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Gelatinization Properties of Navy Bean Starch
Author(s) -
Lee James J.,
Uebersax Mark A.,
Zabik Mary E.,
Steffe James F.
Publication year - 1995
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19950470902
Subject(s) - starch , swelling , thixotropy , starch gelatinization , food science , phaseolus , chemistry , viscosity , rheology , viscometer , apparent viscosity , materials science , botany , composite material , biology
Gelatinization properties of navy bean ( Phaseolus vulgaris ) starch under different combinations of concentration (6, 8, 10 and 12%) and cooking temperature (75, 85 and 95°C) were studied using a rotational viscometer. The torque response due to swelling and/or breakdown of starch granules approached equilibrium after either a gradual increase or a relatively rapid increase to a peak followed by a decline during cooking. For every condition, the difference between the final torque values obtained for the rapid and the slow heating processes was not significant. In general, the viscosity of the paste increased as the starch concentration and/or cooking temperature increased. However, cooking temperature of 75°C did not cause a significant gelatinization or swelling of starch granules in pastes of 6 or 8% concentration. Maximum final viscosity values were obtained at 85°C for all starch concentrations except for a maxium at 95°C for 6%. Thixotropic breakdown was observed at 10 and 12% concentrations during initial shearing at 85 and 95°C. The threshold concentration for singnificant viscosity effects in this study was in the range of about 8 to 10% or 95°C. The calculated activation energy (14.5 Kcal.g −1 mole −1 ) of navy bean starch gelatinization was similar to values reported for rough rice and rice starches.