In recent years, with the increase in awareness of the benefits of consuming compounds with antioxidant properties and the desire of producers and consumers to natural products, a lot of research has been done to find resources rich in natural antioxidants. Many of the antioxidant and antimicrobial properties of plant extracts are due to the presence of substances such as phenol and flavonoids and similar compounds. Natural antioxidants are found in almost all plants, microorganisms, fungi, and even animal tissues. The main group of natural antioxidants are phenolic compounds, the most important of which are tocopherols, flavonoids, and phenolic acids. Extraction is the first major step in various researches and applications. Solvent extraction technique is one of the most common extraction methods. This method was often cost-effective, time-consuming, with high solvent consumption with low extraction coefficient and adverse and harmful effects on the extracted compounds and products. For this reason, the use of various methods to accelerate and facilitate the extraction of phenolic compounds has received much attention. One of the new methods of extraction, known as green technology, is extraction by subcritical water; Which is very effective in extracting effective compounds. In this method, with increasing temperature and pressure, the physicochemical properties of water change and water becomes a fluid with a wide range of extraction of compounds with different polarities.

Extraction Phenolic compounds Subcritical water