Ageratum conyzoides: Proximate Composition and Ultrasound-Assisted Extraction Kinetics for Bioactive Compound Recovery

Mentrasto (Ageratum conyzoides) is a medicinal weed traditionally used due to its anti-inflammatory, analgesic, and antidiarrheal properties, attributed to its bioactive constituents, including polymethoxylated flavonoids, alkaloids, polyphenols, and sterols (Singh et al., 2013). Ultrasound-assisted extraction (UAE) is a sustainable technology that reduces energy and solvent consumption and processing time while enhancing extraction yields (Chemat et al., 2011). This study aimed to characterize the proximate composition of mentrasto and mathematically model its UAE extraction kinetics to optimize bioactive compound recovery. Mentrasto plants were collected, cleaned, dried at 60 °C for 20 h and ground. The mentrasto flour (MF) was characterized in terms of moisture, protein, ash, lipids, dietary fiber, and starch according to AOAC (2005). Ultrasound-assisted extraction (UAE) kinetics were evaluated using 1 g of MF and 50 g of 50% (w/w) hydroethanolic solution at 500 W and 20 kHz, with extraction times of 3, 6, 9, 12, 18, 24 and 30 min and temperature maintained at 2 ± 1 °C. Extraction kinetics were assessed based on the global extraction yield (X₀) and total reducing capacity (TRC) (Singleton et al., 1999). X₀ and TRC data were analyzed by ANOVA and Tukey’s test in RStudio. Experimental curves as a function of extraction time were fitted using a spline model in SAS OnDemand for Academics. Regarding the proximal composition, the MF presented low moisture content (3.89 ± 0.06%) and, on a dry basis, a predominance of carbohydrates (56.39%), with a high proportion of insoluble fiber (44.44 ± 0.90%). Important amounts of proteins (21.53 ± 0.40%), ash (11.56 ± 0.04%), and lipids (10.52 ± 1.88%) were also observed. Additionally, during the kinects experiments, the maximum global extraction yield (X₀) and total reducing capacity (TRC) were 22.38 ± 0.78 g extract/100 g and 15.34 ± 0.13 mg/g of sample, respectively. X₀ stabilized after 18 min, while TRC stabilized after 24 min, with no significant differences thereafter. Approximately 76.89% of the total extractable material was recovered within the first 3 min, consistent with the constant extraction rate (CER) period, during which 70–90% of soluble compounds can be extracted due to their greater accessibility to the solvent (Meireles, 2008; Pereira et al., 2023). These findings highlight the potential of mentrasto (Ageratum conyzoides) as a source of bioactive compounds and demonstrate the efficiency of UAE in achieving high extraction yields within short processing times. Furthermore, kinetic modeling helped characterize the extraction process, providing a basis for its optimization and supporting the sustainable use of this plant.

The authors acknowledge FAPESP (processes numbers 2025/19948-1, 2026/06902-6 and 2025/17032-0), CNPq (420526/2023-4) and CAPES (Finance Code 001) for their financial support.