scholarly journals Description of Cumbeba (Tacinga inamoena) Waste Drying at Different Temperatures Using Diffusion Models

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1818
Author(s):  
João P. L. Ferreira ◽  
Wilton P. Silva ◽  
Alexandre J. M. Queiroz ◽  
Rossana M. F. Figueirêdo ◽  
Josivanda P. Gomes ◽  
...  

One approach to improve sustainable agro-industrial fruit production is to add value to the waste generated in pulp extraction. The processing of cumbeba (Tacinga inamoena) fruits generates a significant amount of waste, which is discarded without further application but can be a source of bioactive compounds, among other nutrients. Among the simplest and most inexpensive forms of processing, convective drying appears as the first option for the commercial utilization of fruit derivatives, but it is essential to understand the properties of mass transfer for the appropriate choice of drying conditions. In this study, cumbeba waste was dried at four temperatures (50, 60, 70 and 80 °C). Three diffusion models were fitted to the experimental data of the different drying conditions. Two boundary conditions on the sample surface were considered: equilibrium condition and convective condition. The simulations were performed simultaneously with the estimation of effective mass diffusivity coefficients (Def) and convective mass transfer coefficients (h). The validation of the models was verified by the agreement between the theoretical prediction (simulation) and the experimental results. The results showed that, for the best model, the effective mass diffusivities were 2.9285 × 10−9, 4.1695 × 10−9, 8.1395 × 10−9 and 1.2754 × 10−8 m2/s, while the convective mass transfer coefficients were 6.4362 × 10−7, 8.7273 × 10−7, 8.9445 × 10−7 and 1.0912 × 10−6 m/s. The coefficients of determination were greater than 0.995 and the chi-squares were lower than 2.2826 × 10−2 for all simulations of the experiments.

Author(s):  
Raquel P. F. Guine ◽  
Mariana F. S. Brito ◽  
Jéssica R. P. Ribeiro

AbstractThe present work aimed at studying the mass transfer properties of two plant foods, kiwi (a fruit) and eggplant (a vegetable). For this convective drying experiments were conducted at different temperatures (from 50 to 80 ºC) and an air flow rate of 0.5 m/s, using slices with 6 mm thickness for both products. For the mathematical modelling two different methods were used, one based on the thin layer model and the other based on the Fick’s second law of diffusion. The results obtained allowed concluding that different methodologies allowed to obtain different values of the mass transfer properties, so care must be taken when choosing an appropriate calculation method. Regarding the values of diffusivity and mass transfer coefficient, in all cases they were found to increase with increasing operating temperature. Both the activation energy and the activation energy for convective mass transfer were similar for kiwi and for eggplant, indicating that both foods behave in a very similar way when exposed to the drying conditions tested.


2009 ◽  
Vol 6 (4) ◽  
pp. 102036 ◽  
Author(s):  
Conrad R. Iskra ◽  
Chris James ◽  
Prabal Talukdar ◽  
Carey J. Simonson ◽  
Phalguni Mukhopadhyaya ◽  
...  

2002 ◽  
Vol 72 (9) ◽  
pp. 756-763 ◽  
Author(s):  
Elizabeth Gramling McFarland ◽  
Wallace W. Carr ◽  
Stephen Michielsen

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