title: Heat-induced gelation of bovine serum albumin/low-methoxyl pectin systems and the effect of calcium ions.
abstract: Influence of low-methoxyl pectin (LM pectin) and calcium ions (3 mM) on mechanical behavior and microstructure of bovine serum albumin (BSA) gels (pH 6.8, in 0.1 M NaCl) was evaluated. Protein and LM pectin concentrations were fixed at 2, 4, and 8 wt % and 0.21, 0.43, and 0.85 wt %, respectively. Rheological measurements and confocal laser scanning microscopy coupled with texture image analysis by use of the co-occurrence method were performed. Heat treatment of BSA/LM pectin mixtures induced protein gelation and a phase separation process between the two biopolymers, which was kinetically trapped. Calcium ions induced pectin gelation and modified BSA gel properties. Depending on biopolymer concentrations, a balance between pectin and/or protein gel contribution on final gel strength exists. The microstructures of the mixed systems in the presence of calcium can be interpreted as interpenetrated structures. Texture image analysis allowed one to classify more precisely the different microstructures observed in relation with mechanical properties.
authors.affiliation: Unité de Physico-Chimie des Macromolécules, INRA, Rue de la Géraudière, BP 71627, 44316 Nantes Cedex 03, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Donato
authors.forename: Catherine
authors.initials: C
authors.lastname: Garnier
authors.forename: Bruno
authors.initials: B
authors.lastname: Novales
authors.forename: Sylvie
authors.initials: S
authors.lastname: Durand
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Doublier
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry*; D002417:Cattle; D005782:Gels / Q000737:chemistry; D006358:Hot Temperature; D008970:Molecular Weight; D010368:Pectins / Q000737:chemistry*; D012709:Serum Albumin / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005782:Gels; D012709:Serum Albumin; D010368:Pectins; D002118:Calcium