Ultrasound extraction optimization for bioactive molecules from Eucalyptus globulus leaves through antioxidant activity

Antioxidant products present a very high added value and are demanded in the market. The optimization of their extraction is a high-stakes matter for both economic and environmental points of view. Ultrasound extraction has been considered one of the most promising methods, so the relative importance of key parameters may have decisive economic significance. For this reason, different parameters that have influence on the extraction capacity such as ultrasound power, time, temperature, pH and % ethanol in water have been studied to know the relationships between the independent parameters and their influence on the extraction from Eucalyptus globulus leaves. An experimental Box-Behnken factorial design and subsequent analysis by neural networks have been used. The relative influence of each parameter varies according to the nature of the extracted compound. In this regard, the higher capacity of extraction of the selected antioxidant compounds by means of the variation of the operation conditions can be facilitated. For all the studied compounds, temperature has been the most important parameter for their extraction. The relative content (%) of bioactive compounds (terpenes) in the optimized Eucalyptus globulus extract has been performed by GC–MS analysis.