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NMR imaging of the wheat grain cooking process
Author(s) -
Stapley Andrew G. F.,
Hyde Thomas M.,
Gladden Lynn F.,
Fryer Peter J.
Publication year - 1997
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1046/j.1365-2621.1997.00122.x
Subject(s) - steaming , boiling , absorption of water , moisture , condensation , latent heat , materials science , homogeneous , steam explosion , chemistry , chemical engineering , composite material , pulp and paper industry , thermodynamics , food science , organic chemistry , physics , engineering
NMR imaging has been used to study the boiling and steaming of intact wheat grains by mapping the distribution of water on the central cross section of grains after various cooking times. The results show different distributions of water occurring with boiling and steaming. Boiled grains showed a front of moisture which gradually moved towards the centre of the grain, although some water was able to diffuse ahead of the front. Steamed grains showed no such front, but showed a homogeneous distribution of water which gradually increases with cooking time. The different results for boiling and steaming imply that different mechanisms control the influx of water in each case, and provide important data for modelling these processes. It is postulated that absorption of water during steaming is slowed by the grain temperature rising above that of the steam temperature as a result of the latent heat associated with the condensation of steam being taken up by the grain.