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

Abstract

The aqueous batch extraction of bioactive compounds from yerba mate leaves was evaluated in view of their potential application in the food industry. The influence of temperature (20–80 °C) and stirring (0–400 rpm) was investigated by central composite design. The concentrations of the bioactive compounds over time were investigated using three mathematical models (equilibrium‐dependent, Peleg and intra‐particle diffusion). The results indicated that higher temperatures resulted in increased extraction of the bioactive compounds, while stirring showed only a minor influence. According to the kinetics data, the extraction process approached equilibrium after around 120–180 min. The conditions that maximized the extraction were 80 °C and 400 rpm, which resulted in 591.81, 48.31, 814.90, and 122.56 mg L−1 of chlorogenic acid, rutin, caffeine, and theobromine, respectively, after a 30 min process. The Peleg model was found to be the most suitable to describe the extraction process due the best fit with the experimental data. Practical applications Yerba mate contains bioactive compounds that have the potential to prevent degenerative diseases. Caffeine, theobromine, chlorogenic acid, and rutin are the main compounds found in yerba mate and they have properties which are beneficial to health, such as antioxidant capacity and diuretic action. These compounds can be removed from the leaves by solid–liquid extraction and added to food products to increase their nutraceutical value. The extraction is influenced by several parameters that need to be adjusted to ensure maximum extract yield and quality. Thus, due to the significant potential of yerba mate as a source of bioactive compounds, the aim of this study was to evaluate the extraction of individual bioactive compounds from the leaves.

Yerba Mate—A Long but Current History

“…Gerke et al determined the best extraction conditions of the raw material to ensure maximum yield and quality of the aqueous extract (30 min, 80 • C, stirring 400 rpm). The beverages obtained under these conditions are characterized by high concentrations of chlorogenic acid, caffeine, and theobromine, at 591.81, 814.90, and 122.56 mg/L, respectively [85]. Similarly, the study by Fenoglio et al demonstrated that spray drying of Yerba Mate extract provided lower moisture content, as well as the highest polyphenol content (135.4 mg GAE/g extract) and oxidative stability compared to freeze-dried samples.…”

Thermal and dynamic mechanical behavior of epoxy composites reinforced with post‐consumed yerba mate

“…In addition to them, YM has vitamins such as B2, B1, and C 2,5 . Consequently, it is widely applied in health areas such as pharmaceutical, cosmetological, and alternative medicine 5–8 …”

Kinetics of aqueous extraction of phenolic compounds from processed yerba mate leaves

“…Studies have been reported on the content of total phenolic compounds and their antioxidant properties in yerba mate leaves [19,20,21,22,23,24]; however, there are few studies related to the extraction kinetics of phenolic compounds in yerba mate leaves and the conditions for their operation on an industrial scale [20,25,26,27,28].…”