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Pursuing enhanced nutritional value in bakery products through technological advancements and new recipes is a promising facet of the food industry. This study focuses on incorporating rice and buckwheat brans, additional raw materials rich in biologically active substances, into bakery products. Utilizing a second-order rotatable plan, optimal ratios were determined—5% rice bran and 10% buckwheat bran. The application of these brans influenced dough and bread quality, reducing sugar content by 5% in dry form and 29% in the fermented brew, potentially aiding in diabetes prevention and cholesterol control. Introducing brans, especially in fermented brew, positively impacted microbiological stability, reducing the risk of mold and potato disease. The developed bread technology using rice and buckwheat brans in fermented brew significantly increased nutritional value, satisfying adult daily protein needs by 31.2%, fats by 15%, and dietary fibers by 18.4%. This innovative approach ensures a sufficient intake of essential vitamins and minerals, showcasing a promising avenue for creating healthier and more nutritious bakery products. [ABSTRACT FROM AUTHOR]

One of the oldest biotechnological processes used in bread manufacture is sourdough production which relies on wild yeast and lactobacillus cultures naturally present in flour. The aim of this paper was to evaluate the influence of selected flours of different cereal grains (ancient wheat, corn, and rye), different dough variations, and temperature of fermentation on the quality of spontaneous sourdough. Two values of fermentation temperatures were tested (25 °C and 35 °C), and for each temperature analyzed, three backslopping steps were carried out to obtain mature doughs according to the traditional type I sourdough scheme. In total, 14 different sourdoughs were produced, and microbiology, pH, and total titration acidity for 96 h were determined. Optimal pH values for the samples determined that the optimal fermentation period was 48 h. The acidification rate of the dough was faster at 35 °C than at 25 °C. This fact became evident via the pH values obtained in the first 24 h. However, from this point, the pH values were lower in the samples kept at 25 °C, showing that a cooler fermentation temperature allows the acidification activity of the microorganisms to be prolonged for a longer time. In the study carried out, the ideal fermentation time for the population of LAB and yeasts is 72 h at a temperature of 25 °C, and the most productive sourdoughs were the dough with 100% Einkorn wheat flour and the dough obtained from the 1:1 combination of flour rye and corn flours. [ABSTRACT FROM AUTHOR]

Pursuing enhanced nutritional value in bakery products through technological advancements and new recipes is a promising facet of the food industry. This study focuses on incorporating rice and buckwheat brans, additional raw materials rich in biologically active substances, into bakery products. Utilizing a second-order rotatable plan, optimal ratios were determined—5% rice bran and 10% buckwheat bran. The application of these brans influenced dough and bread quality, reducing sugar content by 5% in dry form and 29% in the fermented brew, potentially aiding in diabetes prevention and cholesterol control. Introducing brans, especially in fermented brew, positively impacted microbiological stability, reducing the risk of mold and potato disease. The developed bread technology using rice and buckwheat brans in fermented brew significantly increased nutritional value, satisfying adult daily protein needs by 31.2%, fats by 15%, and dietary fibers by 18.4%. This innovative approach ensures a sufficient intake of essential vitamins and minerals, showcasing a promising avenue for creating healthier and more nutritious bakery products.

Baking bread is currently experiencing a profound transformation, propelled by an escalating interest in health and wellness, global cuisines, and sustainability efforts. The surface of fruits harbors various microbes, such as yeasts and lactic acid bacteria (LAB). In contrast to Saccharomyces cerevisiae, a commercial yeast, the microbial flora present on the surface of fruits allows bread with greater flavor, texture, and health benefits as seen in sourdough starters. In this research, sourdough starters were created using dried longan and raisin. The microbial flora of the sourdough starters and the fermentation profile were examined, and possible bacteriocin genes were identified. The dried longan starter exhibited bubbling, stickiness, and a drop in pH value from 5.80 to 4.45 at the third day of fermentation. Meanwhile, the raisin starter began bubbling on the sixth day with no change in fluid viscosity, and a small pH value decreased from 4.00 to 3.82. The dried longan starter contained Weissella cibaria, W. paramesenteroides, S. cerevisiae, Pediococcus pentosaceus, Torulaspora delbrueckii and Leuconostoc citreum. On the other hand, raisin starter only contained Candida krusei and T. delbrueckii. To detect antibacterial property in W. paramesenteroides and P. pentosaceus, four bacteriocins, Gassericin A (gaaA), Lactacin F (lafA), Plantaricin S (pls) and Pediocin (ped) were explored. Polymerase chain reaction (PCR) results revealed that gaaA and lafA were present in W. paramesenteroides, which suggested that this strain possessed antimicrobial properties. [ABSTRACT FROM AUTHOR]

One of the oldest biotechnological processes used in bread manufacture is sourdough production which relies on wild yeast and lactobacillus cultures naturally present in flour. The aim of this paper was to evaluate the influence of selected flours of different cereal grains (ancient wheat, corn, and rye), different dough variations, and temperature of fermentation on the quality of spontaneous sourdough. Two values of fermentation temperatures were tested (25 °C and 35 °C), and for each temperature analyzed, three backslopping steps were carried out to obtain mature doughs according to the traditional type I sourdough scheme. In total, 14 different sourdoughs were produced, and microbiology, pH, and total titration acidity for 96 h were determined. Optimal pH values for the samples determined that the optimal fermentation period was 48 h. The acidification rate of the dough was faster at 35 °C than at 25 °C. This fact became evident via the pH values obtained in the first 24 h. However, from this point, the pH values were lower in the samples kept at 25 °C, showing that a cooler fermentation temperature allows the acidification activity of the microorganisms to be prolonged for a longer time. In the study carried out, the ideal fermentation time for the population of LAB and yeasts is 72 h at a temperature of 25 °C, and the most productive sourdoughs were the dough with 100% Einkorn wheat flour and the dough obtained from the 1:1 combination of flour rye and corn flours.

The microbial fermentation behind sourdough bread is among our oldest technologies, yet there are many opportunities for sourdough science to learn from traditional bakers. We analyzed 16S rRNA sequences in R to assess the bacterial community structure and performance of 40 starters grown from 10 types of flour over 14 days, and identified six distinct stages of succession. At each stage, bacterial taxa correlate with determinants of bread quality including pH, rise, and aromatic profile. Day 1 starter cultures were dominated by microorganisms commonly associated with plants and flour, and by aromas similar to toasted grain/cereal. Bacterial diversity peaked from days 2-6 as taxa shifted from opportunistic/generalist bacteria associated with flour inputs, toward specialized climax bacterial communities (days 10-14) characterized by acid-tolerant taxa and fruity (p < 3.03e -03), sour (p < 1.60e-01), and fermented (p < 1.47e-05) aromas. This collection of traits changes predictably through time, regardless of flour type, highlighting patterns of bacterial constraints and dynamics that are conserved across systems and scales. Yet, while sourdough climax communities exhibit similar markers of maturity (i.e., pH ≤ 4 and enriched in Lactobacillus (mean abundance 48.1%), Pediococcus (mean abundance 22.7%), and/or Gluconobacter (mean abundance 19.1%)), we also detected specific taxa and aromas associated with each type of flour. Our results address important ecological questions about the relationship between community structure and starter performance, and may enable bakers to deliberately select for specific sourdough starter and bread characteristics. [ABSTRACT FROM AUTHOR]

The microbial fermentation behind sourdough bread is among our oldest technologies, yet there are many opportunities for sourdough science to learn from traditional bakers. We analyzed 16S rRNA sequences in R to assess the bacterial community structure and performance of 40 starters grown from 10 types of flour over 14 days, and identified six distinct stages of succession. At each stage, bacterial taxa correlate with determinants of bread quality including pH, rise, and aromatic profile. Day 1 starter cultures were dominated by microorganisms commonly associated with plants and flour, and by aromas similar to toasted grain/cereal. Bacterial diversity peaked from days 2–6 as taxa shifted from opportunistic/generalist bacteria associated with flour inputs, toward specialized climax bacterial communities (days 10–14) characterized by acid-tolerant taxa and fruity (p < 3.03e−03), sour (p < 1.60e−01), and fermented (p < 1.47e−05) aromas. This collection of traits changes predictably through time, regardless of flour type, highlighting patterns of bacterial constraints and dynamics that are conserved across systems and scales. Yet, while sourdough climax communities exhibit similar markers of maturity (i.e., pH ≤ 4 and enriched in Lactobacillus (mean abundance 48.1%), Pediococcus (mean abundance 22.7%), and/or Gluconobacter (mean abundance 19.1%)), we also detected specific taxa and aromas associated with each type of flour. Our results address important ecological questions about the relationship between community structure and starter performance, and may enable bakers to deliberately select for specific sourdough starter and bread characteristics.

Technological prospecting was performed on documents related to sourdough microbiota using SCOPUS, Web of Science, Google Scholar, Espacenet and Patent Inspiration databases. Scientific articles and patents were analyzed based on three different perspectives: macro (year of publication, country, and institutions), meso (categorization as different taxonomies according to the subject evaluated), and micro (in-depth analysis of the main taxonomies, gathering the documents in subcategories). The main subject addressed in patents was the starter and product preparation, while 58.8% of the scientific publications focused on sourdough starter microbiota (identification and selection of microorganisms). Most patents were granted to companies (45.9%), followed by independent inventors (26.4%) and universities (21.8%). Sourdough products are in the spotlight when the subject is the bakery market; however, a closer integration between academia and industry is needed. Such a collaboration could generate a positive impact on the sourdough market in terms of innovation, providing a bread with a better nutritional and sensory quality for all consumers. Moreover, sourdough creates a new magnitude of flavor and texture in gastronomy, providing new functional products or increasing the quality of traditional ones. [ABSTRACT FROM AUTHOR]

Brynza occupies an important place among cheeses in Ukraine. Brynza is a highly concentrated polydisperse system, the features of which are determined by the size of the particles of the dispersed phase. It has a white (close to white) color, uniform throughout the mass. The taste and smell of cottage cheese are sour-milk, moderately salty. Physicochemical, biochemical and microbiological processes in cheese and their intensity depend on the concentration and quality of rennet enzymes. Renal enzymes during cheese ripening inhibit the vital activity of putrefactive bacteria in cheese, while in certain concentrations they contribute to the development of lactic acid microflora of leavening preparations and their production of amino acids. Studies show that cheese contains a wide range of microflora such as Lactococcus spp., Lactobacillus spp., Leuconostoc spp., Enterococcus spp. and contaminating bacterial cells. Pasteurization of raw milk not only has a positive effect on the yield of cheese, but also protects the consumer from pathogenic microflora. Milk after pasteurization was used for the experiment. The mass fraction of fat in milk was 3.2 %, the acidity was at the level of 18.5 °T. For the experiment, 5 groups of milk samples of 100.0 cm³ each were formed. Fermentation of milk was carried out with the help of sourdough starter for cheese and rennet enzyme. The antimicrobial drug streptomycin was used to inactivate cells of yeast microorganisms and active centers of rennet enzymes. Weighed 1.0 g was dissolved in 1500 ml of distilled water. Milk with an antibiotic content of 2.0 to 4.0 U/cm³ after fermentation with sourdough and rennet enzyme had 2.6-2.9 times lower titrated acidity than in the control. A regularity was revealed that with the increase in the content of streptomycin sulfate in milk, the titrated acidity of the final product decreases. When the largest amount of antibiotic was added to milk (IV and V experimental groups of samples), the effect of leaven and enzyme preparation was not manifested, as a result of which the final product of fermentation did not differ much from fresh milk in terms of titrated acidity. [ABSTRACT FROM AUTHOR]

Sourdough breadmaking on an industrial scale requires robust, well-performing starters that bring attractive characteristics to the product. The active nature of liquid starters provides a faster fermentation process compared to their dehydrated counterparts. However, liquid sourdough starters require meticulous management in order to maintain stability and functionality during cold storage at 4 °C. This study investigated the stability of three liquid sourdough starters during storage and also the impact of prolonged fermentation, the addition of diastatic malted wheat flour, and a neutralising agent (CaCO 3 ). The sourdough starters were evaluated for their microbial viability and metabolic activity at three individual time points during 16 weeks of cold storage. The microbial composition was analysed using culture-dependent and culture-independent methods, and metabolic changes were investigated using chromatographic methods. Two types of sourdough starter showed satisfying viability of lactic acid bacteria (> 7 log CFU/g) and metabolic stability throughout 16 weeks of cold storage. The introduction of malted wheat flour and CaCO 3 caused a decline in viability to <7 log CFU/g within 8 weeks in the third sourdough starter type and additionally revealed an ongoing metabolic activity of this sourdough starter during cold storage. Prolonged fermentation influenced the free amino acid profile, whereas adjusting the sourdough starter formula resulted in a different fungal microbiota and increased levels of fermentable substrates (maltose), organic acids (lactic acid), and aromatic compounds (alcohol and aldehydes). These findings provide stakeholders and researchers in sourdough fermentation technology with new insights concerning the stability of cold-stored liquid sourdough starters., Competing Interests: Declaration of competing interest The authors have no competing interest to declare., (Copyright © 2024. Published by Elsevier B.V.)

While research on the sourdough microbiome has primarily focused on lactic acid bacteria (LAB) and yeast, recent studies have found that acetic acid bacteria (AAB) are also common members. However, the ecology, genomic diversity, and functional contributions of AAB in sourdough remain unknown. To address this gap, we sequenced 29 AAB genomes, including three that represent putatively novel species, from a collection of over 500 sourdough starters surveyed globally from community scientists. We found variations in metabolic traits related to carbohydrate utilization, nitrogen metabolism, and alcohol production, as well as in genes related to mobile elements and defense mechanisms. Sourdough AAB genomes did not cluster when compared to AAB isolated from other environments, although a subset of gene functions was enriched in sourdough isolates. The lack of a sourdough-specific genomic cluster may reflect the nomadic lifestyle of AAB. To assess the consequences of AAB on the emergent function of sourdough starter microbiomes, we constructed synthetic starter microbiomes, varying only the AAB strain included. All AAB strains increased the acidification of synthetic sourdough starters relative to yeast and LAB by 18.5% on average. Different strains of AAB had distinct effects on the profile of synthetic starter volatiles. Taken together, our results begin to define the ways in which AAB shape emergent properties of sourdough and suggest that differences in gene content resulting from intraspecies diversification can have community-wide consequences on emergent function., Importance: This study is a comprehensive genomic and ecological survey of acetic acid bacteria (AAB) isolated from sourdough starters. By combining comparative genomics with manipulative experiments using synthetic microbiomes, we demonstrate that even strains with >97% average nucleotide identity can shift important microbiome functions, underscoring the importance of species and strain diversity in microbial systems. We also demonstrate the utility of sourdough starters as a model system to understand the consequences of genomic diversity at the strain and species level on multispecies communities. These results are also relevant to industrial and home-bakers as we uncover the importance of AAB in shaping properties of sourdough starters that have direct impacts on sensory notes and the quality of sourdough bread.

In this study, yeast, lactic acid bacteria, and acetic acid bacteria were isolated from traditional Chinese sourdough to enhance the organoleptic quality of whole wheat steamed bread. The Saccharomyces cerevisiae, Lactobacillus johnsonii, and Acetobacter pasteurianum showed superior fermentability and acid production capacity when compared with other strains from sourdough, which were mixed to produce the compound starter. It was found that the volume of whole wheat steamed bread leavened with compound starter increased by 12.8% when compared with that of the whole wheat steamed bread made by commercial dry yeast (DY-WB). A total of 38 volatile flavors were detected in the whole wheat steamed bread fermented by the compound starter (CS-WB), and the type of volatile flavors increased by 14 species when compared to the bread fermented by the dry yeast. In addition, some unique volatile flavor substances were detected in CS-WB, such as acetoin, 3-hydroxy-butanal, butyraldehyde, cuparene, etc. Moreover, the hardness and the chewiness of CS-WB decreased by 31.1 and 33.7% when compared with DY-WB, respectively, while the springiness increased by 10.8%. Overall, the formulated compound starter showed a desirable improvement in the whole wheat steamed bread and could be exploited as a new ingredient for steamed bread. [ABSTRACT FROM AUTHOR]

Technological prospecting was performed on documents related to sourdough microbiota using SCOPUS, Web of Science, Google Scholar, Espacenet and Patent Inspiration databases. Scientific articles and patents were analyzed based on three different perspectives: macro (year of publication, country, and institutions), meso (categorization as different taxonomies according to the subject evaluated), and micro (in-depth analysis of the main taxonomies, gathering the documents in subcategories). The main subject addressed in patents was the starter and product preparation, while 58.8% of the scientific publications focused on sourdough starter microbiota (identification and selection of microorganisms). Most patents were granted to companies (45.9%), followed by independent inventors (26.4%) and universities (21.8%). Sourdough products are in the spotlight when the subject is the bakery market; however, a closer integration between academia and industry is needed. Such a collaboration could generate a positive impact on the sourdough market in terms of innovation, providing a bread with a better nutritional and sensory quality for all consumers. Moreover, sourdough creates a new magnitude of flavor and texture in gastronomy, providing new functional products or increasing the quality of traditional ones.

In this study, yeast, lactic acid bacteria, and acetic acid bacteria were isolated from traditional Chinese sourdough to enhance the organoleptic quality of whole wheat steamed bread. The Saccharomyces cerevisiae, Lactobacillus johnsonii, and Acetobacter pasteurianum showed superior fermentability and acid production capacity when compared with other strains from sourdough, which were mixed to produce the compound starter. It was found that the volume of whole wheat steamed bread leavened with compound starter increased by 12.8% when compared with that of the whole wheat steamed bread made by commercial dry yeast (DY-WB). A total of 38 volatile flavors were detected in the whole wheat steamed bread fermented by the compound starter (CS-WB), and the type of volatile flavors increased by 14 species when compared to the bread fermented by the dry yeast. In addition, some unique volatile flavor substances were detected in CS-WB, such as acetoin, 3-hydroxy-butanal, butyraldehyde, cuparene, etc. Moreover, the hardness and the chewiness of CS-WB decreased by 31.1 and 33.7% when compared with DY-WB, respectively, while the springiness increased by 10.8%. Overall, the formulated compound starter showed a desirable improvement in the whole wheat steamed bread and could be exploited as a new ingredient for steamed bread.

Sourdough influences in a good way all aspects of the bakery products quality. Sourdough fermentation has gained the worldwide attention due to its positive influence on sensorial, textural, nutritional and shelf life of baked goods. For this work, four commercial starter cultures were selected, in order to assess their influence on products quality. The major lactic bacteria in the starter cultures were: Lactobacillus brevis, Lactobacillus sanfrancisco and according the producer, specific facultative hetero-fermentative lactic strains. The obtained sourdoughs, fermented according to their supplier specifications, were added to wheat dough at 5 - 30 % amount level. The starters’ performance was assessed in 2 stages protocol. Firstly, all starters were assessed by analysing the results of physico-chemical and sensorial properties. In the second stage, three starters were selected and the protocol was performed again. Physico-chemical analyses (porosity, elasticity, H/D, L/w, acidity) were performed according to SR 91/2007. Aroma profile and sensory analysis were assessed using a hedonic test. All starter cultures showed good performance on improving the bread quality in the conditions of this experiment, differences could be noticed in relation to textural and sensorial properties.

The objectives of the present work were to study the evolution of the sensory properties and overall liking of four sourdough breads over their lifespans and to determine their sensory shelf life (SSL). We also intended to identify the main sensory characteristics leading to a decrease in overall liking and the end of the consumption of the breads. Seventy‐eight consumers evaluated different 1 kg sourdough breads at home. Two methods were used to describe the evolution of the sensory properties and overall liking: one based on ratings of descriptors' intensities and the other based on the magnitude of the changes observed since the previous consumption. As expected, the results showed that sensory properties and liking scores evolved over time. While the aroma and taste properties changed little, the texture deteriorated significantly. The overall liking scores decreased steadily over time, while the percentage of subjects who stopped eating bread increased. "Easiness to cut with the teeth," "easiness to chew," "crispness," and "softness" were the main characteristics positively correlated with the overall liking scores and negatively correlated with the percentage of rejection. In contrast, "dryness of the crumb" was negatively correlated with the liking scores and positively correlated with the percentage of rejection. A survival analysis determined that the SSL (50% rejection) of the breads was approximately 2.5 days. Interestingly, we highlighted that the average liking score corresponding to the SSL was just below the middle of the overall liking scale. Practical Application: The results of this work could be of interest to bread‐making professionals who will be able to use the main conclusions to advise their clients and possibly adapt the bread format to their sensory shelf life. This work was also an opportunity to highlight sourdough bread, which offers more flexibility than French baguette in managing the consumption of the bread purchased. The alternative approach tested to measure the evolution of sensory characteristics and overall liking could interest the professionals of sensory analysis. [ABSTRACT FROM AUTHOR]

This study aimed to produce sourdough bread using an encapsulated kombucha sourdough starter culture without the addition of baker's yeast. The bioactive metabolites of kombucha sourdough starter and sourdough starter without kombucha were identified using 1H‐NMR analysis with multivariate analysis. The physical properties, including loaf volume, specific loaf volume, firmness, and water activity were determined following standard methods. The shelf life and consumer acceptability of the bread were also being evaluated. The principal component analyses showed the presence of 15 metabolites in kombucha sourdough starter. The major compounds that contributed to the differences from sourdough starter without kombucha were alpha‐aminobutyric acid, alanine, acetic acid, riboflavin, pyridoxine, anserine, tryptophan, gluconic acid, and trehalose. The encapsulated kombucha sourdough starter increased the loaf volume (976.7 ± 25.2 mL) and specific loaf volume (4.38 ± 0.12 mL/g) compared to yeast bread. Thus, significant (P < 0.05) reduction was observed in the crumb firmness (116.07 ± 6.28 g) compared to traditional sourdough bread and yeast bread. The encapsulated kombucha sourdough starter extended the shelf life of bread by 5 to 10 days at room temperature. The sourdough bread prepared using the encapsulated kombucha sourdough starter demonstrated significantly (P < 0.05) higher taste and overall acceptability scores compared to the other bread. The findings indicate that the encapsulated kombucha sourdough starter is promising to produce functional sourdough bread with extended shelf life and improved quality. Practical Application: Encapsulated kombucha sourdough starter culture that appropriately refreshed can be used primarily as a dough leavening agent in the bread industry without the addition of baker's yeast. This starter culture applied in sourdough bread production extended the shelf life and improved the biological function of sourdough bread. [ABSTRACT FROM AUTHOR]

The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, 139 yeasts isolated from cereal-based fermented foods were in vitro characterized for their phytase and antioxidant activities. The molecular characterization at strain level of the best 39 performing isolates showed that they did not derive from cross contamination by baker's yeast. Afterwards, the 39 isolates were in vivo analyzed for their leavening ability, phytase activity and polyphenols content using five different wholegrain flours, obtained from conventional and pigmented common wheat, emmer and hull-less barley. Combining these findings, through multivariate permutation analysis, we identified the 2 best performing strains, which resulted diverse for each flour. Doughs singly inoculated with the selected strains were further analyzed for their antioxidant capacity, phenolic acids, xanthophylls and anthocyanins content. All the selected yeasts significantly increased the total antioxidant activity, the soluble, free and conjugated, forms of phenolic acids and anthocyanins of fermented doughs. This study revealed the importance of a specific selection of yeast strains for wholegrain flours obtained from different cereals or cultivars, in order to enhance the pro-technological, nutritional and nutraceutical traits of fermented doughs. [ABSTRACT FROM AUTHOR]

Abstract Aim of the study was to produce traditional and typical breads using stabilized sourdough starter without the addition of baker's yeast activator. To this end, the spray drying technique was investigated as an alternative tool to freezing, freeze drying and drying techniques to preserve sourdough starter. The stabilized sourdoughs were used in breadmaking to assess the ability to leaven and ferment the doughs and to evaluate the effect of their use on the sensory characteristics of the obtained breads. Positive and encouraging results were obtained mainly with the spray-dried sourdoughs that better preserved the vitality of both yeasts and lactic acid bacteria when compared to the traditional techniques. Furthermore, the results suggested that spray-dried sourdough, opportunely refreshed, can be successfully used for breadmaking without the use of baker's yeast activator, producing breads with sensory characteristics highly comparable to those produced using fresh sourdoughs. Highlights • Spray drying technique preserves good vitality of both yeast and LAB in sourdough. • Spray drying sourdough can be successfully used in breadmaking, without any added yeast. • Breads obtained with spray dried sourdough have high sensory characteristics. [ABSTRACT FROM AUTHOR]

This study focused on the performance of the dextran producer Leuconostoc citreum as starter culture during 30 days of wheat flour type I sourdough propagation (back-slopping). As confirmed by RAPD-PCR analysis, the strain dominated throughout the propagation procedure, consisting of daily fermentations at 20 °C. The sourdoughs were characterized by consistent lactic acid bacteria cell density and acidification parameters, reaching pH values of 4.0 and mild titratable acidity. Carbohydrates consumption remained consistent during the propagation procedure, leading to formation of mannitol and almost equimolar amount of lactic and acetic acid. The addition of sucrose enabled the formation of dextran, inducing an increase in viscosity of the sourdough of 2–2.6 fold, as well as oligosaccharides. The transcriptional analysis based on glucosyltransferases genes (GH70) showed the existence in L. citreum FDR241 of at least five different dextransucrases. Among these, only one gene, previously identified as forming only α-(1–6) glycosidic bonds, was significantly upregulated in sourdough fermentation conditions, and the main responsible of dextran formation. A successful application of a starter culture during long sourdough back-slopping procedure will depend on the strain robustness and fermentation conditions. Transcriptional regulation of EPS-synthetizing genes might contribute to increase the efficiency of industrial processes. [ABSTRACT FROM AUTHOR]

This study was carried out to compare the influence of sugar contents (0.5, 1, 1.5%) and fermentation times (8, 16, 24 h) of Lactobacillus plantarum as sourdough specific starter culture on properties and staling of Barbari breads produced with two different extraction rate flours (69 and 76%). The effect of the above mentioned parameters on properties of sourdoughs prepared from these two types of wheat flour was evaluated in a split plot design. The results showed that, different fermentation times and sugar contents had significant effect (P≤0.05) on sourdoughs total titerable acidity. After processing of Barbari breads with sourdough treatments, the specific volume, crumb firmness (texture analysis) and porosity (Image j method) were examined during 4 days of storage. Based on the results, 96 h after baking the lowest and highest amounts of crumb firmness were observed in Barbari bread prepared from 76% extraction rate flour and 24 h sourdough fermentation and 1% sugar content and also Barbari bread prepared from 69% extraction rate flour and 24 h sourdough fermentation and 1.5% sugar content, respectively. Furthermore, most of Barbari breads prepared from 76% extraction rate flour had higher specific volume and porosity and also less total acceptance than the Barbari breads prepared from 69% extraction rate flour.

In the present research, lactic acid bacteria (LAB) and yeasts which were isolated from sourdough samples were investigated for their technologically useful properties for the production of improved food products. LAB and yeast isolates were cultured and the DNA was extracted; restriction analyses were applied to obtain profile groups and representative strains were sequenced. Lactobacillus sanfranciscensis was the most isolated species followed by Lactobacillus namurensis, Lactobacillus pentosus, Lactobacillus paralimentarius, Lactobacillus sakei, Lactobacillus crustorum, Pediococcus parvulus, Leuconostoc citreum, and Weissella cibaria. Saccharomyces cerevisiae was the most frequently detected yeast species. Minor yeast species were Kazachstania humilis (Candida milleri) and Wickerhamomyces anomalus. The majority of the LAB strains produced CO2; after 4 h of fermentation, the two strains of L. citreum B435 and B521 reached pH values below 5.00, 19 strains reached values below 4.00 after 24 h of fermentation, while after 72 h of fermentation all the strains lowered their pH below 3.60. Two strains, L. citreum B435 and L. sanfranciscensis B450, produced exopolysaccharides. All the LAB strains were able to degrade gluten with different intensity; the strain of L. sakei B433 and the strains of L. pentosus B506, B508, and B512 exhibited the highest intensity of degradation. All the yeast strains were able to grow at a pH value of 2.5. S. cerevisiae L973 and W. anomalus L1081, showed amylolytic properties; excluding the C. milleri L999 all the strains were maltose-positive. According to the technological features, LAB and yeasts strains which are thus isolated are potential starters to be used for improved bakery products. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria were isolated from hemp ( Cannabis sativa L.) flour, spontaneously fermented dough, and type I sourdough. Isolates were identified and further selected based on pro-technological, nutritional and functional properties. Lactobacillus plantarum /s5, Pediococcus acidilactici /s5, and Leuconostoc mesenteroides /s1 were used as mixed starter to produce hemp sourdough. Significant decreases of the concentration of phytic acid, condensed tannins, and total saponins were observed during fermentation. The in vitro protein digestibility increased up to 90%. Experimental wheat breads were made adding 5% to 15% (w/w) hemp sourdough to the formula, characterized, and compared to baker's yeast wheat bread manufactured without hemp sourdough. The use of hemp sourdough improved the textural features of wheat bread, without adversely affect the sensory profile. Proportionally to the fortification with hemp sourdough, protein digestibility of the breads increased, while the predicted glycemic index significantly decreased (87 vs 100%). This work demonstrated that the fermentation with selected starters improved nutritional functionality of hemp flour, allowing its large-scale use in different food applications, meeting the consumers and producers request for novel fermented baked goods with a well-balanced nutritional profile. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to optimize of the instant active dry yeast (A) and the dried chickpea sourdough (B) amount in bread formulation and to evaluate of usage possibilities of dried chickpea sourdough in bread production by examining some quality parameters.Response surface methodology was used to determine the effects of the variable factors (Aand B) on the product volume (V), acceptability value (AV) and pore factor (PF) of the bread. The usage rates were determined 0.63% for A and 10.21% for B.The bread produced according to optimized model (OB) was compared with control bread in terms of some quality parameters. The pore structures of bread samples and microtextural features obtained scanning electron microscopy during shelf life were examined by Image Analysis. Smaller and more homogeneous pore structures were obtained in the bread texture; antioxidant activity, mineral content, microbial shelf life were improved, and the volume and crust thickness of the bread increased by the usage of chickpea sourdough. Practical applications: Chickpea sourdough was dried in oven at low temperature short time condition.The protection of microbial vitality was ensure during the drying processes.The level of instant active dry yeast (A) and dried sourdough (B) were optimized with RSM. The usage rates were determined 0.63% for A and 10.21% for B.Optimized bread and control bread were compared in terms of various quality properties. The antioxidant activity, mineral content, microbial shelf life, and physicochemical properties were improved. [ABSTRACT FROM AUTHOR]

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The aim of this study was to assess whether wheat endophytic lactic acid bacteria (LAB) are able to dominate in sourdough ecosystem. To do that, a first experimental phase considered doughs produced under semi-sterile conditions and singly inoculated with different strains of endophytic LAB and Lactobacillus sanfranciscensis A4 isolated from sourdough. Notwithstanding the high frequency of Lactobacillus plantarum in the sourdoughs prepared in laboratory, only one of the starter strains, L. plantarum LB2, was detected after five days of back-slopping. Subsequently, the ability of this strain to dominate traditional sourdoughs was evaluated at bakery and laboratory level. Contamination of sourdoughs with L. plantarum LB2 caused an increased number of LAB and, accordingly, higher acidification, compared to the sourdoughs before this event. After six days of propagation, the wheat endophytic strain L. plantarum LB2 was retrieved as a component of the bacterial population, in all the sourdoughs and regardless of the place of propagation. In addition, the contamination event caused a modification of the lactic acid bacterium biota, which in turn influenced some sourdoughs biochemical features. In conclusion, this study showed that wheat endophytic LAB could represent a potential reservoir for selecting robust strains to be used as sourdough starters. [ABSTRACT FROM AUTHOR]

Aiming at meeting the consumers' demand in terms of bio-preservation, the potential of the combination of the lactic acid bacteria fermentation and the addition of hop extract as natural preservative in breadmaking, was exploited. The antifungal properties of a hop ( Humulus lupulus ) extract were investigated, showing a significant inhibition of the hyphal growth of Aspergillus parasiticus , Penicillium carneum , Penicillium polonicum , Penicillium paneum , Penicillium chermesinum , Aspergillus niger , Penicillium roqueforti . Lactic acid bacteria belonging to species of Enterococcus feacium , Lactobacillus plantarum , Lactobacillus brevis , Lactobacillus helveticus , Lactobacillus curvatus , Pediococcus pentosaceus , and Pediococcus acidilactici were isolated from hop and subjected to selection based on kinetics of growth and acidification. The sourdough (hS) enriched with hop extract (hE), started with three selected strains, had phenols concentration and antioxidant activity higher than those obtained in the same condition but without the hE. Hop-sourdough used in breadmaking delayed the fungal growth (14 days), giving a bread characterized by free aminoacids concentration, antioxidant and phytase activities higher than bread started only with baker's yeast, with or without the addition of hE. Specific volume and cell-total area of the bread containing hE improved, and its sensory profile was characterized by typical sourdough attributes, and a moderate bitter/herbaceous perception. [ABSTRACT FROM AUTHOR]

Sourdough is a type of dough fermented by yeast and lactic acid bacteria (LAB) used as sponge dough in bread making. Sourdough may have four classifications according to the fermentation type and the technological process used. On sourdough type I, the fermentation of yeasts and LAB present in the flour occurs spontaneously whereas in type II, fermentation occurs after the inoculation of a starter culture. Type III is simply type II sourdough dehydrated and type IV is a mixture of type I and type II sourdough, produced on laboratory scale. With LAB's growth during fermentation, pH decreases with subsequent hydrolysis of starch and protein, favoring the growth of yeasts. The yeast in turn, releases amino acids during autolysis, contributing to the growth of LAB. Due to this synergistic growth of LAB and yeasts, the products obtained from sourdough show more concentration of flavor, more elastic dough, and a longer shelf life than bread fermented only by yeast. Although, the benefits of this technology, using sourdough, is present just in a few countries, where it is also possible to obtain the dehydrated sourdough starters, for domestic use, in local supermarkets. Due to its fermentative process complexity, this paper presents updated information about the fabrication process of sourdough, main factors affecting this process, benefits of sourdough use for bakery products, and the varieties of dehydrated sourdough commercially available throughout the world. [ABSTRACT FROM AUTHOR]

Lactobacillus sanfranciscensis is the predominant lactic acid bacteria (LAB) species in Chinese traditional sourdoughs and conduces to the flavor and rheology properties of Chinese steamed bread, a staple food originated in China over 1500 years ago. The aim of this study is to describe the intraspecific diversity of 98 L. sanfranciscensis isolates from 11 Chinese traditional sourdoughs in different regions by multilocus sequence typing (MLST) and multiplex random amplified polymorphic DNA-polymerase chain reaction (multiplex RAPD-PCR). MLST scheme was reduced from six gene fragments ( gdh , gyrA , mapA , nox , pgmA and pta ) to five ( gdh , gyrA , mapA , nox and pta ) since the fragment of pgmA displayed only one allele. 10 different sequence types (STs) were revealed by MLST and 6 of them containing 79.8% of the isolates were classified into one clonal complex, demonstrating a close relationship among them. The multiplex-RAPD analysis was performed by employing the combined primers OPL-05 + RD1 and divided the 98 L. sanfranciscensis isolates into 6 types with the similarity level of 70%. According to the result, it seems that the genotypic variations of L . sanfranciscensis strains showed by MLST have no relations to geographical origin. MLST seems to have a higher discriminatory power compared with multiplex-RAPD since it produced more groups, but multiplex-RAPD could help to distinguish some strains in the same ST. Hence, an optimal genotypic characterization of L . sanfranciscensis was obtained under the combination of MLST and multiplex-RAPD analysis, targeting different genetic variations. [ABSTRACT FROM AUTHOR]

Background Sourdough is a cereal flour-water mixture that is fermented by communities of yeasts and lactic acid bacteria (LAB) and that is used for the production of baked goods. Its use has been subject to a renewed interest in the past years. The classical classification concept of sourdoughs distinguishes two major types (I and II), based on the process conditions applied for their production. Scope and approach In this study, both species diversity (LAB and yeasts) and processing conditions of sourdoughs were taken into account for the classification of sourdoughs. Therefore, a meta-analysis of such literature data on hundreds of backslopped sourdoughs is described. Key findings and conclusions The meta-analysis agreed with the subdivision into Type I and Type II sourdoughs. In general, the number of prevalent yeast species in a given sourdough was lower than the number of prevalent LAB species. Also, a lower number of prevalent LAB and yeast species characterized the microbial species diversity of Type I sourdoughs compared to Type II ones. This could be attributed to the prevalence of Lactobacillus sanfranciscensis in sourdoughs of the former type. The process conditions impacted the yeast species diversity, as differences were found for the fermentation temperature, dough yield, and fermentation time between sourdoughs. No influence could be found concerning the region of origin, albeit that literature data reflected regionally important sourdoughs. [ABSTRACT FROM AUTHOR]

This study describes the optimization and application of repetitive element-PCR (rep-PCR) technique directly on microbial DNA extracted from type I sourdoughs for fast monitoring of a Lb. plantarum starter strain (P1FMC) throughout daily back-slopping. The challenge was to follow and study the performance of a starter culture directly in sourdoughs without cultivation on selective media. The extraction of good quality microbial DNA suitable for amplification from a complex matrix such as dough was the first target. In addition, the objective to obtain a clear rep-PCR profile referable to a specific starter strain among a microbial community was pursued. Co-inoculum trials, in flour matrix, with Lb. plantarum P1FMC and L. lactis LC71 strains and, subsequently, type I sourdough back-slopping trials were performed. The rep-PCR amplification profiles obtained were clearly referable to that of Lb. plantarum P1FMC starter in both co-inoculum trials (also when it was present with one order of magnitude less with respect to L. lactis LC71) and back-slopping trials where it dominated the fermentation process with loads of 108 cfu g−1 and prevailed on the autochthonous microbiota. Thus, the approach proposed in this paper could be considered a methodological advancement, based on a culture-independent one-step rep-PCR, suitable for fast monitoring of starter performance. [ABSTRACT FROM AUTHOR]

Volatile fatty acid (VFA) production stimulated by saponin (SP), an environmentally friendly bio-surfactant, was investigated during sludge alkaline fermentation in laboratory studies and pilot applications. The combined use of SP and pH 9 condition significantly enhanced VFA production to approximately 425 mg COD/g VSS, which was 4.7-fold of raw sludge and 1.5-fold of sole pH 10 adjustment (the optimum pH for alkaline fermentation). Further results indicated that SP & pH 9 condition provided sufficient substrates for acidification and decreased the consumption of VFAs through methanogenesis. Moreover, SP accompanied by moderate alkaline condition (i.e. pH 9) showed weaker inhibitory effects on key enzyme activities and metabolic potential of acidification microorganisms than sole pH 10 adjustment. On this basis, a pilot-scale system involving anaerobic fermentation and anaerobic-anoxic-aerobic step-feed bioreaction tanks was established to study the potential of VFAs as supplementary carbon sources for wastewater treatment. The influent of the pilot system was sanitary wastewater characterized by low C/N ratios from a scenic rural area. After flocculation and nutrient precipitation, the fermentation supernatant was mixed with the influent at a volume ratio of 1:30. With this approach, nitrogen and phosphorus concentrations in effluent fulfilled the first-A wastewater discharge standard in China. [ABSTRACT FROM AUTHOR]

This research was carried out to characterise lactic acid bacteria (LAB) isolated from wholegrain millet sourdoughs and to provide scientific data on the health functionality of the microorganisms responsible for sourdoughs fermentation. A total of 127 LAB isolates were observed on de Man Rogosa Sharpe (MRS) agar, while sixteen of the LAB isolates were characterized with respect to dominance in the fermentation process with percentage occurrence of 63% for Lactobacillus plantarum, Lactobacillus pentosus (12%), Pediococcus pentosaceous (19%) and Lactobacillus brevis (6%) using API 50 CHL. Lactic acid bacteria were assessed for probiotic attributes with respect to their in vitro health promoting effects, in terms of ability to tolerate low acidic pH, different bile salt concentrations, antimicrobial and antibiotic activities under conditions simulating the human gastrointestinal tract (GIT). The isolates displayed a good tolerance to acidic environment of Hydrochloric acid (pH. 3.0) with survival rate between 2.0 - 227.0 and tolerance to bile salt at 0.3% concentration. Furthermore, they exhibited clear zones of inhibition (2.0 mm- 14.0 mm) against all the tested pathogens and revealed strong resistance to four of the antibiotics; gentamycin, ampicillin, rifampicin and norfloxacin. [ABSTRACT FROM AUTHOR]

Lactic Acid Bacteria (LAB) were isolated from cereals and seeds from Argentinean markets. Colonies representing different morphological appearances were isolated and differentiated based on phenotypic characteristics. Fifty strains were identified by 16S rRNA gene sequencing analysis obtaining LAB from genera Enterococcus , Lactobacillus and Pediococcus . Technological and nutritional characteristics (acidifying capacity, antimicrobial production, proteolytic activity, folate production) were analyzed. Lactobacillus pentosus ES124 and Lactobacillus plantarum ES137 presented high production of folate (61 and 57 ng/mL, respectively) as did Enterococcus mundtii ES63 which reached a total folate production of 70 ng/mL. Six LAB strains produced bacteriocin-like inhibitory substances (BLIS) with antilisterial activity. Eight strains were selected for use as sourdough starters and in situ applications based on their important technological properties. [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]

Aims To analyse lactic acid bacteria ( LAB) diversity and technological-functional and safety properties of strains present during spontaneous fermented quinoa sourdoughs. Methods and Results Fermentation was performed by daily backslopping at 30°C for 10 days. Autochthonous LAB microbiota was monitored by a biphasic approach combining random amplified polymorphic DNA ( RAPD)- PCR and rRNA gene sequencing with PCR-denaturing gradient gel electrophoresis ( DGGE) analysis. Identification and intraspecies differentiation allowed to group isolates within nine LAB species belonging to four genera. A succession of LAB species occurred during 10-days backslopping; Lactobacillus plantarum and Lactobacillus brevis were detected as dominant species in the consortium. The characterization of 15 representative LAB strains was performed based on the acidifying capacity, starch and protein hydrolysis, γ-aminobutyric acid and exopolysaccharides production, antimicrobial activity and antibiotic resistance. Conclusion Strains characterization led to the selection of Lact. plantarum CRL1905 and Leuconostoc mesenteroides CRL1907 as candidates to be assayed as functional starter culture for the gluten-free ( GF) quinoa fermented products. Significance and Impact of the Study Results on native LAB microbiota present during quinoa sourdough fermentation will allow the selection of strains with appropriate technological properties to be used as a novel functional starter culture for GF-fermented products. [ABSTRACT FROM AUTHOR]

The microbial composition of the sourdough starter affects the sourdough bread properties. Therefore, it is crucial to find a tool for rapid, time-saving, and economical identification of the sourdough microbiota. We focused on the rapid identification of sourdough yeasts. We designed a panfungal real time-PCR targeting the ITS2 region (ITS-amplicon) and a fragment of D1/D2 region of 26S rRNA gene (U-amplicon) and used high resolution melting analysis (HRM) for subsequent species identification. The sensitivity and specificity of our method were tested on the reference yeast cultures. We obtained divergent melting peaks (Tm). The further analysis of melt curves suggests the possibility to discriminate yeasts on the genus- and some on species-specific level in the mixed sample. The applicability of this method in routine practice was evaluated on nine sourdough samples. Revealed melt curves of U-amplicons were predominantly characteristic of the sourdough. The evaluation of the Tm and the shape of the melt curve was used to assess the sourdough yeasts. Additionally, using the HRM-PCR method the contamination with the ergot fungus DNA was revealed. Our data showed HRM-PCR is a simple, rapid, and inexpensive tool useful in identifying sourdough yeasts. [Display omitted] • HRM-PCR technique was used to detect and identify sourdough yeasts. • Discrimination of yeasts on the genus and species levels was assessed. • Detection of sourdough contaminants was evaluated. • Ergot fungus Claviceps purpurea DNA was revealed. [ABSTRACT FROM AUTHOR]

We recommend that the future of religion and science involve more partnerships between scholars, amateurs, and artists. This reimagines an underdeveloped aspect of the history of religion and science. Case studies of an undergraduate course examining religious ritual and technology, seminarians reflecting on memory and identity in light of Alzheimer's disease, environmentalists responding to their guilt and shame about climate change, and Chicagoans recognizing the presence of nature in the city show how these partnerships respect insights and experiences of our varied partners, identify and resolve community problems, and advance scholarship. Sourdough starter, a new metaphor, describes these collaborative, nourishing partnerships. [ABSTRACT FROM AUTHOR]

This study aimed at describing the main chemical and technology features of eight Iranian wheat flours collected from industrial and artisanal mills. Their suitability for bread making was investigated using autochthonous sourdough starters. Chemical analyses showed high concentration of fibers and ash, and technology aptitude for making breads. As shown through 2-DE analyses, gliadin and glutenin subunits were abundant and varied among the flours. According to the back slopping procedure, type I sourdoughs were prepared from Iranian flours, and lactic acid bacteria were typed and identified. Strains of Pediococcus pentosaceus , Weissella cibaria , Weissella confusa , and Leuconostoc citreum were the most abundant. Based on the kinetics of growth and acidification, quotient of fermentation and concentration of total free amino acids, lactic acid bacteria were selected and used as sourdough mixed starters for bread making. Compared to spontaneous fermentation, sourdoughs fermented with selected and mixed starters favored the increase of the concentrations of organic acids and total free amino acids, the most suitable quotient of fermentation, and the most intense phytase and antioxidant activities. Although the high concentration of fibers, selected and mixed starters improved the textural features of the breads. This study might had contribute to the exploitation of the potential of Iranian wheat flours and to extend the use of sourdough, showing positive technology, nutritional and, probably, economic repercussions. [ABSTRACT FROM AUTHOR]

Six Albanian soft and durum wheat cultivars were characterized based on chemical and technological features, showing different attitudes for bread making. Gliadin and glutenin fractions were selectively extracted from flours, and subjected to two-dimensional electrophoresis. Linja 7 and LVS flours showed the best characteristics, and abundance of high molecular weight (HMW)-glutenins. Type I sourdoughs were prepared through back slopping procedure, and the lactic acid bacteria were typed and identified. Lactobacillus plantarum and Leuconostoc mesenteroides were the predominant species. Thirty-eight representative isolates were singly used for sourdough fermentation of soft and durum wheat Albanian flours and their selection was carried out based on growth and acidification, quotient of fermentation, and proteolytic activity. Two different pools of lactic acid bacteria were designed to ferment soft or durum wheat flours. Sourdough fermentation with mixed and selected starters positively affected the quotient of fermentation, concentration of free amino acids, profile of phenolic acids, and antioxidant and phytase activities. This study provided the basis to exploit the potential of wheat Albanian flours based on an integrated approach, which considered the characterization of the flours and the processing conditions. [ABSTRACT FROM AUTHOR]

BACKGROUND The main goal of this research was to show how to use a qualitative assessment of some technological properties of lactic acid bacteria ( LAB), combined with the evaluation of the growth index ( GI), to select promising starter cultures for sourdough. RESULTS Fifty-four strains of LAB were isolated from a single factory, identified by molecular tools and studied for their growth as a function of NaCl (20, 40 and 65 g L−1), temperature (45, 15 and 10 °C), pH 9.2 and acidification in MRS broth. The growth was evaluated through absorbance and data were modelled as GI. GIs were used to build frequency histograms and to run a principal component analysis ( PCA). In this way, six strains, identified as Lactobacillus plantarum and able to grow in a wide range of conditions (temperature, pH and salt) and/or able to decrease the pH by 1.77-2.0 units, were selected and tested in a model system (flour and water) to study the acidification after 24 h and their viability after 14 days. CONCLUSION The main result of this paper was to show how a simple step-by-step approach could be a useful tool to select promising starter cultures for sourdough. The method was based on (1) strain identification, (2) assessment of some traits through the GI, combined with simple statistical approaches (frequency histograms and PCA), and (3) preliminary validation in model systems. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: The main topic of this research was to select some suitable functional starter cultures for cereal-based food or beverages. This aim was achieved through a step-by step approach focused on the technological characterization, as well as on the evaluation of the probiotic traits of yeasts; the technological characterization relied on the assessment of enzymatic activities (catalase, urease, β-glucosidase), growth under various conditions (pH, temperature, addition of salt, lactic and acetic acids) and leavening ability. The results of this step were used as input data for a Principal Component Analysis; thus, the most technologically relevant 18 isolates underwent a second selection for their probiotic traits (survival at pH 2.5 and with bile salts added, antibiotic resistance, antimicrobial activity towards foodborne pathogens, hydrophobic properties and biofilm production) and were identified through genotyping. Two isolates (Saccharomyces cerevisiae strain 2 and S. cerevisiae strain 4) were selected and analyzed in the last step for the simulation of the gastric transit; these isolates showed a trend similar to S. cerevisiae var. boulardii ATCC MYA-796, a commercial probiotic yeast used as control. [Copyright &y& Elsevier]