乳酸调控玉米醇溶蛋白基面团流变特性和微观结构的研究

改善无麸质谷物食品品质一直是科学家关注的热点。本研究以玉米醇溶蛋白、玉米淀粉、沙蒿胶为原料,制备玉米醇溶蛋白基无麸质面团。采用两种乳酸引入方式,通过调节面团中乳酸和玉米醇溶蛋白的比例（L/Z比）,探究乳酸对玉米醇溶蛋白基无麸质面团的流变性质和面团中玉米醇溶蛋白微观结构的影响规律。结果表明:面团中L/Z比的增加,会导致乳酸添加组（T面团）和乳酸预处理玉米醇溶蛋白组面团（C面团）的储能模量（G′）下降,损耗系数（tanδ）逐渐上升。乳酸引入方式的不同,会导致面团的流变性能存在差异。当L/Z比一定时,T面团的G′低于C面团,tanδ高于C面团。随面团中L/Z比增加,T面团的拉伸性能呈先上升后下降趋势,当L/Z比从0:10增加到2:10时（T0~T2）,T面团的拉伸性逐渐提高,面团中玉米醇溶蛋白团块状聚集减少,逐渐联结成网;T2拉伸性能最佳,面团中玉米醇溶蛋白网络质地均一,具备应用潜力;T3~T5时,面团的拉伸性逐渐下降,面团中玉米醇溶蛋白网络变弱,对淀粉颗粒包裹水平下降。C面团拉伸性较差,无法有效进行相关实验,可能与面团中未能构建起结实而连贯的蛋白质网络有关。     

揉混时间对酸化面团中玉米醇溶蛋白的影响

以玉米醇溶蛋白（zein）、玉米淀粉、沙蒿胶为原料,制备了zein基无麸质模拟面团（Z面团）。基于粉质检测,比较了不同乳酸含量的zein模拟面团在揉混成型时（扭矩达1.1Nm;设为ZS面团）与揉混12 min时（设为ZL面团）面团的揉混扭矩、水分组成情况,以及蛋白分布状态;研究耐揉混面团的最佳乳酸添加量,通过一定时长揉混作用下,不同乳酸含量的面团中zein理化性质,讨论了经长时间揉混面团逐渐弱化的原因,为zein模拟面团的加工、相关谷物制品的制备提供参考。结果表明,添加少量乳酸能促使zein在面团中构建起蛋白质网络,但长时间的揉混会导致酸化面团强度下降,破坏面团中zein网络连贯性,降低zein对淀粉颗粒包裹水平,面团中弱结合水占比下降、游离水占比增加,zein发生脱酰胺反应、表面疏水性上升、相对分子质量下降。面团经长时间的揉混逐渐弱化,是因为揉混作用会扩大乳酸对面团中zein的作用效果,促使蛋白质表面疏水性增加、蛋白质碎片化,进而导致zein网络连贯性下降。     

四种亲水胶体对小麦淀粉、面筋蛋白特性及面条品质的影响

以4种亲水胶体蜡制马铃薯原淀粉、羟丙基淀粉、羟丙基磷酸酯二淀粉、沙蒿胶为研究对象,按不同比例添加到面粉中,采用mixolab混合实验仪分析面团特性,并制作面条进行感官评价。结果表明1%沙蒿胶,3%或7%的羟丙基淀粉的面团和面条品质较好,复配使用沙蒿胶和羟丙基淀粉添加量分别为1%和5%、1.25%和7%的面团和面条品质较好。     

响应面优化无麸质大米面包复合改良剂配方的研究

针对无麸质大米面包制作时存在的成型难,品质差等问题,研究了沙蒿胶、单甘酯、羟丙基淀粉、乳清蛋白等改良剂对无麸质大米面包品质的影响,并在单因素实验的基础上,以面包的比容为响应值,选用响应面分析法优化其复合改良剂的配方。结果显示,沙蒿胶、单甘脂、羟丙基淀粉、乳清蛋白对无麸质大米面包的质构、比容及感官均有改善作用。最终确定无麸质大米面包复合改良剂的最佳配方为:沙蒿胶0.4%、单甘酯1.5%、羟丙基淀粉3.2%、乳清蛋白8.7%。在此配方下,无麸质大米面包的感官评分为88,比容为3.54,硬度为4.675 N,弹性为86.710 mm。     

玉米醇溶蛋白的提取、功能特性及其应用研究

研究玉米醇溶蛋白的提取、功能特性及其在面条品质改良中的应用。通过正交试验确定最优提取条件为乙醇浓度70%、超声波处理时间120 min、料液比1∶12、pH11,玉米醇溶蛋白的提取率为86.6%。研究玉米醇溶蛋白功能特性,结果表明,玉米醇溶蛋白的持水性优于谷朊粉,乳化性和乳化稳定性略好于谷朊粉。将玉米醇溶蛋白按一定比例添加到面条中,利用质构仪进行拉伸试验,结果表明,添加玉米醇溶蛋白的面条拉伸长度和破断功均比空白组有所提高,面条的延展性和咀嚼性得到改善。玉米醇溶蛋白可以提高面条的弹性和咀嚼性,总评分较高。玉米醇溶蛋白作为新型天然小麦粉品质改良剂是可行的。     

工艺条件对沙蒿面条感官品质的影响

主要探讨了加工工艺条件对沙蒿面条感官品质的影响,分析了不同添加量的沙蒿粉对面团流变学特性、色泽、表观状态、熟断条率、韧性、粘弹性、光滑性、口味等感官品质的影响,通过单因素实验探讨了加工工艺条件对沙蒿面条感官品质的影响.结果表明,在沙蒿粉添加量6%,和面加水量42%,和面水温40℃,和面时问10min,熟化时间8min.蒸煮时间5min的条件下,显著改善了沙蒿面条的流变学特性及面条的韧性和粘弹性,大大降低了熟断条率,沙蒿面条光滑爽口,具有特殊的沙蒿风味.     

沙蒿籽胶对玉米混合粉流变特性和面条品质的影响

以玉米粉与小麦粉(6∶4)的混合粉为原料,研究了添加沙蒿籽胶的玉米混合粉的流变特性和面条加工品质的变化。结果表明,添加沙蒿籽胶能改善玉米混合粉的粉质,使面团具有良好的流变特性,并能显著增加面团的粘弹性,从而使面条的粘弹性增强、断条率降低、糊汤程度减小,面条口感滑润耐咀嚼。     

1BL/1RS易位小麦面筋蛋白的分离重组及其面条品质研究（网络首发、推荐阅读）

利用聚丙烯酰胺凝胶电泳（SDS-PAGE）、酸性聚丙烯酰胺凝胶电泳（A-PAGE）技术鉴定分析两种优质面条小麦粉的高分子量麦谷蛋白亚基（HMW-GS）的组成及醇溶蛋白1BL/1RS易位情况,再通过分离重组法,将小麦中醇溶蛋白与麦谷蛋白分离提取,然后按比例重新配粉,制作面条,对重组面条进行蒸煮品质及质构特性分析,找出醇溶蛋白和麦谷蛋白与面条品质之间的影响规律。结果表明,当蛋白含量一定时,重组面条的吸水率与（谷∶醇）呈显著负相关（P<0.05）;干物质损失率与（谷∶醇）无显著相关性;重组面条硬度、坚实度、拉伸力等均与（谷∶醇）呈显著正相关（P<0.05）;粘度与（谷∶醇）呈显著负相关（P<0.05）。同时发现,在两种优质面条小麦粉高分子量麦谷蛋白和麦醇溶蛋白性质相同的情况下,只有低分子量麦谷蛋白组成与沉淀值有较明显的差异,但重组后的面条性质基本接近,因此发现高分子量麦谷蛋白对面条质量影响较大。     

超声辅助面团醒发对面条品质的影响

面团醒发对面条的品质具有重要影响,本实验将功率超声引入面团的醒发过程,以期提高面条品质。利用质构仪和综合加权评分法对所制备的面条品质进行分析,考察超声功率密度、超声作用时间、面胚厚度和醒发温度等因素的影响。结果发现：在超声功率密度为25.55 W/L时,相对空白组（常规醒发）,面条的弹性显著增加15.9%,硬度则显著降低7.8%,面条的蒸煮特性也有一定程度的提高;当超声功率密度25.55 W/L、超声作用时间30 min、面胚厚度6 mm、醒发温度30 ℃时,面条的综合加权评分最高;扫描电子显微镜观察结果显示,当超声功率密度超过25.55 W/L时,小麦淀粉颗粒表面出现明显的孔洞和剥落现象。总体看来,超声辅助面团醒发工艺是可行的,超声能够提高面条的质构特性和蒸煮特性,改善面条的品质。     

黍子粉对小麦面团流变特性和面条品质的影响

为探究黍子粉对小麦面团粉质特性、黏弹特性和面条品质的影响以及面团流变学特性与面条品质之间的相关性分析。在小麦粉中添加0%、10%、20%、30%、40%比例的黍子粉,测定不同黍子粉添加量面团的流变学特性和面条的蒸煮特性、质构特性。结果表明:面团的弱化度、弹性模量和黏性模量,面条的断条率和蒸煮损失率随着黍子粉添加量的增加呈上升趋势;而面团的吸水率、稳定时间和形成时间,面条的粘聚性、回复性、拉伸力和拉伸距离则呈下降趋势。当黍子粉添加量为20%时,面条的硬度、胶着度、咀嚼性分别为777.8 g、637.7、588.06,与其他黍子粉添加量相比均达到最优。黍子小麦混合粉面团的弹性模量、黏性模量和弱化度与面条的拉伸力、拉伸距离等呈负相关,证明了黍子粉在面条品质定向改变方面的应用潜力。     

Zein molecules in aqueous acetic acid solution: Self-assembling behaviors and formation mechanism of gluten-free doughs

The assembly behavior of biopolymers is affected by the type of solvent used. Previous investigations have focused on the self-assembly of zein molecules in aqueous ethanol. In this study, the self-assembly behavior of zein molecules in aqueous acetic acid solutions and their application in the development of zein-based gluten-free doughs was investigated. Zein molecules in low concentrations of acetic acid (30%–60%, v/v) assembled into irregular entities, in medium concentrations (70%, v/v) there was intermediate transition, and at high concentrations (80%–100%, v/v) they formed regular spheres. Interestingly, protein fibril formation was found to occur in 50% zein solutions in 50% and 60% acetic acid, as self-standing gels with solid-like properties resulted and the findings were verified using rheology. The 50% zein solutions in 70% acetic acid could form viscoelastic masses after anti-precipitation with the addition of excess water. Gluten-free dough with wheat-like properties was obtained by mixing the viscoelastic zein masses with wheat starch at room temperature. SEM observations showed that the formation mechanism for zein-based doughs involves the dispersion of starch granules in a three-dimensional zein network. These results will help to improve our understanding of zein assembly behavior regulation, and provide technical support for the development of zein in gluten-free food products.     

Effect of dry- and wet-milled rice flours on the quality attributes of gluten-free dough and noodles

The rheological and cooking properties of gluten-free noodles prepared with dry- and wet-milled rice flours were characterized. Dry-milled rice flour with a higher degree of starch damage exhibited greater water hydration properties than wet-milled rice flour at room temperature. However, the pasting results of rice flour suspensions demonstrated that wet-milled rice flour showed a higher value of peak viscosity due to its great swelling power upon starch gelatinization. The similar thermo-mechanical tendency was observed in a rice dough system by Mixolab. In the planar extensional test, the noodle dough sample prepared with dry-milled rice flour exhibited higher elongational viscosity which could be favorably correlated to more resistance of dry-milled rice noodle strands to extension. When rice noodles were cooked, increased cooking loss was observed in dry-milled rice noodles which was attributed to great water solubility derived from a higher degree of starch damage.     

Starch-based noodles: Current technologies,properties, and challenges

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.     

转谷氨酰胺酶对玉米面团加工特性的影响

考察不同转谷氨酰胺酶(TGase)添加量对玉米面团(玉米粉添加量质量分数为30%)的流变特性、微观结构、保水力和质构性质的影响,并对所制面条的烹调损失率进行分析。结果表明,当酶的添加量为50~150 U/g面粉时,玉米面团的弹性模量和黏性模量显著增加;保水力增加了32.6%~46.4%;质构分析结果表明,玉米鲜湿面条的硬度、弹性和咀嚼性显著增加,咀嚼性增加了1.56~6.11倍。扫描电镜分析结果表明,玉米面团的微观结构发生了变化,表现为蛋白质发生了交联的同时,淀粉的分布状态也发生了改变。蒸煮得率从194%提高到206%。可以看出,添加TGase有利于改善玉米面团及所制面条的品质。     

Utilization of Lentinus edodes mushroom β-glucan to enhance the functional properties of gluten-free rice noodles

β-Glucan-rich fractions (BGRFs) were prepared from Lentinus edodes mushrooms and utilized to improve the functional properties of gluten-free extruded rice noodles. The mixture of rice flour and BGRFs in a slurry exhibited increased water absorption index and swelling power at room temperature. However, the water hydration properties were significantly reduced with increasing levels of BGRFs upon starch gelatinization, consequently reducing the pasting parameters of rice flour. On the other hand, the incorporation of BGRFs into a rice dough system caused a distinct increase in the thermo-mechanical Mixolab properties of rice flour, probably contributing to the formation of a rigid dough structure. It could be closely correlated with the enhanced extensibility and firmness of BGRF-incorporated rice noodles. Moreover, BGRFs played a positive role in improving the cooking qualities of rice noodles by significantly reducing their swelling index and cooking loss.     

超微粉碎对苦荞面条品质特性的影响

为提高苦荞麦的利用价值和苦荞面条的食用品质,利用超微粉碎技术制备超微苦荞麦粉,考察超微粉碎和超微粉粒径对苦荞麦粉的粉质特性及其面条品质特性的影响。结果表明,随着粒径的减小,苦荞麦粉的破损淀粉质量分数显著增加（P＜0.05）,面粉亮度值由72.20升高至77.48。同时,随着粒径的减小,苦荞麦粉的峰值黏度、谷值黏度和最终黏度均显著上升（P＜0.05）。超微粉碎技术的应用提升了苦荞麦粉的整体糊化特性,使得面团能够更快成型,稳定时间延长,面团的黏弹性增强,内部网络结构愈发均匀致密。利用超微粉制作全苦荞麦面条,断条率显著下降（P＜0.05）,最佳蒸煮时间和蒸煮损失最多减少约50%,质构特性显著改善。     

Influence of amylose content on cooking time and textural properties of white salted noodles

White salted noodles were prepared from reconstituted flours of various amylose content to determine the effects of amylose content on noodle dough properties and texture of noodles cooked for optimum cooking time. With decrease of amylose content from 26.5 to 3. 0%, optimum water absorption of noodle dough increased from 39 to 49% and cooking time of noodles decreased from 16 to 7 min. Hardness of cooked noodles prepared from reconstituted flour consistently decreased with increase in proportion of waxy starch. Noodles less than 12.4% amylose content exhibited higher springiness and cohesiveness than noodles greater than 17.1% amylose content. Cohesiveness and springiness of noodles prepared with partial waxy starches, of which amylose content ranged from 16. 6 to 22. 7%, were comparable to those of noodles prepared from <12. 4% amylose content. Amylose content of starch was significantly correlated with hardness, springiness, and cohesiveness of cooked noodles prepared from reconstituted flours.     

玉米-小麦混合粉面团流变学特性、面条品质及两者相关性

采用不同的配比将玉米粉与小麦粉混配,用混合粉制作面条,测定混合粉面团的流变学特性及面条的蒸煮与质构品质,并对面团流变学特性与面条品质进行相关性分析。结果表明:随着玉米粉配比的增加,混合粉面团的吸水率、稳定时间、评价值、拉伸能量、延伸度和最大拉伸阻力呈逐渐减少的趋势,形成时间也有所减小,而弱化度则有所增大,面条的蒸煮损失率呈上升趋势,而硬度、胶着性、咀嚼性和剪切力则逐渐减小。参考面条用小麦粉及挂面国家标准,同时考虑到玉米粉的利用率,得出玉米粉、小麦粉配比为15:85的混合粉适合制作面条。玉米-小麦混合粉面团的流变学特性与面条的蒸煮及质构品质高度相关,可作为预测玉米-小麦混合粉面条品质优劣的有效指标。