Extraction and quantification of anthocyanins and total phenolic compounds from the plant Commelina erecta L.

Natural colorants have gained prominence due to concerns about the adverse effects of artificial dyes, such as allergies and carcinogenesis, driving the search for safer alternatives for food applications. In this context, Commelina erecta L., a plant from the Commelinaceae family widely recognized for invading agricultural crops, presents nutritional and pharmacological properties, including the presence of bioactive compounds such as anthocyanins, which have great potential as natural pigments due to their characteristic color and functional properties. Microwave-assisted extraction stands out as a green and sustainable technology by reducing energy and solvent consumption while preserving the integrity of thermosensitive compounds. This study aimed to recover and quantify anthocyanins from Commelina erecta flowers using microwave-assisted extraction, applying a 2² DCCR design with water + NaCl (2 M) as solvent, power ranging from 147.5 to 652 W, and solid-to-liquid ratios (S/L) from 1:8.8 to 1:51.2, with a fixed time of 30 s. The dependent variables were total phenolic content (TPC) and total monomeric anthocyanins. Stable blue-colored extracts were obtained for at least one week, with TPC values ranging from 0.71 to 1.32 mg GAE/g and anthocyanin concentrations from 0.19 to 0.30 mg/g. For TPC, the S/L ratio was the only significant variable (p<0.05), with higher concentrations for S/L < 1:20, while for anthocyanins, both the S/L ratio and its interaction with power were significant (p<0.05), with maximum concentrations observed at power < 200 W and S/L > 1:33, likely due to lower thermal effects and solvent saturation. The models showed R² values of 60% for TPC and 70% for anthocyanins. These results demonstrate that microwave-assisted extraction enables the production of stable blue extracts in short extraction times, with energy savings and the use of environmentally friendly solvents, positioning Commelina erecta and microwave technology as a promising source and method for obtaining natural anthocyanins.