Extraction of Essential Oils from Medicinal Plants and their Utilization as Food Antioxidants

Background: The use of essential oils is receiving increasing attention worldwide, as these oils are good sources of several bioactive compounds. Nowadays essential oils are preferred over synthetic preservatives thanks to their antioxidant and antimicrobial properties. Several studies highlight the beneficial effect of essential oils extracted from medicinal plants to cure human diseases such as hypertension, diabetes, or obesity. However, to preserve their bioactivity, the use of appropriate extraction technologies is required. Method: The present review aims to describe the studies published so far on the essential oils focusing on their sources and chemical composition, the technologies used for their recovery and their application as antioxidants in food products. Results: The review has been structured in three parts. In the first part, the main compounds present in essential oils extracted from medicinal plants have been listed and described. In the second part, the most important technologies used for extraction and distillation, have been presented. In detail, conventional methods have been described and compared with innovative and green technologies. Finally, in the last part, the studies related to the application of essential oils as antioxidants in food products have been reviewed and the main findings discussed in detail. Conclusions: In summary, an overview of the aforementioned subjects is presented by discussing the results of the most recent published studies.