Deterpenation techniques of citrus essential oils and the role of oxyterpenes in food industry

Application of EOs in the food industry are wide-ranging from preservation to production of food packaging materials. As a flavouring agent, citrus oil is one of the most popular EO used in food and beverages with other EOs. For instance, there are many studies relating the volatile compounds of sweet orange and more than 200 components of sweet orange EOs have been described as ‘components of flavor’. Oxygenated derivatives, such as alcohols, ketones, aldehydes, esters and epoxides, provide preservative and flavour effects on food products but their levels are no more than 10% in citrus EOs generally. Therefore, deterpenation methods can be applied to EOs and oxygenated derivative concentrations would be increased. This study reviews primary oxyterpenes existing in citrus EOs, their use in the food industry, deterpenation methods applied to some types of citrus EOs and gives information about their main advantages and disadvantages. In conclusion, membrane separation techniques are proposed in order to purify citrus EOs on the basis of being environmentally friendly and not required any solvents both for separation.