Recent Advances in the Use of Sourdough Biotechnology in Pasta Making

The growing consumers' request for foods with well-balanced nutritional profile and functional properties promotes research on innovation in pasta making. As a staple food and a common component of diet, pasta can be considered as a vector of dietary fiber, vegetable proteins, vitamins, minerals, and functional compounds. The conventional process for pasta production does not include a fermentation step. However, novel recipes including sourdough-fermented ingredients have been recently proposed, aiming at enhancing the nutritional and functional properties of this product and at enriching commercial offerings with products with new sensorial profiles. The use of sourdough for pasta fortification has been investigated under several aspects, including fortification in vitamin B, the reduction of starch digestibility, and gluten content. Sourdough fermentation has also been successfully applied to non-conventional flours, (e.g., from pseudocereals and legumes), in which an overall increase of the nutritional value and health-promoting compounds, such as a significant decrease of antinutritional factors, were observed. Fermented non-conventional flours, obtained through spontaneous fermentation or using selected starters, have been proposed as pasta ingredients. As the result of wheat replacement, modification in textural properties of pasta may occur. Nonetheless, fermentation represents an efficient tool in improving, besides nutritional and functional profile, the sensory and technological features of fortified pasta.Peer reviewe

Challenges and opportunities for wheat alternative grains in breadmaking : Ex-situ- versus in-situ-produced dextran

Background: The use of grains as an alternative to wheat in breadmaking has rapidly grown in the last few years, driven by the Sustainable Development Goals toward improving food security and promoting sustainable agriculture. Flours from legumes, pseudo-cereals, minor cereals and milling by-products, such as bran, are of particular interest. The production of partially substituted or wheat-free bread is, however, a challenging task in terms of texture and flavour attributes. Scope and approach: The present review covers recent advances in the application of dextrans in improving dough rheology, baking performance and bread flavour characteristics. Emphasis has been given to in situ application of dextran via sourdough technology as a & lsquo;clean label & rsquo; alternative to commercial hydrocolloid additives. Key findings and conclusions: In-situ dextran production leads to bread with higher specific volume, softer crumbs and increased moisture content. Dextran also provides an anti-staling effect attributable to its ability to reduce water mobility and retard starch retrogradation. A structure & ndash;function relationship has suggested that dextran with high molecular weight and less branching is superior in enhancing bread quality. Furthermore, mild acidification favours the functionality of dextran in dough and bread systems, while intensive acidification results in adverse effects. Lactic acid bacterial strains belonging to the genus Weissella exhibiting mild acidification are therefore appreciated in regard to the utilisation of in-situ produced dextran. This review highlights the novel application of dextran as a flavour masking agent to minimise off-flavours (e.g. beany flavour, bitter taste, and aftertaste) originating from non-wheat grains, consequently improving the acceptability of the final products.Peer reviewe

Use of Selected Lactic Acid Bacteria and Quinoa Flour for Manufacturing Novel Yogurt-Like Beverages

This study aimed at investigating the suitability of quinoa for making yogurt-like beverages. After the selection of the adequate technological parameters, the fermentation was carried out by using different lactic acid bacteria strains: a probiotic (Lactobacillus rhamnosus SP1), an exopolysaccharides (EPS)-producing (Weissella confusa DSM 20194), and one isolated from quinoa (Lactobacillus plantarum T6B10). During the 20 h of fermentation, W. confusa caused the highest viscosity increase. All the strains had improved concentration of free amino acids and γ-Aminobutyric acid (GABA), polyphenols availability, antioxidant activity (up to 54%), and protein digestibility. The nutritional index (NI) was the highest when L. rhamnosus SP1 was used. The starch hydrolysis index in vitro ranged from 52 to 60. During storage at 4 °C, viscosity and water holding capacity decreased with the exception of the beverage fermented with W. confusa, while all the nutritional characteristics remained stable or slightly increased. Sensory analyses showed that beverages had good textural and organoleptic profiles. Besides the well-known positive properties of the raw matrix, fermentation allowed the obtainment of beverages with different features. Due to the nutritional and functional characteristics conferred to the quinoa beverages, the use of the probiotic and EPS-producing strains showed adequate potential for the industrial application

Editorial: The Sustainability Challenge: New Perspectives on the Use of Microbial Approaches and Their Impact on Food and Feed

Non peer reviewe

The role of dextran and maltosyl-isomalto-oligosaccharides on the structure of bread enriched with surplus bread

Occurrence of surplus bread (SB) is common in the baking industry. Edible surplus bread can be utilized as a new bread dough ingredient; however, it creates technological challenges that affect the quality of the new bread. In this study, the interactions of SB with dough macromolecules were studied in a gluten-starch model dough system and subsequent model bread. Moreover, dextran or maltosyl-isomalto-oligosaccharides (MIMO) were produced by dextransucrase preparation, incorporated into the dough containing SB, and their individual in-fluence on dough rheology and bread structure was investigated. Compared to control model dough/bread, the addition of SB at 10% level significantly decreased extensibility of the dough, dough level, and specific volume (SV) of bread, despite standardized gluten content and optimized water absorption (WA). This confirms that SB constituents (especially gelatinized starch) deteriorate the dough structure-forming by interactions with gluten network. Dextran addition at appropriate level (0.7%) with optimized WA, shielded the gluten network from the interactions of SB, thus, increasing dough extensibility and softness. Furthermore, dextran-enrichment signifi-cantly reduced the hardness and staling of breads and increased the SV to the control model bread level. MIMOs, especially at low concentration, induced stronger interactions with gluten proteins than dextran. However, the addition of MIMOs reduced the SV of breads containing SB and did not reduce the overall crumb hardness despite partially preventing starch retrogradation in the early phase of storage. The protective interactions of dextran with dough macromolecules showed that in vitro dextran could be utilized to enable recycling of edible SB.Peer reviewe

Fermentation Conditions Affect the Synthesis of Volatile Compounds, Dextran, and Organic Acids by Weissella confusa A16 in Faba Bean Protein Concentrate

Fermentation with Weissella confusa A16 could improve the flavor of various plant-based sources. However, less is known about the influence of fermentation conditions on the profile of volatile compounds, dextran synthesis and acidity. The present work investigates the synthesis of potential flavor-active volatile compounds, dextran, acetic acid, and lactic acid, as well as the changes in viscosity, pH, and total titratable acidity, during fermentation of faba bean protein concentrate with W. confusa A16. A Response Surface Methodology was applied to study the effect of time, temperature, dough yield, and inoculum ratio on the aforementioned responses. Twenty-nine fermentations were carried out using a Central Composite Face design. A total of 39 volatile organic compounds were identified: 2 organic acids, 7 alcohols, 8 aldehydes, 2 alkanes, 12 esters, 3 ketones, 2 aromatic compounds, and 3 terpenes. Long fermentation time and high temperature caused the formation of ethanol and ethyl acetate and the reduction of hexanal, among other compounds linked to the beany flavor. Levels of dextran, acetic acid, and lactic acid increased with increasing temperature, time, and dough yield. Optimal points set for increased dextran and reduced acidity were found at low temperatures and high dough yield. Such conditions would result in hexanal, ethyl acetate and ethanol having a relative peak area of 35.9%, 7.4%, and 4.9%, respectively

Dextran produced in situ as a tool to improve the quality of wheat-faba bean composite bread

The incorporation of faba bean flour into wheat-based products is a sustainable way to obtain protein-enriched food items. However, developing breads with a higher content of faba bean flour is challenging due to the poor textural/sensory properties of the final product. A potential solution is to use hydrocolloids as structuring agents to increase the viscoelastic properties of the composite bread. Microbial dextran is a natural hydrocolloid which can be used as a bread texture improver either as a pure food ingredient or by in situ production during sourdough fermentation. The aim of this study was to compare the influence of dextran produced in situ by Weissella confusa VTT E-143403 (E3403) and Leuconostoc pseudomesenteroides DSM 20193 in faba bean sourdoughs on the quality of wheat bread supplemented with 43% faba bean sourdough. The impact of dextran on the rheological properties of dough and textural properties of the final bread were evaluated. Dextran formed by W. confusa and L. pseudomesenteroides reached a level of 5.2 and 3.6% (flour basis), respectively. Incorporation of faba bean sourdough containing dextran synthesized by W. confusa improved the dough viscoelastic properties, and also increased the specific volume (similar to 21%) and reduced crumb hardness (similar to 12%) of the final bread, compared to control breads. Similar positive effects were not obtained with sourdough containing dextran from L. pseudomesenteroides, probably due to its higher acidity. Dextran synthesized in situ by W. confusa is a promising clean label hydrocolloid option to improve the quality of wheat bread enriched with faba bean flour.Peer reviewe

Biosynthesis of gamma-aminobutyric acid by lactic acid bacteria in surplus bread and its use in bread making

Aims The aim of this study was to investigate the effectiveness of bread as substrate for gamma-aminobutyric acid (GABA) biosynthesis, establishing a valorization strategy for surplus bread, repurposing it within the food chain. Methods and Results Surplus bread was fermented by lactic acid bacteria (LAB) to produce GABA. Pediococcus pentosaceus F01, Levilactobacillus brevis MRS4, Lactiplantibacillus plantarum H64 and C48 were selected among 33 LAB strains for the ability to synthesize GABA. Four fermentation experiments were set up using surplus bread as such, added of amylolytic and proteolytic enzymes, modifying the pH or mixed with wheat bran. Enzyme-treated slurries led to the release of glucose (up to 20 mg g(-1)) and free amino acid, whereas the addition of wheat bran (30% of bread weight) yielded the highest GABA content (circa 800 mg kg(-1) of dry weight) and was the most suitable substrate for LAB growth. The selected slurry was ultimately used as an ingredient in bread making causing an increase in free amino acids. Conclusions Besides the high GABA concentration (148 mg kg(-1) dough), the experimental bread developed in this study was characterized by good nutritional properties, highlighting the efficacy of tailored bioprocessing technologies as means to mitigate food wastage. Significance and Impact of Study Our results represent a proof of concept of effective strategies to repurpose food industry side streams.Peer reviewe

Impact of in situ produced exopolysaccharides on rheology and texture of fava bean protein concentrate

The aim of this study was to investigate the impact of in situ produced exopolysaccharides (EPS) on the rheological and textural properties of fava bean protein concentrate (FPC). EPS (dextrans) were produced from sucrose by two lactic acid bacteria (LAB). The acidification, rheology, and texture of FPC pastes fermented with Leuconostoc pseudomesenteroides DSM 20193 and Weissella confusa VTT E-143403 (E3403) were compared. A clear improvement in rheological and textural parameters was observed in sucrose-added pastes after fermentation, especially with W. confusa VTT E3403. Only moderate proteolysis of fava bean protein during fermentation was observed. The microstructure of the protein in FPC pastes, as observed by confocal laser scanning microscopy, revealed a less continuous and denser structure in EPS-abundant pastes. The beneficial structure formed during EPS-producing fermentation could not be mimicked by simply mixing FPC, isolated dextran, lactic acid, and acetic acid with water. These results emphasize the benefits of in situ produced EPS in connection with the LAB fermentation of legume protein-rich foods. Fermentation with EPS-producing LAB is a cost-effective and clean-labeled technology to obtain tailored textures, and it can further enhance the usability of legumes in novel foods.Peer reviewe

Fermentation of cereal, pseudo-cereal and legume materials with Propionibacterium freudenreichii and Levilactobacillus brevis for vitamin B12 fortification

The present study investigated the in situ production of vitamin B12 in eleven cereal, pseudo-cereal and legume materials by fermentation with Propionibacterium freudenreichii DSM 20271 and Levilactobacillus brevis (formerly Lactobacillus brevis) ATCC 14869. P. freudenreichii was used as the vitamin producer and L. brevis was selected to improve the consistency and microbial safety of the process. The study showed that more than 300 ng/g dw of vitamin B12 (daily requirement: 2.4 ug) were produced during fermentation in most of the studied brans and legumes. The highest vitamin B12 production was observed in the fermentation of the rice bran (ca. 742 ng/g dw), followed by the fermentation of buckwheat bran (ca. 631 ng/g dw). Furthermore, partial least squares (PLS) regression analysis suggested that the production of vitamin B12 was greatly influenced by the nutrient composition of the fermented raw materials. Meanwhile, L. brevis was found to effectively inhibit the growth of Enterobacteriaceae during fermentation. These results demonstrated that fermentation of cereal, pseudo-cereal and legume materials with P. freudenreichii and L. brevis is effective in fortifying plant-based food with vitamin B12.Peer reviewe