title: In vitro fermentability and prebiotic potential of soyabean Okara by human faecal microbiota.
abstract: At present, there is a huge interest in finding new prebiotics from agrofood industrial waste, such as the soyabean by-product Okara, rich in insoluble dietary fibre. A previous treatment of Okara with high hydrostatic pressure assisted by the food-grade enzyme Ultraflo ® L achieved a 58·2 % increment in its soluble dietary fibre (SDF) contents. Therefore, potential prebiotic effect of both treated and native Okara was assayed using 48 h, pH-controlled, anaerobic batch cultures inoculated with human faecal slurries, which simulate the human gut. Changes in faecal microbiota were evaluated using 16S rRNA-based fluorescence in situ hybridisation, whereas release of SCFA and lactic acid was assessed by HPLC. Both Okara samples exhibited potential prebiotic effects but Okara treated to maximise its SDF content showed higher SCFA plus lactic acid, better growth promotion of beneficial bacteria, including bifidobacteria after 4 and 48 h and lactobacilli after 4 h of fermentation, and a greater inhibition of potentially harmful bacterial groups such as clostridia and Bacteroides. Differences found between fructo-oligosaccharides and Okara substrates could be attributed to the great complexity of Okara's cell wall, which would need longer times to be fermented than other easily digested molecules, thus allowing an extended potential prebiotic effect. These results support an in vitro potential prebiotic effect of Okara.
authors.affiliation: 1Metabolism and Nutrition Department,Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN),Consejo Superior de Investigaciones Científicas (CSIC),José Antonio Novais 10,Ciudad Universitaria,E-28040 Madrid,Spain.
authors.forename: E
authors.initials: E
authors.lastname: Pérez-López
authors.affiliation: 2Food & Nutritional Sciences Unit,School of Chemistry, Food and Pharmacy,University of Reading,Reading,UK.
authors.forename: D
authors.initials: D
authors.lastname: Cela
authors.affiliation: 2Food & Nutritional Sciences Unit,School of Chemistry, Food and Pharmacy,University of Reading,Reading,UK.
authors.forename: A
authors.initials: A
authors.lastname: Costabile
authors.affiliation: 4Departamento de Nutrición y Bromatología II,Bromatología, Facultad de Farmacia,Universidad Complutense de Madrid,Ciudad Universitaria,E-28040 Madrid,Spain.
authors.forename: I
authors.initials: I
authors.lastname: Mateos-Aparicio
authors.affiliation: 1Metabolism and Nutrition Department,Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN),Consejo Superior de Investigaciones Científicas (CSIC),José Antonio Novais 10,Ciudad Universitaria,E-28040 Madrid,Spain.
authors.forename: P
authors.initials: P
authors.lastname: Rupérez
mesh_terms: D004043:Dietary Fiber / Q000032:analysis; D005243:Feces / Q000382:microbiology*; D005285:Fermentation; D005511:Food Handling; D006801:Humans; D019344:Lactic Acid; D064307:Microbiota; D056692:Prebiotics; D013025:Glycine max / Q000737:chemistry*
chemical_list: D004043:Dietary Fiber; D056692:Prebiotics; D019344:Lactic Acid
keywords: DNS; FOS fructo-oligosaccharides; Fermentation; Food by-products; HHP high hydrostatic pressure; Hydrostatic pressure; IDF; Microbiota; Okara; Prebiotics; SDF soluble dietary fibre; Ultraflo
                 ® L enzyme; dinitrosalicylic acid method; insoluble dietary fibre