title: Drying process of pullulan edible films forming solutions studied by ATR-FTIR with two-dimensional correlation spectroscopy.
abstract: Drying phenomenon of aqueous pullulan solutions at 50°C was investigated by ATR-FTIR spectroscopy and two-dimensional correlation infrared spectroscopy. Two-dimensional asynchronous spectrum at 1800-1500cm(-1) wavenumber was resolved into three separate bands, which were assigned to aggregated water with strong hydrogen bond (AW-S), aggregated water with moderately hydrogen (AW-M) bond, and free water (FW), respectively. Curve fitting results indicated that the quantities of the three species of water were constant during the first 55min of drying process. However, the area of the three bands (at around 1047, 1022 and 998cm(-1)) varied as drying progressed, implying the formation of more-ordered pullulan chains structure, as well as increased pullulan chain-chain interactions. Further analysis using 2D asynchronous correlation spectroscopy in 1200-950cm(-1) wavenumber regions revealed the sequence of spectral changes during the drying process.
authors.affiliation: School of Food Science and Technology, Hunan Agricultural University, 410128 Hunan, 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, 214122 Jiangsu, China.
authors.forename: Qunyi
authors.initials: Q
authors.lastname: Tong
authors.affiliation: Department of Food Science, University of Guelph, N1G 2W1 Ontario, Canada.
authors.forename: Loong-Tak
authors.initials: LT
authors.lastname: Lim
mesh_terms: D063566:Biodegradable Plastics / Q000737:chemistry*; D003890:Desiccation; D018857:Food Packaging / Q000295:instrumentation*; D005936:Glucans / Q000737:chemistry*; D006860:Hydrogen Bonding; D017550:Spectroscopy, Fourier Transform Infrared; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry
chemical_list: D063566:Biodegradable Plastics; D005936:Glucans; D014867:Water; C009109:pullulan
keywords: 2D; ATR-FTIR; AW-M; AW-S; Drying process; FW; HATR; Pullulan; Two-dimensional correlation spectroscopy; aggregated water with moderately hydrogen; aggregated water with strong hydrogen bond; attenuated total reflection Fourier transform infrared spectroscopy; free water; horizontal attenuated total reflectance; two-dimensional