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Copyright of Çukurova Journal of Agriculture & Food Sciences is the property of Cukurova University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Relying on auto-ethnography, I reflect on the role sourdough and bread-making practices have played during the COVID-19 pandemic. I explore the agency of a non-human entity—the sourdough—and the relations that emerge from nurturing it. In particular, I inquire what living relationally means for me—a professional migrant—in a time that is not only challenging, due to the pandemic and consequent lockdown away from my country of origin, but which has also forced me to proactively and creatively respond to being in a precarious employment. Sourdough and bread-making practices have allowed me to create, recreate, and reinforce new and existing relations. I, thus, indicate to what extent such practices activate kin making and knowledge making, whilst counterbalancing the alienation and distress that come from experiencing a pandemic. [ABSTRACT FROM AUTHOR]

Abstract Previous investigations on pizza dough lactic acid bacteria (LAB) revealed that facultative heterofermentative species (FHS) were more represented than obligate heterofermentative species (OHS) within the Lactobacillus genus. Thus, the main hypothesis of this work was that facultative and obligate heterofermentative Lactobacillus species can impact differently the appreciation of baked pizza. The performances of different Lactobacillus , including L. sanfranciscensis , L. brevis and L. rossiae among OHS and L. plantarum , L. graminis and L. curvatus among FHS were tested in single or multiple combinations during pizza production. The values of pH, total titratable acidity and LAB levels indicated that the acidification process was almost comparable among trials. The fermentation quotient of FHS trials was above 4.0. All trials were dominated by the added LAB and for the trials with the multiple strain starter inoculums, the species found at the highest cell densities were L. sanfranciscensis , L. brevis and L. plantarum. Significant differences among pizzas were found for weight loss, colour, morphology and volatile organic compounds (VOCs). The last analysis revealed the presence of eight chemical classes with aldehydes, esters, alcohols and acids as major compounds and allowed the separation of the trials FHS and OHS. Sensory attributes were significantly different for judges and pizzas and the most relevant differences were found for crust colour, presence of bubbles, resistance to tearing, crispness and chewiness. The overall assessment reached the highest scores for the mixed culture of OHS and FHS together. Highlights • Facultative and obligate heterofermentative Lactobacillus grew similarly. • Pizza doughs were dominated by L. sanfranciscensis , L. brevis and L. plantarum. • Facultative heterofermentative species determined the highest fermentation quotient. • Chemical and physical analyses indicated differences among trials. • The best results were registered in the presence of the most complex mixed inoculums. [ABSTRACT FROM AUTHOR]

Highlights • The dominant microorganisms are Lactobacillus , Pediococcus , and Wickerhamomyces. • Some sourdoughs showed better fermentation effects than baker's yeast. • Wickerhamomyces may significantly improve the potato steamed bread quality. • Sourdough can be used to ameliorate the quality of potato steamed bread. Abstract To improve the quality of potato steamed bread, the microbial diversity of 5 different sourdoughs and their effects on potato steamed bread were studied. The proximate composition analysis differentiated the Chinese traditional sourdough (CTS) with different levels of nutrients and pH (3.82–6.22). High-throughput sequencing revealed the predominant microbes in the five CTSs were Lactobacillus , Pediococcus , and Wickerhamomyces. Similarities of bacterial and fungal compositions were observed within them. The fermentation rheological results suggested CTS1 and CTS3 had higher total gas production value (2355.5 mL and 2249.5 mL respectively) than baker's yeast. CTSs resulted in various effects on the appearance and texture properties of potato steamed bread with CTS1 showed the highest specific volume (2.38 mL/g) and sensory score (7.43). Wickerhamomyces significantly correlated with the total gas production, hardness, resilience, and lightness of potato steamed bread. The study suggested a potential application of CTSs in fermented potato staple foods. [ABSTRACT FROM AUTHOR]

Abstract In traditional sourdough fermentation recipes of artisan bakeries, often extra ingredients are added to the flour-water mixture. This may accentuate the aroma and taste of the baked products produced from such sourdoughs. This is made possible, for instance, by stimulating certain microbial activities during fermentation. This study examined the effects of the addition of citrate (a food-grade organic acid present in milk and lemons) on wheat sourdough fermentation in the presence of a citrate-positive, homofermentative, lactic acid bacterial starter culture strain, namely Lactobacillus crustorum LMG 23699. Both liquid and firm wheat sourdoughs were produced. The starter culture strain was able to steer all wheat sourdough fermentations performed, as it always prevailed due to its competitiveness, as shown through culture-dependent microbiological plating and culture-independent bacterial community profiling. Moreover, it possessed all enzyme-encoding genes (as unraveled through genome mining) necessary to convert citrate into desirable compounds such as lactic acid, acetic acid, succinate, acetoin, diacetyl, and 2,3-butanediol. Indeed, citrate addition to the wheat flour-water mixture had an impact on the sourdough fermentation dynamics and thus on the aroma profile of the liquid and firm sourdoughs produced and breads made thereof. A higher final pH, higher total titratable acidity values, and low yeast counts were found in wheat sourdoughs produced with citrate. In particular, the starter culture strain added converted the supplemented citrate into more l -lactic acid as well as acetoin and diacetyl (buttery aroma compounds), which was independent of the dough yield. The buttery aroma compounds were also accentuated in the concomitant breads produced. Further, organic acid production was stimulated in the sourdoughs, whereas increased pyrazine concentrations occurred in the breads. Consequently, citrate supplementation to wheat sourdoughs could be of interest to produce baked goods with enhanced buttery aroma compounds and notes. Highlights • The addition of citrate impacts wheat sourdough fermentations. • Lactobacillus crustorum is able to steer wheat sourdough fermentations. • Lactobacillus crustorum converts citrate into lactate, acetoin, and diacetyl. • Citrate metabolites impact the aroma of wheat sourdoughs and breads produced thereof. [ABSTRACT FROM AUTHOR]

The effect of sourdough amount and storage time on starch digestibility and estimated glycemic index (eGI) of tef bread was investigated. The rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) of 0–30% sourdough fresh tef breads ranged from 49 to 58, 16 to 29 and 20 to 26 g/100 g starch, respectively. Storage of tef breads up to 5 days decreased the RDS by more than 2-fold while SDS and RS increased by 2 and 3 fold, respectively. The eGI for fresh and stored breads ranged from 39 to 89. Addition of sourdough increased the eGI of fresh breads while no uniform pattern was seen in the stored breads. As the storage time increased, all the breads showed a decrease in eGI. In vivo study is necessary to further investigate the effect of sourdough on GI of tef bread. [ABSTRACT FROM AUTHOR]

The impact of processing conditions on the microbial quality of par-baked wheat and sourdough bread was investigated. Processing conditions included par-baking time (8 and 13 min), temperature (150 and 200 °C), amount of steam (200 and 600 mL), and packaging (air and modified atmosphere (MA)). Total anaerobic mesophilic plate counts, moulds and yeasts and spore-forming bacteria, together with pH and a w of the par-baked breads were evaluated. Data were used to make predictive models showing the impact of the main effects and their interactions. Sourdough addition could extend the time of acceptable bread quality based on the anaerobic counts from 8 to more than 13 days. Visual growth of moulds and yeasts (presence/absence of single spots) was most efficiently suppressed by the combination of MA-packaging and the highest baking temperature and time. Microbiological analysis of moulds and yeasts however, showed that again sourdough had the best preservation potential, followed by MA-packaging. This study showed that adjusting the par-baking conditions, bread composition and packaging can increase the shelf-life of par-baked bread in a natural way. [ABSTRACT FROM AUTHOR]

The lactic acid bacterial diversity of wheat sourdoughs collected in Ya'an city, Sichuan province was investigated by culture-dependent methods combined with 16S rRNA gene sequencing, and the exopolysaccharide (EPS) production characteristics of ropy lactic acid bacteria (LAB) strains from these sourdoughs were evaluated. Two hundred nineteen LAB strains were isolated, and genotypic characterization indicated that the isolated LAB strains included Lactobacillus plantarum ( L. plantarum ), L. pantheris , Leuconostoc citreum ( Leu. citreum ), Weissella viridescens , Leu. pseudomesenteroides , Lactococcus lactis ( L. lactis ), L. raffinolactis , and Leu. mesenteroides . All the isolates were found to harbor genes coding for EPS, and the yield of EPS produced by “ropy” LAB strains ranged between 2.3 and 229.5 mg/g wet cell weight. The present study enhances our knowledge about LAB diversity in Ya'an sourdoughs and provides information about the EPS-producing LAB strains in sourdough samples, which might be favorable for the application of specific LAB strains in sourdough technology. [ABSTRACT FROM AUTHOR]

Sourdough (SD), as a natural ingredient, has the highly promising potential to compensate the effect of salt reduction on flavour and the consequent influence on further sensory characteristics in bakery products. The objective of this research was to determine the impact of SD (5, 10 and 20% flour basis) on the structure, flavour and quality characteristics of puff pastry with reduced fat (− 40%) and salt (− 30%) content (RFRS) as well as the rheological properties of the resulting dough. A range of empirical rheological tests was carried out including dough extensibility, dough stickiness and GlutoPeak test. Subsequently, the baked puff pastry quality was investigated using a VolScan, texture analyser, C-Cell and sensory analysis. SD addition significantly changed rheological properties of the basic dough reduced in fat and salt as well as a number of major quality characteristics for the resulting puff pastry. Dough resistance decreased and dough stickiness increased (p < 0.05). Gluten formation was delayed for the higher in salt control and accelerated upon salt reduction as well as increasing levels of SD incorporation. Furthermore, SD addition weakened the gluten network. To some extent, RFRS containing SD were significantly enhanced in texture. Peak firmness of RFRS with SD was significantly decreased when compared to RFRS without SD. Furthermore, the specific volume of RFRS with 5 and 10% SD was significantly higher than for RFRS containing no SD. Finally, supported by a sensory study, the flavour and texture of reduced fat and salt pastry were distinctly improved by 10% SD addition. [ABSTRACT FROM AUTHOR]

Chickpea, a relevant legume worldwide, can be nutritional and functionally improved by fermentation with lactic acid bacteria (LAB). In order to select suitable autochthonous starter cultures, we isolated and identified LAB from kabuli chickpeas cultivated and consumed in northwestern Argentina, and screened their relevant techno-functional properties. Chickpeas were milled and spontaneously fermented with daily back-slopping at 37 °C for 6 days and evolution of microbial populations were followed by plate counting. Phenotypic and genotypic methods including (GTG) 5 -based PCR fingerprinting and 16S rDNA sequencing were used to differentiate and identify the isolates to species level. A marked increase of LAB counts was observed throughout fermentation raising from 0.88 ± 0.35 log CFU/g of unfermented flours to 9.61 ± 0.21 log CFU/g after 5 back-slopping steps with a concomitant pH decline from 6.09 ± 0.05 to 4.40 ± 0.03. Eighteen strains belonging to four LAB genera and six species: Enterococcus durans, E. mundtii, Lactococcus garvieae, Pediococcus pentosaceus , Weissella cibaria and W. paramesenteroides were identified in chickpea sourdoughs. Based on their abilities, Weissella cibaria CRL 2205 (acidification capacity), W. paramesenteroides CRL 2191 (proteolytic activity), Pediococcus pentosaceus CRL 2145 (gallate decarboxylase and peptidase activities), Lactococcus garviae CRL 2199 (α-galactosidase activity) and E. durans CRL 2193 (antimicrobial activity), were selected to design novel fermented chickpea products. [ABSTRACT FROM AUTHOR]

Previous studies have reported a substantial decline in in vitro digestibility of proso millet protein upon cooking. In this study, several processing techniques and cooking solutions were tested with the objective of preventing the loss in pepsin digestibility. Proso millet flour was subjected to the following processing techniques: high pressure processing (200 and 600 MPa for 5 and 20 min); germination (96 h); fermentation (48 h); roasting (dry heating); autoclaving (121 °C, 3 h), and treatment with transglutaminase (160 mg/g protein, 37 °C, 2 h). To study the interaction of millet proteins with solutes, millet flour was heated with sucrose (3–7 M); NaCl (2–6 M); and CaCl 2 (0.5–3 M). All processing treatments failed to prevent the loss in pepsin digestibility except germination and treatment with transglutaminase, which resulted in 23 and 39% increases in digestibility upon cooking, respectively, when compared with unprocessed cooked flours. Heating in concentrated solutions of sucrose and NaCl were effective in preventing the loss in pepsin digestibility, an effect that was attributed to a reduction in water activity (a w ). CaCl 2 was also successful in preventing the loss in digestibility but its action was similar to chaotrops like urea. Thus, a combination of enzymatic modification and cooking of millet flour with either naturally low a w substances or edible sources of chaotropic ions may be useful in processing of proso millet for development of novel foods without loss in digestibility. However, more research is required to determine optimum processing conditions. [ABSTRACT FROM AUTHOR]

The dietary fiber complex of cereal whole grain is an important source of host beneficial molecules, such as: beta-glucans, fructans, resistant starch and arabinoxylans. The bioavailability of these compounds from whole grain products is generally dependent to different physiological and technological issues, likewise: genotype and maturation stage, dough preparation, fermentation options and baking process. This study regards the production of breads from cereal whole grains, taking into account two wheat genotypes harvested at mature and immature stages and processed through different conditions, varying temperature, time of baking and fermentation parameters. The aim is to highlight the different impact of these aspects on the amount and the bioavailability of the aforementioned four bioactive molecules. Our results showed that the best product, in terms of content of beneficial compounds, is that obtained from the flour of advanced maturation stage processed with brewer's yeast fermentation. Given the great interest in finding better technological processes to increase the daily dietary fiber intake, our findings could be very useful for the food industry to design the exact formulation and best process for the increase of bio-active molecules concentration in cereal whole grains products. [ABSTRACT FROM AUTHOR]

The aim of this work was to develop an innovative formulation of fresh pasta, which combined semolina and liquid sourdough. Quality and shelf-life of pasta were monitored on unpacked fresh pasta and on pasta packed in modified atmosphere after pasteurization. The addition of sourdough and the pasteurization were responsible for a yellowness increase of pasta. After in vitro digestion of cooked pasta, a lower proportion of slowly digestible starch (SDS; 43.0 g/100 g) and a higher proportion of inaccessible digestible starch (IDS; 40.2 g/100 g) was found in sourdough pasta than the control (49.8 and 34.5 g/100 g of SDS and IDS), and in pasteurized pasta (44.0 and 39.3 g/100 g of SDS and IDS) than the fresh pasta (48.8 and 35.4 g/100 g of SDS and IDS). FT-Raman spectra of pasteurized sourdough pasta showed a higher level of retrograded starch, as indicated by the lower value (479.14 cm −1 ) of the frequency of the band peaked at ∼480 cm −1 , than the pasteurized control (479.47 cm −1 ). Unpacked sourdough pasta could be stored for one week without mould growth, which on the contrary appeared in the control. The pasteurization was more effective in sourdough pasta, with the complete disappearance of the microorganisms. [ABSTRACT FROM AUTHOR]

Sourdough, a mixture of wheat flour and water, fermented by the action of lactic acid bacteria (LAB) and yeasts, presents some technological advantages, such as improvement in dough structure, flavor, aroma, bread texture, and shelf life. Few studies related to methods of preservation of sourdoughs are currently available. This work aimed to test the cryoprotective effect of trehalose on microorganism survival and its effect on freezing, freeze-drying and storage of freeze-dried sourdough, and to molecularly identify predominant bacteria and yeasts. Refined and whole wheat flour were used to prepare the sourdough. On the 14th day of production, varying amounts of trehalose were added (0, 10 and 15%) and the sourdough was freeze-dried. The cryoprotective effect of trehalose was evaluated before and after freezing, after freeze-drying, and after 15, 30 and 45 days of storage. Predominant microorganisms were molecularly identified through amplification and sequencing of rDNA fragments. Addition of trehalose promoted a cryoprotective effect survival of microorganisms, and it was more significant for LAB. Lactobacillus plantarum, Lactobacillus fermentum, Saccharomyces cerevisiae, Pichia anomala and Pediococcus pentosaceus, were the main species recovered. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effects of liquid or dietary supplementation of sourdough on quail performance, composition of caecal microbiota and ileum histomorphology. A total of 120 healthy 14 d old quail (Coturnix cot. Japonica) were divided into three dietary treatments with 4 replicates each including 10 mixed sex quail (5 males and 5 females). Treatments were 1) Control, 2) liquid sourdough (4 ml/l) in drinking water, 3) dried sourdough (5 g/kg) in experimental diet. The experiment lasted 21 days. Live weight gain (LWG), feed intake (FI), and feed conversion ratio (FCR) recorded weekly. Caecum microbiota and ileum histomorphology were determined at the 21st day of the experiment. Results showed that the dietary sourdough supplementation increased LWG and FCR (P<0.05). FI was not affected by any treatments. Dietary sourdough supplementation decreased liver weight (P<0.05). Both dietary and liquid sourdough supplementation increased the colonisation from 5.74 to 7.60 and 6.90 cfu g-1 of yeast in the caecum respectively (P<0.05). Lactic acid bacteria (LAB) count tended to increase without any statistical difference. The colonisation of Enterobactericaea, E. coli and Coliforme bacteria were not affected by any treatments, but Coliformes counts tended to decrease. Dietary sourdough supplementation increased villi length and villi width compared to control and liquid sourdough supplemented group (P<0.05). To conclude, sourdough showed a probiotic effect and enhanced growth performance by affecting caecum microflora and increasing ileum villi length when given with the diet. Further studies with different animal species and different methods of application are needed. [ABSTRACT FROM AUTHOR]

Yeast strains collected from three spontaneous laboratory sourdoughs, prepared over 10 days and using a traditional Spanish protocol, and formulated with (non-essential) different ingredients were identified and described. In addition to wheat flour (Triticum aestivum) and water, organic apples (5 days juice fermented at 40°C), or plain yogurt, or organic white grapes (2 days must fermented at 20°C) were used at the beginning of each sourdough production. One-hundred-eighteen yeast colonies were collected from the different phases of sourdoughs (ingredients preparation, pre-sourdough, and ripe sourdough propagation) using WL agar and Lysine agar media. Yeast isolates were clustered into 8 groups using PCR-RFLP analysis of the 5.8S-ITS rRNA region. One strain of each group was chosen for sequencing to confirm yeast identification at species level. The specifically prepared fruit ingredients, apple and grape, provided diversity of non-Saccharomyces yeast to the respective sourdoughs. The dominant species in the pre-sourdough phase were Meyerozyma guilliermondii for apple sourdough and Hanseniaspora uvarum for grape sourdough. For yogurt sourdough, Saccharomyces cerevisiae was already the dominant yeast in the pre-sourdough phase with a low proportion of Meyerozyma guilliermondii and Wickerhamomyces anomalus. In the three sourdoughs, regardless of the different ingredients used, Saccharomyces cerevisiae was the dominant yeast in the ripe phase. [ABSTRACT FROM AUTHOR]

Effects of additions of buckwheat flour and sourdough on the total phenols content, antioxidant activity, and sensory properties of crackers were examined. Different mixtures of wheat flour with addition of buckwheat flour and sourdough were used for the prepartion of crackers. Two types of lactic acid bacteria (Lactobacillus plantarum and Lactobacillus brevis) were used for the preparation of buckwheat sourdough. Properties of crackers made with addition of buckwheat flour and sourdough were analysed in comparison to control crackers made only with wheat flour. Significant increase of total phenols in comparison to wheat flour dough (0.73 mg gallic acid equivalent (GA)/g of dry basis (d.b.)) was accomplished by adding buckwheat flour (1.12 mg GA/g d.b.) and sourdough (1.77 and 1.79 mg GA/g d.b.) regardless of the type of lactic acid bacteries used. All samples showed the decrease in total phenol content during baking process. Crackers with sourdough had higher antioxidant activity (16.84 and 15.84 mmol Fe3+/g d.b.) compared to crackers made with addition of buckwheat flour (10.42 mmol Fe3+/g d.b.) and control sample (7.76 mmol Fe3+/g d.b.). The result of sensory analysis showed positive influence of sourdough on taste and texture of crackers and insignificant differences in odour and appearance of tested samples. Also, the chewiness of crackers made with the addition of buckwheat flour and sourdough was improved compared to control crackers made from wheat flour. [ABSTRACT FROM AUTHOR]

A sourdough for the industrial production of Colomba , a traditional Italian sweet-leavened baked good, was characterized in terms of microbiota composition, pH, a w , carbohydrates, organic acids, and VOCs. pH of the ripened sourdough was low (3.55), and the content of acetic acid limited (0.77 g/kg). A small biodiversity, in terms of both LAB and yeasts, was observed. Culture dependent analyses identified two biotypes of Lactobacillus sanfranciscensis and a dominant yeast species, Torulaspora delbrueckii. Metataxonomic analysis confirmed bacterial composition, whereas Candida humilis was the most represented yeast. The VOCs profile was strongly affected by bakers' yeast addition, resulting in higher amounts of acetaldehyde, acetoin, ethanol, and phenethyl alcohol. As a whole, a stable and abundant microbial community loosing competitiveness only after addition of S. cerevisiae was described. This robustness and simplicity can represent an advantage in terms of stable and easier propagation, allowing the production of more reproducible lots of Colomba . [ABSTRACT FROM AUTHOR]

Benzoxazinoids (Bx) and their metabolites are molecules with suggested health effects in humans, found in cereal grains and consequently in cereal foods. However, to date little is known about the amount of Bx in our diet. In this study, deuterated standards 2-hydroxy-1,4-benzoxazin-3-one (HBOA-d 4 ) and 2-hydroxy- N -(2-hydroxyphenyl) acetamide (HHPAA-d 4 ) were synthesized, to allow quantification of nine Bx and their metabolites in 30 breads and flours from Nordic countries by UHPLC-MS/MS. Samples containing rye had larger amounts of Bx (143–3560 µg/g DM) than the ones containing wheat (11–449 µg/g DM). More Bx were found in whole grain wheat (57–449 µg/g DM) compared to refined wheat (11–92 µg/g DM) breads. Finnish sourdough rye breads were notably high in their 2-hydroxy- N -(2-hydroxyphenyl) acetamide (HHPAA) concentration (40–48 µg/g DM). This new information on Bx content in flours and breads available in the Nordic countries will be useful for future work on determining dietary exposure to Bx. [ABSTRACT FROM AUTHOR]

Aim Insect frass samples were collected from Drosophila melanogaster, Plodia interpunctella, Rhyzopertha dominica, Sitophilus granarius, Sitophilus oryzae, Sitophilus zeamais, Tribolium confusum and Tribolium castaneum to elucidate if they can be the origin of Type I sourdough micro-organisms ( Lactobacillus sanfranciscensis and Candida milleri). Methods and Results Selective enrichments were carried out to isolate lactic acid bacteria (LBA) and yeast. A metagenetic analysis, targeted on bacterial 16S rRNA gene and fungal ITS region, was performed by using Illumina MiSeq protocol. In cultivation conditions, Lactococcus garvieae and Rhodotorula mucilaginosa were the most frequently species among LAB and yeasts respectively. The Next Generation Sequencing approach revealed that Enterobacteriaceae, Pseudomonadacae and Bacillaceae were the dominating taxa, accounting for 61% of the bacterial community. Lactobacillus genus showed a relative abundance of only 0·36%, but L. sanfranciscensis proved to be the species most frequent between lactobacilli and predominant in faecal samples of T. castaneum and T. confusum larvae. The core fungal microbiota was constituted by Saccharomycetales, Pleosporaceae and Nectriaceae that attained the 51% of recognized OTUs. While the most abundant yeast genus was Candida (17·1%), sequences belonging to C. milleri were not found. Conclusions Frass released by the insects of stored cereal products can be the natural reservoir of L. sanfranciscensis. Significance and Impact of the Study Insect dejections are potential sources of novel strains for controlled bakery productions. [ABSTRACT FROM AUTHOR]

Different lactic acid bacteria (LAB) from spontaneous wheat sourdough were isolated, identified, and characterized by their growth, acidification rate, and carbohydrate metabolism. The combinations of isolated LAB ( Pediococcus pentosaceus LUHS183 and Leuconostoc mesenteroides LUHS242, P. pentosaceus LUHS183 and Lactobacillus brevis LUHS173, P. pentosaceus LUHS183 and Enterococcus pseudoavium LUHS 234, P. pentosaceus LUHS183 and Lactobacillus curvatus LUHS51, Lactobacillus plantarum LUHS135 and L. curvatus LUHS51, L. plantarum LUHS135 and P. pentosaceus LUHS183) were used for wheat sourdough production, and the effects of LAB fermentation in sourdoughs on wheat bread quality parameters and acrylamide formation were evaluated. All of the tested strains (except E. pseudoavium LUHS 234) were able to ferment l-arabinose, d-ribose, d-galactose, d-fructose, and d-maltose and showed high tolerance to acidic conditions. The highest overall acceptability (135.8 ± 5.5 mm) was found in the bread produced with L. plantarum and P. pentosaceus sourdough. This group of bread also showed the highest shape coefficient (2.59 ± 0.02), the highest specific volume (3.40 ± 0.03 cm3/g), the highest porosity (76.6 ± 0.3%), and the highest moisture content (33.7%). Selected sourdoughs reduced acrylamide content in bread samples by 29.5% (sourdough prepared with P. pentosaceus and L. mesenteroides) to 67.2% (sourdough prepared with P. pentosaceus and L. curvatus). These cultures potentially can be used to reduce acrylamide in breads. Practical Application The data of this study have practical applications. L. plantarum and P. pentosaceus sourdoughs increases overall acceptability, specific volume, and porosity of wheat bread. Besides the fact that sourdoughs produced by using combinations of selected LAB strains improved the quality parameters of bread, fermentation with prepared sourdoughs also reduced the acrylamide content in wheat bread samples by 29.5% (sourdough prepared with P. pentosaceus and L. mesenteroides) to 67.2% (sourdough prepared with P. pentosaceus and L. curvatus). [ABSTRACT FROM AUTHOR]

The effects of the substitution of wheat flour with faba bean flour and faba bean sourdough on the properties of composite bread were investigated. Bread was prepared by replacing wheat flour with 30% of faba bean flour, native or after sourdough fermentation. The addition of faba bean flour influenced the structure of the breads, causing a slight decrease of volume and higher hardness compared to wheat bread. However, when fermented faba bean flour was added, the crumb porosity of the bread was not affected. The addition of 30% of faba bean flour increased wheat bread protein content from 11.6 up to 16.5% of dry matter. The addition of native faba bean flour did not affect the in vitro protein digestibility, resulting similar to wheat bread (64%). On the contrary, faba bean sourdough bread showed higher protein digestibility (73%). Generally, the addition of native faba bean flour caused an improvement of the nutritional indexes of the composite bread, further enhanced when fermentation was carried out. The free amino acid profile, protein chemical score, and biological value index were the highest in faba bean sourdough bread. In addition, the predicted glycemic index was the lowest in faba bean sourdough bread. [ABSTRACT FROM AUTHOR]

There is an increasing prevalence of celiac disease, which is gradually encroaching into Africa and Nigeria ranks first among sorghum-producing African countries. It is important to select starter cultures that can improve the functional properties of peculiar flour such as sorghum for the development of novel gluten-free diets. Therefore, this study aimed at screening of functionally important lactic acid bacteria (LAB) and yeasts as starter cultures for the development of sorghum-based sourdough. A total of 103 LAB and 20 yeast isolates obtained from Nigerian sorghum flour were screened for functional properties essential for sourdough preparation. Three LAB isolates were selected based on proteolytic activities, exopolysaccharide production and acidification properties, while one yeast strain was selected based on its gas production ability, low pH and acetic acid tolerance. Pediococcus pentosaceus SA8, Weissella confusa SD8 and P. pentosaceus LD7 showed highest proteolytic activity (24.7 mm), exopolysaccharide production (753.3mg/100 ml) and acidification property (0.25 g/100 g lactic acid) respectively. Saccharomyces cerevisiae YC1 had vigorous gas production (CO 2 > 20 mm at 8 h), tolerated pH 2.5 and 0.1% acetic acid, and had highest leavening activities (60.87% at 1 h). The selected LAB and yeast strains possessed promising attributes as functional starter cultures for the production sourdoughs breads. [ABSTRACT FROM AUTHOR]

The aim of this work was to monitor the survival of rope-forming Bacillus subtilus ATCC6633 during three stages of sourdough fermentation with or without Lactobacillus acidophilus 20552 and/or Bifidobacterium lactis Bb 12. Strains of lactic acid bacteria (LAB) and one strain of bifidobacterium were tested for their antimicrobial activities, wherein L. acidophilus ATCC20552 recorded the greatest inhibition zones, followed by Bf. lactis Bb12, while L. acidophilus ATCC4495 and Lactobacillus plantarum ATCC14917 exhibited moderate activities. Sourdoughs were made using L. acidophilus and/or Bf. lactis with added B. subtilus and fermented for 72 h. Microbiological and physicochemical properties of dough samples were periodically (at three stages) determined. Total bacterial, yeasts and molds counts (logo cfu/g) gradually increased during fermentation and reached the maximum at the third stage. Addition of LAB strains, individually or in combination, recorded lower total bacterial counts as well as higher yeasts and molds counts than other treatments. Starter treatments recorded the highest LAB initially and during all fermentation stages. Spore-forming bacteria counts were sharply decreased during fermentation stages in all starter treatments while counts gradually increased in positive control (with only B. subtilis). At the end of fermentation, spore-forming bacteria were not detected in starter treatments. pH values of sourdoughs decreased gradually till the end of fermentation. Starter treatments recorded the lowest pH values during all fermentation stages. Total titratable acidity (TTA) increased after the first fermentation stage and these increments were higher in starter treatments than both positive and negative controls. It could be concluded that using three-stage fermentation method gives L. acidophilus and Bf. lactis the chance to completely inhibit rope-forming B. subtilus. Practical Applications Cereal-based foods represent an important source of biological as well as of cultural diversity, as testified by the wide range of derived fermented products. A trend that is increasingly attracting bakery industries as well as consumers is the use of biotechnology to produce novel products, characterized by peculiar flavor, better nutritional value and longer shelf life. The aim of our work was to monitor the survival of rope-forming B. subtilus during stages of sourdough fermentation with or without LAB. The results showed that LAB recorded low total bacterial counts, low pH values and high TTA in sourdough. Using three-stage fermentation method may give LAB the chance to inhibit rope-forming B. subtilus. [ABSTRACT FROM AUTHOR]

The optimisation of the quantity of sourdough (A) prepared with two different fermentation methods, [spontaneous fermentation (F1) vs. starter of lactic acid bacteria-added fermentation (F2)], instant active dry yeast (B) and wheat bran (C) for a nutritionally improved bread formulation has been studied by evaluating the bioavailability and bioactive properties. The bread produced according to the optimised formula and fermentation types of F1 ( OBF1) and F2 ( OBF2) was compared with control bread ( CB). The optimised levels for F1 were 11.45% for sourdough, 1.10% for dry yeast and 1.58% for wheat bran and for F2 6.99% for sourdough, 1.02% for dry yeast and 38.84% for wheat bran. The addition of sourdough significantly ( P < 0.05) affected antioxidant activity, total phenolic content, in vitro ash and protein digestibility, and enzyme resistance starch contents of bread. The F1 fermentation method was found to be more effective in terms of bread properties examined. [ABSTRACT FROM AUTHOR]

The primary aim of the industrial use of sourdough is to improve bread quality and to replace additives. This study investigates the applicability of frozen stored barley sourdough in wheat bread. Sourdough was fermented with Weissella cibaria in the presence of sucrose and xylanase, and stored frozen for 4, 8, or 12 weeks. During storage, the number of viable cells in the sourdough declined. Softer dough and crumb were obtained after the sourdough was stored for a longer period (4 weeks), while bread specific volume was unaffected by the sourdough storage time. The highest bread specific volume, shape, crumb softness, and sensory liking were obtained with 20% of the sourdough. This study demonstrates the possibility for the industrial application of frozen barley sourdough, since it can improve the quality of bread compared to the native barley flour. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The process of dough preparation is an important stage in the production of bread, which has a significant effect on quality of the end product. Bakery yeast ( Saccharomyces cerevisiae) and sourdough are used for dough fermentation worldwide and are very important for bread quality. Flavor and aroma of bread are important factors for acceptance of bread, which can be affected by the method of dough production. The effect of sourdough, bakery yeast, sodium bicarbonate and combination of bakery yeast and sodium bicarbonate for the production of flat bread (Lavash), on volatile compounds and sensory properties of bread, was studied. The changes in the headspace aroma volatiles were assessed using solid-phase micro-extraction (SPME) GC-MS analysis. A total of 31 compounds were identified in the samples. The obtained results showed differences in the volatile composition of the different types of bread. Bread produced by the combination of bakery yeast and sodium bicarbonate had most volatile compounds. The abundant volatile compounds identified in bakery yeast-raised bread were butanal-3-methyl,butanol-3-methyl and hexanal, in the sourdough bread, they were ethanol, furan-2-metyhl and pentan, in the sodium bicarbonate bread, they were benzene-1,3-dimethyl, 2,4 nonadiene and limonene and in the combination of sodium bicarbonate and bakery yeast bread, they were furan-2-methyl, butanol-3-methyl and hexanal. Practical Applications The present study evaluated the effect of sourdough, bakery yeast, sodium bicarbonate and combination of yeast and sodium bicarbonate on the volatile compounds of Lavash bread. Some of the volatile compounds were found in the four samples. The number of volatile compounds in bread produced from the combination of yeast and sodium bicarbonate was higher than that of other samples. The sensory evaluation of samples (shape, upper and beneath surface, odor, flavor, color, firmness and softness of texture and chewing ability) showed that bread produced from the combination of yeast and sodium bicarbonate has higher score than other samples based on the scoring of a panelist group. [ABSTRACT FROM AUTHOR]

The microbial ecology of faba bean sourdoughs obtained from an Italian (Ita) and a Finnish (Fi) cultivar, belonging respectively to Vicia faba major and V . faba minor groups, was described by 16S rRNA gene pyrosequencing and culture-dependent analysis. The sourdoughs were propagated with traditional backslopping procedure throughout 14 days. Higher microbial diversity was found in the sourdough deriving from V . faba minor (Fi), still containing residual hulls after the milling procedure. After 2 days of propagation, the microbial profile of Ita sourdough was characterized by the dominance of the genera Pediococcus , Leuconostoc and Weissella , while the genera Lactococcus , Lactobacillus and Escherichia , as well as Enterobacteriaceae were present in Fi sourdoughs. Yeasts were in very low cell density until the second backslopping and were not anymore found after this time by plate count or pyrosequencing analysis. Among the lactic acid bacteria isolates, Pediococcus pentosaceus , Leuconostoc mesenteroides and Weissella koreensis had the highest frequency of occurrence in both the sourdoughs. Lactobacillus sakei was the only lactobacillus isolated from the first to the last propagation day in Fi sourdough. According to microbiological and acidification properties, the maturity of the sourdoughs was reached after 5 days. The presence of hulls and the different microbial composition reflected on biochemical characteristics of Fi sourdoughs, including acidification and phenolic compounds. Moreover, proteolysis in Fi sourdough was more intense compared to Ita. The microbial dynamic of the faba bean sourdoughs showed some differences with the most studied cereal sourdoughs. [ABSTRACT FROM AUTHOR]

In the present study we evaluate the effect of honey on the growth and fermentative ability of two sourdough fermenting lactic acid bacteria (LAB), Pediococcus pentosaceus and Lactobacillus fermentum , and the impact that honey and LAB have on gluten microstructure. Growth kinetics and fermentative analyses were carried out through cell viability and potenciometry assays, respectively. Honey supplementation of sourdough increased LAB population. L. fermentum exhibited a higher growth rate, while P. pentosaceus was more acidifying. The fermentative profile of LAB was not altered by the presence of honey. The microstructure analyses were performed through scanning electron microscopy (SEM) and revealed that the microstructure of dough was modified by the fermenting activity of LAB, being involved in the development of gluten fibrils. In addition, honey induced changes in the microstructure of those dough whose pH value were higher than 4, disclosing a strong association between protein subunits. [ABSTRACT FROM AUTHOR]

In order to explore the community of lactic acid bacteria (LAB) and yeasts present in two major typical Sicilian sourdoughs, seven mature sourdoughs for "Pane Nero di Castelvetrano" (CV1 - CV3 samples) and "Pane di Monreale" (MR1 - MR4 samples) were analysed through a culturedependent and culture-independent approach. The highest values of microbial counts were revealed in MR1 sourdough. In particular, LAB counts were at about 109 CFU/g in media specific for typical sourdough LAB, such as SDB and SFM, while levels of 106 CFU/g were registered for yeasts. The total DNA form each sourdough sample was extracted and subjected to a multiplex-PCR in order to recognize the major groups of LAB. Seventy-six LAB with a rod shape, presumptively Lactobacillus, were phenotypically grouped and subjected to a genotypic identification by sequencing of the 16S rRNA gene and further confirmed by species-specific PCRs. Yeasts were isolated and identified by a combined genotypic approach consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and sequencing of D1/D2 domain of the 26S rRNA gene. The LAB species identified were Lactobacillus sanfranciscensis, Lactobacillus paralimentarius, Lactobacillus brevis and Lactobacillus coryniformis. Among yeasts, Saccharomyces cerevisiae, Pichia guiliermondii, Pichia segobiensis, Rhodotorula acuta and Rhodotorula mucilaginosa were the species hosted in Sicilian sourdough. The multiplex PCR carried out on total DNA of sourdoughs allowed the rapid identification of the majority of sourdough lactobacilli but the culture-dependent methodology was confirmed to be necessary for the detection of the species, such as Lactobacillus coryniformis not included in the system. [ABSTRACT FROM AUTHOR]

Organic farming preserves biodiversity and organic products can be the source of many microbial species. The species diversity in organically grown wheat, spelt and rye was investigated in order to find strains suitable for sourdough fermentation. Colonies representing various morphological appearances were isolated and catalase-negative colonies were identified by mass spectrometer Microflex LT ™ MALDI-TOF. The fermentation products (lactic, acetic, formic and phenyllactic acid) were determined by high performance liquid chromatography, while the antifungal activity was determined using an overlay agar method. Wheat flours showed less microbial biodiversity than the rye and spelt flours. The most common genera in the tested flour were Lactobacillus, Pediococcus and Enterococcus. Isolated Lactobacillus farciminis, Pediococcus pentosaceus, Leuconostoc citreum and Lactobacillus brevis showed the best acidification activity. Lactobacillus brevis, Pediococcus pentosaceus, Weissella cibaria and Lactobacillus farciminis showed significant antifungal activity against A. niger 357 and Penicillium sp. 505. The prefermented medium of Lactobacillus farciminis were characterized by high content of lactic and phenyllactic acid. [ABSTRACT FROM AUTHOR]

The purpose of the research was to obtain innovative yeast-free doughs leavened by Zymomonas mobilis and Lactobacillus sanfranciscensis . Z. mobilis , as well as Saccharomyces cerevisiae, produces an equimolar mixture of ethanol and CO 2 through glucose, fructose or sucrose fermentation. In the present work, the inability of Z. mobilis to metabolize maltose has been circumvented by the addition of L. sanfranciscensis in the formulation. Indeed, L. sanfranciscensis, a heterofermentative lactic acid bacterium (LAB) typical of sourdough environment, hydrolyzes maltose releasing glucose which can be used by Z. mobilis for its metabolism. Biomass samples of Z. mobilis subs. mobilis DSM 424 and L. sanfranciscensis DSM 20663 were grown separately in liquid media and then associated in a model dough. Leavening trials set up by using three different microbial combinations ( Lactobacillus:Zymomonas 80 + 80 mg, 15 + 145 mg and 145 + 15 mg biomass, i.e. 1:1, 1:10 and 10:1 respectively on cell dry weight basis) evidenced CO 2 production levels (mL) higher than the mathematical sum of CO 2 produced by the single bacteria. In particular, when the biomass combination of L. sanfranciscensis and Z. mobilis was 1:1 (80 + 80 mg cdw) and 10:1 (145 + 15 mg cdw) a CO 2 production of 46.3–41.4 mL versus 26.7–28.5 mL was achieved. The calculated productivity gain showed positive performances of the microbial combination up to 180–240 min leavening. The subsequent efficiency loss may be due several factors, above all glucose shortage for Z. mobilis, as well as decrease of dough pH that can negatively affect both Lactobacillus and Zymomonas metabolism. As in traditional sourdoughs, L. sanfranciscensis was responsible for the souring activity with positive effects on both dough tasting and reduction of spoilage microbiota; Z. mobilis was instead responsible for most of the CO 2 production. A bakery product leavened with the unconventional association Z. mobilis - L. sanfranciscensis will be addressed to people having adverse responses to the ingestion of bakery goods, thus providing innovation in the area of yeast-free leavened food. [ABSTRACT FROM AUTHOR]

The preparation of sourdough in bakeries may include the use of inocula, e.g. fruits, flowers or rumen cuts to accelerate the process of selection of suitable microorganisms. The aim of this work was to investigate the effect of these inocula on the microbial evolution in sourdoughs. First, the microbiota of nineteen traditional sourdoughs that were initially started with diverse inocula was identified. Second, de novo sourdoughs were started with plant materials and the evolution of sourdough microbiota was investigated by culture, and by high-resolution melting curve quantitative PCR (HRM-qPCR). This study developed a new protocol for HRM-qPCR analysis of yeast microbiota in sourdough, and indicates this independent culture method suitable for characterization of yeasts. Microbiota of traditional sourdoughs were largely independent from the use of inoculum, however, Acetobacter spp. were identified only in sourdoughs started with apple flowers or apple pulp. In de novo sourdoughs started with plant materials, microbiota rapidly stabilized, and were characterized by Lactobacillus sanfranciscensis , Lactobacillus plantarum , Lactobacillus graminis , or Lactobacillus rossiae , and Saccharomyces cerevisiae as dominant species. Competition experiments revealed that the ecological fitness of L. plantarum , L. graminis , and L. rossiae in wheat or rye malt sourdoughs was lower when compared to L. sanfranciscensis , demonstrating that their presence in de novo sourdoughs reflects dispersal limitation. In conclusion, establishment of microbiota in de novo sourdoughs is dispersal limited. This study provides scientific support for the artisanal practice to inoculate de novo sourdoughs with flowers, berries, or related plant material. [ABSTRACT FROM AUTHOR]

A total of 249 Lactic Acid Bacteria (LAB) isolates were found in traditional Turkish wheat sourdoughs from Eastern Black Sea region of Turkey. Genotypic characterization of these isolates revealed the presence of 47 distinct LAB strains belonging to 11 different species: Lactobacillus plantarum , Lactobacillus paraplantarum , Lactobacillus curvatus , Lactobacillus rossiae , Lactobacillus sanfranciscensis , Lactobacillus brevis , Lactobacillus paralimentarius , Weissella paramesenteroides , Leuconostoc mesenteroides , Leuconostoc pseudomesenteroides and Weissella cibaria . The sourdough LAB microbiota differed depending on the sample origin and the collection period and heterofermentative LAB were dominant. The number of different species within a sourdough varied from 3 to 6 with the association of different hetero- and homofermentative LAB species. Exopolysaccharide (EPS) production characteristics of the isolates were determined and strain specific properties appeared to be important for the final EPS yields. Genes required for homopolysaccharide ( gtf and lev ) and heteropolysaccharide ( epsA , epsB , p-gtf ) production were PCR detected and several distribution patterns were observed. Results of this study confirmed the biodiversity of LAB species in traditional Turkish sourdough and highlighted the importance of EPS production in sourdough LAB strains. [ABSTRACT FROM AUTHOR]

The interplay of sourdough microbiology and generated volatile compounds that define its sensory characteristics was studied. In order to detail the flavour generating potential of microorganisms, eight single-strain dough fermentations were studied, four of them never investigated before. Moreover, for the first time, both ex-novo and traditional wheat sourdoughs were investigated and compared to chemically acidified dough. HS-SPME-GC-MS was used to sample and analyse volatile compounds, some of which have never been detected before in sourdoughs. Alcohols, esters, carbonyl compounds, and acids mainly characterised the volatile profiles. Different sourdough microbiota resulted in different volatile profiles. PCA indicated that samples could be clustered according to their specific microbiota. Production of aroma compounds was strain-specific, confirming previous findings. This study can contribute to the management of desirable features and differentiate specialty products, as well as selecting new, suitable, sourdoughs after microbial screening. [ABSTRACT FROM AUTHOR]

Spontaneous fermented sourdoughs prepared from amaranth flour were investigated for the presence of autochthonous lactic acid bacteria (LAB) predominating microbiota. The doughs were fermented with daily backslopping on a laboratory scale at 30°C for 10 days. LAB counts ranged from 2·60 to 8·54 log CFU g−1 with a pH declined from 6·2 to 3·8 throughout fermentation. The combined use of randomly amplified polymorphic DNA (RAPD)-PCR analysis and sequence analysis of 16S rRNA was applied for LAB intraspecies differentiation and taxonomic identification, respectively. Enterococcus, Pediococcus and Lactobacillus species were present in amaranth sourdoughs (AS). After the first refreshment step, Lactobacillus plantarum dominated AS until the end of fermentation. In coincidence, when DGGE analysis was performed, the occurrence of a progressive change in bacterial communities allowed the selection of Lact. plantarum as a dominant species. Moreover, technological, functional and safety characteristics of representative RAPD-biotypes were investigated. Lact. plantarum CRL1898 was selected as a potential candidate for gluten-free amaranth sourdough starter. Significance and Impact of the Study Nowadays, there is an increasing interest in ancient noncereal gluten-free (GF) crops such as amaranth, due to their reported nutritional and health benefits. However, the use of these grains is still limited to traditional foods and bread making processes that are not yet well standardized. Results on the dynamics of autochthonous lactic acid bacteria (LAB) microbiota during laboratory spontaneous amaranth sourdoughs (AS) fermentation will contribute to overcome challenges for GF-fermented products development. In addition, knowledge about LAB diversity involving Enterococcus, Pediococcus and Lactobacillus species, with Lactobacillus plantarum predominating during AS fermentation, and their technological and functional properties provides the basis for the selection of autochthonous strains as starters cultures for novel gluten-free bakery products with enhanced nutritional, sensory and/or safety quality. [ABSTRACT FROM AUTHOR]

The fermentation of type I sourdough was studied for 20 d with daily back-slopping under laboratory and artisan bakery conditions using 1 wholemeal and 2 refined soft wheat ( Triticum aestivum) flours. The sourdough bacterial and yeast diversity and dynamics were investigated by plate counting and a combination of culture-dependent and culture-independent PCR-DGGE approach. The pH, total titrable acidity, and concentration of key organic acids (phytic, lactic, and acetic) were measured. Three flours differed for both chemical and rheological properties. A microbial succession was observed, with the atypical sourdough species detected at day 0 (i.e. Lactococcus lactis and Leuconostoc holzapfelii/citreum group for bacteria and Candida silvae and Wickerhamomyces anomalus for yeasts) being progressively replaced by taxa more adapted to the sourdough ecosystem ( Lactobacillus brevis, Lactobacillus alimentarius/paralimentarius, Saccharomyces cerevisiae). In mature sourdoughs, a notably different species composition was observed. As sourdoughs propagated with the same flour at laboratory and artisan bakery level were compared, the influence of both the substrate and the propagation environment on microbial diversity was assumed. [ABSTRACT FROM AUTHOR]

Barley flour is not commonly used for baking because of its negative effects on bread dough rheology and loaf volume. However, barley sourdoughs are promising ingredients to produce improved barley-based breads. Spontaneous barley sourdough fermentations were performed through backslopping (every 24 h, 10 days) under laboratory (fermentors, controlled temperature of 30 °C, high dough yield of 400) and bakery conditions (open vessels, ambient temperature of 17–22 °C, low dough yield of 200), making use of the same batch of flour. They differed in pH evolution, microbial community dynamics, and lactic acid bacteria (LAB) species composition. After ten backsloppings, the barley sourdoughs were characterized by the presence of the LAB species Lactobacillus fermentum , Lactobacillus plantarum , and Lactobacillus brevis in the case of the laboratory productions (fast pH decrease, pH < 4.0 after two backslopping steps), and of Leuconostoc citreum , Leuconostoc mesenteroides , Weissella confusa and Weissella cibaria in the case of the bakery productions (slow pH decrease, pH 4.0 after eight backslopping steps). In both sourdough productions, Saccharomyces cerevisiae was the sole yeast species. Breads made with wheat flour supplemented with 20% (on flour basis) barley sourdough displayed a firmer texture, a smaller volume, and an acceptable flavour compared with all wheat-based reference breads. Hence, representative strains of the LAB species mentioned above, adapted to the environmental conditions they will be confronted with, may be selected as starter cultures for the production of stable barley sourdoughs and flavourful breads. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria were isolated and identified from quinoa flour, spontaneously fermented quinoa dough, and type I quinoa sourdough. Strains were further selected based on acidification and proteolytic activities. Selected Lactobacillus plantarum T6B10 and Lactobacillus rossiae T0A16 were used as mixed starter to get quinoa sourdough. Compared to non-fermented flour, organic acids, free amino acids, soluble fibers, total phenols, phytase and antioxidant activities, and in vitro protein digestibility markedly increased during fermentation. A wheat bread was made using 20% (w/w) of quinoa sourdough, and compared to baker's yeast wheat breads manufactured with or without quinoa flour. The use of quinoa sourdough improved the chemical, textural, and sensory features of wheat bread, showing better performances compared to the use of quinoa flour. Protein digestibility and quality, and the rate of starch hydrolysis were also nutritional features that markedly improved using quinoa sourdough as an ingredient. This study exploited the potential of quinoa flour through sourdough fermentation. A number of advantages encouraged the manufacture of novel and healthy leavened baked goods. [ABSTRACT FROM AUTHOR]

Lactobacillus sanfranciscensis is the predominant key lactic acid bacterium in traditionally fermented sourdoughs. Despite its prevalence, sourdough and their related breads could be different regarding their physicochemical and sensorial characteristics. The intraspecific diversity of L. sanfranciscensis might explain these observations. Fifty-nine strains isolated from French sourdoughs were typed by a polyphasic approach including Multilocus Sequence Typing (MLST) and Pulsed-field Gel Electrophoresis (PFGE), in order to study their genotypic diversity. MLST scheme can be reduced from six to four gene fragments ( gdh , gyrA , nox and pta) without a major loss of discrimination between strains. The genes mapA and pgmA are not good candidates for inclusion in an MLST scheme to type L. sanfranciscensis strains, as they could not be amplified for a set of 18 strains among the 59 studied. This method revealed 20 sequence types (STs). Of these, 19 STs were grouped in one clonal complex, showing a strong relatedness between these strains. PFGE using SmaI discriminated 41 pulsotypes and so distinguished isolates better than the MLST scheme. Both genotypic methods indicate a low diversity between strains isolated from the same sourdough and a higher diversity between strains isolated from different sourdoughs, suggesting an influence of baker practices and/or environmental conditions on the selection of strains. The use of these two methods targeting genetic variations gives an optimal genotypic characterization of L. sanfranciscensis strains. [ABSTRACT FROM AUTHOR]

Eight samples of mature sourdough were collected from five provinces of Turkey. Lactic acid bacteria and yeasts were isolated and identified and used in different combinations to produce liquid sourdoughs. Microbiological and physicochemical characteristics of the experimental sourdoughs made with different flour types and dough yields were studied. The main lactic acid bacteria species identified were Lactobacillus ( L.) sanfranciscensis, Pediococcus pentosaceus, L. plantarum, L. namurencis, L. rossiae, Leuconostoc mesenteroides and L. zymae. L. spicheri, L. paralimentarius, L. mindensis, L. farciminis, L. acetotolerans, L. casei, Enterococcus faecium and Enterococcus durans were also found in sourdoughs at subdominant levels. Among yeasts, mainly Saccharomyces cerevisiae, but also Pichia guiliermondii and Torulaspora delbrueckii were the predominant species of yeasts identified in sourdoughs. Lactic acid bacteria and yeasts of liquid sourdoughs after fermentation were in the range of 9.61-9.89 log cfu/g and 6.55-7.36 log cfu/g, respectively. Various chemical parameters such as pH, total titratable acidity, lactic and acetic acids, ethanol and sugars were determined for liquid sourdoughs. Acidification and metabolite contents of these products were different, depending on the starter culture, flour type and dough yield. Total titratable acidity was more pronounced in the sourdoughs produced with whole wheat flour (14.08 mL NaOH) and rye flour (13.56 mL NaOH), dough yield 250 (13.93 mL NaOH) and control sample (13.12 mL NaOH) which were produced without inoculum. [ABSTRACT FROM AUTHOR]

Wheat bread is the most popular staple food consumed in Tunisia and, despite the niche production of some typical breads ( e.g. Tabouna , Mlawi , Mtabga ), the major part is currently produced with baker's yeast at industrial or, mainly, at artisanal level, while the use of sourdough fermentation is rarely reported. Considering the growing national demand for cereal baked goods, it can be hypothesized that sourdough fermentation through the use of selected lactic acid bacteria as starters could improve the overall quality and the diversification of local products. Different cereal grains were collected from the regions of Ariana, Bizerta, Beja Nabeul, and Seliana, and the autochthonous lactic acid bacteria were isolated, identified, characterized and selected on the basis of the kinetics of acidification, the proteolytic activity, and the quotient of fermentation. Lactobacillus curvatus MA2, Pediococcus pentosaceus OA2, and Pediococcus acidilactici O1A1 were used together as mixed starter to obtain a selected sourdough. According to the backslopping procedure, a type I sourdough was made from a Tunisian flour (spontaneous sourdough). Compared to the use of the spontaneous sourdough, the one obtained with selected and mixed starters by a unique fermentation step, favored the increase of the concentrations of organic acids, phenols, and total free amino acids, the most suitable quotient of fermentation, and the most intense phytase and antioxidant activities, that increased ca. 20% compared to the control. Moreover, the selected starters improved the in vitro protein digestibility ( ca. 82% when selected sourdough was used), textural and sensory features of the breads, as determined by textural profile analysis and panel test, respectively. This study aimed at exploiting the potential of selected autochthonous lactic acid bacteria and extending the use of a sourdough (type II), thanks to the set-up of a two-step fermentation protocol designed for application at the industrial level, and the confirmed nutritional, textural, and sensory advantages of the final product. [ABSTRACT FROM AUTHOR]