Utilization of sprout‐damaged wheat as raw material for sour dough pre‐ferments with mixed cultures of lactic and propionic acid bacteria

The utilization of sprout‐damaged wheat flour in pre‐fermentation for sour dough bread‐baking increased lactic acid formation and titratable acidity several fold in comparison to the use of baker's wheat flour, and also resulted in a lactic acid to acetic acid molar ratio acceptable for sour dough bread. Further, enzymic treatment of the sprout‐damaged wheat flour with malted grain flour appared to be necessary for a properly balanced acid formation although the α‐amylase activity of sprout‐damaged wheat flour was quite high. The accumulation of lactic acid in the pre‐ferment decreased in the presence of yeast, and thus the molar ratio of lactic to acetic acid could be adjusted suitable for sour bread‐baking even with homofermentative lactic acid bacteria. Finally, when using mixed culture pre‐ferments of Lactobacillus brevis and Propionibacterium jensenii, at least 0.1% of propionic acid (based on flour weight), sufficient to prevent mold growth in the final bread, was obtained.     

Influences of lactic acid bacteria on technological, nutritional, and sensory properties of barley sour dough bread

Barley bread was baked with and without admixture of barley sour doughs, individually fermented with seven starter cultures containing lactic acid bacteria (including two with β-glucanase activity).

The aim of the study was to investigate how starter cultures influenced the baking-technological, nutritional and sensory properties of barley bread. Could degradation of β-glucans caused by sour dough admixture result in bread that was more easy to chew?

The starter culture influenced the volume yield, the total titratable acidity (S °) and the sensory properties. The amounts of lactate and acetate ranged from 0.20 to 0.26 and 0.03 to 0.08 g/100 g sour dough bread, respectively. The total titratable acidity in the sour dough breads varied between 4.1 and 5.4 ml 0.1 N NaOH/10 g bread. There were negative correlations between barley taste and total titratable acidity (S °). The acidulous taste of the sour dough breads seemed to mask the barley taste. The phytate of the barley sour dough breads was reduced below 0.5 μ mol/g, which does not inhibit mineral absorption, irrespective of starter culture. There was no significant difference in the total content of β-glucans between bread made with and without admixture of sour dough, irrespective of starter culture, rejecting the hypothesis that barley bread made with sour dough would be more easy to chew.     

Effects of flour from different barley varieties on barley sour dough bread

Twenty flours from 16 different barley varieties cultivated in 1990 and 1992, and a Swedish reference flour, were fermented by Lactobacillus plantarum A1 to sour doughs. Barley breads (40% barley/60% wheat flour) from each flour type were baked with and without an admixture of barley sour dough in order to investigate how the sour dough admixture would affect the baking properties. A trained panel carried out sensory evaluation by conventional profiling on breads made from three of the barley varieties and the Swedish reference flour, made with and without sour dough admixture.

The barley varieties influenced both the sour dough properties and the properties of the barley bread. The pH of bread with sour dough ranged from 4.6 to 4.8 as compared to 5.4 to 5.6 in bread without sour dough. The acidity of the breads with sour dough ranged from 4.1 to 5.0 ml NaOH/ 10 g bread crumb as compared to 2.4 to 3.6 in breads without sour dough. In 14 of the twenty bread types an addition of sour dough lowered the bread volume. Breads with a sour dough admixture scored higher for total taste and acidulous taste than breads without sour dough. The β-glucan content of the flours had no significant influence on the sour dough or the sensory characteristics of the bread, except for the breadcrumb colour.     

Effect of Soda Leavening on Phytic Acid Content and Physical Characteristics of Middle Eastern Breads

The effect of soda (sodium bicarbonate) as a leavening agent on pH, phytic acid hydrolysis and physical quality of a fermentation model system and two popular Middle Eastern breads, Iranian taftoon and Pakistani naan (Arabic) were studied. Supplementing 0.2 and 0.4% soda invariably decreased phytic acid hydrolysis. In sour starter supplemented dough, phytic acid was reduced by 82% after 3 hr. However, when 0.4% soda and sour starter were added loss of phytic acid did not exceed 29%. Supplementing soda in taftoon and naan bread formula significantly lowered phytic acid hydrolysis during fermentation. Soda had no apparent improvement on physical quality of breads but increased the dough water absorption and lengthened the mixing time.     

The microflora of sourdough. XIX. The effect of temperature and dough yield on the proteolytic effect of lactic acid bacteria in sourdough

During fermentation of sour dough the flour proteins are degraded. The proteolysis depends not only on lactic acid bacteria (Lactobacillus plantarum, L. brevis ssp. lindneri, L. fructivorans) but also on the conditions of fermentation of the sour dough. An increase of temperatures between 25 degrees C and 35 degrees C causes an increase in the amino acid content. The water content of the dough (T.A. 150/T.A. 210) influences the proteolytic activity of the bacteria to a lesser degree.     

Ver?nderung der Malat- und Citratgehalte bei der Herstellung von Sauerteigbroten

Zusammenfassung Die Veränderung von mehleigenem Malat und Citrat im Verlauf des Herstellungsprozesses von Sauerteigbrot bei Zusatz von Konservierungsstoffen, bei Spontansauer- und Vorteigführung sowie bei Verwendung von Roggenbackschroten wurde untersucht.Von den Konservierungsstoffen hemmt Calcium-propionat im Gegensatz zu Sorbinsäure Panosorb den Malat- und Citratabbau.In einem spontan gärenden Roggenteig werden Malat und Citrat wie in einem herkömmlichen Sauerteig abgebaut.Der Malatgehalt eines mit Weizenmehl-Vorteig hergestellten Brotes lag mit 38 mg/100 g i.Tr. ebenso hoch wie bei einem Brot aus langstehendem Grundsauer.Die Malatgehalte der Schrotbrotkrumen betrugen 14–26 mg/100 g i. Tr., die Citratgehalte 18–28 mg/100 g i. Tr. und lagen damit deutlich höher als bei Mehlbroten analoger Herstellung.

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Changes of malate and citrate content in the production of sour dough breads2. Influence of Preservatives, Spontaneous Rye Dough Fermentation, Wheat Predough, Rye Meal Sour Dough

Summary Changes in malate and citrate content in sour dough bread were examined as related to addition of antifungal preservatives, use of spontaneous fermenting rye dough, use of wheat predough and use of coarse ground rye grain.Calcium propionate retards reduction of malate and citrate in dough, whereas Panosorb (sorbic acid for use in bread) does not influence the degradation of these acids.In spontaneously fermenting rye dough without addition of starter sour dough the speed of reduction of malate and citrate content is equal to conventional sour dough, whereas bread made up from this spontaneous sour dough is of poor sensory quality.The amount of malate in bread from wheat predough was 38 mg/100 g dry matter, which is equal to bread from sour dough with long fermentation times.Malate content of sour dough bread from coarse ground rye grain was in the range of 14 and 26 mg/100 g dry matter, citrate content in the range of 18 and 28 mg/100 g dry matter, which is higher than in flour breads with analogous sour dough process.

     

Acidification properties of lactic acid bacteria in rye sour doughs

The acidification properties of 33 different sour dough bacteria and starter cultures, one spontaneously generated sour dough and one commercial sour dough starter, a ‘Reinzuchtsauer’ from West Germany, were characterized. The bacteria were tested in three different sour dough processes, the Berliner short-sour-process, the Detmolder one-stage-process and the recently developed Lönner one-stage-process.The Lönner one-stage-process showed a number of advantages in comparison with the other processes. The organisms produced their lowest pH-values and their highest acid equivalents in this process. The rates of pH-decrease were also higher as well as the fermentation quotients. Some of the organisms previously isolated from sour doughs, showed very good properties of acidification. Among the homofermentative organisms, Lactobacillus acidophilus, L. alimentarius, L. plantarum and the unidentified organisms Lactobacillus spp. I and f showed the best properties. Among the heterofermentative organisms the best properties were displayed by L. brevis ssp. lindneri I and II and the unidentified Lactobacillus spp. e, g, h, k and n.     

Changes in dietary fibre, phenolic acids and activity of endogenous enzymes during rye bread-making

The content and composition of dietary fibre (DF), phenolic acids and ferulic acid dehydrodimers as well as the activity of endogenous enzymes were measured in freeze-dried samples of rye wholemeal, dough and bread during the rye bread-making process. Activities of !-amylase, #-xylosidase, !-arabinofuranosidase, and cinnamoyl esterase(s) were found in extracts of wholemeal and in dough after mixing and proofing, whereas activity of endo-xylanase was only found in the wholemeal. As a result of dough mixing, the content of total DF decreased by 21%, which was caused by a decrease in the amount of water-unextractable (WUE) DF. The content of water-extractable (WE) DF was unchanged during the bread-making process, but the relative content of WE DF increased. The content of total ester-bound phenolic acids and ferulic acid dehydrodimers decreased from 1575 µg/g in the wholemeal to 1472 µg/g in rye bread. The most pronounced effect occurred in an imitated sour dough (acidified with lactic and acetic acid instead of by lactic acid bacteria). The observed changes in content and solubility of DF in the dough could be explained by the activity of endogenous enzymes and mechanical disaggregation, whereas the changes observed in the imitated sour dough indicated that some acid hydrolysis might also have taken place.     

发酵时间对俄式面包面团有机酸形成及其酸感的影响

为了解发酵面团中有机酸组成及其随时间的变化,用高效液相色谱法(HPLC)分别对面团发酵6、12、18、24 h进行有机酸组成及含量的测定,并用电子舌对比分析其滋味轮廓。结果表明:面团中共检测到5种有机酸,面团发酵18 h时酸感更加柔和适中,说明其中各种有机酸含量及比例适宜,乳酸402.00 mg/100 g、乙酸73.40 mg/100 g、苹果酸13.20 mg/100 g、柠檬酸43.50 mg/100 g、草酸7.10 mg/100 g;此时,面团的pH3.98,TTA为4.37。电子舌分析发现,发酵时间不同的面团滋味有显著差异;发酵18 h面团酸味相对强度值为10.547,其中乳酸和乙酸对面团的酸味贡献值分别为52.50和5.82。因此,面团最适发酵时间为18 h,此时有机酸含量及比例合适对面团酸感柔和起到促进作用。     

Ver?nderung der Malat- und Citratgehalte bei der Herstellung von Sauerteigbroten

Zusammenfassung Die Veränderung von mehleigenem Malat und Citrat wurde über die einzelnen Phasen verschiedener Varianten der Sauerteigführung und der Teigherstellung bei Roggenmischbrot, Mischbrot und Weizenmischbrot verfolgt. Der stärkste Abbau der beiden Säuren erfolgte bei Vollsauerführung. Bei Grundsauerführung ist der Restgehalt von Malat und Citrat im Teig und Brot bei längerer Stehzeit des Grundsauers höher als bei kurzer Stehzeit.In Richtung auf höhere Malat- und Citratgehalte wirken ferner: Kurze Teigführung mit Schnellknetung und ohne Teigruhe, niedrigere Saueranteile bei höherem Weizenanteil.In der Brotkrume lagen die Malatwerte zwischen 1,6 und 36 mg/ 100 g i. Tr., die Citratwerte zwischen 11 und 22 mg/ 100 g i. Tr.Damit ist es nicht möglich, zwischen reiner Sauerteigführung und kombinierter Führung zu unterscheiden.

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Changes of malate and citrate content in the production of sour dough bread1. Mixed rye and wheat bread with one and two stage sour dough

Summary Changes in malate and citrate content were followed during the phases of sour dough, production dough making and bread production. Different methods of the sour dough process and different proportions of rye and wheat flour were used. Highest reduction of malate and citrate values in bread occured when using the two stage sour dough process. When one stage sour dough was used, malate and citrate in the dough and bread were higher with longer fermentation times.Other factors favouring higher malate und citrate in bread were a short dough process using rapid kneading without a dough rest period and use of a lower proportion of sour dough in the bread while increasing the wheat content.Malate content of bread crumb was in the range of 1.6 and 36 mg/100 g dry matter, citrate content in the range of 11 and 22 mg/ 100 g dry matter.From these findings it can be concluded that it is impossible to distinguish pure sour dough bread and bread produced by combination of sour dough and bread improvers containing lactic and acetic acids.

     

Tolerance of acetate,propionate and sorbate by Saccharomyces cerevisiae and Torulopsis holmii

Several strains of Saccharomyces cerevisiae and one of Torulopsis holmii were investigated with regard to their tolerance of acetate, propionate and sorbate. The S. cerevisiae strains had poor acetic acid tolerance in sour dough pH 4·3, the dough raising power decreasing on average by 67% in the presence of 0·34% sodium acetate, while T. holmii was not affected by this concentration. Propionate (0·16%) and sorbate (0·08%) were more inhibitory than acetate, inhibiting the dough raising power even in normal dough at pH 5·9. Torulopsis holmii also had a good tolerance of propionate and sorbate and seems suitable for raising sour doughs.     

Relationship between thermomechanical properties and baking expansion of sour cassava starch (Polvilho azedo)

The factors involved in the baking expansion of native and sour cassava starch doughs were compared with those of native corn starch. Unlike corn starch dough, native and sour cassava starch doughs showed expansion properties during baking. The storage modulus E ′ decreased for cassava starch doughs before baking expansion, but remained unchanged for corn starch dough. Expansion during the baking of sour cassava starch was attributed to water vaporisation and the fluidity of starch paste. The fact that temperature and weight loss variations at adequate water contents were significantly greater for cassava than corn starch dough is indicative of the important role played by starch melting in expansion. Expansion ability could be correlated with changes in dough–crumb thermomechanical properties when close to the starch melting temperature. © 2001 Society of Chemical Industry     

The microflora of sourdough. XVIII. The protein degrading capabilities of lactic acid bacteria in sourdough

Acidification of the dough by the use of sourdough or acidifiers is necessary not only for good baking quality of rye flour but it is also very important for development of the typical sensory characteristics of rye bread. We confirmed that the lactic acid bacteria of sour dough are proteolytic. Proteolytic effects are observed in the increase of the amino acid content during fermentation. A marked increase was found in the content of leucine, alanine, valine, isoleucine, glutamic acid, glutamine, arginine, lysine, methionine, phenylalanine, tyrosine and serine. Lactobacillus plantarum showed a higher proteolytic activity than L. brevis ssp. lindneri or L. fructivorans.     

Amino Acid Profiles of Fermenting Wheat Sour Doughs

The free amino acid patterns of unfermented and fermented wheat sour doughs started with Lactobacillus plantarum were related by factor analysis to dough yield, ash content of flour, fermentation temperature and presence/absence of yeast, from data corresponding to a central composite design of samples. Individual levels of hydrophobic, acid and basic amino acids as well as total amino acid content positively correlated with extraction rate of flours. The presence of yeast promoted metabolism of histidine, aspartic acid and asparagine, particularly in samples made with whole and wholemeal flours. Proliferation of predominant amino acids by enzymatic release was more notable at higher fermentation temperatures and wholemeal samples. Sour doughs with maximum levels of hydrophobic and basic amino acids were started with no yeast bacterial cultures, made with whole and wholemeal flours and fermented at 35°C.     

Controlled delivery of propionic acid from chitosan films for pastry dough conservation

A study was undertaken to evaluate the feasibility of using chitosan active films designed to control the release of an antimicrobial agent. In this context, the efficacy of propionic acid as both a medium for chitosan dissolution and an antimicrobial agent was examined. This work was focused on studying the potential application of chitosan active films developed to conserve a pastry dough product, modeling the release profile and evaluating the effectiveness of the active agent by extending the product shelf life.     

A Modified Sourdough Procedure for Non-Wheat Bread from Maize Meal

This study developed a procedure for the production of sour bread from 100% maize meal. The modified method combined sponge and dough methods in two mixing stages to form a batter rather than stiff dough. The baking quality of the maize meal was improved by using starter cultures of lactic acid bacteria selected from indigenous micro-flora of the maize meal. Lactobacillus plantarum lowered the pH of fermenting maize meal (3.1) more than other starters; Lactobacillus brevis produced the highest amount of diacetyl (180.8 mg) while Leuconostoc mesenteroides recorded the highest final viscosity value of 144.0 RVU. The sour maize bread fermented with a mixed culture of the three selected cultures had the best physical (weight 122 g, height 3.7 cm, crumb dry matter 69%) and sensory properties (taste and overall acceptability 4.8 on a five-point hedonic scale), which were significantly different (P ≤ 0.05) from bread samples produced with other test starters). The mixed cultures are recommended for sour maize bread production for good rheological properties, proper acidification, and acceptable flavor development.     

Functional properties of selected starter cultures for sour maize bread

This paper focuses on the functional properties of maize sour-dough microflora selected and tested for their use as starter cultures for sour maize bread. Lactic acid bacteria and yeasts isolated from spontaneously fermented maize dough were selected based on dominance during fermentation and presence at the end of fermentation. Functional properties examined included acidification, leavening and production of some antimicrobial compounds in the fermenting matrix. The organisms previously identified as Lactobacillus plantarum, Lb. brevis, Lb. fermentum, Lb. acidophilus, Pediococcus acidilactici, Leuconostoc mesenteroides and Leuconostoc dextranicum and Saccharomyces cerevisiae were used singly and as mixed cultures in the fermentation (fermentation time: 12h at 28+/-2 degrees C) of maize meal (particle size >0.2mm). The pH fell from an initial value of 5.62-3.05 in maize meals fermented with Lb. plantarum; 4.37 in L. dextranicum+S. cerevisiae compared with the value for the control (no starter) of 4.54. Significant differences (P 相似文献   

毕赤酵母对酸粥滋味品质形成的评价

将毕赤酵母与乳酸菌进行复配发酵制备酸粥样品,同时使用乳酸菌单一发酵作为对照,并采用电子舌技术结合多元统计学 方法对其滋味品质进行评价。 结果表明,酸味是发酵酸粥的主要滋味特性。 通过马氏距离聚类分析发现复配组与乳酸菌组发酵酸粥聚 为一类,进一步利用多元方差分析发现,两组发酵酸粥滋味品质差异不显著（P＞0.05）,毕赤酵母对酸粥滋味品质形成无积极影响。     

Microbial Sour Doughs Influence Acidification Properties and Breadmaking Potential of Wheat Dough

Breads from sour doughs were started with Lactobacillis plantarum (L-73, or B-39) or Lactobacillus brevis (L-62)-, and incorporated at 10, 17.5, or 25%. Lactic and acetic acid production depended on bacterial starter and yeast. Started doughs had longer mixing time, stability, more softening with time; lower resistance to extension; shorter fermentation, less stability, and greater oven rise. Breads had greater volume, lower density, softer crumb and higher slice height. Interactive effects between inoculum and microbial composition of starter were reflected in sensory scores. Adequate sour dough inoculum was lower for heterofermentative strains (10%, L-62) than for homofermentative strains (17.5%, B-39; 25%, L-73), due to deleterious effects on rheological properties.