Extraction of essential oil from fresh basil leaves (Ocimum basilicum L.) using solvent-free microwave extraction method: Extraction parameter optimization, electric consumption, and CO₂ emission study

Essential oil extraction is often still done using conventional methods. This process requires a long time, a lot of energy, and a large amount of solvent. Therefore, solvent-free microwave extraction (SFME) was chosen as a better and greener alternative. The objectives of this study were: (i) to determine the optimum conditions for basil oil extraction in the SFME method using Box-Behnken Design (BBD) and (ii) to analyze the electric consumption and CO₂ emissions produced during the extraction process. The results showed that microwave power, F/D ratio, and extraction time to obtain optimum conditions were 600 W, 100 g/L, and 18.12 min, respectively. Extraction using hydro distillation (HD) method consumes 1 kWh of electricity and produces 0.80 kg of CO₂ emission more than the SFME method. The yield of essential oil carried out using SFME method produces more oil than the HD method. The use of less energy and more optimal results make the extraction process with SFME greener and environmentally friendly.