| Popis: |
IMPACT and compression rheological models, derived from continuum mechanics, were developed to predict the force response of an impacting and a slowly compressed blueberry, respectively. A relaxation modulus was used in the models. An equation to calculate the absolute value of the complex modulus from mechanical impedance test data was developed by using the dimensional analysis method. A rapid method for determining berry mass and the relaxation modulus (G0, xj by impacting a berry onto a force transducer was developed from the impact model. The predicted berry mass correlated well (R = 0.98) with actual mass while the elastic modulus (G0) predicted quickly from the impact data correlated somewhat less (R = 0.92) with the elastic modulus derived from a more time consuming curve fitting procedure involving the impact and compression models and data. The relaxation time constant (TJ was unpredictable. |
