title: Phase composition and interface of starch-gelatin blends studied by synchrotron FTIR micro-spectroscopy.
abstract: The well recognized complex issue of compatibility between starch and gelatin was investigated based on their interface and phase composition using synchrotron FTIR micro-spectroscope. A high amylose (80%) corn starch grafted with flexible and hydrophilic hydroxpropyl groups and plasticized by poly(ethylene glycol) (PEG) was used in this work. The FTIR beam focused on a 5 μm×5 μm detection region and the micro-spectroscope was scanned across the gelatin-starch interface. It was found that there was about a 20 μm thickness layer where gelatin and starch were in co-existence, indicating that gelatin and starch are compatible to a certain degree in this system. The ratio of the areas of the saccharide CO bands (1180-953 cm(-1)) and the amide I and II bands (1750-1483 cm(-1)) was used to monitor the relative distributions of the two components of the blends. FTIR 2 and 3-dimensional maps indicated that gelatin constituted the continuous phase up to 80% of starch content. The PEG was homogeneously distributed in both gelatin and starch phases, and blurred the interface between gelatin and starch in the chemical maps, indicating that PEG acted not only as a plasticizer but as a compatibilizer for the gelatin-starch blends.
authors: CSIRO, Materials Science and Engineering, Clayton, Vic. 3169, Australia.
authors: Nuozi
authors: N
authors: Zhang
authors: Xingxun
authors: X
authors: Liu
authors: Long
authors: L
authors: Yu
authors: Robert
authors: R
authors: Shanks
authors: Eustathios
authors: E
authors: Petinaks
authors: Hongsheng
authors: H
authors: Liu
mesh_terms: D005780:Gelatin / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D017356:Synchrotrons
chemical_list: D011092:Polyethylene Glycols; D005780:Gelatin; D013213:Starch