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Short communication: Effect of pre‐soaking on the rate of thermal softening of soybeans
Author(s) -
GANDHI A. P.,
BOURNE M. C.
Publication year - 1991
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 - 10.1111/j.1365-2621.1991.tb01147.x
Subject(s) - softening , imbibition , boiling , chemistry , horticulture , food science , botany , materials science , composite material , germination , biology , organic chemistry
Summary Whole soybeans and dehulled soybean cotyledons were soaked in water at ambient temperature for 0, 8 and 12h then cooked in boiling water at atmospheric pressure for up to 6h. In every case there was an initial rapid rate of softening followed by progressively slower softening until, after about 3h, there was little change in firmness. The kinetics of softening of every sample was consistent with the two substrate theory of thermal softening. The firmness ranking in descending order after 15 min cooking was no soak, whole beans > 12h, soak cotyledons > no soak, cotyledons > 8h soak, whole beans > 12h soak, whole beans. This ranking was maintained for the entire cooking period. For whole beans the soaked samples were less firm than the unsoaked samples while for the cotyledons the soaked samples were more firm than the unsoaked. This reversal in behaviour may be caused by the seed coat (skin) retarding the imbibition of water in the whole beans thus delaying the onset of enzyme activity in the bean tissue.