Optimization of Microwave-Assisted Extraction of Cherry Laurel Fruit

Abstract

Response surface methodology was used to optimize the influence of microwave power (300–600 W), plant material-to-solvent ratio (0.05–0.2 g/cm³), and extraction time (10–30 min) on the efficiency of microwave-assisted extraction of the cherry laurel (Prunus laurocerasus L.) fruit. From experimental data, a quadratic polynomial mathematical model (R² = 0.9949) was developed to predict the extract yield. All considered factors were statistically significant for extraction efficiency, while the most important factor was extraction time. Microwave power of 550 W, plant material-to-solvent ratio of 0.05 g/cm³, and time of 25 min were determined as optimal conditions with a maximum yield of 9.36 g/100 g fresh plant material, which was confirmed through laboratory experiments (9.12 ± 0.61 g/100 g fresh plant material). An economic condition for simultaneous maximum extract yield (7.58 g/100 g fresh plant material) with minimal energy and solvent consumption was determined by the desirability function method (18.2 min, 300 W, and 0.2 g/cm³). Additionally, the total phenol and flavonoid quantification and antioxidant activity of both extracts were tested. There is no statistically significant difference in the total flavonoid content in the extracts obtained under both proposed conditions, while the total phenolic content and antioxidant activity of the extract obtained under economic conditions were slightly lower.

Keywords:

• cherry laurel
• extraction
• microwave
• response surface methodology