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STRESS RELAXATION OF DEFORMED FRUITS AND VEGETABLES
Author(s) -
PELEG M.,
CALZADA J. F.
Publication year - 1976
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.1365-2621.1976.tb01163.x
Subject(s) - deformation (meteorology) , relaxation (psychology) , rheology , compression (physics) , stress relaxation , materials science , composite material , residual , chemistry , mathematics , creep , psychology , social psychology , algorithm
The force relaxation curves of deformed specimens of apples, pears and potatoes were studied in compression tests. It was found that ln all three commodities two relaxation curves could cross one another even if one of them started at conditions in which both the deformation and the initial force had higher values. It was also noticed that for deformations bigger than about 5% the residual force was dependent on the rate at which the deformation had been reached. The values of the residual forces of samples deformed at a rate of 10 cm/min were smaller than the values of those samples which were deformed at 1 cm/min. These characteristics of the relaxation phenomenon could be explained by physical irreversible changes which occur during the deformation of the biological material. They could also be represented by a modified rheological model in which the number of active elements and their mode of mechanical response is a function of the deformation and its application rate.