Frozen and Unfrozen Water Contents of Wheat Flours and Their Components

The properties of frozen and unfrozen water in two different wheat flours (hard and soft), and in their main components (gluten, starch, damaged starch, water-soluble and water-insoluble pentosans), were described using modulated differential scanning calorimetry (DSC). As a reference, enthalpy valu...

Full description

Saved in:
Bibliographic Details
Published in:Cereal chemistry 2002-07, Vol.79 (4), p.471-475
Main Authors: Roman-Gutierrez, Alma Delia, Guilbert, Stéphane, Cuq, Bernard
Format: Article
Language:English
Subjects:
Biochemistry
Biochemistry, Molecular Biology
Biological and medical sciences
Cereal and baking product industries
crystallization
differential scanning calorimetry
enthalpy
Food industries
freezing
Fundamental and applied biological sciences. Psychology
heat
Life Sciences
melting
pentosans
starch
temperature
water content
wheat flour
wheat gluten
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The properties of frozen and unfrozen water in two different wheat flours (hard and soft), and in their main components (gluten, starch, damaged starch, water-soluble and water-insoluble pentosans), were described using modulated differential scanning calorimetry (DSC). As a reference, enthalpy values of crystallization (298 J/g) and melting (335 J/g) of pure water were determined from the total heat flow curves. The separation of thermal events between the reversing and nonreversing heat flows with modulated DSC was not effective due to disturbances in the modulated temperature scan. For wheat flours and their components, linear regressions described well the changes in frozen water content calculated from enthalpies of freezing (R2 = 0.970-0.982) or melting (R2 = 0.7830.996). The unfrozen water content (UFWC) calculated for the hard wheat flour (29-31%, db) was close to that calculated for the soft wheat flour (30-32%). The UFWC of wheat gluten (38-47%), starch (38-42%), damaged starch (37-40%), water-soluble pentosans (51%), and water-insoluble pentosans (40-44%) were higher than the corresponding values for the flours. The simple summation of the contributions of each component cannot be used to estimate the overall behavior of flours.
ISSN:0009-0352
1943-3638
DOI:10.1094/CCHEM.2002.79.4.471