海藻糖和卡拉胶寡糖对冷冻面团冻藏稳定性和烘焙特性的影响

为了提高冷冻面团和面包的产品品质,将不同比例的海藻糖(1%、1.5%、2%,质量分数)和卡拉胶寡糖(0.3%、0.5%、0.8%,质量分数)加入面团,通过测定冻藏0、2、4周后冷冻面团的发酵特性、流变特性、水分分布、蛋白质二级结构、微观结构以及面包的比容、质构和内部纹理结构特性,研究冷冻面团冻藏期间的稳定性及面包烘焙特性。结果表明,随着冻藏时间的延长,添加海藻糖和卡拉胶寡糖的冷冻面团在冻藏4周后,其发酵特性及流变特性相对于对照组均有所改善。冻藏4周后,对照组、海藻糖-1.5%组、卡拉胶寡糖-0.5%组α-螺旋相对含量分别下降了45.73%、27.13%、15.71%;β-折叠相对含量升高了31.32%、15.51%、13.79%。电镜扫描图显示,随着冻藏时间的延长,海藻糖和卡拉胶寡糖组的冷冻面团相比对照组具有更致密的网络结构。对照组、海藻糖-1.5%组、卡拉胶寡糖-0.5%组在冻藏1个月后其面包比容分别下降了30.86%、21.48%、15.80%。综上,卡拉胶寡糖相对于海藻糖对冷冻面团冻藏稳定性及烘焙特性具有更好的保护效果,可作为一种新型抗冻剂用于冷冻面团生产中。     

海藻酸丙二醇酯对面团流变学和面包烘焙特性的影响

采用粉质仪、拉伸仪和质构分析仪研究添加不同比例(0.1%、0.2%、0.3%和0.4%)的海藻酸丙二醇酯(PGA)对面团流变学特性和面包烘焙特性的影响。结果表明,添加PGA能改善面团的粉质和拉伸特性,能显著提高面团的吸水率,延长面团的稳定时间,提高粉质评价指数,增大面团的延展性、拉伸阻力和拉伸比值。添加PGA能增大面包比容,显著提高面包的弹性,降低面包硬度,改善面包的口感,提高面包的感官评分。PGA添加量在0.2%~0.3%时,对面团和面包的改善效果最为显著,面包品质最好。     

海藻酸丙二醇酯对馒头品质的影响研究（网络首发、推荐阅读）

将不同浓度的海藻酸丙二醇酯（PGA）加入小麦粉中，探究PGA对小麦粉糊化特性、面团流变性、微观结构及馒头质构和感官品质的影响。结果显示，添加PGA后小麦粉的糊化温度由58.8 ℃升高至59.5 ℃、最大拉伸阻力由518 EU增加至597 EU，增加了近15%，同时水分在面团中的分布更加均匀，面团的硬度增加、流变特性中的损耗角的正切值tanδ（G''/G"）持续增加，最终导致馒头的比容、光泽度和咀嚼性增加。实验结果表明，当小麦粉中PGA浓度为500~1 000 mg/L时的馒头品质最佳，过量的PGA会缩小馒头体积，使馒头口感变硬。PGA的亲水亲油性质促使水分更加均匀分布在面团结构中，显著影响面团的操作特性，促进馒头品质提升。     

海藻酸丙二醇酯对酸性湿面条质构影响研究

通过粉质仪测定海藻酸丙二醇酯(PGA)对面粉粉质特性影响,经TPA全质分析、蒸煮实验和感官鉴评,研究PGA添加量对面条硬度、粘着性、拉伸收缩比等指标影响。结果发现,PGA对面条品质改良效果较为明显,其在面条中最适添加量为0.3%。     

藻酸丙二醇酯对冷冻面团品质影响的研究

通过添加不同量藻酸丙二醇酯对冷冻面团拉伸特性、失水率及可冻结水含量的影响,研究了藻酸丙二醇酯对冷冻面团品质与特性的影响。研究结果表明:随着冻藏时间的延长,冷冻面团的品质呈现下降的趋势,在相同的冻藏时间下,藻酸丙二醇酯添加量0.2%时,冷冻面团的内部结构稳定,失水率和可冻结水的含量降低,面团品质较好。     

海藻酸丙二醇酯(PGA)对凝固型酸乳结构的影响

将不同量的海藻酸丙二醇酯(PGA)添加到原料乳中进行发酵,对其特性进行检测。结果表明,添加PGA后,酸乳的黏度显著增大,且形成了触变环,是1种触变性流体。其中PGA添加量为0.20%的触变环面积最大,为20 431.43。酸乳的表观黏度随剪切时间的变化曲线符合幂函数y=kx-n的变化规律,R2=0.975 3;实验表明,PGA不同的添加量能不同程度地影响酸乳的结构,以0.20%的添加量的效果最好:此时样品的持水力上升10.9%?乳清析出量下降26.0%,硬度8g。     

γ-聚谷氨酸对全麦冷冻面团烘焙特性的影响

将γ-聚谷氨酸(γ-PGA)添加至全麦冷冻面团中,通过全麦粉持水率、酵母存活率研究γ-PGA的保水性和抗冻活性;以面包比容和质构等作为评价指标,研究γ-PGA对冷冻面团制作的全麦面包烘焙品质的影响。结果表明,添加γ-PGA可提高冷冻全麦面团的酵母存活率和发酵高度,增大全麦面包比容,减小面包硬度,促进面包芯中形成大气孔;贮藏3 d后,添加γ-PGA的全麦面包硬度和老化率显著降低(P<0.05),且γ-PGA的最佳添加量为1%。     

海藻酸钠对冷冻面团面包烘焙特性的影响

研究添加不同比例(0.1%、0.3%、0.5%和0.7%)海藻酸钠对冷冻面团面包烘焙特性的影响。结果表明,添加海藻酸钠能提高冷冻面团的持水率,减少冷冻面团醒发时间;增大面包的比容,降低面包的硬度和咀嚼性,提高弹性,改善冷冻面团面包的品质。感官评定显示,冻藏不同天数后,添加0.3%的海藻酸钠面包感官评分值最高。     

冷冻速率对面团发酵和烘焙性质的影响

研究了冷冻速率对冷冻面团体系中酵母发酵(包括酵母产气力、酵母存活率)和面团微结构的影响;以及对冷冻面团烘焙性质的影响(包括面包比容,面包评分和面包保质期).结果显示冷冻速率同时影响酵母活力和面团的超微结构,进而影响面包的品质和体积,综合考虑,确定面团在-32℃下快速冷冻至-18℃(冷冻速率约-5℃/min),并在-18℃下冻藏,较适合冷冻面团的生产.     

冻藏时间对冷冻面团馒头品质的影响

为探究冻藏时间对冷冻面团馒头品质的影响,本文通过采用酵母菌活性测定、馒头质构特性测定、面筋蛋白二级结构测定、扫描电镜观察等方法,从宏观和微观的角度上分析了冻藏时间的延长对冷冻面团馒头品质的影响。结果表明,随着冻藏时间的延长,酵母菌数量及存活率均呈下降趋势,其中冻藏1周后,表面和内芯的酵母菌数量均减少5.8 lg CFU/g;经过5周冻藏后,冷冻面团馒头的硬度、咀嚼性、胶着性分别增大74.6%、75.7%、75.6%;面筋蛋白二级结构中α-螺旋也随着冻藏时间的延长呈下降趋势,蛋白二级结构稳定性逐渐下降;经过扫描电镜观察发现,面筋网络结构逐步减少,淀粉颗粒与面筋结构分离,部分淀粉颗粒完全裸露。因此表明冻藏时间的延长,会导致冷冻面团馒头品质下降。本研究结果为后续提高冷冻面团馒头品质应用研究提供理论依据。     

糯麦粉对冷冻面团发酵流变特性和面包烘焙特性的影响

采用发酵流变测定仪和质构分析仪研究不同比例的糯麦粉对冷冻面团发酵流变学特性和面包烘焙特性的影响。结果表明：无论面团冷冻与否,随着糯麦比例增加,面团发展的最大高度(Hm)和持气率(R)逐渐下降,而气体释放曲线最大高度(H＇m)和CO2产气量(Vco2)在一定程度上增加。随着冻藏时间的延长,面团各种参数(Hm、H＇m、R等)逐渐降低,但是下降的幅度随糯麦粉添加量的增加而减小,如与冻藏7d相比,添加质量分数0%、10%、20%和30%的糯麦面团经冻藏60d后Hm分别下降了12.9%、9.6%、7.7%和7.5%,而R则分别下降了2.8%、2.1%、1.6%和1.7%。在冷冻贮藏过程中,面包品质虽有一定程度的下降,但添加糯麦粉的面包品质下降程度较慢,抗老化效果好,且由感官评定可知,冻藏不同天数后,添加10%糯麦粉的面包最易受人们喜爱。     

Effect of Amino Acids and Peptides on Mixing and Frozen Dough Properties of Wheat Flour

Free amino acids, peptides, and vital wheat gluten were investigated to determine their effect on the mixing and frozen dough baking properties of wheat flour. Addition of 1% cysteine and aspartic acid decreased and glutamic acid, histidine, arginine, and lysine increased the mixing tolerance of flour. Cystine, methionine, tryptophan, and phenylalanine increased but isoleucine, histidine, glycine, arginine, glutamic acid, aspartic acid, and lysine decreased loaf volume of nonfrozen dough breads. However cystine, methionine, tryptophan, and phenylalanine did not increase loaf volume of bread prepared from frozen dough. Vital wheat gluten increased mixing tolerance and bread loaf volume only for the nonfrozen dough. However, wheat gluten hydrolysate, corn, and bonito peptides decreased mixing tolerance after optimum mixing time and were effective in increasing loaf volume for both frozen and nonfrozen dough. As the amount of corn and bonito peptide increased, specific loaf volumes also increased. Addition of 2.5% corn peptide was most effective in increasing loaf volume of frozen dough bread. Crust browning and crumb stickiness increased, whereas crumb softness decreased with addition of peptides. Addition of less than 1% peptide did not adversely affect the aftertaste and off‐flavor of bread. These results suggest that addition of peptides are effective for improving the baking quality of frozen dough, whereas amino acids and gluten have no effect.     

Effects of Waxy Wheat Flour and Water on Frozen Dough and Bread Properties

ABSTRACT:  The quality of bread made from frozen dough is diminished by changes that occur during freezing. New cultivars of waxy wheat flour (WWF), containing less than 2% amylose, offer unique properties for the production of baked products. In this study, dough properties and bread quality were investigated at various levels of WWF (0% to 45% flour weight) and water (55% to 65%). Dough stickiness increased with higher levels of WWF and water. During frozen storage, dough with greater WWF and lower water had less change in stickiness. Maximum resistance to extension (MRE) decreased with higher WWF and water. Dough with greater WWF and less water had less change in extensibility after frozen storage. Dough with greater WWF and water was more extensible. Nuclear magnetic resonance (NMR) studies showed that frozen dough with higher WWF content had lower transverse relaxation ( T ₂) time of 9 to 11ms. After frozen storage, dough with higher WWF still showed lower T ₂. Dough with 15% WWF had higher yeast activity. Bread made from 15% and 30% WWF had higher volume in bread made from unfrozen and frozen dough. Bread firmness decreased with higher amounts of WWF and water. This research demonstrated that specific combinations of WWF and water produced a better quality of frozen dough and bread.     

藻酸丙二醇酯粘度的研究

研究了食品增稠剂藻酸丙二醇酯（ＰＧＡ）的粘度特性。实验表明：ＰＧＡ的粘度与其浓度之间存在着半对数线性关系（Ｒ２＝０．９７４０）；在ｐＨ２～１０范围内，ＰＧＡ的粘度几乎无变化，但当ｐＨ≥１１时，ＰＧＡ的粘度下降；ＰＧＡ与羧甲基纤维素（ＣＭＣ）具有良好增粘效应，但与海藻酸钠之间的效应较复杂。     

全麦冷冻面团研究进展

冷冻面团是全麦食品的一种良好载体,可简化生产操作,降低加工难度,加快全麦食品的工业化生产。综述了全麦食品中的膳食纤维对面团及冷冻面团品质的影响,在冷冻和冷藏过程中全麦冷冻面团的发酵特性和流变学特性的变化,以及食品改良剂对全麦冷冻面团的品质改善等研究。通过分析全麦冷冻面团中面筋蛋白、淀粉、发酵特性、流变学特性等在冷冻和冷藏过程中劣变原因,为改善全麦冷冻面团的品质提供理论基础和实践参考。     

糯麦粉及转谷氨酰胺酶(TGase)在冷冻糯性糕团中的应用

以糯米粉和含10%(以粉质量计)糯麦粉的糯米-糯麦组合粉为研究对象,在研究不同添加量(0、0.5%、1%,以粉质量计)转谷氨酰胺酶(TGase)对其糊化特性影响的基础上,探讨TGase对这2种不同体系制得的糯性糕团样品所产生的影响,并对含TGase的糕团样品的冻藏特性进行研究。结果表明：与糯米粉相比,添加10%糯麦粉会使得组合粉的峰值黏度、低谷黏度和最终黏度相对降低。而经TGase处理后,组合粉的峰值黏度和最终黏度分别增加了15.19%和15.23%。在糯米粉中混入糯麦粉可降低糯性糕团的硬度,延缓样品老化。而添加TGase,可明显降低糯米粉和糯米-糯麦组合粉制作的糕团的塌陷度。此外,在用糯麦-糯米组合粉制作的糯性糕团中添加1% TGase,可使冻藏6周的糯性糕团仍保持90%的表面完好率。因此,通过糯麦粉和TGase的应用可制得抗老化的、弹性大且冻藏稳定性好的糯性糕团产品。     

全麦粉的添加对油馕面团品质的影响

考察添加不同比例的全麦粉,对油馕面团粉质特性、拉伸性、糊化特性、混合粉溶剂保留特性、面团水分分布和面团面筋蛋白二级结构的影响。结果表明,随着全麦粉含量的增加面团加工性质变差,面团吸水率由65.18%增加至最大值80.30%,面团形成时间从4.13 min增加到最大值5.34 min;面团的峰值黏度、谷值黏度、回生值和衰减值呈下降趋势,而糊化温度则不断提高;拉伸能量由87 cm2降低至30 cm2,延展度由156 mm降低至92 mm,拉伸阻力由302 EU降低至242 EU。当全麦粉完全取代精粉时与精粉组相比（全麦粉取代率为0%）,混合粉的碳酸钠、蔗糖和水溶剂保留率分别增加了20.56%、18.69%和34.94%,而乳酸溶剂保留率则降低23.47%;核磁结果显示,面团中水分分布变化情况为A21/A2升高,A22/A2和A23/A2下降;傅里叶变换红外光谱仪测定结果显示,面筋蛋白结构中α-螺旋和β-折叠的总相对含量由68.57%下降为50.89%,无规卷曲相对含量增加了31.5%,稳定的二级结构下降、不稳定的二级结构相对含量上升,导致面筋蛋白结构变差。     

Effect of Peroxidase on Textural Quality of Dough and Arabinoxylan Characteristics Isolated from Whole Wheat Flour Dough

Effect of peroxidase on arabinoxylans (pentosans) isolated from whole wheat flour and instrumental textural parameters of whole wheat flour dough were studied. Significant increase in dough hardness and decrease in adhesiveness was observed on treatment of dough with peroxidase. Arabinoxylans isolated from peroxidase treated dough had higher molecular weight, viscosity, arabinose to xylose ratio, ferulic acid, and protein contents as compared to that of untreated dough. Arabinoxylans isolated from treated dough had higher absorption at 280 and 320 nm indicating the association of proteins and ferulic acid with arabinoxylans. Thus, the treatment of dough with peroxidase may catalyze the formation of cross-linking between arabinoxylans as well as protein-arabinoxylan that could be responsible for the alteration of the whole wheat flour dough characteristics.     

酵母产气力对冷冻面团稳定性及烘焙质量的影响

简述了酵母产气力在冷冻面团稳定性及烘焙产品质量中的作用.酵母菌在冷冻面团生产中起重要作用,叙述了冷冻面团生产过程中各因素对冷冻面团稳定性的影响.冷冻面团的稳定性可以通过酵母种类的选择、配方的改善、制作方法及冷冻解冻循环的控制来解决.     

Adding Rice Starch to Hard Wheat Flour for Improving its Dough Properties and Baking Quality

Results show that the addition of rice starch to hard wheat flour improves the dough properties and baking quality as demonstrated by the tests and the readings of Farinograph, Extensograph and Amylograph as well as increases the reducing sugars, acidity and the volume of the produced bread. Experiments proved that best results were observed when rice starch was added to hard wheat flour at 6 to 8%.