共查询到19条相似文献,搜索用时 78 毫秒
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应用动态流变仪,Brabender拉伸仪,扫描电子显微镜(SEM)研究了葡萄糖氧化酶和谷氨酰胺转胺酶对冷冻面团粘弹模性量粘弹模量,抗拉伸阻力R5及微结构影响。空白面团(未加添加剂),含有葡萄糖氧化酶面团和含有谷氨酰胺转胺酶面团于-18℃冷冻贮藏7,21,35d,随冷冻贮藏时间延长,面团弹性模量(G′)降低。在同一冷冻贮藏时期内空白面团弹性模量最小,添加葡萄糖氧化酶面团弹性模量最大;含有葡萄糖氧化酶和含有谷氨酰胺转胺酶面团抗拉伸阻力R5大于空白面团。葡萄糖氧化酶和谷氨酰胺转胺酶使新鲜面团(未冷冻面团)面筋网络增强,淀粉颗粒镶嵌于交错的面筋网络之间,在-18℃经过35d冷冻贮藏,空白面团面筋网络不再连续,支离破碎,并与淀粉颗粒分离,而且面筋膜变薄。含有葡萄糖氧化酶和含有谷氨酰胺转胺酶面团依然有大量连续面筋网络存在。葡萄糖氧化酶和谷氨酰胺转胺酶抑制了面团弹性模量和抗拉伸阻力R5的恶化,而且抑制冰晶对面团中面筋三维网络结构的破坏。 相似文献
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采用差示扫描量热仪和F3流变发酵仪研究重组华根霉脂肪酶(RCL)和转谷氨酰胺酶(TG)共同作用对冷冻面团抗冻发酵特性的影响。将面团于-18℃冻藏0、7、21、35d,结果发现:随着冻藏时间的延长,甘油含量有所降低,可冻结水含量增加;引入RCL和TG到冷冻面团中可以显著增加面团中的甘油含量,显著降低面团中可冻结水的含量,减少冰晶体的形成,并且可以提高酵母的存活数。F3流变发酵仪测定面团的发酵流变学特性,结果表明:RCL和TG同时作用可以显著降低冻藏对面团发酵高度的削弱作用,改善酵母的发酵性能和增加面团的持气率。 相似文献
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提高冷冻面包面团稳定性的研究 总被引:6,自引:0,他引:6
阐述了冷冻面包面团的生产工艺,并通过测定面团醒发时间和面包比容,研究了影响冷冻面包贮藏稳定性的因素,结果表明:适当的面团配方和工艺条件能有效地提高冷冻面团的稳定性。 相似文献
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应用动态流变仪,研究了食品添加剂硬脂酰-2-乳酸钠(SSL)、刺槐豆胶(LBG)、葡萄糖氧化酶(GOD)、木聚糖酶(XY)及葡萄糖氧化酶和木聚糖酶(GOD+XY)复合对面团动态流变学特性以及对冷冻面团烘焙特性的影响。结果表明,在频率0.1~40Hz扫描过程中,与未添加任何添加剂的面团相比,添加SSL的面团弹性模量、粘性模量和损耗角正切都减小;添加LBG的面团弹性模量和粘性模量增大.损耗角正切减小;添加GOD的面团弹性模量增大.粘性模量和损耗角正切减小;含有XY的面团弹性模量和粘性模量减小,损耗角正切增大;而含有GOD+XY的面团弹性模量和粘性模量增大,损耗角正切减小。 相似文献
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冷冻面团的研究与发展 总被引:5,自引:0,他引:5
冷冻面团是面包生产的一种新工艺,本文对冷冻面团开发的背景、现状和主要技术问题作了简要的介绍,探讨了酵母耐冷冻性的研究。可通过两种途径提高酵母的耐冷冻性:一方面利用改良剂来保护酵母细胞;另一方面通过生物技术培养发酵良好的耐冻藏酵母,最后对我国冷冻面团的发展前景作了展望。 相似文献
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本文主要采用F3肖邦流变发酵仪研究了海藻糖、起酥油、食盐、面团温度和乳酸对冷冻甜面团的发酵特性(Hm、Hm’、CO2产气量)的影响作用。结果表明,起酥油和海藻糖对Hm’和CO2产气量的影响效果是高度显著的,而食盐、面团温度和海藻糖对Hm的影响作用比较大。应用响应面分析法建立了描述各因素与响应值之间关系的模型。所有回归模型与测定数据(p<0.05)显示出良好的相关性,Hm、Hm’、CO2产气量和面包比容的R2值分别为93.67%、98.37%、98.12%和91.43%,表明响应面法可以作为推测研究海藻糖、起酥油、食盐、面团温度和乳酸各因素以及它们之间交互作用对冷冻甜面团发酵特性影响效果的适宜方法。 相似文献
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Influence of yeast and frozen storage on rheological, structural and microbial quality of frozen sweet dough 总被引:2,自引:0,他引:2
Smail Meziani Jordane JasniewskiPablo Ribotta Elmira Arab-TehranyJean-Marc Muller Mohamed GhoulStéphane Desobry 《Journal of food engineering》2012,109(3):538-544
The aim of the present study was to investigate the effect of yeast content and frozen storage (9 weeks at −40 °C) on the structural and rheological parameters, and fermentative activity of frozen sweet dough. Two types of dough were studied (to estimate dough shelf life): simple yeasted dough (SY) and double yeasted dough (DY). Fermentative activity (yeast viability, gassing power, and dough volume), rheological and textural parameters were assessed for frozen sweet doughs.These effects were explored by different and complementary methods: Fourier transform infrared (FTIR), dynamic rheology, texture profile analysis (TPA) and differential scanning calorimetry (DSC).The data showed that the longer the frozen storage time at −40 °C, the higher the decreased of frozen sweet dough quality. The rheological attributes such as hardness, ΔS, springiness, tan δ and yeast activity declined significantly during frozen storage. This modification led to lower specific volume of frozen sweet dough during proofing.The observed changes of the frozen sweet doughs rheological properties after thawing may be attributed to the damage on the gluten cross-linking, mainly produced by the ice crystallization during frozen storage. The storage effect was particularly concentrated in the first 27 days of storage. 相似文献
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在冷冻甜面团的研究开发中,通过感官评价小组采用描述性分析对面包样品的风味剖析,同时采用固相微萃取(SPME)技术分别提取样品中的挥发性风味物质,并经气相色谱-质谱(GC-MS)联用法进行鉴定,重点研究了冷冻甜面团在不同冷冻储存阶段所制作的面包的风味变化问题。结果发现,用冷冻甜面团制作的面包与相同配方制得的新鲜面包相比,在冷冻期间21~28d内,烘焙风味的劣化即呈现出来并急速降级,如酸含量明显升高,醇类明显降低,醛类相对较高,酯类、呋喃类有所升高但芳香族化合物却较低,并在长达70d的冷冻储存期间趋于不可逆转的稳定状态。 相似文献
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Weight loss of frozen bread dough under isothermal and fluctuating temperature storage conditions 总被引:1,自引:0,他引:1
Yuthana Phimolsiripol Ubonrat SiripatrawanDonald J. Cleland 《Journal of food engineering》2011,106(2):134-143
Evaporative weight loss from food leads to both loss of saleable weight and quality deterioration so it need to be minimized. The effect of isothermal and fluctuating conditions on frozen dough weight loss was measured and compared with kinetic, physical and artificial neural network (ANN) models. Frozen dough samples were regularly weighed during storage for up to 112 days in loose-fitting plastic bags. The storage temperatures were in the range of −8 to −25 °C with fluctuations of ±0.1 °C (isothermal), ±1, ±3 or ±5 °C about the mean. For each combination of temperature and fluctuation amplitude, the rate of dough weight loss was constant. The rate of weight loss at constant temperature was nearly proportional to water vapour pressure consistent with standard theories for evaporative weight loss from packaged foods but was also accurately fitted by Arrhenius kinetics. Weight loss increased with amplitude of temperature fluctuations. The increase could not be fully explained by either the physic model based on water vapour pressure differences or the kinetic model alone. An ANN model with six neurons in the input layer, six neurons in hidden layers and one neuron in the output layer, achieved a good fit between experimental and predicted data for all trials. However, the ANN model may not be accurate for product, packaging and storage systems different to that studied. 相似文献
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BackgroundFrozen dough technology could effectively extend the shelf life of bread to ensure the freshness, which is widely used and gradually replace the traditional bread production. However, during the production and storage of frozen dough, a series of problems could take place, such as inhibition of yeast activity, damage of the structure of the dough, leading to the deterioration of dough quality.Scope and approachThis review summarizes the factors that affect the final quality of frozen dough, including yeast activity, dough structure and dough properties. Some effective methods for improving freeze tolerance of yeast, dough structure and dough properties are discussed, including addition of various additives, use of genetic engineering technique, optimization of freezing and storage conditions, and employment of novel freezing technology.Key findings and conclusionsThe addition of additives can not only improve the freeze tolerance of yeast but also maintain the rheological and thermophysical properties of dough. Through the modification of gene, freeze tolerance and fermentation ability of yeast can be improved. Optimizing freezing and storage conditions ensures the activity of yeast as well as dough network structure so that freezing damage due to ice crystals can be minimized. In addition, novel freezing technology such as ultrasound-assisted freezing can simultaneously accelerate the freezing process as well as generate fine and uniform ice crystals, thus protecting dough network structure. 相似文献
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Megumi Miyazaki Tomoko Maeda Naofumi Morita 《European Food Research and Technology》2008,227(2):503-509
Rheological properties of dough and bread quality of frozen dough-bread containing 18.4% of hydroxypropylated (HTS), acetylated
(ATS), and phosphorylated cross-linked (PTS) tapioca starch with different degrees of modification and 1.6% of dried powdered
gluten were compared to the same amount of native tapioca starch (NTS) or wheat flour-bread. Doughs substituted with native
or modified tapioca starches had the same mixing tolerance as 100% wheat flour. The dough was frozen and stored for 1 week
at −18°C, and thawed (one freeze-cycle). The amount of freezable water in the dough substituted with native or modified tapioca
starches was not significantly different from that of wheat flour. Frozen dough-bread substituted with highly modified HTS
(degree of substitution; DS 0.09–0.11) retarded bread staling, while lowly modified HTS (DS 0.06–0.07) or ATS (DS 0.02–0.04),
and PTS (0.004–0.020% phosphoryl content) substitution fastened bread staling as compared with frozen dough-bread baked from
wheat flour. The breadcrumbs containing HTS and ATS felt tacky, whereas the bread containing PTS was dry feel. HTS and ATS
swelled and collapsed easily during heating, while PTS was difficult to swell and disperse as compared with NTS, therefore
the gelatinization properties seemed to affect the texture of bread. Breadcrumb containing HTS showed small firmness during
storage, and highly modified HTS-h (DS 0.1) was the smallest. This means highly hydroxypropylated tapioca starch significantly
retards bread staling. Staling properties and texture of frozen dough-bread with various tapioca starches were the same as
conventional bread baked with the same amount of tapioca starches. These results suggest that a one freeze–thaw cycle and
a 1-week frozen period do not change characteristics of starch, gelatinization and retrogradation properties as compared with
the conventional method, and the highly modified HTS-h is prominent anti-staling food-stuff in frozen dough. 相似文献
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Combined effects of freezing rate, storage temperature and time on bread dough and baking properties 总被引:2,自引:0,他引:2
This study compares the effects of freezing temperature and rate as well as storage temperature and time on the quality of frozen dough. Yeasted bread dough was frozen using four freezing rates (19-69 °C/h), then stored at −10, −20, −30, or −35 °C for up to 180 days. Dough strength diminished with longer storage time and higher storage temperatures. Cryo-SEM showed that dough stored at −30 and −35 °C had the least damaged gluten network. NMR studies showed that more rapidly frozen dough, and that stored at lower temperatures had lower transverse relaxation (T2) times (9-10 ms). However, dough stored at −20 °C displayed the highest yeast activity among samples. Bread loaf volume decreased with storage time, and bread made from dough stored at −20 °C showed the highest loaf volume. Breads produced from −30 and −35 °C stored dough displayed less change in the texture profile during storage as well as less change in T2 values. Response surface analysis showed that optimal properties occurred at freezing rates of around 19-41 °C/h and storage temperatures of −15 to −20 °C. 相似文献