24 research outputs found
Emulsifying properties of defatted rice bran concentrates enriched in fiber and proteins
BACKGROUND: Rice bran (RB), a by-product of the rice milling industry, constitutes around 10% of the total weight of rough rice. The interest in the use of RB is centered on its nutritional quality, its low cost, and its extensive worldwide production. As RB is commonly used for oil extraction, the defatted rice bran (DRB) is obtained as a second by-product. The aim of this work was to obtain a defatted rice bran concentrate (DRBC), enriched in protein and fiber, from defatted rice bran flour (DRBF) and to determine its physicochemical and emulsifying properties. RESULTS: To obtain the DRBC, the starch was efficiently hydrolyzed (> 98%) with α-amylase and amyloglucosidase, with a concomitant increase in the proportions of crude protein (from 154.7 to 274.3 g kgâ1) and total dietary fiber (from 276.1 to 492.3 g kgâ1). Defatted rice bran concentrate exhibited a loss of protein solubility and increased surface hydrophobicity compared with DRBF. Defatted rice-bran concentrate dispersions with and without previous ultrasound treatment were prepared. The sonication led to an increase in the apparent viscosity. Emulsions were prepared with dispersions with and without previous ultrasound treatment and showed high stability in quiescent conditions over 28 days. However, the emulsions prepared with dispersions treated with ultrasound resulted in lower D4,3 values and higher elastic and viscous moduli. CONCLUSION: The rice bran concentrate can be used to obtain stable oil-in-water (O/W) emulsions, including both soluble and insoluble fractions, in acidic and neutral conditions. These innovative findings thus contribute to increasing the added value of this important by-product of the rice-milling industry.Fil: Bonifacino, Carla. Universidad de la RepĂșblica. Facultad de QuĂmica; UruguayFil: Franco Fraguas, Eugenia. Universidad de la RepĂșblica. Facultad de QuĂmica; UruguayFil: LĂłpez, DĂ©bora Natalia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias BioquĂmicas y FarmacĂ©uticas. Departamento de QuĂmica y FĂsica. Ărea FisicoquĂmica; Argentina. Pontificia Universidad CatĂłlica Argentina "Santa MarĂa de los Buenos Aires". Facultad de QuĂmica e IngenierĂa-Rosario; ArgentinaFil: Wagner, Jorge Ricardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂa. Laboratorio de InvestigaciĂłn en Funcionalidad y TecnologĂa de Alimentos; ArgentinaFil: Cabezas, Dario Marcelino. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂa. Laboratorio de InvestigaciĂłn en Funcionalidad y TecnologĂa de Alimentos; ArgentinaFil: Panizzolo, Luis Alberto. Universidad de la RepĂșblica. Facultad de QuĂmica; UruguayFil: Palazolo, Gonzalo GastĂłn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂa. Laboratorio de InvestigaciĂłn en Funcionalidad y TecnologĂa de Alimentos; ArgentinaFil: Abirached, Cecilia. Universidad de la RepĂșblica. Facultad de QuĂmica; Urugua