title: Characterization and in vitro digestibility of bovine beta-lactoglobulin glycated with galactooligosaccharides.
abstract: Galactooligosaccharides (GOS) are well-known prebiotic ingredients which can form the basis of new functional dairy products. In this work, the production and characterization of glycated beta-lactoglobulin (beta-LG) with prebiotic GOS through the Maillard reaction under controlled conditions ( a(w) = 0.44, 40 degrees C for 23 days) have been studied. The extent of glycation of beta-LG was evaluated by formation of furosine which progressively increased with storage for up to 16 days, suggesting that the formation of Amadori compounds prevailed over their degradation. RP-HPLC-UV, SDS-PAGE, and IEF profiles of beta-LG were modified as a consequence of its glycation. MALDI-ToF mass spectra of glycated beta-LG showed an increase of up to approximately 21% in its average molecular mass after storage for 23 days. Moreover, a decrease in unconjugated GOS (one tri-, two tetra-, and one pentasaccharide) was observed by HPAEC-PAD upon glycation. These results were confirmed by ESI MS. The stability of the glycated beta-LG to in vitro simulated gastrointestinal digestion was also described and compared with that of the unglycated protein. The yield of digestion products of glycated beta-LG was lower than that observed for the unglycated protein. The conjugation of prebiotic carbohydrates to stable proteins and peptides could open new routes of research in the study of functional ingredients.
authors: Instituto de Química Orgánica General (CSIC), C/ Juan de la Cierva 3, 28006 Madrid, Spain.
authors: María
authors: M
authors: Luz Sanz
authors: Marta
authors: M
authors: Corzo-Martínez
authors: Robert A
authors: RA
authors: Rastall
authors: Agustín
authors: A
authors: Olano
authors: F Javier
authors: FJ
authors: Moreno
mesh_terms: D000818:Animals; D002417:Cattle; D004063:Digestion; D005690:Galactose / Q000378:metabolism*; D006031:Glycosylation; D066298:In Vitro Techniques; D007782:Lactoglobulins / Q000737:chemistry* / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007782:Lactoglobulins; D009844:Oligosaccharides; D005690:Galactose