Evaluation of two different diffusive models to describe the drying of passion fruit peels with and without blanching

In the present work, drying of passion fruit peels was carried out in an oven (with and without pretreatment with blanching) at temperatures of 60 and 70 °C. The objective of this work is to apply two diffusive models to describe the drying of passion fruit peels, and use them to analyze the effects of temperature and pre-treatment on the drying parameters of the process. For this, two numerical solutions were developed considering shrinkage and diffusivity as a function of the local moisture content. These two solutions were obtained from two different boundary conditions. According to the statistical indicators obtained, the two models proposed adequately fitted to the experimental data, providing parameters with low degrees of uncertainty with a probability of 95.4%. The influence of both pre-treatment and temperature on the equilibrium moisture content was observed. However, it was concluded that the blanching had greater influence on the equilibrium moisture content. Blanching also had a strong influence on the duration of the falling rate period, since the blanched samples showed a shorter falling rate period.