Study of volatile and oxygen heterocyclic compounds in lemon essential oils: seasonal variation and authenticity analysis
Creators: name: Liu, Siyu
Publisher: name: No Publisher Supplied
Year: 2022

description: Human beings have been consuming lemon fruits for thousands of years. Except for fresh market, more than 70% lemon fruits are processed to two main products: lemon juice and lemon essential oil. Lemon essential oil has much higher value than juice nowadays. It is very versatile and popular in flavor and fragrance industry for decades due to the worldwide acceptance for the natural fresh zest of lemon aroma. Since the 21st century, Argentina is the biggest lemon growing and processing country worldwide which supplies more than half of the lemon oils in the market. However, the in-depth study to analyze Argentine lemon oil is very scarce. The first aim of this research is to investigate the volatile and oxygen heterocyclic compounds in Argentine lemon oils from industrial processing scale as well as the compositions variation trend throughout the lemon season 2021.For many reasons, such as the restricted cultivation areas and environmental effects among others, the adulteration of lemon essential oil has been very common and severe for a long time. There are a lot of studies focused on lemon essential oil but mainly delved into the volatile fractions because of its flavoring application. The non-volatile fractions, oxygenated heterocyclic components from lemon essential oil have been overlooked for a long time because they are much smaller percentage (less than 2% by weight) in lemon essential oil and they are not contributing typical lemon aroma. Recently, there are some researchers studied these oxygenated heterocyclic components from citrus essential oils because of (1) their potential bioactive activities (2) phototoxicity regulation on furocoumarins. Using HPLC-UV, most oxygenated heterocyclic compounds from lemon essential oil can be separated and identified. Current adulteration approaches are focused on meeting GC requirements and other analysis published by Food Chemical Codex (FCC) since these are the typical tests conducted in flavor and fragrance industry. Therefore, the main oxygenated heterocyclic compounds from lemon essential oil are very promising to differentiate the authentic and adulterated lemon essential oils. In this study, there are substantial numbers of industrial lemon essential oils supplied from lemon processor and commercial sources analyzed and studied. The second objective of this study is to identify and quantify the main oxygenated heterocyclic compounds in various industrial lemon essential oils to classify the authenticity and adulteration of lemon essential oils through HPLC-UV analysis.Lastly, there is a rising interest about the taste effects contributed by oxygenated heterocyclic compounds from citrus essential oils. Some flavor companies have noticed certain taste enhancing ability and taste modifing effects by adding the non-volatile fractions of citrus essential oils into food and beverage applications. Hence, the third goal of this study is to evaluate the sensory effects of main coumarins found in lemon essential oil and develop the potential applications of these coumarins in beverage.