title: In situ synthesis of exopolysaccharides by Leuconostoc spp. and Weissella spp. and their rheological impacts in fava bean flour.
abstract: 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.
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland. Electronic address: xu.z.yan@helsinki.fi.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland.
authors.forename: Rossana
authors.initials: R
authors.lastname: Coda
authors.affiliation: Division of Food Hygiene and Environmental Health, University of Helsinki, P.O. Box 66, FI-00014 University of Helsinki, Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Säde
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland.
authors.forename: Päivi
authors.initials: P
authors.lastname: Tuomainen
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland.
authors.forename: Maija
authors.initials: M
authors.lastname: Tenkanen
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland.
authors.forename: Kati
authors.initials: K
authors.lastname: Katina
mesh_terms: D005285:Fermentation; D005433:Flour / Q000382:microbiology*; D005511:Food Handling / Q000379:methods*; D019649:Food Industry / Q000379:methods; D007934:Leuconostoc / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D012212:Rheology; D013395:Sucrose / Q000378:metabolism; D031307:Vicia faba / Q000378:metabolism* / Q000382:microbiology; D014783:Viscosity; D058836:Weissella / Q000378:metabolism*
chemical_list: D011135:Polysaccharides, Bacterial; D008353:Mannitol; D013395:Sucrose
keywords: Exopolysaccharides; Fava bean; Fermentation; Lactic acid bacteria; Texture modification