Investigating Variables of Time, Extraction Solvent Composition and Ratio of Solvent-to-plant on Antioxidant and Antibacterial Characteristics of Striata Plants and Olive Leaves Using Microwave and Ultrasonic Extraction Methods

It is critical to use modern extraction strategies to show ideal characteristics of the plant extricates. In this study, antioxidant and antimicrobial characteristics of the extracts of Scrophularia striata plant and olive leaves were assessed using microwave and ultrasound extraction strategies.

After designing the experiment using Box-Behnken method, extractions were carried out using microwave devices to check effects of microwaves and ultrasonic bath. Phenolic content and antioxidant characteristics were assessed using total phenolic compound and 2,2-Diphenyl-1-picrylhydrazyl methods, respectively. Microdilution broth method was used to assess the minimum inhibitory concentration for Listeria monocytogenes.

The most effective independent variable in extraction in the two methods and in plants was the ratio of solvent to plant. The ratio of ethanol in the extractor solvent affected total phenolic compound and yield. Ultrasound extraction yielded the highest total phenolic compound concentrations for olive leaves (5.34 ±0.26) and Scrophularia striata (2.89 ±0.14 mg.g-1). The best minimum inhibitory concentration (0.47 ±0.005 mg.ml-1) was reported for the olive leaves using ultrasound extraction.

The two extraction methods included various effects on characteristics of the extracts due to the structure and compounds in the two plants. The ultrasound extraction method extracted the highest quantity of phenolic compounds from the two plants. The highest quantity of antioxidant characteristics was linked to microwave extraction. It can be concluded that olive leaves and Scrophularia striata plants can potentially decrease Listeria monocytogenes contamination.