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Thermal Transitions in Gelatinized Wheat Starch at Different Moisture Contents by Dynamic Mechanical Analysis
Author(s) -
VODOVOTZ Y.,
CHINACHOTI P.
Publication year - 1996
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1996.tb10905.x
Subject(s) - endotherm , materials science , moisture , melting temperature , glass transition , skewness , starch , analytical chemistry (journal) , differential scanning calorimetry , composite material , thermodynamics , polymer , chemistry , chromatography , mathematics , organic chemistry , statistics , physics
Gelatinized starch was analyzed by DMA and the resulting overlapped tan 5 curve was characterized. At high moisture contents (>30% w/w), transitions around ice melting region of tan 5 peak (>50°C wide) showed skewness at the low temperature side. After deconvolution, a symmetrical, sharp, main peak was correlated with the ice melting endotherm but the cause of the lower temperature asymmetrical peak was not identified. At <30% moisture, two deconvoluted Gaussian peaks indicated at least two separate, broadly distributed domains (slightly frequency dependent). Transitions (other than ice melting), if caused by glassy rubbery transitions, were small in tan 5 and broad (50–100°C wide).