酵子面包在贮藏过程中理化及微生物指标的变化

测定在25 ℃条件下贮藏期间酵子面包和酵母面包的理化指标及微生物指标的变化,得出面包老化的物性参数变化规律,揭示其抗老化机理。对感官指标、硬度、水分活度、热特性、自由水含量、电镜扫描、破碎率、膨润度、质构分析特性等理化指标及微生物指标进行测定。结果表明：随贮藏时间延长,面包水分含量显著下降,硬度明显上升。与酵母面包相比,酵子面包具有水分含量较高,硬度较小,淀粉颗粒更容易发生团聚等特性,物性学研究结果显示,将传统发酵剂酵子应用于面包生产,具有较好地延缓淀粉回生和老化的效果。确定面包老化的定量物性参数范围,为由定性分析向定量参数分析转变作了有益探索。     

天然酵母发酵对面包老化的影响

以梨和脐橙两种水果为培养基质,得到两种水果天然酵母,研究了两种水果天然酵母对储藏期间面包的硬度、水分含量、水分活度和老化焓值的影响,并通过分析不同分离菌株对面包老化特性的影响,探究优势微生物对面包老化的影响机理。结果表明,天然酵母发酵能够减缓面包在储藏期间水分的损失,降低淀粉的回生焓值,其中梨组天然酵母面包(PSB)的淀粉回生焓值为对照组面包(CB)的76.01%,脐橙组天然酵母面包(OSB)的淀粉回生焓值为CB的80.66%。此外,乳酸菌发酵对减缓水分损失和抑制淀粉回生焓值的增长有积极影响。     

豌豆蛋白面包的制作工艺优化及其品质

为了拓宽豌豆蛋白的产品范围,满足食品营养多样化的需求,本文研制一种在传统面包中添加豌豆蛋白粉的新型面包。以小麦粉为主要原料,辅以豌豆蛋白粉、大豆油、鸡蛋、奶粉、糖、盐、酵母与黄油等辅料,研制豌豆蛋白面包。以感官评价为指标,运用单因素实验和响应面分析法优化了豌豆蛋白面包的制作工艺条件,并对其品质进行评价。结果表明,最佳工艺条件为:豌豆蛋白粉添加量8%,酵母添加量1.5%,糖添加量8%,发酵时间60 min。此条件下制得的面包的感官评分为82分,水分含量35.8%,酸度值3.23,比容3.35 mL/g,持水性98.2%,口感得分20分,香味得分17分。因此,优化的工艺条件合理、可行,豌豆蛋白面包具有较好品质特性。     

响应面法优化葡萄干天然酵母面包的配方

目的:为了优化葡萄干天然酵母面包的配方。方法:在单因素实验的基础上,选择葡萄干天然酵母液添加量、白砂糖添加量、黄油添加量为影响因素,感官评分为响应值,采用Box-Behnken试验设计方法,对面包配方进行优化,并对其理化和微生物指标进行测定。结果:葡萄干天然酵母面包的最佳工艺配方为:葡萄干天然酵母液添加量12%、白砂糖添加量18%、黄油添加量9%,改良剂添加量0.3%,此条件下面包产品感官评分为86,与理论预测值相比,其相对误差约为2.38%。在此条件下制得的面包的理化和微生物指标如下:水分含量30%,酸度5.1 °T,比容5.8 mL/g,菌落总数201 CFU/g,大肠菌群0,霉菌计数2 CFU/g,致病菌未检出。结论:优化的面包配方条件合理,葡萄干天然酵母面包具有较好的品质。     

基于动态密度法对面团发酵的研究

在面包制作中,面团的发酵是一个重要环节,发酵的好坏直接影响面包的品质。本文采用数字图像处理方法测定面团在发酵过程中的动态密度,通过密度的变化检测面团的发酵程度。通过酵母含量、发酵温度、面团含水量三个单因素实验对面团发酵过程进行研究。结果表明,动态密度随发酵时间的增加而减小,随温度的升高而增大;面团水分增加,酵母含量增加,动态密度变化趋势增大。本研究对新型面包醒发箱的设计与面包的大批量生产都具有重要指导意义。     

高糖高活性干酵母的发酵力及烘焙特性研究

对目前国内出售的高糖型即发高活性干酵母样品进行理化指标检测和面包的烘焙实验,重点对高糖即发干酵母产品的水分含量、蛋白质含量、发酵力及面包制品的烘焙效果进行客观评价和比较,结果表明:不同品牌的酵母具有不同的发酵力,不同的发酵力又决定了酵母在面包烘焙制作中的不同结果。从酵母的发酵力能够预测到面包的发酵和烘焙性能,并预知烘烤后的面包品质特性。研究为调控面团发酵体积的大小、控制面包产品的品质提供一定的参考,进而为烘焙企业根据自身需要正确选择和使用高糖即发干酵母提供依据。     

基于电子鼻检测技术分析不同马铃薯粉添加量对面包品质的影响

通过测定面包的比容、水分含量、水分活度、色泽和质构,研究不同马铃薯粉添加量(0、5%、10%、15%、20%和25%)对面包品质的影响,并结合电子鼻分析,进行马铃薯面包品质的快速检测。结果表明,在不同马铃薯粉添加量条件下,面包的比容、水分含量、水分活度、色泽和质构存在显著差异(p<0.05)。随着马铃薯粉添加量的增加,面包的硬度和咀嚼性呈现先减小后增大的趋势,而弹性先增大后减小;比容呈现先减小后增加再减小的趋势,而粘附性先降低后增加再降低,水分含量、红色度a*逐渐升高,水分活度、亮度L*值、内聚性逐渐降低。马铃薯粉添加量在15%时,面包的综合品质得到改善。同时,电子鼻检测数据结果与面包的比容、水分含量、水分活度、色泽和质构之间具有较好的相关性,相关系数均在0.8以上。因此,采用电子鼻对面包品质评价具有一定的可行性,可以很大程度上代替多种检测仪器设备对面包品质进行综合评价,是一种方便快捷的检测方法。     

响应面法优化马铃薯面包的制作工艺及品质分析

以马铃薯全粉和普通面粉作为主要原料制作面包,以面包的硬度作为评价指标,采用响应面分析法优化马铃薯面包的制作工艺。在单因素试验的基础上,选取马铃薯全粉含量、酵母添加量、水分添加量作为自变量,面包硬度和弹性作为响应值,利用Box-Behnken中心组合设计原理和响应面分析法,研究各变量及其交互作用对马铃薯面包硬度的影响。结果表明:马铃薯面包制作的最佳工艺条件为全粉添加量10%、酵母1.60%、水分含量55%时,在此条件下面包的硬度值为27.46 N,与理论预测值25.34 N,仅相差2.12 N,说明通过响应面优化后得出的方程具有一定的实践指导意义。运用该配方制作的马铃薯全粉面包,质地较柔软,面包芯颜色比普通面包颜色稍深,必需氨基酸含量比普通面包高、营养丰富,能够被人们接受。     

质构仪对面包品质改良剂效果评价的应用

采用质构仪对普通面包和添加有品质改良剂的面包在贮存过程中的质构变化进行了研究.通过与水分含量的测定结果和感官评价结果之间的相关性分析得出,具有保水作用的面包品质改良剂能有效控制面包的老化程度,质构仪测试指标最大破碎力、探头位移等能够较好的表征面包品质改良剂的实际效果.     

蚕蛹蛋白营养面包的研制

将蚕蛹蛋白应用于面包的生产.通过单因素试验发现蚕蛹蛋白、水、酵母以及面包改良剂添加量对面包品质影响较大;通过正交试验确定蚕蛹蛋白营养面包的最佳工艺配方.结果表明:蚕蛹蛋白面包的最佳工艺配方为蚕蛹蛋白2％,酵母1.2％,面包改良剂0.1％,水55％,在此工艺条件下,蚕蛹蛋白面包风味和品质最佳.     

乳酸菌发酵酸面团对青麦仁面包品质的影响

为研究乳酸菌发酵酸面团对青麦仁面包品质的影响,利用植物乳杆菌发酵制作酸面团,添加到青麦仁面包中,并测定小麦面包、青麦仁面包、青麦仁酸面团面包3种样品的质构、感官评价、慢消化性淀粉含量(SDS)、挥发性风味物质等.结果表明:添加酸面团能显著降低样品的硬度、咀嚼性,增大弹性(P＜0.05);添加酸面团的样品其感官评分接近于...     

产单宁酶乳酸菌发酵红豆、扁豆酸面团的生化特性及其对馒头体外消化的影响

本研究利用一株本课题组前期从自然发酵的豆粉中筛选出的高产单宁酶的发酵乳杆菌D23,来分别发酵红豆、扁豆两种豆类酸面团并制作成馒头,通过测定酸面团发酵前后缩合单宁等抗营养因子含量、多肽分子量分布、游离总酚、游离氨基酸含量,以及馒头淀粉、蛋白质体外消化率,对酸面团的生化特性及馒头的体外消化进行了对比研究。结果表明:通过菌株D23的发酵作用,两种豆类酸面团中缩合单宁含量显著下降(P<0.05),在红豆、扁豆酸面团中分别降低了57.87%、53.54%;大分子量肽含量降低,小分子肽含量升高;游离总酚含量分别升高了75.74%、65.94%;必需氨基酸含量增加了429.31%、358.20%;同时相比普通馒头,酸面团馒头最终消化液中的还原糖含量分别增加了3.27%、5.55%,淀粉的体外消化率得到了提升;蛋白质的最终体外消化率也分别由67.68%、70.21%增加为73.21%、76.97%。因此,该株具有高单宁酶活力的发酵乳杆菌D23可以通过酸面团的发酵作用有效降低豆类基质中缩合单宁等抗营养因子带来的不利影响,并增强最终馒头产品的营养价值,在发酵豆类制品中拥有良好的应用潜力。     

高产植酸酶乳酸菌发酵对黑豆面包蛋白质品质及烘焙特性的影响

从实验室获得1 株高产植酸酶乳酸菌（L-19）并应用于黑豆酸面团面包,同时选用不产植酸酶的乳酸菌（K-12）作为对照。通过分析面包氨基酸组成和营养指标、蛋白质体外消化率、质构特性、超微结构和感官评定,研究其对黑豆酸面团面包蛋白质营养及烘焙学特性的影响。结果表明：添加乳酸菌黑豆酸面团后,面包蛋白营养和烘焙品质都得到了明显改善,其中L-19酸面团面包（L-19SDB）效果最显著。与黑豆面包（BB）相比,L-19SDB植酸含量下降60.68%,蛋白质体外消化率由64.70%升高至73.93%,总氨基酸含量提高73%。同时与其他3 组相比,L-19SDB有更好的氨基酸特征：其必需氨基酸与总氨基酸之比、必需氨基酸指数和生物价均为最高。面包烘焙品质方面,相比黑豆面包BB,L-19SDB和K-12SDB比容分别提高了31.45%和23.59%,硬度降低了68.79%和56.59%。通过ImageJ分析发现,L-19SDB芯囊组织更加均匀,感官评价总体可接受度最高（7.72 分）。     

Effect of sourdough at different concentrations on quality and shelf life of bread

The objective of this work was to study the effect of sourdough obtained with selected exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) strains on the quality of bread and its shelf life. Two sourdough concentrations were used in order to ascertain the best bread composition. Fresh bread quality was studied by means of microbiological, physical, chemical and mechanical analysis, whereas physical, thermal and mechanical properties were investigated to study the product shelf life. The results showed that dough prepared with 30 g/100 g of sourdough had a negative impact on bread quality properties in the absence of EPS-producing LAB strains, whereas the opposite was observed in the presence of EPS-producing strains: bread samples at 30 g/100 g of sourdough showed higher volume, higher moisture content and better mechanical properties during storage than samples at 20 g/100 g of sourdough. Moreover, 30 g/100 g of sourdough showed a protective effect on bread staling, thus confirming the effect of sourdough concentration and the positive role of EPS on functional properties.     

Effects of sourdough and enzymes on staling of high-fibre wheat bread

The effects of sourdough and enzyme mixture (α-amylase, xylanase and lipase) on the specific volume, staling and microstructure of wheat pan bread supplemented with wheat bran were studied. Staling of bread was followed for 6 days by measuring the crumb firmness, changes in crystallization of amylopectin (DSC), increase in signal from the solid phase (NMR) and by light microscopy. The most effective treatment in improvement of quality was the combination of bran sourdough and enzyme mixture. During storage the rate of changes in crumb firmness, amylopectin crystallinity and rigidity of polymers were greatest for the white wheat bread. The most pronounced microstructural changes were swelling of starch granules and separation of amylose and amylopectin in the starch granules. Least changes in crumb firmness, amylopectin crystallinity and rigidity of polymers were observed in bran sourdough bread with enzymes. In contrast to white wheat bread, the starch granules were very much swollen in bran sourdough bread with enzyme mixture. This was hypothesized to be due to the higher water content of bran bread, and degradation of cell wall components leading to altered distribution of water among starch, gluten and bran particles during storage.     

乳酸菌冻干粉剂发酵全麦酸面包工艺优化及储藏特性分析

目的：为了利用植物乳杆菌冻干粉剂发酵制作全麦酸面团面包（Whole wheat sourdough bread,WWSB）,并优化其加工工艺以及分析其储藏特性。方法：在单因素实验基础上,选择全麦酸面团（Whole wheat sourdough,WWSD）添加量以及全麦酸面团发酵时间为影响因素,面包最终的pH、总酸度值（Total acidity,TTA）、比容、硬度、感官得分作为响应值,使用中心组合试验设计方法,对全麦酸面包的工艺配方进行优化。并在此基础上以普通小麦面包（Wheat bread,WB）和普通全麦面包（Whole wheat bread,WWB）为空白组及对照组,均于4℃进行为期一周的储藏,分别于第0、1、3、5、7 d时取样,分析三种面包的全质构特性以及水分迁移情况。结果：全麦酸面包的最佳工艺配方：全麦酸面团添加量18%,全麦酸面团发酵时间16 h,此时的全麦酸面包pH4.82、TTA 5.62 mL、比容3.47 mL/g、硬度5.59 N、感官得分83。在此加工条件下三种面包的储藏特性指标如下：WWSB在整个储藏期间的硬度增长速率在前期和后期（35.75%和21....     

利用酸面团降低面包中致乳糜泻因子的研究进展

乳糜泻是由于摄入麸质蛋白而引起的一种肠道自身免疫疾病。目前,对付乳糜泻的唯一方法是控制饮食中麸质蛋白的摄入,尤其是麦醇溶蛋白的摄入。酸面团是一种多菌种混合发酵剂,是将面粉、水混合后经微生物发酵制成,在世界范围内的面制品生产上有着广泛应用。酸面团中的微生物以乳酸菌和酵母菌为主,其中乳酸菌可以产生一系列蛋白酶及肽酶,从而显著降低面包中的麸质蛋白含量。本文主要对乳糜泻的发病机制,以及利用酸面团降解致乳糜泻因子的机制及研究进展进行了概述,以期为推动无致乳糜泻毒性的产品开发提供新的方法和思路。     

Flavour of sourdough wheat bread crumb

This study investigates the effect of adding sourdough to wheat bread dough on the production of flavour compounds in wheat bread crumb. The sourdoughs were fermented with starter cultures of lactic acid bacteria alone and in combination with sourdough yeasts. The volatile compounds in the bread crumb were isolated by a dynamic headspace technique and extraction analysis, analysed by gas chromatography (GC), and identified on the basis of GC retention times for reference compounds and mass spectrometry (MS). The chemical analyses were combined with sensory evaluation. The volume of the loaves increased significantly when the doughs had 5–20% sourdough added compared with the control bread (bread without sourdough). In the sourdough bread, the content of acetic acid, 2-methylpropanoic acid, and 3-methylbutanoic acid was generally higher, and loaves made with the addition of sourdoughs fermented withLactobacillus plantarum, L. delbrueckii, orL. sanfrancisco had a higher content of 2- or 3-methyl-1-butanol than control bread. Interactions were seen between the starter cultures and the sourdough yeasts, and the production of the following compounds was increased depending on the starter culture used and on the sourdough yeast: ethanol, 2-methylpropanol, 2/3-methyl-1-butanol, 2-phenylethanol, benzyl alcohol, acetic acid, 2-methylpropanoic acid, and 3-methylpropanoic acid. Bread made with an addition of 5% to 15% sourdough fermented withL. sanfrancisco had a pleasant, mild and sour odour and taste.L. plantarum bread had a strong, sour and unpleasant odour and a metallic sour taste with a sour aftertaste, but when the sourdough was also supplemented with the sourdough yeastSaccharomyces cerevisiae, the bread attained a more aromatic wheat bread flavour, which may be caused, in part, by a higher content of 2/3-methyl-1-butanol, 2-methylpropanoic acid, 3-methylbutanoic acid and 2-phenylethanol.     

米酒老面添加量对面团及馒头品质的影响

本文研究了米酒老面添加量(40%、50%、60%、70%和80%)对面团的pH、湿面筋含量、面筋指数及馒头的比容、硬度、白度、感官评分的影响。结果表明:随着米酒老面添加量的增加,面团pH呈现下降的趋势。米酒老面添加量为60%的面团中湿面筋含量显著低于其他四种添加量(P<0.05),馒头的比容、硬度、白度和感官评分显著高于其他四种添加量(P<0.05)。相关性分析表明,面团pH与馒头的感官评分呈极显著负相关(P<0.01);面团湿面筋含量与馒头比容呈显著负相关(P<0.05),与馒头硬度呈显著正相关(P<0.05),与馒头白度呈极显著负相关(P<0.01)。面团面筋指数与馒头比容呈极显著正相关(P<0.01),与馒头硬度呈极显著负相关(P<0.01),与馒头白度呈显著正相关(P<0.05)。米酒老面的添加会改变面团和馒头的品质,其最适添加量为60%。     

Exploitation of buckwheat sourdough for the production of wheat bread

This study investigates the exploitation of buckwheat sourdough for the production of wheat bread. The fermentation induced extensive hydrolysis of buckwheat main storage proteins, but did not influence the total protein, starch and polyphenols content of buckwheat. Buckwheat sourdough was incorporated at 10 and 20?% (w/w) in wheat dough, and control doughs were produced with the addition of a chemically acidified (CA) buckwheat batter. The addition of buckwheat sourdough greatly affected the rheological properties of the dough, by inducing a strengthening of the gluten network and decrease in elasticity. The acidification of wheat dough also stimulated the baker’s yeast activity during proofing, resulting in higher release of CO₂ in shorter times (volume of CO₂ released (ml), control dough, 1,671.5; dough with 10?% sourdough, 2,600; dough with 10?% chemically acidified dough, 2,715.5). The properties of wheat bread were enhanced by the addition of 10?% buckwheat sourdough, which led to higher specific volume (control, 3.41?ml/g; bread with 10?% sourdough, 4.03?ml/g) and softer crumb (crumb hardness, control, 5.28?N; bread with 10?% sourdough, 3.93?N). On the other hand, the higher acidification level did not influence the bread volume, but slightly hardened the crumb (crumb hardness, bread with 20?% sourdough, 7.41?N; bread with 20?% chemically acidified dough, 6.48?N). The fermentation positively influenced the nutritional properties of buckwheat flour and wheat bread, in terms of polyphenols (control bread, 8.84?mg GAE/100?g; bread with 10 and 20?% sourdough, 17.83 and 18.20?mg GAE/100?g, respectively) and phytic acid contents. Incorporation of buckwheat sourdough also led to an extension in the shelf life of wheat bread, which became more evident for the higher addition level. Overall, the results of this study suggest that buckwheat sourdough represents a suitable tool for enhancing the overall quality and nutritional properties of wheat bread.