Search Results (229)

Background/Objectives: The intake of bread has been associated with gastrointestinal discomfort in some individuals. The primary aim of this study was to investigate gut symptoms upon consuming sourdough bread compared to baker’s yeast bread. Secondary endpoints were changes in targeted gut microbial taxa, micronutrient levels, and metabolic markers. Methods: This randomised, controlled, double-blind cross-over study included twenty healthy participants. Sourdough or baker’s yeast bread was consumed for one week before crossing over. Before and after the interventions, participants reported gut symptoms, and they also provided blood samples to analyse micronutrients, metabolic markers, and faecal samples for targeted gut microbial taxa analyses. Results: The breads were made of whole grain wheat with similar macronutrients content. The sourdough bread contained less fructose than the baker’s yeast bread. The consumption of sourdough bread caused a significant reduction in the diarrhoea sub-dimension score (p = 0.016) and a borderline significant reduction in the overall GSRS-IBS score compared to baker’s yeast (p = 0.051). Several gut bacteria were significantly increased after intake of sourdough bread compared to baker’s yeast bread: Alistipes putredinis (p = 0.029), Alistipes shahii (p = 0.015), Bifidobacterium adolescentis (p = 0.042), Bifidobacterium longum (p = 0.010) and Bifidobacterium longum subspecies longum (p = 0.021). There was a significant correlation between changes in diarrhoea score and changes in Alistipes shahii (r= −0.353, p = 0.025). Conclusions: This exploratory cross-over study did not demonstrate a statistically significant difference in the overall GSRS-IBS score between the two breads. A nominal difference in the diarrhoea sub-dimension and selected targeted microbial taxa was observed between the two breads, but these findings require further investigations. Full article

Chinese steamed bread (CSB) is an important fermented wheat product, but controlled strategies for modulating its volatile profile remain limited. This study evaluated defined composite sourdoughs comprising Wickerhamomyces anomalus CRFSZY16 or Kluyveromyces marxianus FYY7 in combination with Lactiplantibacillus plantarum SDgsM3 for CSB production using the direct fermentation method (DFM) and the refrigerated sponge-dough method (RSDM). Technological stress tolerance, preliminary safety-related phenotypes, acidification capacity, volatile organic compounds (VOCs), multivariate profiles, and specific volume were assessed. SDgsM3 showed dough-relevant stress tolerance and rapid acidification, while both yeasts tolerated moderate fermentation stresses. Headspace solid-phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry (HS-SPME-GC-TQ-MS) revealed stage-dependent remodeling of volatile profiles from mature sourdough to fully proofed main dough and final CSB. RSDM selectively modified representative alcohols, aldehydes, furans, ketones, and esters rather than uniformly increasing all VOCs. In the final CSB, the K. marxianus-based RSDM system showed relatively higher levels of 3-methyl-1-butanol, whereas the W. anomalus-based RSDM system showed relatively higher levels of hexanal, nonanal, 1-hexanol, and 2-pentylfuran. Composite sourdough treatments also yielded specific volumes of 2.56–2.66 mL/g versus 2.44 mL/g for the commercial yeast control. These findings demonstrate strain- and process-dependent modulation of CSB volatile profiles and support flavor-oriented composite sourdough design. Full article

Sourdough fermentation is an important technological process in bread production, influencing acidification, product quality, and storage stability. The present study developed and comparatively evaluated two-strain and multi-strain bacterial starter cultures for application in different flour matrices and under semi-industrial bread-making conditions. The starter cultures comprised selected strains of Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, Levilactobacillus brevis, Limosilactobacillus fermentum, Fructilactobacillus sanfranciscensis, and Propionibacterium freudenreichii subsp. shermanii. Baker’s yeast was added separately during final dough preparation and was not part of the bacterial starter combinations. Starter performance was assessed through viable cell counts, titratable acidity, in vitro antimicrobial activity, dough fermentation time, bread volume, descriptive sensory evaluation, and the onset of visually detectable microbial spoilage under the tested storage conditions. The selected combinations adapted to the investigated flour matrices, maintained high viable cell concentrations, supported acidification, and were successfully applied in semi-industrial bread production. Several formulations showed favorable technological and descriptive sensory characteristics and delayed the appearance of visible bacterial and fungal spoilage compared with the corresponding controls. Overall, the findings demonstrate the practical potential of the developed multi-strain starter cultures for application across different flour matrices and provide a strong basis for further technological refinement and mechanistic characterization of these sourdough systems. Full article

The aim of this study is to provide an alternative bakery practice by evaluating the effects of cold fermentation (backslopping at 7 and 15 °C) and cold storage (stored at 7 and 15 °C) after backslopping on Type I sourdough characteristics and the technological performance of the corresponding breads. Sourdough characteristics (pH, acidity, and microbial counts), bread quality (texture and color), storage behavior, and volatile compound profiles (VoC) were investigated to compare the extent to which these treatments improve product quality. No significant difference was observed in pH and total titratable acidity among the sourdoughs. However, the fermentation quotient of the cold storage group was higher than that of the cold fermented group. Backslopping at cold fermentation temperatures (7 and 15 °C) caused a significant reduction in lactic acid bacteria counts. Conversely, cold fermentation and cold storage at 15 °C led to a significant increase in yeast counts. From a technological perspective, bread produced with sourdough backslopped at 15 °C exhibited a higher specific volume than breads produced with the other cold-treated sourdoughs. At the end of the storage period, the bread made with cold-backslopped sourdough at 7 °C had the highest hardness value, while others remained similar. Principal component analysis (PCA) of volatile compounds revealed that cold-stored sourdoughs were clustered apart from room-temperature-stored sourdoughs, mainly driven by ethyl hexanoate and hexyl acetate. Heptanoic acid was among the key VOCs contributing to the positioning of breads made with cold-stored sourdoughs in the PCA. In conclusion, these findings demonstrate that backslopping and storage at 15 °C offer an industrially relevant production strategy while improving textural properties and VoC profiles. Full article

Lactic acid bacteria (LAB) are Gram-positive cocci or rods from different genera and species that synergistically coexist with yeasts in cereal sourdoughs. Although the production and consumption of sourdough breads have increased in the last decade, there are still few studies that identify the LABs present in sourdoughs of different origins. In this study, we identified LAB strains isolated from wheat sourdoughs sourced from bakeries in north-western Spain and from experimental sourdoughs developed by a baker with four different cereal flours: wheat, rye, spelt, and tritordeum. Through a combination of MALDI-TOF and pheS gene sequence analyses, we identified Lactiplantibacillus plantarum and Levilactobacillus brevis in all analysed sourdoughs. Moreover, Lactiplantibacillus paraplantarum, Lacticaseibacillus paracasei, Lactococcus lactis, Pediococcus pentosaceus, and Weissella paramesenteroides were identified in different sourdoughs. These species were also isolated from sourdoughs obtained in other European countries, although we did not identify the other LAB genera identified in some of them. Our results demonstrate the need to identify the LAB species from sourdoughs of different origins prior to designing suitable starters for inoculated sourdoughs, particularly those produced with innovative flours. To our knowledge, this is the first report on the identity of LABs present in tritordeum sourdoughs in Spain. Full article

Although some lactic acid bacteria species harbor genes encoding α-glucanotransferases (4,6-α-GTase and 4,3-α-GTase), the technological and functional implications of these enzymes within sourdough ecosystems remain poorly understood. This study investigated the effects associated with α-GTase-positive and α-GTase-negative strains of Limosilactobacillus reuteri and L. fermentum on sourdough microbiota, bread quality, and starch digestibility. Starter culture inoculation steered the assembly of the sourdough microbiota, resulting in stable acidification and altered microbial community structures. High-throughput sequencing analysis showed that starter culture addition generally increased taxonomic richness, while Shannon and Simpson diversity indices varied according to strain genotype and inoculation level. Sourdoughs fermented with α-GTase-positive strains exhibited higher viscosity while maintaining shear-thinning behavior, which was putatively linked to in situ enzymatic synthesis. Additionally, inoculation with these strains improved bread specific volume, suggesting a possible structural modification of the starch matrix or the overlapping effects of fermentation metabolites. During storage, the 4,3-α-GTase-positive L. fermentum PFC282 strain delayed the increase in bread hardness, reflecting a possible mitigation of amylopectin retrogradation and indicating a potential anti-staling effect. In addition, the 4,6-α-GTase-positive L. reuteri PFC338 strain produced breads with lower estimated glycemic index values, suggesting a lower susceptibility to enzymatic starch hydrolysis likely due to the hypothesized alterations in structural linkages. Overall, the findings highlight the potential of α-GTase-positive sourdough starter cultures to modulate the technological and nutritional properties of bread. Full article

Bread is a global dietary staple, but its susceptibility to fungal spoilage causes substantial food waste, economic losses, and greenhouse gas emissions. Volatile organic compounds (VOCs) produced by sourdough microorganisms can contribute to the prevention of bread spoilage; however, the specific VOCs that exert the protective effect in the bread matrix have not been precisely identified. Our study investigated the antifungal activity of sourdough lactic acid bacteria (LAB) consortia, both alone and in combination with yeast and acetic acid bacteria (AAB), as well as the VOC profiles of sourdough and sourdough bread. The consortium comprising Lactiplantibacillus plantarum 9-5 and Levilactobacillus brevis 9-2 (LAB), Monosporozyma unispora R3SD1d (yeast), and Acetobacter fabarum WB and Komagataeibacter rhaeticus Ch2 (AAB) extended the mold-free shelf life of sourdough bread by 8–20 days after challenge tests. VOC analysis revealed that sourdough bread had significantly higher concentrations of ethyl esters of hexanoic and octanoic acids with 6.3- to 9.7-fold increase in peak areas after three days of refrigerated storage, assuming their decisive role in prevention of fungal spoilage. In conclusion, the use of this consortium is promising to significantly extend bread shelf life, but also to enrich the bread VOC profile. Full article

Broccoli by-products represent an underutilized source of dietary fiber and bioactive compounds with potential as functional food ingredients. This study evaluated the effect of enzymatic treatment with Viscozyme^® L on broccoli by-products and their incorporation into gluten-free (GF) sourdough breads. Three GF bread formulations were developed: a control bread (BCT), a bread enriched with untreated broccoli by-products (BBC), and a bread enriched with enzymatically treated broccoli by-products (BBE), using a commercial GF bread (COM) as reference. Nutritional composition, antioxidant activity, starch digestibility, and sensory characteristics were evaluated. The incorporation of broccoli by-products significantly improved protein, total dietary fiber, and antioxidant activity compared with COM, with all reformulated breads meeting the EU “high fiber” claim. Enzymatic treatment with Viscozyme^® L further enhanced these properties, with BBE reaching 2.66 g 100 g⁻¹ soluble dietary fiber and 13.51 µM TE g⁻¹ in FRAP, while exhibiting the highest slowly digestible starch content (20.39 g 100 g⁻¹), suggesting a potentially more favorable starch digestibility profile. Sensory evaluation confirmed that these nutritional improvements were achieved without significantly compromising consumer acceptability. Overall, Viscozyme^® L-treated broccoli by-products represent a sustainable, clean-label ingredient for nutritionally enhanced GF bakery products, supporting agri-food by-product valorization within a circular economy framework. Full article

This study aimed to evaluate the technological, functional and nutritional effects of exopolysaccharide-producing lactic acid bacteria (LAB) strains, isolated from artisanal Tulum cheese as type II sourdough starters. The objective of this study was to improve bread quality, delay staling, and enhance bioactive properties, such as antioxidant capacity and estimated glycaemic index (eGI). Six LAB strains (Loigolactobacillus coryniformis, Lactiplantibacillus plantarum, Levilactobacillus brevis, Lacticaseibacillus paracasei, Lactobacillus helveticus, and Lacticaseibacillus rhamnosus) were individually used for sourdough fermentation. Bread samples were analyzed for pH, titratable acidity (TA), LAB counts, specific volume, colour, total phenolic content (TPC), antioxidant activity (DPPH and ABTS), starch digestibility, eGI, staling kinetics (Avrami model) and amylopectin retrogradation (DSC). Strain-dependent improvements in bread functionality were observed. L. brevis and L. coryniformis strains increased sourdough acidity to a greater extent, and resulting in lower pH values. Accordingly, bread produced with sourdough fermented by these strains exhibited higher specific volume than the control. Although higher ABTS radical scavenging activity and TPC were detected in sourdough bread compared to the control bread, no significant differences were observed among the breads in terms of total antioxidant activity measured by DPPH. L. rhamnosus significantly improved antioxidant activity and reduced the eGI. L. coryniformis, L. plantarum and L. brevis were the most effective at retarding staling, reducing the increase in hardness and limiting amylopectin retrogradation. This study is the first to demonstrate the functional potential of LAB strains from artisanal Tulum cheese as sourdough starters. These findings reveal the potential for developing clean-label bakery products with an extended shelf life and improved health-related functionality. Full article

The growing over-75 population has increased the demand for functional foods tailored to the nutritional needs of the elderly. Within the AURA project, an innovative oat okara sourdough was developed to produce bread with enhanced nutritional and functional properties. Breads were produced using oat okara sourdough, oat sourdough, and wheat sourdough for comparison. All samples were subjected to microbiological, physical-chemical, technological, and metabolomic analysis. In addition, bread digestibility was evaluated. The results showed that oat okara flour is an excellent fermentable substrate, yielding sourdoughs with high counts of lactic acid bacteria and yeasts. The breads made with oat okara and oats were softer and brownish due to the oat presence and higher relative yeast. Moreover, oat okara bread exhibited a lower proportion of rapidly digestible starch (RDS) and a higher proportion of slowly digestible starch (SDS), suggesting potential benefits for post-prandial glycaemic control. Metabolomic profiling highlighted lipids, particularly steroidal glycosides (saponins) and fatty acyls, as discriminant metabolites in fermented samples, suggesting enhancement of bioactive compounds through sourdough fermentation. Overall, the use of oat okara in sourdough represents a sustainable approach to upcycle agro-industrial by-products while producing nutritionally valuable bakery products aligned with circular economy principles. Full article

Fermentation is a type of biological process conducted domestically or commercially to preserve foods and beverages, produce alcohol, add nutritional value and improve aroma and flavor. The natural fermentation of flour in water to obtain a leaven for baking, lately scrutinized in the laboratory with the application of metagenomic methods, has been ubiquitous since the dawn of civilization. Commercially, single culture or defined mixtures of microorganisms are used for their predictability, but regularly fed two-domain microorganism cultures are favored in less industrialized and domestic operations. Fungi principally produce the carbon dioxide responsible for leavening. The bacteria produce acid in the bread commonly known as sourdough for its aroma and flavor. A leaven made by fermentation using flour and water can be stored while it is dormant. We studied a mature culture that is fed twenty-fold with water and flour by incubating it for 24 h, sampling it regularly for pH measurements, and plating it. The colonies were suspended for micrography and DNA extraction for PCR and Sanger sequencing. The metagenomic DNAs were analyzed for bacterial and fungal composition. The proportions of the plant and microbial DNA endogenous to the flour decline rapidly, and the predominant bacteria and fungi in mature leaven propagate, without overlap between the respective microbiomes. Full article

The current understanding of microbiota–flavor correlations in Chinese sourdough steamed bread is predominantly derived from the central provinces, with comparatively limited investigation in northeastern and northwestern regions. This study bridges this gap by analyzing traditional starters from Heilongjiang (HLJ) and Ningxia (TX) versus an industrial starter (JM) through integrated metagenomics and untargeted metabolomics. HLJ was dominated by Limosilactobacillus fermentum (14.75%), while TX featured a synergistic Lactiplantibacillus plantarum–Fructilactobacillus sanfranciscensis consortium. Metabolic pathway analysis revealed enhanced glycolysis, amino acid metabolism, and glycerophospholipid transformation driving flavor biosynthesis and dough rheology improvement, supported by nitrogen-metabolizing Bradyrhizobium spp. (6.00–6.61%). Core pathway enrichment established molecular foundations for region-specific flavors: HLJ generated sulfury/pungent notes via the enzymatic conversion of pentyl glucosinolate to isothiocyanates, whereas TX developed caramel–roasted aromas through stachyose/xylose-derived Maillard reactions forming 2-(methylthiomethyl)furan. Both consortia exhibited higher bitterness and lower umami than JM, with HLJ showing marginally higher umami and lower bitterness than TX. These findings elucidate the microbial mechanisms underlying regional flavor differentiation. Full article

The growing demand for high-quality gluten-free bread requires innovative technological and functional approaches. This study investigates, for the first time, the use of Lacticaseibacillus paracasei SP5 in free and immobilized form on traditional Greek trahanas for producing GF sourdough bread based on rice and buckwheat flour. Sourdough breads produced with free and immobilized cells displayed greater performance than the control sourdough bread in microbial stability and physicochemical properties, with the immobilized form showing the best results. In particular, the application of immobilized L. paracasei SP5 led to gluten-free sourdough bread with enhanced acidification (pH 4.55; total titratable acidity 12.9 mL) and remarkable lactic (2.20 g/kg) and acetic acid (0.76 g/kg) levels, extending the shelf life to 7.0 days against mold and 7.5 days against rope spoilage, statistically significantly higher than the other two gluten-free sourdough samples. It also showed the strongest antifungal activity and improved technological characteristics, including higher loaf volume (2.84 mL/g), greater height (5.50 cm), and lower baking loss (17.42%). Total phenolic content (87.3 mg GAE/100 g) and antioxidant activity were also statistically significantly increased. Overall, immobilized L. paracasei SP5 on trahanas appears to be a promising clean-label strategy to improve the quality, shelf life, and functional value of GF bread. Full article

Nutritional strategies based on sourdough fermented breads with wholemeal ancient grains and legumes are emerging as promising modulators of (neuro)immune processes. This study investigated whether prolonged consumption of a sourdough bread enriched with a mixture of ancient cereals and legumes, commercially available in Italy (Primus^® bread, P^®B), modulates neuroimmune systemic responses to repeated lipopolysaccharide (LPS) challenge in mice. For this study, male C57BL/6J mice were fed for 14 days with either a standard diet (SD) or P^®B. Animals then received intraperitoneal LPS (3 mg/kg/day for 3 days) or vehicle. Body weight and food intake were monitored throughout. Pain-like behaviours were assessed by von Frey, plantar and tail flick tests, and plasma cytokine (32-plex panel), splenocyte and peritoneal macrophage cytokine expression, and expression of pro-inflammatory cytokines in sciatic nerves, dorsal root ganglia (DRG) and the spinal cord were analyzed by Reverse Transcription–quantitative Polymerase Chain Reaction (RT-qPCR). P^®B prevented LPS-induced body weight loss and reduced splenomegaly. Unlike SD mice, which exhibited widespread plasmatic cytokine upregulation, P^®B-fed mice displayed only limited increases Interleukin (IL)-1β, IL-12p40 and Tumor Necrosis Factor (TNF)α. Ex vivo cultures of splenocytes and macrophages confirmed attenuated cytokine overexpression. LPS-induced hypersensitivity to mechanical, thermal and nociceptive stimuli was significantly reduced in P^®B mice. Molecular analyses revealed that the P^®B diet blunted the pro-inflammatory cytokine expression present after LPS challenge in the sciatic nerves and DRG, with partial attenuation in the spinal cord. Our findings highlight the great potential of functional foods as affordable dietary strategies to mitigate systemic immune and neuroimmune dysregulation. Full article

Raisin syrup sourdough is a popular traditional leavening method in Japan, yet its specific impact on bread aroma evolution and shelf life stability remains scientifically underexplored. This study characterized the fermentation dynamics and volatile profiles of raisin syrup sourdough bread compared to a commercial yeast control over a 3-day shelf life, utilizing comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC-TOFMS) and primary metabolite profiling of sugars, amino acids, and organic acids. The analysis resolved over 760 volatiles and revealed a fundamental kinetic divergence. While the yeast control exhibited a 24 h metabolic lag, the raisin sourdough achieved rapid activation, establishing a higher initial volatile load immediately post-baking. Driven by lactic acid bacteria dominance and extensive proteolysis, the sourdough’s acidic environment facilitated the retention of fruity esters and malty branched-chain aldehydes while effectively suppressing lipid oxidation markers like 9,17-Octadecadienal. Key aromatic markers, including benzenepropanol and Octanoate <isopentyl->, were significantly elevated and stabilized in the sourdough group. These findings demonstrate that raisin syrup fermentation generates a superior, stable aromatic profile, providing a scientific basis for optimizing clean-label artisan bread production in the Japanese market. Full article