天然酵母面包研究现状及发展趋势

在面包的制作过程中添加天然酵母,因其天然、健康,使得面包广受好评。文章依据天然酵母面包的内涵及其现状,分析天然酵母面包的发展趋势,对天然酵母面包的推广具有理论性意义,对提倡制作并食用天然食品具有现实的指导意义。     

浅谈天然酵母面包的现状及发展趋势

面包是利用酵母的生物发酵作用,经烘烤制作成的一类面点制品,是西式面点中很重要的一类产品。文章对天然酵母面包的概述、现状、天然酵母面包的发展未来趋势做粗浅的研究,以期在大众生活中更好的推广天然酵母面包。     

天然酵母面包发酵液的配方工艺优化

以水果天然酵母为研究对象,通过验证实验对工艺参数优化后的天然酵母液进行发酵力的测定与对比,并分别使用优化后的水果天然酵母液和传统干酵母制作面包。结果表明,在天然酵母液培养原料为红提,培养时间为5 d,培养温度为30℃,料液比为4∶10时,其发酵力最高可达0.073 5 g,可以有效提升面包的比容和改善面包的硬度,同时在感官评价指标上,红提天然酵母面包均优于普通干酵母面包,说明优化后的水果天然酵母液可替代干酵母用于面包的发酵工艺中。     

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。     

2种面包贮存过程中感官品质的变化

通过感官评分实验及质构仪分析了贮存对安琪酵母及白神天然酵母制作的面包感官品质的影响。实验结果表明:室温7 d贮存会显著降低2种面包的口感、气味及余味感官指标,能极其显著地增强2种面包的硬度、胶黏性及咀嚼性;降低内聚性和回复性。对比2种不同酵母制作的面包发现,不论贮存前后白神天然酵母制作面包的"弹性"都显著优于安琪酵母,这表明天然酵母制作的面包在某些质构特性上有一定优势。然而安琪酵母制作的新鲜面包在纹理结构、口感、气味及其他质构特性上显著优于白神面包;贮存第7天,安琪面包仅在气味及其他质构特性上仍然显著优于白神面包;这提示着天然酵母可能需要类似2次发酵等更复杂的工艺才能体现其风味上的优势。     

不同酵母对无糖面包品质及风味成分的影响

研究了即发高活性干酵母、低糖高活性干酵母和天然酵母液对无糖面包品质及风味成分的影响。结果表明,制作的无糖面包用低糖高活性干酵母发酵时,面包硬度、黏性、咀嚼性、弹性、粘结性、回复性明显优于用即发高活性干酵母和天然酵母液制作的面包。即发高活性干酵母、低糖高活性干酵母、天然酵母液制作的无糖面包含有风味物质分别为29、63、36种。低糖高活性干酵母更适合于制作无糖面包。     

含天然酵母粉发酵面包的营养与老化特性及风味化合物特征

采用质构仪（texture anylyzer,TA）、差示量热扫描仪（differential scanning calorimetry,DSC）、高效液相色谱（high performance liquid chromatography,HPLC）以及固相微萃取-气相色谱-质谱联用（solid phase microextraction-gas chromatographic-mass spectrometry,SPME-GC-MS）技术,以普通酵母发酵面包为对照,分析天然酵母发酵面包营养特性（主要是游离氨基酸含量）、老化特性和挥发性风味化合物的特征。结果表明：1）天然酵母发酵显著提高了面包中12 种游离氨基酸的含量,包括缬氨酸、蛋氨酸、苯丙氨酸、异亮氨酸、亮氨酸、赖氨酸等人体必需氨基酸;2）天然酵母发酵降低了面包贮藏期内的硬度和老化焓值,延缓了面包的老化;3）天然酵母发酵增加了面包中风味化合物的种类,出现D-柠檬烯、3,7-二甲基-1-辛醇和2-甲基-1-癸醇等新的风味化合物,同时使各类风味化合物的相对含量发生变化;4）天然酵母发酵提高面包的总体可接受度,并获得更高的感官评定得分。     

天然酵母种的制作及其在面包生产中的应用分析

面包是很多国家与地方的主食,据相关的调查发现,人类早在3000年前就已经开始运用酵母制作面包。当时应用的是天然酵母,也是人类应用最早的微生物,可以满足人们日常的生活需求。一、天然酵母种的制作天然酵母是由附着于谷物、果实上以及自然界多种细菌培养而成,比一般酵母更具有价值,整体风味更佳,可以促使面粉充分吸收水分,熟成时间较长,使面包风味呈现出多样化。     

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。     

天然酵母面包研究现状及发展趋势

当前烘焙数量不断增加,人们更加注重饮食安全,但烘焙技术相对落后。本文针对天然酵母面包研究现状进行分析,且探究天然酵母面包的发展趋势,结合市场经济现状进行论述。     

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...     

传统食品源乳酸菌对酸面团面包风味的影响

乳酸菌在酸面团制作中扮演着重要角色,对其风味等品质有显著影响。不同种类的乳酸菌在性能上存在差异,为了选育特色酸面团用乳酸菌发酵剂,开发差异化酸面团面包,本研究对来自不同种类传统发酵食品中的乳酸菌,进行糖代谢能力、产有机酸能力及风味特征评估,并验证其对酸面团和面包风味的影响。结果显示,有6株乳酸菌具有较强的糖代谢能力和产酸性能,风味特征优良。其产生的挥发性风味物质主要包括醇类、酯类、酮类、醛类、酸类和其他类化合物。其中有2株植物乳杆菌可为酸面团面包贡献酸味、果味和酒酿味等特殊风味。这些筛选出的菌株为开发具有特征性香气成分的酸面团发酵剂提供了资源,具有工业应用潜力。     

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.     

Quality attributes and firming kinetics of partially baked frozen wholewheat bread with sourdough

Partially baked frozen (PBF) process prolongs bread shelf life, but diminishes its volume and crumb texture. Therefore, we investigated the possibility of using sourdough for the quality improvement in PBF wholewheat bread. Sourdough was fermented with either Lactobacillus plantarum, Lb. brevis or Leuconostoc mesenteroides mixed with yeast Candida humilis and added at 7.5, 15, 22.5 or 30% on bread dough basis. The choice of sourdough starter significantly affected bread acidity characteristics, flavour, specific volume, shape and crumb firmness. The sourdough amount and acetic acid content of bread inversely correlated to flavour score, specific volume, shape and crumb softness. The overall quality of PBF wholewheat bread was most efficiently improved after adding Lb. plantarum sourdough at 15–22.5%, resulting in retarded firming rate (74–94%) and improved specific volume (25–28%) in comparison with PBF bread without sourdough. Such sourdough has lactic to acetic acid higher than previously recommended for traditional sourbreads.     

Impact of sourdough on the texture of bread

Sourdough has been used since ancient times and its ability to improve the quality and increase the shelf-life of bread has been widely described. During sourdough fermentation, lactic acid bacteria (LAB) produce a number of metabolites which have been shown to have a positive effect on the texture and staling of bread, e.g. organic acids, exopolysaccharides (EPS) and/or enzymes. EPS produced by LAB have the potential to replace more expensive hydrocolloids used as bread improvers. Organic acids affect the protein and starch fractions of flour. Additionally, the drop in pH associated with acid production causes an increase in the proteases and amylases activity of the flour, thus leading to a reduction in staling. While improving the textural qualities of bread, sourdough fermentation also results in increased mineral bioavailability and reduced phytate content. In this review we will be discussing the effect of sourdough on wheat and rye bread as well as the potential of sourdough to improve the quality of gluten-free bread.     

Lactobacilli in sourdough fermentation

Sourdough technology is widely used; it is employed in bread making and for the production of cakes. Sourdough is characterized by a complex microbial ecosystem, mainly represented by lactic acid bacteria and yeasts, whose fermentation confers to the resulting bread its characteristic features such as palatability and high sensory quality. Investigation of the microbial composition of sourdough is relevant in order to determine the potential activities of sourdough microorganisms. This review focuses on the role of the most important group of sourdough fermenting bacteria that consists of lactobacilli; species that belong to the Lactobacillus genus are the main responsible of flavor development, improvement of nutritional quality as well as stability over consecutive refreshments of sourdough. Lactobacilli also establish some durable microbial associations. An overview of the tools for monitoring predominant species is also reported.     

Application of Bifidobacteria as Starter Culture in Whole Wheat Sourdough Breadmaking

This investigation is aimed at developing a new cereal-based product, with increased nutritional quality, by using Bifidobacterium pseudocatenulatum ATCC 27919 as starter in whole wheat sourdough fermentation and evaluating its performance. Four different sourdough levels (5%, 10%, 15%, and 20% on flour basis) in bread dough formulation were analysed. The effects of the use of bifidobacteria in sourdough bread were comparatively evaluated with controls (yeast and/or chemically acidified sourdough with antibiotics). The sourdough and dough fermentative parameters analysed were pH, total titratable acidity, d/l-lactic and acetic acids. Bread performance was evaluated by specific volume, slice shape, crumb structure and firmness, crust and crumb colour, pH, total titratable acidity, and d/l-lactic and acetic acids, phytate, and lower myo-inositol phosphate contents. The sourdough breads showed similar technological quality to the control sample, with the exception of specific bread volume (decreased from 2.46 to 2.22 mL/g) and crumb firmness (increased from 2.61 to 3.18 N). Sourdough inoculated with bifidobacteria significantly increased the levels of organic acids in fermented dough and bread. The Bifidobacterium strain contributed to the fermentation process, increasing phytate hydrolysis during fermentation owing to the activation of endogenous cereal phytase and its own phytase, resulting in bread with significantly lower phytate levels (from 7.62 to 1.45 μmol/g of bread in dry matter). The inclusion of sourdough inoculated with bifidobacteria made possible the formulation of whole wheat bread with positive changes in starch thermal properties and a delay and decrease in amylopectin retrogradation.     

Use of selected sourdough strains of Lactobacillus for removing gluten and enhancing the nutritional properties of gluten-free bread

Forty-six strains of sourdough lactic acid bacteria were screened for proteolytic activity and acidification rate in gluten-free (GF) flours. The sourdough cultures consisted of Lactobacillus sanfranciscensis LS40 and LS41 and Lactobacillus plantarum CF1 and were selected and used for the manufacture of GF bread. Fermentation occurred in two steps: (i) long-time fermentation (16 h) and (ii) fast fermentation (1.5 h) using the previous fermented sourdough as inoculum (ca. 43%, wt/wt) with Saccharomyces cerevisiae (baker's yeast). GF bread started with baker's yeast alone was used as the control. Gluten was added to ingredients before fermentation to simulate contamination. Initial gluten concentration of 400 ppm was degraded to below 20 ppm only in the sourdough GF bread. Before baking, sourdough GF bread showed phytase activity ca. sixfold higher than that of GF bread started with baker's yeast alone. Atomic absorption spectrophotometric analysis revealed that the higher phytase activity resulted in an increased availability of free Ca2+, Zn2+, and Mg2+. The concentration of free amino acids also was the highest in sourdough GF bread. Sourdough GF bread had a higher specific volume and was less firm than GF bread started with baker's yeast alone. This study highlighted the use of selected sourdough cultures to eliminate risks of contamination by gluten and to enhance the nutritional properties of GF bread.     

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.     

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....