**5. Green technologies for extraction**

The main goal of green extraction procedures is to obtain a rapid extraction, increased efficient energy usage, higher mass and heat transfer, smaller apparatus, and fewer processing stages [3]. Several novel alternatives to traditional techniques for obtaining target compounds from a variety of crude drugs have been proposed, such as ultrasound-assisted extraction (UAE), subcritical and supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), and accelerated solvent extraction (ASE) [33]. These extraction methods, which are alternatives to traditional procedures, have piqued the curiosity of academics, who see future applications for recovering bioactive molecules from plants in less time using green solvents. Most of these new methods have already shown promise in extracting high-value chemicals, particularly natural antioxidants, from various sources such as plants or food processing by-products [34].

## **5.1 Expression**

It is a physical technique in which pressure is employed to extract the oil or juice from a material. A tincture press was used to do this. When essential oils are temperature sensitive, this approach is used. It's used to extract essential oils from citrus peels like lemons and oranges. Squeezing any plant material at high pressures to extract oils or other liquids is known as expression. In remote rural locations, hand-operated presses or crushes are used, while in industrial hubs, massive mechanical presses are used. However, the products obtained are impure and frequently contain impurities such as water, mucoid particles, and cell tissues, making them murky, and pressing the volatile oil in plants completely is difficult. As a result, the crushed residue is frequently steam distilled to remove all volatile oils. Black soybean oil, for example, is frequently extracted using the low-temperature pressing process [31].
