Title
Water content or water activity: What rules crispy behavior in bread crust?
Author
van Nieuwenhuijzen, N.H.
Primo-Martín, C.
Meinders, M.B.J.
Tromp, R.H.
Hamer, R.J.
van Vliet, T.
TNO Kwaliteit van Leven
KvL
Publication year
2008
Abstract
A dry crust loses its crispness when water migrates into the crust. It is not clear if it is the amount of water absorbed or the water activity (a w) that leads to a loss of crispness. The hysteresis effect observed when recording a water sorption isotherm allowed us to study the effects of aw and moisture content separately. All experiments were carried out on model bread crusts made from Soissons bread flour. The effect of water content and water activity on the glass transition of model bread crusts was studied in detail using two complimentary techniques: phase transition analysis (PTA) and nuclear magnetic resonance (NMR). The results were compared with sensory data and results from a puncture test, which provided data on acoustic emission and fracture mechanics during breaking of the crusts. The water content of the crust was found to be decisive for the transition point as measured by PTA and NMR. However, both water content and water activity had an effect on perceived crispness and number of force and sound peaks. From this may be concluded that the distribution of the water in the samples with a history of high water content is more inhomogeneous, which results in crispy and less crispy regions, thus making them overall more crispy than samples with the same water content but higher aw. © 2008 American Chemical Society.
Subject
Nutrition
starch
water
article
bread
chemistry
food handling
human
physical chemistry
sensation
transition temperature
Bread
Chemistry, Physical
Food Technology
Humans
Sensation
Starch
Transition Temperature
Water
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http://resolver.tudelft.nl/uuid:e58213e1-25d2-4e1b-97e6-8cd7cefaf8b6
DOI
https://doi.org/10.1021/jf800522c
TNO identifier
240952
ISSN
0021-8561
Source
Journal of Agricultural and Food Chemistry, 56 (15), 6432-6438
Document type
article