Effect of ultrasound treatment on the hydration kinetics and cooking times of dry beans ( Phaseolus vulgaris ).

The effect of ultrasound on the hydration kinetics and cooking times of six bean varieties was studied. Samples of beans were exposed to ultrasound treatments (10, 20 and 30 min; 40 KHz, 130 W) at 30°C in addition to control treatments. In most cases, the observed maximum moisture content of the dry beans (1.16 ± 0.03 to 1.22 ± 0.02 g/g) after soaking did not vary with the bean variety and ultrasound exposure time. Effective diffusivity significantly increased (P < 0.05) up to 45 times, and the time to obtain the equilibrium moisture content was reduced by 17.6–58.8%, with respect to control treatments, when treated with ultrasound for 30 min. The percentage reduction in cooking time ranged from 5.4 to 43.0. Ultrasound treatment significantly reduced the soaking and cooking times of the bean varieties studied, but the extent of such reduction depended on the bean variety and ultrasound exposure time. [ABSTRACT FROM AUTHOR]