Modeling of Water Absorption of Chickpea During Soaking

Chickpea are known as an important source of protein, grown as specialty crop in Iran and is exported around the world. Soaking of grains is usually used before hulling and cooking. Understanding water absorption of different seeds during soaking was considered by researchers. Materials under differentconditions of soaking have different water absorption rate and capacity. Relationship between moisture content of materialsversus time during soaking has been expressed by different models. In this study the different standard models were used to predict the moisture ratio of three varieties of chickpeas in Iran (Desi, small Kabuli and large Kabuli). The experiments were carried by using distilled water at three temperatures (5, 25 and45°C) and three replicate. Amount of water absorption by varies seeds were determined 5, 10, 15, 30 minutes and one hour after immersion. The tests followed at intervals of one hour toward gelatinized seeds. Fourteen standard models of moisture absorptionwere fitted to the experimental data by using Matlab software. Toevaluate the models, three parameters; coefficient of determination (R2), chi-square (x2) and root mean square error (RMSE) were used. Based on maximum value of coefficient of determination and minimum value of chi-square and root mean square error, the best model was chosen. The result showed that the Binomial model is the most appropriate for each of the three varieties in each experimental temperature to predict ratio moisture changes by the time in soaking. So, moisture ratio versus time was plotted for each case, by using Binomial equation. The plotted curves for each variety of chickpea indicated that moisture ratio is decreasing withincreasing temperature.

Keywords:

Immersion , moisture ratio , Binomial model , Matlab software , statistical index