Multiple studies have been released on how to maximize the concentration of essential oils through the use of enzyme extraction. Essential oils can be used in a wide variety of ways. From cooking to holistic healing, these oils can provide enriched sources from a variety of botanical materials. That being said, the best oils are the ones that have the highest yields, and the trick becomes how best to accomplish that. When comparing the traditional physical and chemical extraction processes to enzyme extraction, the results are clear.
Cellulase Enzyme Extraction
One of the most commonly used enzymes in botanical extraction is cellulase. Cellulase is an enzyme that takes cellulose and converts it into glucose or disaccharides (a substance composed of two molecules of simple sugars). Basically, it breaks down the tougher parts of the plant’s exterior cell wall and converts them into sugars that can be easily absorbed into the oil. This means that parts of the plant that would typically be thrown away (stems, rinds, even roots) can still be utilized. In one study — published by the journal Industrial Crops and Production — the use of cellulase increases the yield of rosemary and thyme essential oils by an average of 63.5 percent. Another study published in Chemical Papers found that cellulase increased citrus oil yields by more than ten percent when used with orange and lemon peels.
Other Enzyme Combinations
In addition to cellulase, there are other enzyme combinations that can work better or worse depending on the botanical material. Hemicellulase works like cellulase, but it breaks down other compounds in the plant besides cellulose. Pectinase is an enzyme that breaks down pectin, a complex polysaccharide (a large molecule made up of many simple sugars) found in apples, sunflower heads, cloves, citrus peels and more. Finally, amylase is an enzyme common in the human digestive systems that helps us to break down food in general. When combining these enzymes to improve extraction, yields have been seen to go up as high as 109 percent.
The Downside of Enzyme Extraction
According to a study of clove extraction published in the South Asian Journal of Experimental Biology enzyme use can increase yields in essential oil extraction. However, there is also the possibility that this enzyme can cause physical and structural deterioration of the plant material. While this may lead to a lowering of purity of the essential oil’s chemical compounds, there is an upside. 
The study found that this could lead to an increase in antibacterial effects. Depending on the intended use of the essential oil, the additional plant materials could be seen as a positive or as a negative.
1- Hosni K, Hassen I, Chaâbane H, Jemli M, Dallali S, Sebei H, Casabianca H, Enzyme-assisted extraction of essential oils from thyme (Thymus capitatus L.) and rosemary (Rosmarinus officinalis L.): Impact on yield, chemical composition and antimicrobial activity. Industrial Crops and Products, volume 4.
2- Chávez-González, Mónica L., López-López, Lluvia I., Rodríguez-Herrera, Raúl, Contreras-Esquivel, Juan C. and Aguilar, Cristóbal N.. “Enzyme-assisted extraction of citrus essential oil” Chemical Papers, vol. 70, no. 4, 2016, pp. 412-417.
3- Amudan, Rajalakshmi & Kamat, D & Kamat, S. (2011). Enzyme‐assisted extraction of essential oils from Syzygium aromaticum. South Asian Journal of Experimental biology. 1. 248-254. 10.38150/sajeb.1(6).p248-254.