tests and cookie and bread-making quality were analyzed. The grain milling conditions in disc mill and grain hardness influenced the amount of damaged starch. The solvent absorption of flours, as measured by Solvent Retention Capacity Profile (SRC) and Alkaline Water Retention Capacity (AWRC), was significantly incremented by the damaged starch content. There was a consistent loss in cookie quality as the damaged starch content increased. In spite of the fact that the proteins were not affected by flour milling, bread quality decreased as the damaged starch content increased.     

Industrial Roller Milling Process Characterisation for Targeted Bread Quality Optimization

Out of all satisfying and palatable foods, wheat and other cereals play an essential role in human nutrition. In recent years, customers demand for functionalized flours with engineered properties contributing to well-being. This fuels the need for deeper understanding of the milling process and establishment of relationships between flour properties and product characteristics. To address this shortcoming, structural and functional aspects of starch and protein were investigated in all 33 flour passages obtained during the standard roller milling process of the most widely produced bread flour. Starch and protein alterations were examined on flour, dough and bread levels. Repeated milling cycles and higher impact towards tail-end passages result in compositional differences and increase in damaged starch. This creates weakened gluten networks exhibiting reduced elasticity and extensibility. Decreased viscoelasticity and hence gas-holding capacity result in low loaf volume. With multiple multivariate linear regression, a model could be established allowing for a 95% precise prediction of the loaf volume of the passages and composite flour produced with the same mill settings. This quality prediction of bread quality based on easily measurable parameters on flour levels offers a straightforward approach for a targeted optimization of the milling process.