Analysis of mass transfer equations during solid-liquid extraction and its application for vanilla extraction kinetics modeling

Mass transfer modeling of the antioxidant extraction of roselle flower (Hibiscus sabdariffa)

“…In this study, partition coefficients varied in the ranges 0.73-2.41 kg solid/kg solution for TPC, 0.69-1.35 kg solid/kg solution for TFL and 0.56-1.45 kg solid/kg solution for TAC. Results are similar to that found for total soluble solids (0.86 kg product/kg solvent) for total solids of vanilla pods (ethanol-water 60% v/v, 30-50°C, 10:1 mL solvent/g product) (Castillo-Santos et al 2017).…”

“…TPC, TFC and TAC diffusivities were between 0.72-2.66 9 10 -11 , 0.25-2.37 9 10 -11 and 1.19-5.79 9 10 -11 m 2 /s, respectively. Diffusivity values are comparable to those found for anthocyanins (3.9 9 10 -11 -1.35 9 10 -10 m 2 /s, 25-90°C) in Hibiscus sabdariffa (Cissé et al 2012) and other bioactive compounds in vegetable matrices during solid-liquid extraction such as vanilla pods (total solids; 1.2-2.4 9 10-11 m 2 /s; ethanol-water 60% v/v; 30-50°C; 10:1 mL solvent/g product) and yerba mate (water soluble solids; 6.1-9.5 9 10 -11 m 2 /s; water; 40-70°C) and hot (40-115°C) and freeze dried grape stalks (antioxidant activity as measured by trolox method; 0.2-14.2 9 10 -12 m 2 /s; ethanol-water 80% v/v, 60°C, 22:1 mL solvent/g product) (Garcia-Perez et al 2010;Linares et al 2010;Castillo-Santos et al 2017). Krishnan et al (2015) modeled the kinetics of antioxidant extraction of Origanum vulgare and Brassica nigra as a two-stage diffusion process.…”

“…Extraction curves are very often modeled by an unsteady-state diffusion model based on Ficks second law (Garcia-Perez et al 2010;Linares et al 2010;Cissé et al 2012;Krishnan et al 2015;Castillo-Santos et al 2017). However, literature data on the characterization of dynamic (diffusivity values) and equilibrium (partition coefficients) periods for mass transfer during solid-liquid extraction are scarce.…”

“…However, literature data on the characterization of dynamic (diffusivity values) and equilibrium (partition coefficients) periods for mass transfer during solid-liquid extraction are scarce. In addition, diffusion coefficients and equilibrium properties during solid-liquid extraction are very often characterized in terms of total (bulk) extracted solutes (Linares et al 2010;Krishnan et al 2015;Castillo-Santos et al 2017), instead of the observed antioxidant activity (Garcia-Perez et al 2010) or the real diffusing substances or chemical groups (Winitsorn et al 2008). Thus, ''there is a need for mathematical modeling, which readily facilitates optimization, simulation, design, and process control, while also contributing to the effective utilization of energy, solvent and time'' as highlighted by some authors (Krishnan et al 2015).…”

Comparative Evaluation of Soxhlet and Ultrasonics on the Structural Morphology and Extraction of Bioactive Compounds of Lemon (Citrus limon L.) Peel

“…The cell walls were damaged and the soxhlet extracted samples seemed to curve reducing the surface area in touch with the solvent, while the USAE samples seemed to spread out with each pulse allowing for the greater interaction of the extracting solvent ( Figure 6-7). Apart from the increase in the abrasive effects or turbulence caused by ultrasonic waves, intensification of mass transport due to physical effects on the surface of the particles has also been suggested and the mass transfer coefficient has been shown to increase when the solid matrix is exposed to such disturbances [34]. USAE enhances mass transfer and the solvent's ease of access to the cell material.…”