ANALYSIS OF THE DRYING KINETICS OF S. BARTOLOMEU PEARS FOR DIFFERENT DRYING SYSTEMS

Pears of the variety S. Bartolomeu (Pyrus communis L.) are used in Portugal to produce a traditional food product, obtained by open-air sun drying. The traditional processing has many disadvantages, namely the efficiency and the sanitary quality of the final product. For these reasons, attempts were made to study alternative production methodologies, including the use of a solar stove, a solar drier and a drying tunnel.In this work pears of the variety S. Bartolomeu, were dried in the three alternative systems mentioned, and their drying kinetics was studied. Eight different models from literature were tested and their performance was evaluated in terms of some statistical indicators.The results allowed concluding that the models Henderson & Pabis, Logarithmic and Vega-Lemus were the best to fit the experimental data. Furthermore, it was concluded that the solar drying was very dependent on the weather conditions. It was also possible to observe that the loss of water was much more uniform in the drying tunnel system when compared to the solar dryings, because in the tunnel the operating temperature and air velocity were constant.