Application of thermosonication to improve soaking and cooking properties of chickpea

In this study, the effects of time, temperature and ultrasounds on soaking and cooking operations of chickpea were investigated. For moisture absorption, Fick?s, Weibull, Peleg and Asymptotic first order models, for texture only Asymptotic first order model were used during soaking. Increase of soaking/cooking temperature, power of US and US treatment significantly (P<0.05) increased rate of moisture absorption, decrease texture of chickpea and affected the leaching characteristics of chickpea. High frequency US (40 kHz US) did not significantly (P>0.05) affect the water absorption of chickpea during soaking. Water diffusion coefficient (Deff) value of chickpea from Fick?s and Weibull models, Peleg rate constant (K1) and hydration rate constant (kH) of Asymptotic first order model increased with temperature and US (25 kHz 100 W, 40 kHz 100 W and 25 kHz 300 W). Texture model rate constant (kF) also increased with temperature and 25 kHz 100 W, and 25 kHz 300 W US treatments. Degree of cooking of chickpea starch was investigated using DSC, unreacted-core model, electrical conductivity and birefringence images methods. The unreacted-core model very well fitted (R2=0.8949-0.9727) gelatinization of the chickpea starch. There was a good linear relationship between degree of cooking and electrical conductivity data of cooking water and chickpea seeds. The cooking time (?) of chickpea found as 240 min at 92 oC by birefringence images, DSC and EC of chickpea in contrast to unreacted-core model (183 min) due to different mechanisms of models. 25 kHz 100 W and 25 kHz 300 W US treatments represented a 40 min and 80 min decrease in cooking time of chickpea for every temperature, respectively.