Abstract
The essential oil fraction obtained from the rind of Citrus spp. is rich in chemical compounds of interest for the food and perfume industries, and therefore has been extensively studied during the last decades. In this manuscript, we provide a comprehensive review of the volatile composition of this oil fraction and rind extracts for the 10 most studied Citrus species: C. sinensis (sweet orange), C. reticulata (mandarin), C. paradisi (grapefruit), C. grandis (pummelo), C. limon (lemon), C. medica (citron), C. aurantifolia (lime), C. aurantium (bitter orange), C. bergamia (bergamot orange), and C. junos (yuzu). Forty-nine volatile organic compounds have been reported in all 10 species, most of them terpenoid (90%), although about half of the volatile compounds identified in Citrus peel are non-terpenoid. Over 400 volatiles of different chemical nature have been exclusively described in only one of these species and some of them could be useful as species biomarkers. A hierarchical cluster analysis based on volatile composition arranges these Citrus species in three clusters which essentially mirrors those obtained with genetic information. The first cluster is comprised by C. reticulata, C. grandis, C. sinensis, C. paradisi and C. aurantium, and is mainly characterized by the presence of a larger abundance of non-terpenoid ester and aldehyde compounds than in the other species reviewed. The second cluster is comprised by C. junos, C. medica, C. aurantifolia, and C. bergamia, and is characterized by the prevalence of mono- and sesquiterpene hydrocarbons. Finally, C. limon shows a particular volatile profile with some sulfur monoterpenoids and non-terpenoid esters and aldehydes as part of its main differential peculiarities. A systematic description of the rind volatile composition in each of the species is provided together with a general comparison with those in leaves and blossoms. Additionally, the most widely used techniques for the extraction and analysis of volatile Citrus compounds are also described.
Highlights
Citrus essential oils, widely used to the procurance of natural fruity perfumes and as flavoring ingredients in food, pharmaceutical and cosmetic products (Tranchida et al, 2012; Palazzolo et al, 2013; Othman et al, 2017), are obtained mainly from the fruit rind, flowers or leaves have been used
The main objective of this review is to gather in a single manuscript the information on volatile and semi-volatile compounds that has been described up to date in rinds, flowers and leaves of the most studied Citrus species over the last two decades, when most of the work on Citrus essential oils has been performed
According to the results reported in our literature review, the SPME-fibers used most often to analyze Citrus flower and leaf volatiles seems be the minor polar 100 μm PDMS or 75 μm/85 μm CAR/PDMS fibers, while the 65 μm DVB/PDMS fiber is more used for Citrus essential oil
Summary
Widely used to the procurance of natural fruity perfumes and as flavoring ingredients in food, pharmaceutical and cosmetic products (Tranchida et al, 2012; Palazzolo et al, 2013; Othman et al, 2017), are obtained mainly from the fruit rind (flavedo), flowers or leaves have been used. Volatile and semi-volatile compounds represent 85–99% of the entire oil fraction (Dugo and Mondello, 2011; Tranchida et al, 2012; Sarrou et al, 2013), which is represented typically by over 200 compounds. Most of the studies regarding the composition of the volatile and semi-volatile fraction in Citrus ssp. There are several papers reporting the volatile composition either from neroli (Citrus flowers EO) (Boussaada and Chemli, 2006; Boussaada et al, 2007; Sarrou et al, 2013; Družic, 2016), and petitgrain (Citrus leaves and little branches EO) (Lota et al, 1999, 2001a,b, 2002; Alonzo et al, 2000; Huang et al, 2000; Brophy et al, 2001; Vekiari et al, 2002, 2004; Fanciullino et al, 2005, 2006; Smadja et al, 2005; Boussaada and Chemli, 2006; Boussaada et al, 2007; Tomi et al, 2008; Singh et al, 2010; Guerrini et al, 2014; Družic, 2016; Paoli et al, 2016) or from extracts of Citrus flowers (Choi, 2003a; Flamini et al, 2007; Jabalpurwala et al, 2009; Flamini and Cioni, 2010; Cheong et al, 2011b) and leaves (Gancel et al, 2002, 2003, 2005)
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call