Mathematical Modeling of Thin Layer Drying of Pomegranate (Punica granatum L.) Arils: Various Drying Methods

For years, sun and hot air drying have been considered as traditional drying methods. Today, using microwave is one the newest methods of drying. Iran is one of the main producers of pomegranate fruit in the world. To manufacture better product, drying needs to be handled in controlled and optimized process, therefore investigation of process condition kinetic is an obligation. In this study, thin layer drying behavior of pomegranate arils using microwave drier at ۴ power levels (۱۸۰, ۳۶۰, ۵۴۰ and ۷۲۰W), oven drier at ۴ temperature levels (۴۵, ۵۵, ۶۵ and ۷۵°C) and sun drying was studied. Page, Henderson and Pabis, Midilli et al., Newton, Logarithmic and Two-Term models were compared according to their Root Mean Square error (RMSE), Chi-square (χ۲), Mean Bias Error (MBE) and correlation coefficient (R۲). The results of the studied models indicated that Midilli et al., model exhibited the best fit to the data obtained for oven, microwave and sun drying. Increasing the oven drier temperature and the microwave drier power lead to an increase in the drying rate. Dried samples at ۷۵˚C exhibited the highest R۲= ۰.۹۹۹۸, and the least RMSE and χ۲, ۰.۲۰۵۹ and ۰.۵۵۷۶ respectively in comparison with other samples. While dried samples by microwave, ۷۲۰W, showed the highest R۲= ۰.۹۹۹۸ and the least RMSE and χ۲ were ۰.۱۸۹۴ and ۰.۴۲۰۳, respectively in comparison with other samples. Sun dried samples had the highest R۲ in Midilli Model, the least RMSE and X۲ were ۰.۰۳۳۸ and ۰.۷۰۵۹ respectively.

Keywords:

Drying modeling , Microwave drier , Oven drier , Pomegranate arils , Sun drying