增稠剂对面粉品质改良机理的研究

通过对增稠剂添加前后面团中蛋白质、淀粉性质、质构特性、微观结构等性质的比较,对增稠剂对面粉品质的改良机理进行研究.结果表明:海藻酸钠、瓜尔豆胶、CMC使得淀粉溶液的碘蓝值减小,淀粉的溶解度、静态提取的麦胶蛋白、酸溶性麦谷蛋白和粘着力都有不同程度的减小,淀粉的膨润力、面筋交联度、水饺皮的硬度、弹性、内聚力、凝胶性、咀嚼性和回复性增加;通过微观结构可以看出,增稠剂与蛋白质相互结合形成大分子基团,淀粉嵌于网络中间,形成坚实的整体结构.     

蛋白质对淀粉的影响及其复合体系应用研究进展

淀粉和蛋白质是食品体系中两种重要的组分,二者之间的相互作用对淀粉的结构、理化性质及淀粉基食品的质构特性和消化性能具有重要影响。近年来,关于外源蛋白质对混合体系中淀粉—蛋白质相互作用的影响及其应用研究成为食品领域的研究热点。文章综述了淀粉和蛋白质相互作用方式,蛋白质对淀粉理化性质(糊化特性、回生特性、流变学特性、热力学特性和质构特性)及淀粉—蛋白质混合体系微观结构的影响,总结了蛋白质对混合体系中淀粉体外消化性的调控作用及机制,综述了该体系在食品加工中的应用研究进展。     

绿豆蛋白对荞麦淀粉糊化和流变特性的影响

为探究蛋白质对淀粉性质的影响,以荞麦淀粉为原料,将不同比例的绿豆蛋白添加到荞麦淀粉中,应用快速黏度分析仪、流变仪、质构仪等研究绿豆蛋白对荞麦淀粉糊化特性、流变特性、质构特性及微观结构的影响。结果表明:绿豆蛋白提高了荞麦淀粉的糊化时间、糊化温度,并降低了峰值黏度、终值黏度、崩解值及回生值;不同比例的绿豆蛋白使荞麦淀粉糊的剪切应力不同程度降低,稠度系数K降低,体系仍为假塑性流体,其中荞麦淀粉与绿豆蛋白质量比为8∶2的复配体系剪切变稀现象更为明显;添加绿豆蛋白使荞麦淀粉的储能模量、损耗模量均降低,损耗角正切值升高,凝胶强度变弱;复配体系的硬度、胶黏性、咀嚼性均降低;通过扫描电镜观察可知,凝胶在微观上呈蜂巢状结构,且随着绿豆蛋白添加比例的增大,蜂巢孔隙变大,孔壁变薄。     

乳化剂与直链淀粉相互作用及其对蛋糕品质影响的研究

通过差示扫描量热分析仪(DSC)和蓝值测定几种乳化剂与淀粉的络合能力,并对其对蛋糕的品质和老化特性的影响进行研究,结果表明,与淀粉络合能力强的乳化剂生产出来的蛋糕的品质和抗老化性要比络合能力弱的乳化剂好.研究和探讨了乳化剂对浆料比重、蛋糕比容和蛋糕质构的影响,结果表明,乳化剂的加入使浆料比重降低,蛋糕比容增加,使得保存1d的蛋糕的硬度降低,弹性和咀嚼性提高,乳化剂对蛋糕的回复性也有一定的影响.     

海藻酸钠结合超低温冷冻处理对甘薯淀粉颗粒结构和性质的影响

为改善甘薯淀粉耐低温、耐热和抗剪切稳定性,通过测定甘薯淀粉颗粒的粒度分布、观察微观结构并测定结晶特性、热力学特性以及糊化特性,研究不同冷冻温度和添加海藻酸钠处理对甘薯淀粉颗粒尺寸、结晶结构、表面结构、糊化性质和热性质的影响.结果表明,冷冻温度由-20℃降至-80℃时,甘薯淀粉颗粒粒径减小,淀粉颗粒表面由数量少的大孔洞转...     

乳化剂-直链淀粉复合物的形成及其对蛋糕抗老化的影响

当乳化剂加入到含有淀粉的食品中进行蒸煮或烘焙时,淀粉和乳化剂可形成复合物,以起到改善产品品质、延长货架期的作用。文中通过差示扫描量热分析仪(DSC)和蓝值测定几种乳化剂与直链淀粉的络合能力,并就其对蛋糕的品质和老化特性的影响进行研究,结果表明:与淀粉络合能力强的乳化剂生产出来的蛋糕的品质和抗老化性要比络合能力弱的乳化剂好。研究和探讨了乳化剂对浆料比重、蛋糕比容和蛋糕质构的影响,结果表明:乳化剂的加入使浆料比重降低,蛋糕比容增加,硬度降低,回复性、弹性和咀嚼性提高。     

酶解处理对糯性玉米淀粉多层次结构特性及热性质的影响

以糯性玉米淀粉为原料,采用酶解处理,通过微滤膜过滤分离获得不同酶解时间处理的玉米淀粉颗粒,进而采用扫描电镜、X-射线衍射和差示扫描量热仪等测定分析了酶解处理前后糯性玉米淀粉颗粒不同层次结构改变和热性质变化。实验结果表明:酶解处理可引起糯性玉米淀粉颗粒微观结构改变,破坏结晶层和无定形层,改变淀粉颗粒生长环结构,降低结晶度,而且酶解过程显著可降低淀粉颗粒粒径。另外,酶解处理会显著改变糯性玉米淀粉颗粒的热性质,糊化熔点、峰值温度先增大然后降低,但是焓变值随酶解时间延长而持续降低。因此,通过控制酶解处理过程可有效改变淀粉颗粒微观结构层次及其热性质,可利用酶解处理开发不同用途的变性淀粉。     

不同大分子乳化剂构建番茄红素纳米乳液的体外消化规律比较

通过体外模拟消化,研究以辛烯基琥珀酸酯化（octenyl succinic anhydride,OSA）变性淀粉、乳清分离蛋白（whey protein isolate,WPI）、酪蛋白酸钠（sodium caseinate,SC）为乳化剂构建的番茄红素纳米乳液的消化规律。结果表明,消化过程中纳米乳液的液滴大小、Zeta电位和微观结构取决于乳化剂类型,OSA变性淀粉和蛋白质类乳化剂构建的纳米乳液分别在肠和胃阶段发生水解,液滴聚集,乳液平均粒径增大,同时Zeta电位绝对值达到最小。经胃肠消化后3 种乳化剂构建的番茄红素纳米乳液游离脂肪酸释放率的大小排序为OSA变性淀粉（92.25%）＞SC（86.53%）＞WPI（79.88%）,高于对照组的48.7%,表明纳米乳液包埋体系能有效改善番茄红素的消化特性,且以OSA变性淀粉构建的纳米乳液表现出比蛋白质类乳化剂更高的番茄红素生物利用率,达到（25.60±3.08）%。     

内源性物质对不同品种大米淀粉消化性的影响

近年来培育出了低高血糖生成指数（GI）大米品种,但是其产生低GI作用机理并不明确,内源性非淀粉物质作为大米关键成分,对不同GI大米淀粉消化率的影响值得探讨。本研究以典型的两种不同GI大米作为研究对象,探究了去除内源性非淀粉物质对大米淀粉体外消化性、理化性质和微观结构的影响。结果表明,对于低GI品种,蛋白质和膳食纤维的去除显著促进了淀粉消化,使最终消化率提升了7.37%~13.28%,但高GI品种的内源性非淀粉物质对于淀粉消化性的影响并不显著。在理化性质上,蛋白质和膳食纤维的去除将淀粉的膨胀力显著提升至17.83±0.30g/g~13.44±0.27g/g,显著改变了米粉的糊化特性和热力学特性,从而使其更容易糊化和消化。在微观结构上,去除蛋白质和膳食纤维使淀粉颗粒结构减小了3~8 μm,蛋白质、膳食纤维和淀粉的相互作用提高了米粉的有序度和聚集结构。     

臭氧氧化处理对非糯性玉米淀粉颗粒结构特性的影响

以非糯性玉米淀粉为原料,配制10%浓度的淀粉悬浮液,构建水-淀粉体系,采用臭氧发生器氧化处理,获得经处理的非糯性玉米淀粉颗粒,通过扫描电镜(SEM)、X射线衍射仪分别测定分析玉米淀粉颗粒形貌和结晶特性,探讨臭氧氧化处理对非糯性玉米淀粉颗粒微观结构特性的影响。结果表明,臭氧氧化处理可显著改变非糯性玉米淀粉颗粒微观结构特征,臭氧氧化处理可在颗粒表面形成孔洞,淀粉颗粒表面微孔数目和微孔大小与氧化时间直接相关,氧化时间越长,淀粉颗粒表面微孔越大,颗粒表面微孔数目越多;臭氧氧化处理不改变非糯性玉米淀粉颗粒结晶类型,但可显著降低淀粉颗粒结晶衍射峰强度,增强淀粉颗粒的结晶度。因此,通过控制臭氧氧化处理可改变淀粉颗粒微观结构特性和结晶强度。试验结果可为多孔淀粉的制备生产提供依据。     

谷朊粉和小麦淀粉添加量对重组面团冻藏品质的影响

面团的冷冻保存品质无法满足鲜湿面条工业化生产的要求。为了研究面团主要组分（面筋蛋白和淀粉）对面团冷冻品质的影响,以高筋小麦面粉（50%）、谷朊粉和小麦淀粉（不同比例）为原料进行面团重组,?18 ℃冻藏20 d分析其水分分布、流变特性、糊化特性、凝胶强度、微观结构以及氢键强度,以100%原小麦面粉作为对照组。结果表明,随着谷朊粉:小麦淀粉比例从4:1减小至1:4,冷冻重组面团中的水分分布逐渐由结合水向自由水迁移,弹性模量从125900 Pa降低至73020 Pa;样品的各项糊化参数增大,凝胶硬度也由114.30 g增大到181.39 g。扫描电镜观察发现,谷朊粉:小麦淀粉比例越低越不利于面筋蛋白网络结构的均匀性。添加了谷朊粉和小麦淀粉后,重组面团中的氢键强度均大于对照组,且随着谷朊粉:小麦淀粉比例的减小不断增大。当谷朊粉:小麦淀粉为4:1时,冻藏20 d的重组面团的弹性模量值比对照组高49.95%,有效延缓了面团在冻藏过程中的品质劣变。将淀粉与面筋蛋白进行面团重组可以提高面团的黏弹性,进而有利于其冷冻保存品质。     

氧化淀粉对小麦面团品质变化影响研究

通过对面筋强度、巯基和二硫键含量测定、面筋蛋白电泳观察分析及面团流变学特性变化,研究氧化淀粉对小麦面团品质特性影响。结果表明,氧化淀粉能增加面筋乳酸溶涨值和透光率,提高面筋强度;对面筋蛋白具有氧化作用,增加大分子麦谷蛋白亚基含量,对面团粉质特性影响不显著;但能改善面团拉伸性能,其中以羧基含量为0.27%至0.40%氧化度氧化淀粉对面团品质变化影响最为显著。     

Laboratory‐scale Dry/Wet‐Milling Process for the Extraction of Starch and Gluten from Wheat

A laboratory‐scale process is presented for the manufacture of starch and gluten from wheat. Main feature of this process is that whole wheat kernels are crushed dry between smooth rolls prior to wet disintegration in excess water in such way that gluten formation is prevented and fibres can be removed by sieving. Centrifugation of the endosperm suspension yields a dough which can be separated into starch and gluten using an established batter process. The results suggest that starch recovery is increased in comparison to a conventional wheat flour process without a concomitant decrease in protein recovery. Although starch purification was omitted, a total starch with a low protein content is obtained. On the other hand, the protein content of the gluten fraction is rather low due to difficulties in removing the starch. Despite this, the effect on dough mechanical properties by the addition of gluten obtained from wet‐milled wheat is comparable to the effect of gluten from flour.     

Influence of wheat starch on rheological,structural and physico-chemical properties gluten–starch dough during mixing

This study mainly explored that the influence of wheat starch source on the rheology behaviours and structural properties of gluten–starch dough, and then the model doughs were prepared by the AK58 wheat gluten and three types of starches from strong (ZM366S), medium (AK58S) and weak gluten wheat (ZM103S) during mixing were studied. The damaged starch content of wheat starch was positively correlated with the wheat gluten strength, while the granule size was negatively. The G', G" and the extension resistance of ZM366S dough were higher than those of other doughs, which implied the source of starch also had a significant influence on the rheological properties. CLSM also observed that ZM366S was more closely bound to the gluten protein network. The glutenin macropolymer (GMP) content of ZM366S model dough was the highest, while the SH content was the lowest. Decreases in elasticity, extension and GMP, and small increase in SH content were displayed during dough mixing. Molecular forces were varied with different wheat starch and mixing time. The covalent bond was the main force between ZM103S and gluten, whereas the hydrogen and covalent bonds were the main force between ZM366S or AK58S and gluten. The interactions between ZM366 starch and gluten were stronger than others starch.     

谷朊粉对糙米粉面团性质影响研究

研究了谷朊粉添加量对糙米粉面团性质的影响,主要包括粉质特性、热机械性质、流变学性质、微观结构等。结果表明:随着谷朊粉添加量增大,面团的吸水率、形成时间、稳定时间、淀粉衰减值和回生程度均在逐渐增长,蛋白弱化度在逐渐降低。糙米粉面团的弹性模量和粘性模量均在增大,且弹性模量大于粘性模量。扫描电镜结果显示:随着谷朊粉添加量增大,面团的网络结构越来越明显,淀粉颗粒镶嵌在蛋白形成的网络结构中,增加了面团的弹性及变形的阻力。     

面团组分及环境因素对面团二硫键形成的影响研究现状

面包、馒头、面条等面制品加工过程的本质是小麦面粉中蛋白与水相互作用形成包裹有淀粉和脂肪的面筋网络结构, 该结构加热后转变为形态固定的食品。面团中二硫键的形成量对面筋网络结构的质量和最终食品的品质起着决定性的作用, 而面团中的蛋白、淀粉等组分和环境因素影响面团中二硫键的形成量。本文综述了近年来面筋蛋白组成、淀粉组成及种类、面团pH、发酵以及面团成熟温度等环境因素对面团中二硫键形成的影响, 提出了未来这方面研究的可能探索方向及相关产业的可能发展趋势, 以期为研究人员和食品生产者分析面制品品质变化提供理论支持, 促进提高面团品质、面制品质量的二硫键调控理论的形成和创建。     

Incorporation of several additives into gluten free breads: Effect on dough properties and bread quality

The objective of this work was to assess the effect of emulsifiers, hydrocolloids and enzymes on gluten-free dough rheology and thermal properties and bread quality, while relating dough properties parameters to bread technological quality. Breads were based on rice flour, cassava starch and full-fat active soy flour, with 65% or 75% (flour-starch basis) of water incorporation. Additives used were emulsifiers (diacetyl tartaric acid ester of monoglycerides – DATEM and sodium stearoyl lactylate – SSL), enzymes (glucose oxidase and α-amylase) and hydrocolloids (xanthan gum, carboxymethylcellulose, alginate and carrageenan). Results showed that additive incorporation modified dough behavior, evidenced by different calorimetric and rheological properties. Besides, the electrophoretic pattern of dough extracted proteins changed with glucose oxidase addition. These modifications resulted in breads with different characteristics, such as specific volume, firmness and firming rate, and crumb structure. Nonetheless, they did not necessarily show better quality parameters than the control bread. The control dough displayed good performance for obtaining gluten-free breads of acceptable volume, crumb structure and, principally, with lower hardening rate during storage. Contrary to widespread opinion, this work shows that the presence of additives is not essential for gluten-free bread production. This fact provides new perspectives to the gluten free market at the moment of selecting raw materials and technological parameters, reducing production costs and facilitating gluten free products development.     

冷冻生坯面制品品质劣变及改良剂的研究进展

冷冻生坯在具有便捷、易于生产等优点的同时,也存在着内部结构发生劣变的可能。市场上常用的改良剂包括抗冻多糖、抗冻蛋白、亲水胶体、变性淀粉、酶制剂和乳化剂等。它们通过各自的作用方式来保护面筋蛋白不被破坏并提高酵母活性,从而抑制品质劣变,提高冷冻生坯的质地和感官。本文讨论了冷冻生坯品质劣变的几种可能的机制以及各种改良剂的作用机理和研究进展,总结了冷冻生坯的劣变机制与各种改良剂的作用方式之间的关系,以期为冷冻生坯面制品的工业发展提供参考。     

中性蛋白酶制剂在饼干中的应用

<正> 在饼干的生产中,如果面筋过强,最终的饼干质量便会出现各种问题,如脆性不好、外形和表面不均匀一致、色泽欠佳等。为了避免这些问题,可以采用低蛋白质含量的软质小麦为原料,使产品容易成型并印制出准确清晰的花纹。另一方面,在传统的工艺中则可以添加面筋柔软剂(还原剂),如常用的偏重亚硫酸钠(SMS),或蛋白酶如中性蛋白酶制剂。     

A composite model for wheat flour dough under large deformation

The mechanical behaviour of dough, gluten and starch were studied in an effort to investigate whether bread dough can be treated as a two phase (starch and gluten) composite material. Mechanical loading tests revealed rate dependent behaviour for both the starch and gluten constituents of dough. There is evidence from cryo-Scanning Electron Microscopy (SEM) that damage in the form of debonding between starch and gluten occurs when the sample is stretched. In addition, a reasonable agreement is seen between the Lodge material model and the compression test data only, indicating again that possibly ‘damage’ is essentially debonding which does not occur under compression, unlike tension and shear loading. A composite finite element model was developed using starch as filler and gluten as matrix. The interface between the starch and gluten was modelled as a cohesive contact interaction. When the interaction of starch and gluten is strong, as indicated for the dough with no damage, the stress-strain curve is always higher than the gluten stress-strain curve under both tension and shear loading. In contrast, when damage is activated in the form of debonding, the dough stress-strain curves under tension are seen to cross over the curves for gluten and therefore leading to lower stress values than in gluten. No damage/debonding occurs under compression when a damage function is used which is in good agreement with the experimental data.