Yousef Abaspour Kalan; Mohammad Nikbakht; Majid Rahnama
Volume 36, Issue 1 , September 2013, , Pages 23-34
Abstract
Drying grape fruit as a strategic product in Iran faces numerous challenges including color change, spoilage, and hygienic issues and long drying time. To this aim, the present research was conducted to kinetically study the thin-layer hot air drying of grape fruit together with mathematical modeling ...
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Drying grape fruit as a strategic product in Iran faces numerous challenges including color change, spoilage, and hygienic issues and long drying time. To this aim, the present research was conducted to kinetically study the thin-layer hot air drying of grape fruit together with mathematical modeling to cover the drying process. The results give a promising opportunity for an appropriate design of a dryer. Experimental setups included four levels of air temperature, 40, 50, 60 and 70 oC and air velocity of 1.2 ms-1. Ten semi-empirical and empirical models were subsequently fitted to the experimental data and statistical criteria, coefficient of determination (R2), Chi square (χ2) and Root Mean Square of Error (RMSE) were investigated. Results showed that air temperature of drying has a meaningful effect on the drying rate in a way that increasing the temperature from 50oC to 60oC led to a 59% reduction in the drying time. It was observed that the whole drying process was located in the falling drying phase. Modeling evaluation of data showed that Midili model fitted best (R2=0.9978, χ2=0.0001679 and RMSE=0.010234) to the experimental results. Additionally, the influence of air temperature on the constants and coefficients of the studied models was extensively assessed.
