Browsing by Subject "Lactic acid bacteria"

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  • Verni, Michela; Vekka, Anna; Immonen, Mikko; Katina, Kati; Rizzello, Carlo Giuseppe; Coda, Rossana (2022)
    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.
  • Koirala, Prabin; Maina, Ndegwa; Nihtilä, Hanna; Katina, Kati; Coda, Rossana (2021)
    BackgroundLactic acid bacteria can synthesize dextran and oligosaccharides with different functionality, depending on the strain and fermentation conditions. As natural structure-forming agent, dextran has proven useful as food additive, improving the properties of several raw materials with poor technological quality, such as cereal by-products, fiber-and protein-rich matrices, enabling their use in food applications. In this study, we assessed dextran biosynthesis in situ during fermentation of brewers spent grain (BSG), the main by-product of beer brewing industry, with Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16. The starters performance and the primary metabolites formed during 24 h of fermentation with and without 4% sucrose (w/w) were followed.ResultsThe starters showed similar growth and acidification kinetics, but different sugar utilization, especially in presence of sucrose. Viscosity increase in fermented BSG containing sucrose occurred first after 10 h, and it kept increasing until 24 h concomitantly with dextran formation. Dextran content after 24 h was approximately 1% on the total weight of the BSG. Oligosaccharides with different degree of polymerization were formed together with dextran from 10 to 24 h. Three dextransucrase genes were identified in L. pseudomesenteroides DSM20193, one of which was significantly upregulated and remained active throughout the fermentation time. One dextransucrase gene was identified in W. confusa A16 also showing a typical induction profile, with highest upregulation at 10 h.Conclusions Selected lactic acid bacteria starters produced significant amount of dextran in brewers' spent grain while forming oligosaccharides with different degree of polymerization. Putative dextransucrase genes identified in the starters showed a typical induction profile. Formation of dextran and oligosaccharides in BSG during lactic acid bacteria fermentation can be tailored to achieve specific technological properties of this raw material, contributing to its reintegration into the food chain.
  • Koirala, Prabin; Maina, Ndegwa H.; Nihtilä, Hanna; Katina, Kati; Coda, Rossana (BioMed Central, 2021)
    Abstract Background Lactic acid bacteria can synthesize dextran and oligosaccharides with different functionality, depending on the strain and fermentation conditions. As natural structure-forming agent, dextran has proven useful as food additive, improving the properties of several raw materials with poor technological quality, such as cereal by-products, fiber-and protein-rich matrices, enabling their use in food applications. In this study, we assessed dextran biosynthesis in situ during fermentation of brewers´ spent grain (BSG), the main by-product of beer brewing industry, with Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16. The starters performance and the primary metabolites formed during 24 h of fermentation with and without 4% sucrose (w/w) were followed. Results The starters showed similar growth and acidification kinetics, but different sugar utilization, especially in presence of sucrose. Viscosity increase in fermented BSG containing sucrose occurred first after 10 h, and it kept increasing until 24 h concomitantly with dextran formation. Dextran content after 24 h was approximately 1% on the total weight of the BSG. Oligosaccharides with different degree of polymerization were formed together with dextran from 10 to 24 h. Three dextransucrase genes were identified in L. pseudomesenteroides DSM20193, one of which was significantly upregulated and remained active throughout the fermentation time. One dextransucrase gene was identified in W. confusa A16 also showing a typical induction profile, with highest upregulation at 10 h. Conclusions Selected lactic acid bacteria starters produced significant amount of dextran in brewers’ spent grain while forming oligosaccharides with different degree of polymerization. Putative dextransucrase genes identified in the starters showed a typical induction profile. Formation of dextran and oligosaccharides in BSG during lactic acid bacteria fermentation can be tailored to achieve specific technological properties of this raw material, contributing to its reintegration into the food chain.
  • Rizzello, Carlo G.; Coda, Rossana; Wang, Yaqin; Verni, Michela; Kajala, Ilkka; Katina, Kati; Laitila, Arja (2019)
    The interest towards legumes in food applications has risen over the past decades. However, the presence of antinutritional factors (ANF) and the poor technological performances still restricts their application in food fortification. In this study, four lactic acid bacteria (LAB) isolated from faba bean were applied as starter cultures for faba bean bioprocessing. None of the strains employed produced exopolysaccharides from raffinose, on the contrary, they did with sucrose as substrate. The fermented doughs were characterized and the strains were compared for their adaptation capacity and metabolic performance including the formation of dextrans, the degradation of ANF and the ability to improve antioxidant activity and in vitro protein digestibility (IVPD). A contribution to the proteolysis was given by the presence of endogenous enzymes, responsible for the increase of peptides and amino acids in dough from irradiated flour. However, the LAB strains further enhanced proteolysis. Weissella cibaria VTT E-153485 led to the highest peptide release and consequentially to the highest IVPD. In doughs fermented with Pediococcus pentosaceus VTT E-153483 and Leuconostoc kimchi VTT E-153484, phytic acid was reduced to more than half the initial concentration. Inoculated doughs had significantly lower content of oligosaccharides after 24 h of incubation compared to the controls. The most efficient raffinose consumption was found for Leuc. kimchi and W. cibaria. Doughs inoculated with weissellas contained > 1% of dextrans. Weissella confusa VTT E-143403 induced a significant increment in viscosity (ca. 7 times higher than the controls). This study revealed that well-characterized, indigenous LAB provided beneficial biotechnological features in faba bean dough processing and contributed to its implementation in the food production.
  • Björkroth, Johanna; Geisen, Rolf; Schillinger, Ulrich; Weiss, Norbert; De Vos, Paul; Holzapfel, Wilhelm H.; Korkeala, Hannu; Vandamme, Peter (American Society for Microbiology (ASM), 2000)
    Lactic acid bacteria (LAB) associated with gaseous spoilage of modified-atmosphere-packaged, raw, tomatomarinated broiler meat strips were identified on the basis of a restriction fragment length polymorphism (RFLP) (ribotyping) database containing DNAs coding for 16S and 23S rRNAs (rDNAs). A mixed LAB population dominated by a Leuconostoc species resembling Leuconostoc gelidum caused the spoilage of the product. Lactobacillus sakei, Lactobacillus curvatus, and a gram-positive rod phenotypically similar to heterofermentative Lactobacillus species were the other main organisms detected. An increase in pH together with the extreme bulging of packages suggested a rare LAB spoilage type called “protein swell.” This spoilage is characterized by excessive production of gas due to amino acid decarboxylation, and the rise in pH is attributed to the subsequent deamination of amino acids. Protein swell has not previously been associated with any kind of meat product. A polyphasic approach, including classical phenotyping, whole-cell protein electrophoresis, 16 and 23S rDNA RFLP, 16S rDNA sequence analysis, and DNA-DNA reassociation analysis, was used for the identification of the dominant Leuconostoc species. In addition to the RFLP analysis, phenotyping, whole-cell protein analysis, and 16S rDNA sequence homology indicated that L. gelidum was most similar to the spoilage-associated species. The two spoilage strains studied possessed 98.8 and 99.0% 16S rDNA sequence homology with the L. gelidum type strain. DNA-DNA reassociation, however, clearly distinguished the two species. The same strains showed only 22 and 34% hybridization with the L. gelidum type strain. These results warrant a separate species status, and we propose the name Leuconostoc gasicomitatum sp. nov. for this spoilage-associated Leuconostoc species.
  • Fu, Y; Qiao, W; Zhu, D; Wang, X; Liu, F; Xu, H; Saris, Per Erik Joakim; Kuipers, Osacar; Qiao, Mingqiang (2018)
    Nisin, an important bacteriocin from Lactococcus lactis subsp., is primarily active against various Gram-positive bacteria. Leucocin C, produced by Leuconostoc carnosum 4010, is a class IIa bacteriocin used to inhibit the growth of Listeria monocytogenes. Because two bacteriocins have different modes of action, the combined use of them could be a potential strategy for effective inhibition of foodborne pathogens. In this study, L. lactis N8-r-lecCI (N8 harboring lecCI gene) coexpressing nisin–leucocin C was constructed based on the food-grade carrier L. lactis N8. Production of both bacteriocins was stably maintained. Antimicrobial measurements showed that the recombinant strain is effectively against Listeria monocytogenes and Staphylococcus aureus and moderately against Salmonella enterica serovar Enteritidis and Escherichia coli because of its stronger antibacterial activity than the parental strain, this result first demonstrated that the co-expression of nisin and leucocin C results in highly efficient antimicrobial activity. The checkerboard assay showed that the antibacterial activity of L. lactis N8-r-lecCI supernatant was enhanced in the presence of low concentration of EDTA. Analysis of the scanning electron microscope image showed the biggest cellular morphology change in L. monocytogenes treated with a mixture of EDTA and L. lactis N8-r-lecCI supernatant. The practical effect was verified in pasteurized milk through time-kill assay. The L. lactis N8-r-lecCI strain expressing both nisin and leucocin C has a promising application prospect in pasteurized milk processing and preservation because of its strong antibacterial activity.
  • Laitila, Tiina (Helsingin yliopisto, 2022)
    Aflatoxin B1 (AFB1) is a naturally occurring toxic compound produced by various types of fungi. The presence of AFB1 in food and feed can lead to severe illness, which makes it a serious threat to humans and animals. Due to global climate change, the cases of AFB1 contamination in food will increase since high temperature and humidity favour fungal growth and the production of AFB1. The bioavailability of AFB1 can be decreased by adsorption or biotransformation. Adsorption happens by the utilization of different AFB1 binding agents, which can be either mineral and organic or biological adsorbents. Mineral and organic adsorbents are only used in feed since they may also bind to nutrients. Biological adsorbents are being studied more actively since they maintain the nutritional value of the food. Studies show that Lactic acid bacteria (LAB) can be used to bind AFB1 from contaminated foods. The aim of this research was to study the capacity of different LAB (viable and nonviable) to adsorb (bind) AFB1 under different pH conditions. The research first evaluated the binding ability of AFB1 by 13 viable and nonviable LAB strains at pH 7. The best binding strains were selected for further study at pH 3 to mimic gastric pH. The AFB1 binding with cells was performed at 25℃ for 90 min. To determine the binding capacity, the solutions were centrifuged and free AFB1 in the supernatant was extracted with acetonitrile, and quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was used to clean up the samples. AFB1 concentration was determined by ultra-performance liquid chromatography and fluorescence detection (UPLC-FLD). The LAB strains used in this research were shown to have the ability to bind AFB1. Binding efficacy of AFB1 depended on the bacterial strain. Viability and pH also affected the binding ability. All nonviable cells showed better binding ability (44.9–71.3%) compared to the viable cells (29.0–49.4%). The strains also had better binding capacity at lower pH regardless of the cell viability. The highest binding efficacy (71.3%) was achieved by the nonviable cell of Lactobacillus helveticus FAM 22155 at pH 3. The results of this thesis showed that some LAB strains bind AFB1 and that the binding is stable under stomach conditions. Studies to investigate the stability of the binding under simulated upper and lower gastrointestinal (GI) tract conditions (in vitro digestion) and in vivo studies are needed in order to provide further evidence of the applicability of LAB in lowering the bioavailability of AFB1.
  • Merivirta, Lauri; Koort, Joanna; Kivisaari, Meija; Korkeala, Hannu; Björkroth, Johanna (Elsevier, 2005)
    Microbiological and sensory changes in vacuum-packaged charcoal-broiled river lampreys from three lamprey processing plants were monitored as a function of time at 8°C. The lampreys were examined every 7 days up to 8 weeks for aerobic plate count (APC) and lactic acid bacteria (LAB). The highest mean APC and LAB were 6.01 log CFU/g and 4.86 log CFU/g, respectively. Only 6 out of 15 lots reached an APC value of 7.0 log CFU/g during storage. The sensory scores remained at the baseline levels after 8 weeks´ storage. Twenty-seven isolates were randomly picked from MRS agar and identified to species level using a 16S and 23S rDNA HindIII RFLP (ribotyping) database and sequencing of the 16S rRNA gene if no database match was obtained. Twelve of the 27 isolates were identified as Lactobacillus curvatus subsp. curvatus, and two Leuconostoc mesenteroides and one Weissella halotolerans strain were also detected. Twelve isolates were not identified by the LAB database. However, they possessed very high (99.9%) 16S gene sequence similarity with either Staphylococcus warneri or Staphylococcus pasteuri type strains. The LAB detected, with the exception of W. halotolerans, have commonly been associated with spoilage of fishery products, but in these vacuum-packaged lampreys they were not the dominant organisms within the developing spoilage population.
  • Wang, Changyin (Helsingfors universitet, 2017)
    Faba bean (Vicia faba L.) is a widely-cultivated legume with high nutritional value, especially rich in protein. However, the presence of antinutitional factors (e.g. phytic acid, condensed tannins, vicine and convicine and others) are hindering its utilization. Lactic acid fermentation is widely applied in food production and it is closely related with the promotion of nutritional, technological and health properties of the fermented food. The aim of this master’s thesis was to explore several functional characteristics of 28 lactic acid bacteria previously isolated from Italian and Finnish faba bean sourdoughs. In this study, phytase activity, β-glucosidase activity and the effect on degradation of condensed tannins, which are potentially directed towards reduction of anti-nutritional factors, were investigated. Three peptidase activities and dextran production capacity of the isolates were also evaluated. Besides, six antibiotics were used to study antibiotic susceptibility among the strains. Leuconostoc mesenteroides I01 and Pediococcus pentosaceus I214 expressed the highest phytase activity while P. pentosaceus I02, F01, F213 had the highest β-glucosidase activity. P. pentosaceus F15 was the most effective to decrease condensed tannins. Among analyzed peptidases, PepL showed the highest activity, especially in Pediococcus strains. High dextran production capacity was observed among isolates of Weissella spp. The strains showing functional traits could be used as starter to improve the nutritional and technological properties of faba bean. Further investigation is still ongoing to evaluate other properties of these lactic acid bacteria as functional starter cultures for faba bean and legume fermentation.
  • Xu, Yan; Coda, Rossana; Holopainen-Mantila, Ulla; Laitila, Arja; Katina, Kati; Tenkanen, Maija (2019)
    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.
  • Xu, Yan; Wang, Yaqin; Coda, Rossana; Säde, Elina; Tuomainen, Päivi; Tenkanen, Maija; Katina, Kati (2017)
    Fava bean flour is regarded as a potential plant-based protein source, but the addition of it at high concentration is restricted by its poor texture-improving ability and by anti-nutritional factors (ANF). Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) are regarded as good texture modifiers. In this study, fava bean flour was fermented with Leuconostoc spp. and Weissella spp. with or without sucrose addition, in order to evaluate their potential in EPS production. The contents of free sugars, organic acids, mannitol and EPS in all fermented fava bean doughs were measured. Rheological properties of sucrose-enriched doughs, including viscosity flow curves, hysteresis loop and dynamic oscillatory sweep curves, were measured after fermentation. As one of the ANF, the degradation of raffinose family oligosaccharides (RFO) was also studied by analyzing RFO profiles of different doughs. Quantification of EPS revealed the potential of Leuconostoc pseudomesenteroides DSM 20193 in EPS production, and the rheological analysis showed that the polymers produced by this strain has the highest thickening and gelling capability. Furthermore, the viscous fava bean doughs containing plant proteins and synthesized in situ EPS may have a potential application in the food industry and fulfill consumers' increasing demands for "clean labels" and plant-originated food materials. (C) 2017 Elsevier B.V. All rights reserved.
  • Suominen, Juulia (Helsingin yliopisto, 2020)
    Sourdoughs are a natural habitat for microbial communities predominated by lactic acid bacteria (LAB) and yeasts. How microbial communities assemble and function is, to a large extent, determined by inter-species interactions. However, evidence for LAB-yeast interactions in rich environments, such as sourdough, is yet largely unavailable. In this study, a set of LAB and yeast species was isolated from rye and wheat sourdoughs. While mainly typical sourdough species were identified, Pediococcus parvulus was, to the best of our knowledge, for the first time isolated from sourdoughs. The isolates were characterized in rich chemically defined culture conditions and screened for interactions. Potential interactions were discovered where LAB growth was enabled by a yeast, or where stable communities were formed despite competition. These findings, the resource of naturally co-occurring species, and the designed chemically defined growth medium present the grounds for future research for uncovering the underlying mechanisms of LAB-yeast interactions in rich environments. LAB and yeasts commonly co-occur rich environments of fermented food processes and also in human gut and soil microbiomes. Therefore, the outcomes of this study support not only the optimization of food fermentations but provide also model systems for complex communities directly influencing human health.
  • Rizzello, Carlo Giuseppe; Hernandez-Ledesma, Blanca; Fernandez-Tome, Samuel; Curiel, Jose Antonio; Pinto, Daniela; Marzani, Barbara; Coda, Rossana; Gobbetti, Marco (2015)
    Background: There is an increasing interest toward the use of legumes in food industry, mainly due to the quality of their protein fraction. Many legumes are cultivated and consumed around the world, but few data is available regarding the chemical or technological characteristics, and especially on their suitability to be fermented. Nevertheless, sourdough fermentation with selected lactic acid bacteria has been recognized as the most efficient tool to improve some nutritional and functional properties. This study investigated the presence of lunasin-like polypeptides in nineteen traditional Italian legumes, exploiting the potential of the fermentation with selected lactic acid bacteria to increase the native concentration. An integrated approach based on chemical, immunological and ex vivo (human adenocarcinoma Caco-2 cell cultures) analyses was used to show the physiological potential of the lunasin-like polypeptides. Results: Italian legume varieties, belonging to Phaseulus vulgaris, Cicer arietinum, Lathyrus sativus, Lens culinaris and Pisum sativum species, were milled and flours were chemically characterized and subjected to sourdough fermentation with selected Lactobacillus plantarum C48 and Lactobacillus brevis AM7, expressing different peptidase activities. Extracts from legume doughs (unfermented) and sourdoughs were subjected to western blot analysis, using an anti-lunasin primary antibody. Despite the absence of lunasin, different immunoreactive polypeptide bands were found. The number and the intensity of lunasin-like polypeptides increased during sourdough fermentation, as the consequence of the proteolysis of the native proteins carried out by the selected lactic acid bacteria. A marked inhibitory effect on the proliferation of human adenocarcinoma Caco-2 cells was observed using extracts from legume sourdoughs. In particular, sourdoughs from Fagiolo di Lamon, Cece dell'Alta Valle di Misa, and Pisello riccio di Sannicola flours were the most active, showing a decrease of Caco-2 cells viability up to 70 %. The over-expression of Caco-2 filaggrin and involucrin genes was also induced. Nine lunasin-like polypeptides, having similarity to lunasin, were identified. Conclusions: The features of the sourdough fermented legume flours suggested the use for the manufacture of novel functional foods and/or pharmaceuticals preparations.
  • Koort, Joanna; Vandamme, Peter; Schillinger, Ulrich; Holzapfel, Wilhelm; Björkroth, Johanna (Society for General Microbiology, 2004)
    On the basis of phenotypic and DNA-DNA reassociation studies, strain CCUG 34545T has been considered to represent a distinct Lactobacillus curvatus subspecies, Lactobacillus curvatus subsp. melibiosus. However, in several independent studies dealing with Lactobacillus sakei and L. curvatus strains, the subspecies division of L. curvatus has been found to be controversial. The original study distinguishing the two subspecies within both L. curvatus and L. sakei also lacked 16S rRNA gene sequence analyses. Therefore, the taxonomic position of L. curvatus subsp. melibiosus CCUG 34545T was re-evaluated in a polyphasic taxonomy study that included 16S rRNA gene sequence analysis, DNA-DNA reassociation, DNA G+C content deternmination, numerical analysis of ribotypes and whole-cell protein patterns and the examination of some fundamental phenotypic properties. The results obtained indicate that strain CCUG 34545T and its duplicate, CCUG 41580T, are Lactobacillus sakei subsp. carnosus strains and that L. curvatus subsp. melibiosus is a later synonym of L. sakei subsp. carnosus.
  • Yassami, Shiva (Helsingfors universitet, 2016)
    Wheat bran is obtained after conventional milling of wheat grains for the production of white flour, which is an important source of dietary fiber, vitamins and minerals, but still remains underutilized in food manufacturing. In spite of the increasing evidence about the health effects of whole-meal and fiber-rich foods, refined white flour is still preferred. Bran also has a negative influence on dough rheology, texture and the sensory quality of bread, which limits its use in bran bread baking. The use of starter culture for sourdough fermentation can drive the fermentation process and confer specific changes on the matrix. Exopolysaccharides (EPS) produced by some lactic acid bacteria (LAB) are important due to their physicochemical properties affecting dough rheology and bread texture, as well as their health-promoting potential. The screening of EPS-producing strains has been carried out mostly on wheat and rye sourdough, and very few studies have considered different matrices. The objective of this work was to determine and compare whole-wheat flour and wheat bran fermentation by two strains of LAB (Leuconostoc spp. and Weissella spp.) in the presence of added sucrose and without, and to study the effect of sourdough obtained with a selected EPS-producing LAB strain on the quality of bread and its shelf-life. Sourdough quality was studied by means of microbiological, rheological and chemical analysis by comparing the growth and acidification performance in the different matrices, and by evaluating EPS production using viscosity measurements. The physical and mechanical properties of fresh bread made using the best EPS producer LAB were investigated to study the product shelf-life by using the seed replacement method and texture analysis test. The results showed that dough prepared with Weissella confusa with added sucrose had a positive impact on viscosity, as well as providing mild acidic sourdough leading to better bread quality properties, whereas in the presence of Leuconostoc pseudomesenteroides, no positive viscosity has observed in whole-wheat sourdough. Bran sourdough samples with Weissella confusa showed a higher volume, better color and shelf-life during storage than samples with un-soured bran, confirming the effect of sourdough and the positive role of EPS on the functional properties of high-fiber bread making.
  • Graça, Carla; Lima, Ana; Raymundo, Anabela; Sousa, Isabel (2021)
    Cereal products are staple foods highly appreciated and consumed worldwide. Nonetheless, due to the presence of gluten proteins, and other co‐existing compounds such as amylase‐trypsin inhibitors and fermentable short‐chain carbohydrates in those products, their preference by consumers has substantially decreased. Gluten affects the small gut of people with celiac disease, triggering a gut inflammation condition via auto‐immune response, causing a cascade of health disorders. Amylase‐trypsin inhibitors and fermentable short‐chain carbohydrate compounds that co‐exists with gluten in the cereal‐based foods matrix have been associated with several gastrointestinal symptoms in non‐celiac gluten sensitivity. Since the symptoms are somewhat overlapped, the relation between celiac disease and irritable bowel syndrome has recently received marked interest by researchers. Sourdough fermentation is one of the oldest ways of bread leavening, by lactic acid bacteria and yeasts population, converting cereal flour into attractive, tastier, and more digestible end‐products. Lactic acid bacteria acidification in situ is a key factor to activate several cereal enzymes as well as the synthesis of microbial active metabolites, to positively influence the nutritional/functional and health‐promoting benefits of the derived products. This review aims to explore and highlight the potential of sourdough fermentation in the Food Science and Technology field.
  • Coda, Rossana; Kianjam, Maryam; Pontonio, Erica; Verni, Michela; Di Cagno, Raffaella; Katina, Kati; Rizzello, Carlo Giuseppe; Gobbetti, Marco (2017)
    The microbial ecology of faba bean sourdoughs obtained from an Italian (Ita) and a Finnish (Fi) cultivar, belonging respectively to Vicia faba major and V. faba minor groups, was described by 16S rRNA gene pyrosequencing and culture -dependent analysis. The sourdoughs were propagated with traditional backslapping procedure throughout 14 days. Higher microbial diversity was found in the sourdough deriving from V. faba minor (Fi), still containing residual hulls after the milling procedure. After 2 days of propagation, the microbial profile of Ita sourdough was characterized by the dominance of the genera Pediococcus, Leuconostoc and Weissella, while the genera Lactococcus, Lactobacillus and Escherichia, as well as Enterobacteriaceae were present in Fi sourdoughs. Yeasts were in very low cell density until the second backslopping and were not anymore found after this time by plate count or pyrosequencing analysis. Among the lactic acid bacteria isolates, Pediococcus pentosaceus, Leuconostoc mesenteroides and Weissella koreensis had the highest frequency of occurrence in both the sourdoughs. Lactobacillus sakei was the only lactobacillus isolated from the first to the last propagation day in Fi sourdough. According to microbiological and acidification properties, the maturity of the sourdoughs was reached after 5 days. The presence of hulls and the different microbial composition reflected on biochemical characteristics of Fi sourdoughs, including acidification and phenolic compounds. Moreover, proteolysis in Fi sourdough was more intense compared to Ita. The microbial dynamic of the faba bean sourdoughs showed some differences with the most studied cereal sourdoughs. (C) 2017 Elsevier B.V. All rights reserved.
  • Lorusso, Anna; Verni, Michela; Montemurro, Marco; Coda, Rossana; Gobbetti, Marco; Rizzello, Carlo (2017)
    Pasta was prepared by replacing 20% of semolina with native and fermented quinoa flour and the effects of substitution on the technological and nutritional characteristics were evaluated. The addition of quinoa reflected the chemical composition of pasta, which had higher fiber, protein, and free amino acids content than semolina pasta, particularly in the case of pasta containing quinoa flour fermented with selected lactic acid bacteria. Furthermore, free amino acids, total phenols, and the antioxidant activity of pasta prepared with fermented quinoa flour were up to twice as high than the other types of pasta. When fermented quinoa flour was used, the water absorption during cooking was the lowest, even though cooking loss was also observed. The use of quinoa flour affected the textural characteristics of pasta, increased the tenacity and, when fermented, also the elasticity. The effects of quinoa fermentation were evident on the nutritional quality of fortified pasta, showing the highest in vitro protein digestibility, protein nutritional indices (Essential Amino Acid Index, Biological Value, Protein Efficiency Ratio, and Nutritional Index), as well as lowest predicted glycemic index. These results indicate the positive effect of fermented quinoa flour on pasta fortification. (C) 2016 Elsevier Ltd. All rights reserved.