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Effect of freeze‐thaw pretreatment on thermal drying process and physicochemical properties of chitosan
Author(s) -
Zhang Wei,
Xia Wenshui
Publication year - 2014
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.41017
Subject(s) - chitosan , freeze drying , chemistry , dpph , browning , spray drying , nuclear chemistry , chemical engineering , food science , chromatography , organic chemistry , antioxidant , engineering
The effect of freeze‐thaw pretreatment on the thermal drying process and physicochemical properties of chitosan was investigated in this study. Results showed that the freeze‐thaw treatment changed the form of chitosan paste and reduced 75.6–77.7% of the water content. The freeze‐thaw treatment decreased the drying time of chitosan from 16–19 h to 2.75–4 h and the dried product was loosely packed powder. After freeze‐thaw treatment, the molecular weight of chitosan was unchanged during the thermal drying. The heat‐induced browning effect of chitosan during drying was greatly alleviated by the pretreatment. Furthermore, the pretreatment increased the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical‐scavenging activity of dried product by 40.4–59.8%. The molecular weight, color, and DPPH radical‐scavenging activity of the pretreated dried chitosan product were close to those of freeze‐dried product. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 41017.