Enzyme-assisted extraction of citrus essential oil

Citrus peels are underutilized in the processing industry and are commonly considered as waste as their chemical composition varies. However, it is possible to recover some value-added products, one of them being essential oil, which is widely used in the food industry. Due to the current increase in global demand for citrus essential oils, it is necessary to implement processes directed to the maximum recovery of oil from waste peels. Numerous efforts have been made without achieving significant improvements in yields. In this work, enzymatic pretreatments of orange, lemon, and grapefruit peels were applied to achieve increased yields of essential oil extracted by hydrodistillation. In two of the sources it was possible to increase the essential oil yield from two to six times. Moreover, a significant amount of fermentable sugars which can be used in the production of certain other compounds of interest through fermentation was obtained. (C) 2015 Institute of Chemistry, Slovak Academy of Sciences