冷冻面团加工技艺

<正> 新鲜面包散发的芳香能增加面包店的销售量,因此自制面包的面包店在亚洲地区迅速流行。 生产面包,面团当然不可少。由于以往的冷冻面团在质量上不及新鲜面团,因而面包店要以新鲜面团来生产味美的面包。经过不良冷冻处理的面团,会使面包出现大小不一的情况。然而,凭藉当今的先进科技,能很好地处理冷冻面团,不会影响产品的质量。     

和面机扭矩与面团和制效果关系的研究

和面过程中面团扭矩变化跟面团形成程度具有一定相关性。以评价面包成品的质构及比容等为指标,分别考察了特定配方、不同配方组成以及不同水温等影响因素下,面团扭矩与面团和制效果的关系。结果表明,在不同和面条件下,单位质量小麦粉扭矩峰值差变化不大,当该峰值差在0.009-0.012 8N·m/g时,所得面团烘焙得到的面包品质最佳。     

Glutenin and dough tenacity

Assuming a random distribution of Cys residues within a glutenin polypeptide chain it has been calculated that about one sixth of an average chain (allowing for an intra-chain SS loop) would be available for unfolding under stress. It is postulated that, because the unfolding of chains under stress has a magnifying effect on the effective molecular length of glutenin, a comparatively small range in the average number of chains per molecule (DP) is sufficient to encompass the levels of dough tenacities encountered in practice. Since the DP depends inversely on the concentration of Theologically active SH groups, according to the linear glutenin hypothesis, an explanation is provided for the great sensitivity of doughs to reducing agents and improvers, and for the indifferent correlation of dough properties with flour SH content.     

冷冻温度对非发酵面团蛋白质结构及面团特性的影响

冷冻温度影响冷冻面团的质量。通过研究不同冷冻温度对非发酵面团中蛋白质结构、面团特性的影响,为冷冻非发酵面团产品冷冻工艺优化提供借鉴。结果表明,随着冷冻温度的降低,面团中聚合体蛋白、谷蛋白大聚体含量增加,游离巯基含量下降,蛋白解聚程度降低;与未冷冻面团相比,-20℃冷冻的面团中α-螺旋、β-转角结构显著下降,β-折叠结构显著上升,-30℃、-40℃冷冻的面团中α-螺旋、β-折叠结构无显著性变化;冷冻后,面团硬度、回复性、黏附性上升,弹性、内聚性下降;-20℃冷冻后面团的硬度最大,弹性、内聚性最低。冷冻面团中蛋白质结构与质构特性具有显著的相关性。降低冷冻温度,可以降低非发酵面团中聚合体蛋白的解聚程度,对蛋白二级结构和面团质构特性的稳定具有积极作用。     

酶制剂对全麦馒头面团水相溶液理化性质的影响

从单一戊聚糖酶(Pn)、葡萄糖氧化酶(Gox)以及双酶复合引起的面团水相理化特性变化层面揭示酶制剂对馒头品质的改良机制。结果表明:Pn和Gox均促进了面团水相溶液得率的提高,水相溶液中的蛋白和戊聚糖含量发生了显著的变化,气泡粒径大小和稳定性得到了显著的改善,界面蛋白吸附膜质地更为致密。Pn或Gox引起的面团水相溶液理化性质的变化,尤其是泡沫稳定性的改善,是全麦馒头比容增大、硬度减小、形成更加均匀和细腻的内部结构的重要原因之一。     

冷冻面团的研究进展

冷冻面团作为一种半成品,通过冷冻贮藏可以维持面团性能,延长面团保存期,被广泛应用于食品连锁加工过程中.本文综述了影响冷冻面团品质的因素,探讨了当前国内冷冻面团研究存在的难点,旨在为我国冷冻面团的发展提供参考.     

Sheeting of wheat flour dough

A combined experimental, analytical and numerical study of sheeting of wheat flour dough was performed. The material behaviour was defined using a non‐linear viscoelastic model calibrated with data obtained from uniaxial compression, loading–unloading and stress relaxation tests. Tests were performed using an instrumented small‐scale rolling rig. The roll speed and roll gap were varied to determine the effect on the steady‐state vertical force and exit thickness. Experiments were performed using one‐stand as well as a two‐stand roll set up. The analytical model which assumed perfect plasticity led to significantly lower forces than the experimental data. The numerical predictions were accurate at small reduction ratios. The exit thickness of the dough sheet was predicted accurately from the numerical model. For the two‐stand rolling, the numerical data were not accurate when a significant level of stress developed in the dough between the two roll stands.     

Comparison of rheological properties between Mixolab-driven dough and bread-making dough under various salt levels

Food Science and Biotechnology - The properties of wheat dough according to salt level and type of mixer were investigated, and parameters derived from each analysis were comprehensively compared....     

过夜种子面团法的应用探索

过夜种子面团法是吸取二次发酵法和快速发酵法的优点研究而成的一种加工面包的新方法,特点是面包体积要比快速发酵法面包大得多,且发酵风味和香气浓郁。该法缩短了生产周期,面包品质好。     

Disulphide interchange in dough proteins

Appreciable disulphide interchange has been found between wheat proteins and cystamine when the latter was incorporated into doughs. If the extent of the protein-protein reaction is of the same order it has been calculated that interchange of this magnitude would be enough to cross-link the glutenin into a continuous structure. Cysteamine was more reactive than cystamine in the disulphide interchange reaction.     

Lipid-protein interactions during dough development

Radionuclide-labelled glycerol triolein has been used to follow the fate of triglyceride lipids during the mixing of wheat flour doughs. After removal of residual free lipid by petrol extraction, initial fractionation of freeze-dried dough identified the acetic acid-soluble protein as being the only component involved significantly in work-induced lipid binding during dough development under nitrogen, and also in lipid release on admission of air. Very little labelled lipid was found in either the water-soluble proteins or the starch residue. Sub-fractionation of the acetic acid-soluble protein by ammonium sulphate precipitation from acetic acid-urea-cetyltrimethyl-ammonium bromide (AUC) solvent showed bound lipid to be distributed almost entirely between high-molecular-weight glutenin and protein which remained soluble in the AUC supernatant even in the presence of 20% ammonium sulphate. Precipitated gliadins contained very little labelled lipid. However, significant levels were found in classical ethanol-extracted gliadin, and were traced predominantly to the same supernatant-protein owing to its solubility in aqueous ethanol. Examination of this AUC-supernatant fraction showed it to contain a hitherto unreported protein which had a molecular weight of about 9000, was strongly complexed with tri-glyceride lipid on a 1:1 molar basis and showed a tendency to aggregate in solution. Its amino acid frequency was found to differ significantly from both glutenin and purothionin, the latter containing in particular very much more cysteine than the supernatant-protein. Representing 10% or more of the total gluten, this small, highly interactive protein is responsible for a significant, if not the major, part of lipid binding activity in dough and may well have a fundamental role in the formation of an insoluble glutenin structure through both —SH and hydrophobic interaction. Accordingly, the name ‘Ligolin’ is proposed, from the Latin ligare: to bind, to tie.     

果胶性稳定剂在冷冻面团中的应用特性

<正> 几年前,焙烤工业主要采用新鲜面团来制造面包。发展至今,采用冷冻面团来制造面包已成为焙烤工业增长最快的市场热点之一,方便性可说是主要的原因之一。较短的加工时间,更大的生产灵活性,较少的废料,以及更有效的资源利用,是采用冷冻面团的工艺特点,其发展之迅速,与目前日益增多的面包店铺密切相关。     

Quantitative fit of a model for proving of bread dough and determination of dough properties

The early stages of bread dough proving were modeled following the diffusion theory and using a newtonian constitutive equation to account for dough rheology. The model was fitted, by constrained minimization of the sum of squared errors function, to experimental growth curves of common dough formulations. Values for the dough viscosity, a first order fermentation rate constant and the bubble size at the beginning of proving were chosen as the degrees of freedom in the fitting procedure. The viscosity value obtained for a plain dough formulation was 30 × 10⁶ Pa s, this value is in the range of viscosity values determined by Rouillé et al. (2005), for wheat dough through creep-recovery and lubricated squeezing flow tests. The results obtained were plotted as a function of dough formulation composition and the trends were observed and analyzed. The observed tendencies and correlations between dough properties and dough formulation follow the trends observed in experimental data reported in the literature for dough systems.     

冷冻工艺条件对发酵面团中抗冻酵母活性的影响

研究了冷冻面团的冷冻终结温度、冻藏温度、冻藏时间对抗冻酵母活性的影响,得出最有利于抗冻酵母活性保持的冷冻工艺条件：冷冻终结温度-18℃,冻藏温度应与冷冻终结温度保持一致,贮存时间不超过30d为宜。     

油脂对面团特性及面制品品质影响研究进展

文章综述了油脂类别、添加量及油脂饱和度对面团特性及面制品品质的影响,指出后续可对有关油脂的内在组分与结构对面团的作用机理,以及油脂、淀粉与蛋白质体系的作用机制进行探究。     

不同醒面次数对烩面面团特性及食用品质的影响

目的 研究不同醒面次数对烩面面团中湿面筋含量、水分状态和面筋网络微观结构变化及品质特性的影响。方法 利用差示扫描量热仪和激光共聚焦显微镜，结合烩面面团湿面筋含量和面筋指数试验指标，同时以烩面拉伸特性、延伸率、蒸煮特性、质构特性及感官评价为指标综合分析。结果 一定的醒面次数能改善烩面面团和烩面品质，当面团中蛋白质、淀粉和水分已形成平衡的连续相和稳定面筋网络结构，再增加醒面次数不能显著改善面团和烩面品质。结论 醒面3次和4次烩面面团和烩面品质各项指标最好，为实际生产提供了理论依据。     

Stress relaxation of reconstituted cassava dough

The viscoelastic characteristics of reconstituted cassava dough were evaluated using a stress-relaxation test. Cassava parenchyma (peeled root) processed under different cooking conditions and left at either −5 or −20 °C for 24 h was used to obtain flour, which was reconstituted into dough. Two stress-relaxation models (Maxwell two-termed and Peleg) were fitted to experimental data. Both models were valid for quantifying the relaxation behaviour; but the Maxwell model was better to predict experimental data. Most dough rheological attributes depend on the cooking method and the storage temperature. Dough samples made with flour from parenchyma boiled and left at −20 °C for 24 h had higher values of elasticity moduli, higher viscosity values and lower values of Peleg constants.     

Influence of acidification on dough viscoelasticity of gluten-free rice starch-based dough matrices enriched with exogenous protein

The impact of acid incorporation (acetic + lactic, 0.5%) into rice starch-based doughs enriched with different proteins (egg albumin, calcium caseinate, pea protein and soy protein isolates) at different doses (0, 5 and 10%) has been investigated on dough viscoelastic and pasting profiles. Oscillatory (stress and frequency sweeps) and creep-recovery tests were used to characterize the fundamental viscoelastic behaviour of the doughs, and thermomechanical assays were performed to assess dough viscometric performance. Supplementation of gluten-free doughs with proteins from vegetal sources led to more structured dough matrices (higher viscoelastic moduli and steady viscosities, and lower tan δ, instantaneous and retarded elastic compliances) effect being magnified with protein dose. Acid addition decreased these effects. Incorporation of proteins from animal source resulted in different viscoelastic behaviours according to the protein type, dosage and acidification, especially for casein. Acidification conferred lower dough deformation and notably higher steady viscosity and viscoelastic moduli for 5 %-casein-added dough. Protein-acid interaction favoured higher viscosity profiles, particularly for doughs with proteins of vegetable origin and lower dosage. Dough acidification decreased the pasting temperatures and the amylose retrogradation. Acidification of protein-enriched rice-starch doughs allowed manipulation of its viscometric and rheological properties which is of relevant importance in gluten-free bread development.     

面团改良剂在面包生产中的应用

<正> 面团改良剂是指能够改善面团加工性能的一类添加剂的统称。在面包生产的过程中,面团的发酵情况是一个关键环节,面团在发酵过程中往往因为面粉中面筋蛋白质分解酶分解而影响面团的发酵,从而使成品面包的质量下降。因此,应使用面团改良剂,其作用是帮助快速发酵,使面包松软可口、抑制老化、延长保鲜期等。所生产的面包其体积、重量、外观、组织和口味都较好,并且营养价值高。它是面包生产过程中重要的添加剂之一。     

传统发酵面团的菌相分析

对传统发酵面团的主要微生物菌群进行了分析,分离得到12株酵母菌,3株乳酸菌,16株醋酸菌,并对分离菌种进行了形态观察,生理生化反应实验,对菌种进行了初步鉴定。所得酵母菌主要为酵母属酵母,汉逊酵母属及毕赤氏酵母;乳酸菌主要为有嗜热链球菌,德氏乳杆菌保加利亚亚种及一种未知乳杆菌;醋酸菌主要为醋化醋杆菌,巴氏醋杆菌,汉氏醋杆菌及液化醋杆菌。