title: Gelatin vs polysaccharide in mixture with sugar.
abstract: The structural behavior of a well-characterized gelatin sample has been revisited to investigate the morphology of its network in the presence of sugar. This was then contrasted with the corresponding properties of the gelling polysaccharides agarose, kappa-carrageenan, and deacylated gellan. Small deformation dynamic oscillation, differential scanning calorimetry in plain and modulated mode, visual observations, and transmission electron microscopy were used to identify the structural characteristics of the biopolymers from the rubbery plateau through the transition region to the glassy state. In contrast to the collapse of the polysaccharide gels at intermediate levels of co-solute, gelatin forms reinforced networks. The drop in polysaccharide network strength is accompanied by a decline in the enthalpy of the coil-to-helix transition, whereas the transition enthalpy is more pronounced in gelatin gels in accordance with their strengthening. Tangible evidence of the molecular transformations was obtained using microscopy, with polysaccharides disaggregating and dissolving in the saturated sugar environment. Gelatin, on the other hand, is visualized in an aggregated form thus producing a phase-separated topology with sugar.
authors.affiliation: Department of Food Science & Nutrition, College of Agricultural & Marine Sciences, Sultan Qaboos University, PO Box 34, Al-Khod 123, Sultanate of Oman. stefan@squ.edu.om
authors.forename: Stefan
authors.initials: S
authors.lastname: Kasapis
authors.forename: Insaf M
authors.initials: IM
authors.lastname: Al-Marhoobi
authors.forename: Marcin
authors.initials: M
authors.lastname: Deszczynski
authors.forename: John R
authors.initials: JR
authors.lastname: Mitchell
authors.forename: Rukmal
authors.initials: R
authors.lastname: Abeysekera
mesh_terms: D002152:Calorimetry, Differential Scanning; D002351:Carrageenan / Q000737:chemistry; D045424:Complex Mixtures; D005780:Gelatin / Q000737:chemistry*; D008854:Microscopy, Electron; D044367:Phase Transition; D011134:Polysaccharides / Q000737:chemistry*; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D012212:Rheology; D012685:Sepharose / Q000737:chemistry; D013395:Sucrose / Q000737:chemistry*; D014783:Viscosity
chemical_list: D045424:Complex Mixtures; D011134:Polysaccharides; D011135:Polysaccharides, Bacterial; D013395:Sucrose; C048288:gellan gum; D002351:Carrageenan; D005780:Gelatin; D012685:Sepharose