Rye Sourdough Research Articles

Development of a new resource-saving technology of rye-wheat bread on liquid rye sourdoughs using recycled bread

Recycling of substandard bread, technological waste and bread from the distribution network is a promising way of waste management and raw materials saving. In order to optimize the old bread recycling process and to improve the quality of finished products, a new resource-saving technology for rye–wheat bread was developed. It was found that use under 25% of bread crumbs instead of flour was possible in a liquid sourdough with a moisture content of 70%. When old bread dosage increased from 50 to 100%, acid accumulation slowed down, the lifting force deteriorated, the viscosity increased, which may makes it difficult or impossible to pump the sourdough in industrial technological process. The liquid sourdough made with 25% of old bread had a better lifting capacity and contained more alcohol and volatile acids than the control. The quality of bread made using sourdough with 25% of old bread was comparable in quality to control bread made using traditional sourdough. Liquid rye sourdough with recycled old bread allowed the bread shelf life extension by slowing down the bread staling. No effect on mold rate was found when using recycled old bread in sourdough.

Role of Kazachstania humilis and Saccharomyces cerevisiae in the strain-specific assertiveness of Fructilactobacillus sanfranciscensis strains in rye sourdough

Sourdough is a common ingredient for baked goods as it improves their texture, shelf life and flavor. One of the dominant key species in type I sourdoughs is Fructilactobacillus sanfranciscensis (formerly Lactobacillus sanfranciscensis), which occurs with a multitude of different strains. Noticeably, this species often shares its habitat with the yeasts Saccharomyces cerevisiae or Kazachstania humilis. It is still unclear, which relationship exists between these organisms and whether it is characterized by coexistence, interaction, or mutualism. In this study, competitiveness of different F. sanfranciscensis strains in rye sourdough was examined and its dependence of co-existing yeasts was explored. In particular, it was investigated whether competitiveness of F. sanfranciscensis strains depends on the presence/absence of S. cerevisiae or K. humilis when co-inoculated in the sourdough. Competitiveness of strains was monitored in rye sourdough using the CRISPR locus length polymorphism (CLLP)—PCR for strain differentiation. It was found that F. sanfranciscensis TMW 1.1150, TMW 1.1221 and TMW 1.1597 were dominant regardless of the presence/absence of both yeast species. Dominance of F. sanfranciscensis TMW 1.392, TMW 1.907 and TMW 1.2137 was significantly and diversely influenced by the presence of S. cerevisiae or K. humilis. F. sanfranciscensis TMW 1.2138 and TMW 1.726 were not able to compete against the other F. sanfranciscensis strains. It was possible to sort the eight strains into three different groups: 1. Strain competitiveness was independent of the presence/absence of yeasts; 2. Strain competitiveness was dependent on yeast species and 3. Strains were not competitive in the presence of strains belonging to group 1 or 2. Interestingly, in fermentations that were not inoculated with any yeast a spontaneous occurrence of S. cerevisiae or K. humilis was observed depending on the synergistic competitiveness of the respective F. sanfranciscensis used. Thus, the level of competitiveness was strain specific and, in some strains, dependent on the presence/absence of specific yeast species.

Persistence and β-glucan formation of beer-spoiling lactic acid bacteria in wheat and rye sourdoughs

Some beverage-spoiling lactic acid bacteria (LAB) produce capsular β-glucans from UDP-glucose, which is accompanied by cell network formation causing viscosity increases of liquids. This feature of certain LAB is feared in breweries but could be useful for structural and nutritional improvement of baked goods, provided that these LAB are suited for the manufacture of sourdoughs. The aim of this study was to investigate the persistence and β-glucan formation of the brewery isolates Levilactobacillus (L.) brevis TMW 1.2112 and Pediococcus (P.) claussenii TMW 2.340 in wheat and rye sourdoughs. Both the wild-type strains and the respective β-glucan-deficient mutants were dominant in wheat and rye sourdoughs and acidified them to characteristic pH ranges. The formation of β-glucan capsules during sourdough fermentations was stable in L. brevis TMW 1.2112 in contrast to P. claussenii TMW 2.340. Wheat sourdoughs fermented with the β-glucan producing L. brevis TMW 1.2112 cells were significantly more viscous than doughs fermented by the P. claussenii TMW 2.340 cells and the applied mutant strains. In conclusion, L. brevis TMW 1.2112 and P. claussenii TMW 2.340 were suited and persistent wheat and rye sourdough starters, while the in situ β-glucan formation in sourdoughs was hardly detectable in case of P. claussenii.

Insights into microbial diversity of traditional Austrian sourdough

In sourdough processing, lactic acid bacteria (LAB) and yeasts are responsible for the bread's unique characteristics. To evaluate the microbial ecology of traditional Austrian sourdoughs, 11 wheat and nine rye sourdoughs were examined. The colony counts of the LAB ranged from <5.00 to 9.59 log10 CFU g−1, while the yeast counts were lower, at < 5.00 to 7.90 log10 CFU g−1. A total of 340 LAB and 171 yeast isolates were assessed by genomic and proteomic identification approaches. The identification of the LAB isolates revealed five different genera and 33 species, with heterofermentative Lactobacillus spp. predominating. Differences in the microbial composition were observed between rye and wheat doughs, with Leuconostoc spp., Streptococcus spp., and Pediococcus spp. primarily identified in wheat sourdoughs. Regarding yeasts, seven species were identified, of which 63% of the isolates were assigned to Saccharomyces cerevisiae. A single sourdough harboured up to eight different LAB and four different yeast species. Total titratable acidity varied from 7.18 to 20.20 mL of 0.1 N NaOH/10 g, and pH values from 3.69 to 4.36. These data indicate the broad microbial diversity in traditional Austrian sourdoughs.

Effect of pentoses, hexoses, and hydrolyzed arabinoxylan on the most abundant sugar, organic acid, and alcohol contents during rye sourdough bread production

AbstractBackground and objectivesBased on the available literature, there are indications that the sugar composition present in rye flour, including pentoses present in arabinoxylan (AX), may have a significant impact on the relative proportions of fermentation products. The purpose of the study was to examine the changes in content of the most abundant sugars, organic acids, and alcohols caused by the addition of hexoses, pentoses, or hydrolyzed AX to rye flour at the beginning of the sourdough fermentation process.FindingsThe HPLC procedures revealed that during rye sourdough fermentation, 1% of added pentoses act differently compared to hexoses. Available pentose residues in flour used for sourdough preparation caused higher acidification of dough, higher acetic acid biosynthesis, and a favorable ratio of lactic acid to acetic acid content.ConclusionsIn order to provide appropriate amounts of arabinose and xylose residues in rye flour, AX could be used as a source of pentoses. However, in this case appropriate xylanase activity during sourdough fermentation must be provided.Significance and noveltyFor the first time, the changes in fermentation products were investigated under standardized conditions during the rye sourdough bread production process in sourdough, dough after final fermentation, and baked bread. This research revealed the influence of AX and xylanases on bread flavor during rye sourdough bread production.

Bacterial community dynamics in spontaneous sourdoughs made from wheat, spelt, and rye wholemeal flour

Sourdough fermentation is a traditional process that is used to improve bread quality. A spontaneous sourdough ecosystem consists of a mixture of flour and water that is fermented by endogenous lactic acid bacteria (LAB) and yeasts. The aim of this study was to identify bacterial diversity during backslopping of spontaneous sourdoughs prepared from wheat, spelt, or rye wholemeal flour. Culture‐dependent analyses showed that the number of LAB (109 CFU/ml) was higher by three orders of magnitude than the number of yeasts (106 CFU/ml), irrespective of the flour type. These results were complemented by next‐generation sequencing of the 16S rDNA V3 and V4 variable regions. The dominant phylum in all sourdough samples was Firmicutes, which was represented exclusively by the Lactobacillales order. The two remaining and less abundant phyla were Proteobacteria and Bacteroidetes. The culture‐independent approach allowed us to detect changes in microbial ecology during the 72‐hr fermentation period. Weissella sp. was the most abundant genus after 24 hr of fermentation of the rye sourdough, but as the process progressed, its abundance decreased in favor of the Lactobacillus genus similarly as in wheat and spelt sourdoughs. The Lactobacillus genus was dominant in all sourdoughs after 72 hr, which was consistent with our results obtained using culture‐dependent analyses. This work was carried out to determine the microbial biodiversity of sourdoughs that are made from wheat, spelt, and rye wholemeal flour and can be used as a source of strains for specific starter cultures to produce functional bread.

Изменение микробиоты густой ржаной закваски в процессе длительного ведения

The article is devoted to the study of the microbial starter cultures preservation during the process of long-term maintenance of the sourdough in the laboratory, as well as the study of the influence of microbiota changes on the physicochemical indicators of the sourdough. The leading role in sourdough is played by lactic acid bacteria and yeast, the quality of the starter culture and bread itself largely depends on the ratio and species diversity of this microorganisms. The strains of L. paracasei / L. casei 5, L. paracasei / L. casei 63, L. plantarum 78 and the yeast C. milleri Chernorechensky are used to prepare sourdough. It was shown that the use of starter cultures of lactic acid bacteria and yeast in the technology of dense rye sourdough leads to the dominance of starter microorganisms and the sourdough production having good biotechnological characteristics already in the first phase of preparinf. However, with long-term maintenance of the sourdough, new species of lactic acid bacteria begin to dominate, which differ from those introduced in first phase. It was found that changes in the starter culture microbiota had a significant effect on the physicochemical indicators of the starter culture quality.

Lactic Acid Bacteria Isolation from Spontaneous Sourdough and Their Characterization Including Antimicrobial and Antifungal Properties Evaluation.

This research effort aimed at isolating and phenotypically characterizing lactic acid bacteria (LAB) isolates from a spontaneous rye sourdough manufactured following traditional protocols, as well as at evaluating their antimicrobial and antifungal properties as key features for future industrial applications. Thirteen LAB strains of potential industrial interest were isolated and identified to species-level via PCR. Most of the sourdough isolates showed versatile carbohydrate metabolisms. The Leuconostoc mesenteroides No. 242 and Lactobacillus brevis No. 173 demonstrated to be gas producers; thus, revealing their heterofermenter or facultative homofermenter features. Viable counts higher than 7.0 log10 (CFU/mL) were observed for Lactobacillus paracasei No. 244, Lactobacillus casei No. 210, L. brevis No. 173, Lactobacillus farraginis No. 206, Pediococcus pentosaceus No. 183, Lactobacillus uvarum No. 245 and Lactobacillus plantarum No. 135 strains, after exposure at pH 2.5 for 2 h. Moreover, L. plantarum No. 122, L. casei No. 210, Lactobacillus curvatus No. 51, L. paracasei No. 244, and L. coryniformins No. 71 showed growth inhibition properties against all the tested fifteen pathogenic strains. Finally, all LAB isolates showed antifungal activities against Aspergillus nidulans, Penicillium funiculosum, and Fusarium poae. These results unveiled the exceptionality of spontaneous sourdough as a source of LAB with effective potential to be considered in the design of novel commercial microbial single/mixed starter cultures, intended for application in a wide range of agri-food industries, where the antimicrobial and antifungal properties are often sought and necessary. In addition, metabolites therefrom may also be considered as important functional and bioactive compounds with high potential to be employed in food and feed, as well as cosmetic and pharmaceutical applications.

Monitoring of Lactobacillus sanfranciscensis strains during wheat and rye sourdough fermentations by CRISPR locus length polymorphism PCR

Lactobacillus (L.) sanfranciscensis is a competitive key species in sourdough fermentations. However, the principles involved in establishing the commonly observed phenomenon of strain dominance are unresolved. This has been studied little because the methods for fast and reliable differentiation of strains and their monitoring during fermentation are tedious and cannot be done with large numbers of isolates. In this contribution, we present a strain-specific, PCR-based typing method that uses length heterogeneities of the clustered regularly interspaced short palindromic repeats (CRISPR) loci as they occur in the genomes of different strains. In silico analysis of 21 genomes revealed 14 different CRISPR genotypes. We then designed a primer set to simultaneously detect different strains in a multiplex PCR assay designated CRISPR locus length polymorphism PCR (CLLP-PCR). The usefulness of this method was evaluated in lab-scale sourdough fermentations conducted with rye and wheat flours. First, the flour was mixed with water to a dough yield of 200. Then each dough was inoculated with four different L. sanfranciscensis strains (TMW 1.1150, TMW 1.392, TMW 1.2142, and TMW 1.2138) at levels of 109 cfu/g each. Sourdoughs were propagated at 28 °C for 5 days by back slopping 5% to the flour mass every 24 h. Samples were collected each day; DNA was isolated, and the presence of strains was detected qualitatively in the sourdoughs with PCR.L. sanfranciscensis TMW 1.392 became dominant as early as 2 days into the fermentation and remained the only detectable strain for the rest of the sampling period. CLLP-PCR proved to be useful in investigating the assertiveness of different strains of L. sanfranciscensis in sourdoughs. Therefore, CLLP-PCR may be used as a tool to investigate assertiveness of microorganisms in food fermentations at the strain level.

Use of expert estimate extrapolation method for selecting sourdough starter technological parameters

The quality of rye bread and bread made of the mixture of rye and wheat flour is largely determined by biotechnological processes occurring during the ripening of the sourdough starter. The factors that allow regulation of this process are the parameters of the nutrient mixture and the starter technology. Among the latter, there is the dosage of malt in the nutrient mixture, the ratio of fermented sourdough and the nutrient mixture, its humidity. The use of the specific decision depends on the experience and professionalism of the technologist. At the same time, given the complexity and multifactorial nature of the problem to be solved, decision making is not always unequivocal and guarantees the stability of the quality characteristics of the starters. Under these conditions, the use of extrapolation methods for unclear expert estimates has been proposed. The essence of this method consists in extrapolating the decision, made based on limited sample by the decision maker (DM) as a result of pairwise comparison, to the entire set of alternatives, identifying the DM’s preferences and constructing a selection mechanism based on the information received. Testing the methods based on the results of the undertaken research allows us to conclude that the proposed methods are effective in solving the problem of choosing the optimal technological parameters for preparing liquid rye sourdough starter.

Stability of ergot alkaloids during the process of baking rye bread

Changes in the concentrations of six major R-configuration ergot alkaloids (EA) and their S-configuration epimers were studied during the entire process of rye sourdough bread production. The EA were practically stable at the sourdough and dough preparation stages; however, significant reductions (α = 0.05) were noted after the thermal processing stage (baking): on average, the EA concentration dropped by 22%, from 3970 ± 582 μg/kg in the flour to 3090 ± 144 μg/kg in the baked bread. It was an outcome showing two opposite trends: the concentration of R-configuration enantiomers dropped by 46%, while that of their S-configuration counterparts increased by 21%. It seems that the process of baking bread, which creates S-configuration epimers of EA, contributes to reducing the toxicity of the final product. However, given their potential cytotoxicity and the possible reversibility of the reaction (during further processing of the bread) towards the formation of R-configuration epimers, both enantiomeric forms should be considered with regards to food safety. The high stability of EA during bread-making processes and lack of any European Union regulations concerning their maximum permissible levels in foodstuffs may pose a risk to the health of people whose diet is based on rye grain-based products.

Исследование влияния новых штаммов молочнокислых бактерий на качество густой ржаной закваски и хлеб

Исследование влияния новых штаммов молочнокислых бактерий на качество густой ржаной закваски и хлеб

Lifestyles of sourdough lactobacilli – Do they matter for microbial ecology and bread quality?

Sourdough is used in production of (steamed) bread as leavening agent (type I sourdoughs) or as baking improver to enhance flavour, texture, and shelf life of bread (type II sourdoughs). The long-term propagation of sourdoughs eliminates dispersal limitation and consistently leads to sourdough microbiota that are composed of host adapted lactobacilli. In contrast, community assembly in spontaneous cereal fermentations is limited by dispersal and nomadic or environmental lactic acid bacteria are the first colonizers of these sourdoughs.Propagation of sourdoughs for use as sole leavening agent (type I sourdoughs) dictates fermentation conditions that select for rapid growth. Type I wheat- and rye sourdoughs are consistently populated by insect-adapted lactobacilli, particularly Lactobacillus sanfranciscensis, which is characterized by a small genome size and a restricted metabolic potential. The diverse fermentation conditions employed in industrial or artisanal Type II sourdough fermentation processes also result in a more diverse microbiota. Nevertheless, type II sourdoughs are typically populated by vertebrate host adapted lactobacilli of the L. delbrueckii and L. reuteri groups. Metabolic traits of host-adapted lactobacilli that enhance competitiveness in intestinal ecosystems also provide technological functionality in bread making. Examples include formation of exopolysaccharides, arginine-, glutamine- and glutamate based mechanisms of acid resistance, and glycosyl hydrolases that reduce FODMAP levels in sourdough and sourdough bread. In conclusion, consideration of the lifestyle of sourdough lactobacilli facilitates the selection of competitive and functional sourdough starter cultures.

Identification of Lactic Acid Bacteria from Spontaneous Rye Sourdough and Determination of Their Functional Characteristics

ABSTRACTThis study aimed to identify Lactic Acid Bacteria (LAB) present in rye and rye bran sourdoughs that were prepared spontaneously and determine their functional characteristics. Genotypic characterization of the isolates revealed the presence of 15 distinct LAB strains belonging to 6 different species; Leuconostoc citreum, Lactobacillus plantarum, Lactobacillus graminis, Lactococcus lactis subsp. cremoris, Weissella confusa, and Weissella cibaria in rye sourdoughs. PCR screening of eps genes required for exopolysaccharide (EPS) production revealed that all strains possessed at least one gene required for EPS production and all strains produced homopolymeric EPS comprised of glucose or fructose two Lactobacillus plantarum strains produced both glucan and fructan type EPS. Antifungal activity of these strains was tested against Aspergillus niger and Penicillium chrysogenum identified in this study and several patterns were observed. The phytase activity of these strains was also determined and all strains showed phytase activity with varying degrees.

Use of Sourdough in Low FODMAP Baking.

A low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet allows most irritable bowel syndrome (IBS) patients to manage their gastrointestinal symptoms by avoiding FODMAP-containing foods, such as onions, pulses, and products made from wheat or rye. The downside of a low FODMAP diet is the reduced intake of dietary fiber. Applying sourdoughs—with specific FODMAP-targeting metabolic properties—to wholegrain bread making can help to remarkably reduce the content of FODMAPs in bread without affecting the content of the slowly fermented and well-tolerated dietary fiber. In this review, we outline the metabolism of FODMAPs in conventional sourdoughs and outline concepts related to fructan and mannitol metabolism that allow development of low FODMAP sourdough bread. We also summarize clinical studies where low FODMAP but high fiber, rye sourdough bread was tested for its effects on gut fermentation and gastrointestinal symptoms with very promising results. The sourdough bread-making process offers a means to develop natural and fiber-rich low FODMAP bakery products for IBS patients and thereby help them to increase their dietary fiber intake.

Complete and Annotated Genome Sequence of the Sourdough Lactic Acid Bacterium Lactobacillus fermentum IMDO 130101.

ABSTRACTLactobacillus fermentum is a species of lactic acid bacteria that is frequently found in sourdough, a fermented flour-water mixture used in the production of bread and other baked goods. Here, we present the complete genome sequence of L. fermentum IMDO 130101, a candidate sourdough starter culture strain isolated from a backslopped rye sourdough.

A Comparison Study on the Production and Recovery of Lactic Acid by Fermenting Dairy By-Products with P. acidilactici and Lb. delbrüeckii spp. bulgaricus

This paper provides a comparative study on the fermentative production of lactic acid (LA) by the novel Pediococcus acidilactici KTU05-7, previously isolated from rye sourdough, and the common dairy Lactobacillus delbrueckii spp. bulgaricus using dairy by-products as a substrate. Lactic acid bacteria growth in different fermentation medium, β-d-galactosidase activity, lactose consumption, distribution of l(+)/d(−)-lactic acid isomers and LA purification using a system of membranes were also examined. The highest LA yield (1.9 g/g) was obtained fermenting the whey permeate for 24 h with the novel P. acidilactici. This strain also showed a better growth in whey permeate, a higher tolerance to low pH conditions and tended to produce mainly l(+)-lactic acid, compared to the standard L. bulgaricus. Furthermore, the proteolytic action of P. acidilactici simplified the membrane filtration procedure, and hindered the formation of protein aggregate in fermented broth as compared to L. bulgaricus. The findings of this research suggest that the Pediococcus acidilactici strain has a potential to improve the biotechnological production of LA from dairy industry waste and its recovery by membrane processes.

Bards use in production technologies rye-wheat bread

A secondary product of the production of bioethanol is pislyaspyrtova dry bard, which is a raw material that incorporates contains proteins, fats, carbohydrates, and essential amino acids. Hence the search for ways to use it as an alternative raw material in technology baking industry since bread - this is the daily hand food among the population. The article analyzes the current state and prospects of processing pislyaspyrtovoyi bards - a secondary product in the production of bioethanol from corn, reasonably and explored ways to use baking industry. An edible product potential. For the research work of drying pislyaspyrtovoyi bards was developed manufacturing process technology and rye - wheat bread yeast. Studied the composition of microflora of sourdough rye and their role in shaping the quality of bread. On this basis, the author PSBC reasonably possible use in a biologically valuable raw materials in the production of bakery industry. Based on research organoleptic, physical, chemical and microbiological parameters PSBC reasonable prospects of using technology in rye-wheat bread. Past studies prove the effectiveness of the use of technology PSBC preparation rye sourdough in the production of rye-wheat bread, produces high quality products that meet the requirements of regulatory documents. To conduct research projects on drying of PSBC was developed process technology and rye - wheat bread to leaven. The composition of the microflora of sourdough rye and their role in shaping the quality of bread.

오미자 발효액을 이용한 호밀 사워반죽(sourdough)의 발효 특성

In this study, the fermentative characteristics of rye sourdough fermented with Omija extract were investigated. The pH and total titratable acidity, numbers of yeast and lactic acid bacteria, and expansion rate were measured. While the pH of Omija rye sourdough decreased from 5.60 to 3.86, the total titratable acidity significantly increased from 2.39 to 8.50 with fermentation time (p<0.05). The numbers of yeast and lactic acid bacteria significantly increased for 18 h of fermentation period (p<0.05). The expansion rate of Omija rye sourdough showed a maximum of 183%, more than 47% more than the highest value of rye sourdough (129%). These results suggest that the application of Omija extract for making sourdough could be a good way to decrease the sanitary risk especially for early stage of sourdough fermentation. In addition, Omija rye sourdough could contribute to improvement of baking quality such as volume increase and flavor improvement of rye bread.

The contribution of P. acidilactici, L. plantarum, and L. curvatus starters and L-(+)-lactic acid to the acrylamide content and quality parameters of mixed rye - Wheat bread

Lactic acid bacteria (LAB) from spontaneous rye sourdough were isolated, identified, and characterized by their growth, acidification rate, and carbohydrate metabolism. The isolated LAB were used for production of rye sourdough, and the influence of sourdough on mixed rye - wheat bread quality and acrylamide formation was evaluated. In addition, comparative studies by using acidification with L-(+)-lactic acid for mixed rye – wheat bread production were performed.Isolated LAB (P. acidilactici, L. plantarum, L. curvatus) demonstrated versatile carbohydrate metabolism, grown at 30 °C and 37 °C, and acidic tolerance. When the isolated strains were used for rye sourdough production, they showed good growth, acidification rates while excreting amylolytic and proteolytic enzymes. Rye sourdoughs delay bread staling, and there was a significant effect of type of dough acidification (with LAB or L-(+)-lactic acid) and the quantity of acidification agent used (5% or 15%) on most of the analyzed bread quality parameters. L. plantarum sourdough (added in the amount of 5% and 15%) decreased the acrylamide content in bread samples (p < 0.0001), unlike dough acidification with L-(+)-lactic acid. Thus the selected LAB could be recommended for improving the quality of bread, including the reduction of acrylamide content.