title: Drying process of sodium alginate films studied by two-dimensional correlation ATR-FTIR spectroscopy.
abstract: Drying process of aqueous sodium alginate solutions at 50°C was investigated by ATR-FTIR spectroscopy and two-dimensional correlation infrared spectroscopy. Two-dimensional asynchronous spectrum at 1,800-1,350 cm(-1) wavenumber could be resolved into five separate bands, which were assigned to O-H bending vibrations in water (around 1,645 cm(-1)), antisymmetric and symmetric stretching vibrations of free and hydrogen-bonded COO(-) groups of alginate (around 1,595, 1,412, 1,572 and 1,390 cm(-1), respectively). As the drying process progressed, absorbance bands at around 1,127 and 1,035 cm(-1) significantly shifted to lower wavenumbers (1120 and 1027cm(-1), respectively). Suggesting that oxygen atoms at the 2th and 3th position in the pyranose ring might have hydrogen bonded with water or alginate chains. Further analysis using 2D asynchronous correlation spectroscopy between 1800-1500 and 1200-960 cm(-1) wavenumber regions revealed the sequence of spectral changes during the drying process.
authors.affiliation: School of Food Science and Technology, Hunan Agriculture University, Hunan 410128, China. Electronic address: baby.qianxiao@gmail.com.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Jiangsu 214122, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Gu
authors.affiliation: Faculty of Engineering & Computer Science, Concordia University, H3G 1M8 Montreal, Canada.
authors.forename: Suo
authors.initials: S
authors.lastname: Tan
mesh_terms: D000464:Alginates / Q000737:chemistry*; D003890:Desiccation / Q000379:methods*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006860:Hydrogen Bonding; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014867:Water / Q000032:analysis*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D014867:Water; D020723:Glucuronic Acid
keywords: ATR-FTIR; Drying process; Sodium alginate; Two-dimensional correlation spectroscopy