KINETICS OF AQUEOUS EXTRACTION OF MATE (ILEX PARAGUARIENSIS) LEAVES

Abstract

Experiments were carried out to investigate the kinetics of infusion of mate leaves. A cylindrical batch extractor made of glass and equipped with a mixer was operated at temperatures between 18 and 80C with comminute leaves of mate in the size range from 4.9 ¥ 10 -4 to 5.7 ¥ 10 -4 m. The experimental kinetic curves of solute concentration in the aqueous phase revealed a diffusion coefficient of soluble species through the leaves in the magnitude of 10 -12 -10 -13 m 2 /s. A negligible influence of agitation and significant effects of solvent temperature and particle size on the rate of extraction of soluble matter were experimentally observed. The kinetics of infusion of mate leaves and the influence of the investigated factors were correctly reproduced by two simplified differential equations referred to as the equilibrium-dependent and diffusion-dependent extraction models. PRACTICAL APPLICATIONSAround US$1 billion is the overall value that emerged from the activities of cultivation, manufacturing and trade of mate leaves involving more than 70 countries across the continents. Despite these positive aspects, the aromatic and bioactive properties of mate could be better explored to obtain several commercial derivatives that would increase the economic impact of this commodity at a global scale. However, the development of most of these new products depends on the availability of the powder extract of mate, which is typically obtained by solid-liquid extraction with hot water. In this framework, the results obtained in the current investigation can be applied as a guideline to design and operate industrial units of mate extraction in order have a maximum extraction yield at the lowest operating cost. bs_bs_banner Journal of Food Process Engineering

Solid–liquid extraction of bioactive compounds from yerba mate (Ilex paraguariensis) leaves: Experimental study, kinetics and modeling

“…The stirring showed a significant effect at low temperatures, due to its influence on the external mass transfer, as reported by Jensen and Zanoelo (). For caffeine, as an example, the diffusion coefficients for the liquid phase (as estimated using the Wilke‐Chang correlation) increased from 4.39 10 −10 m 2 s −1 (at 20 °C) to 1.39 10 −9 m 2 s −1 (at 80 °C); while the liquid phase viscosity (data obtained from software ASPEN PLUS 13™) decreased from 9.13 10 −4 Pa s (at 20 °C) to 1.13 10 −4 Pa s (at 80 °C).…”

“…A mass balance for the solute describes these considerations (Equation 2). The term on the left‐hand side of this equation is the rate of solute accumulation and that on the right is the net rate of solute transfer from the solid to the liquid phase (Jensen & Zanoelo, ). …”

“…Many authors have investigated the aqueous extraction of yerba mate, through addressing the optimization of the process conditions (Murakami et al, 2011;Prudêncio et al, 2012;Sambiassi, Escalada, & Schmalko, 2002) and modeling (Jensen & Zanoelo, 2013;Linares et al, 2010). The main parameters considered are the total soluble and total phenolic compounds concentration.…”

Phase equilibrium diagrams for the system water, inert and solutes from mate (Ilex paraguariensis) leaves at constant temperature and cyclic pressurization

“…The extractor chamber internally equipped with a piston moved with an hydraulic press (15 tons, Schulz, Joinville, Brazil) to set the pressure at 91.4, 182.8 or 365.6 kPa was always immersed in a refrigerated bath (SL 152/10,Solab,Piracicaba,Brazil). In such a way, it was possible to keep the temperature of leaching, a factor with a significant importance on this operation (Zhang et al, 2012;Jensen and Zanoelo, 2013), at 17 C, 32…”

Influence of water quality on nutritional and sensory characteristics of green tea infusion

“…There are various extraction parameters which affect the quality of tea infusion/extract, such as water-to-tea ratio, temperature, time, pH of extractant, and particle size of tea (Chandini, Rao, & Subramanian, 2011;Jensen & Zanoelo, 2013;Vuong, Golding, Stathopoulos, Nguyen, & Roach, 2011;Yang, Hwang, & Lin, 2007;Ye, Zhang, Sun, Chen, & Fang, 2014). Besides, the quality of water used for infusion is a major factor which affects the quality of infusion.…”