Mathematical Modeling of Mass Transfer during Convective Dehydration of Brown AlgaeMacrocystis Pyrifera

Abstract

The aim of this research was to study and to model the drying kinetics of the brown algae Macrocystis pyrifera at 50, 60, 70, and 80 C. GAB equation showed a good fit on the sorption experimental data. Fick's diffusional model, together with Newton, Henderson-Pabis, Page, modified Page, logarithmic, and MidilliKukuc models were applied on the drying kinetics of the alga. The D we increased from 5.56 to 10.22 Â 10 -9 m 2 =s as temperature increased from 50 to 80 C. Midilli-Kukuc and logarithmic models obtained the best-fit quality for drying curves based on the statistical tests. In consequence, both models are excellent tools for estimating the drying time of this product.

Hot-air drying characteristics and energetic requirement of the edible brown seaweedDurvillaea antarctica

“…In addition, an E a of 27.93 ± 4.86 kJ mol −1 was determined, this corresponded to the energy required for the diffusion water process occurrence and a pre‐exponential Arrhenius factor ( D 0 ) of 1.17 × 10 −4 m 2 s −1 was further determined. Similar values of activation energy have been obtained for foods of vegetal origin such as Aloe vera (Vega‐Gálvez, Uribe et al, ), Stevia (Lemus‐Mondaca et al, ) and for other seaweeds such as G. chilensis (39.92 kJ mol −1 ; Vega‐Gálvez, Tello‐Ireland et al, ), H. elongata (37.20 kJ mol −1 ; Gupta et al, ) and M. pyrifera (19.87 kJ mol −1 ; Vega‐Gálvez et al, ).…”

“…At a higher temperature, there is an increase of heating energy and therefore the water molecule activity will increase leading to a higher moisture diffusivity (Zhu & Shen, ). These values were lower than the ones being reported for other seaweeds such as M. pyrifera (Vega‐Gálvez et al, ), G. chilensis (Vega‐Gálvez, Tello‐Ireland et al, ) and brown seaweed H. elongate (Gupta et al, ) however, these values of D eff were higher than for other types of plants such as Aloe vera (5.30 to 17.73 × 10 −10 m 2 s −1 for 50–90°C; Vega‐Gálvez, Uribe, Lemus‐Mondaca, & Miranda, ), Stevia (0.85 to 8.11 × 10 −12 m 2 s −1 for 30–80°C; Lemus‐Mondaca et al, ). These differences might be due to the fact that the effective moisture diffusivity of different products varies according to their characteristics of composition and geometry (for example, thickness or radius) and moisture content (Shi et al, ) thus diffusion process is favored in products with high water amounts and low solid proportions (Gupta et al, ).…”

“…The moisture removal and its dependence on the process variables are expressed in terms of the drying kinetics, being essential for the development of a reliable process model (Gupta et al, ). Dehydration process final result is affected by the drying conditions; therefore an optimization of the process should consider the technological variables involved, experimental designs and the use of statistical programs that help to obtain a higher yield from an operational viewpoint (Vega‐Gálvez, Ayala‐Ponte, Notte, de La Fuente, & Lemus‐Mondaca, ). The main variables involved in the final product quality are the time and temperature of the drying process.…”

Empirical and diffusion models to describe water transport into chickpea (Cicer arietinum L.)

“…Generally, to describe water transport inside food, a mathematical model is used and, among them, the following can be cited: models based on Darcy's laws (Pinheiro et al ., ); empirical models (Turhan et al ., ; Akpinar & Bicer, ; Ghazanfari et al ., ; Sutar & Prasad, ; Ganesapillai et al ., ; Roberts et al ., ; Silva et al ., ; Vega‐Gálvez et al ., ; Hii et al ., ; Diamante et al ., ; Kaleta & Górnicki, ; Bantle et al ., ); and diffusion models (Vega‐Gálvez et al ., ; Silva et al ., , , ; Boeri et al ., ; Mundada et al ., ; Yildirim et al ., ). To describe water transport kinetics through a diffusion model, the initial and boundary conditions must be known.…”

“…To describe water transport kinetics through a diffusion model, the initial and boundary conditions must be known. In the literature, for grains, the usual boundary condition is of the first kind (Silva et al ., , ; Vega‐Gálvez et al ., ; Boeri et al ., ; Mundada et al ., ; Yildirim et al ., ), but third kind is also found in some papers as, for instance, in Silva et al . ().…”