ADVANCED ANALYTICAL TECHNIQUES FOR UNDERSTANDING COFFEE FLAVOUR

Ph.DDOCTOR OF PHILOSOPHY (FOS

Characterisation of volatile compounds in kumquat and calamansi peel oil extracts

10.1080/0972060X.2020.1841683Journal of Essential Oil Bearing Plants2305953-96

Characterisation of volatile and non-volatile compounds in pomelo by gas chromatography-olfactometry, gas chromatography and liquid chromatography-quadrupole time-of-flight mass spectrometry

10.1080/10412905.2019.1677272Journal of Essential Oil Research322132-14

Distinguishing citrus varieties based on genetic and compositional analyses

International audienceSimple sequence repeats (SSR) markers and secondary metabolite composition were used in combination to study seven varieties of citrus for the first time. With reference to established accessions of citrus, two of the varieties (Chanh Giay and Ma Nao Pan) were predicted to be Mexican key limes, while three were mandarin hybrids (Nagpur, Pontianak and Dalandan) and the remaining two (Qicheng and Mosambi) were related to the sweet orange. Notably, Dalandan was genetically more like a mandarin despite often referred to as an orange locally, whereas Mosambi was more likely to be a sweet orange hybrid although it has also been called a sweet lime due to its green peel and small size. Several key secondary metabolites such as polymethoxyflavones (sinensetin, tangeretin etc.), furanocoumarins (bergapten, citropten etc.) and volatiles (citronellol, α-sinensal etc.) were identified to be potential biomarkers for separation of citrus species. However, despite having similar genetic profiles, variations in the volatile profile of the two limes were observed; similarly, there were differences in the secondary metabolite profiles of the three mandarin hybrids despite having a common ancestral parent, highlighting the usefulness of genetic and compositional analyses in combination for revealing both origins and flavour profiles especially in citrus hybrids. This knowledge would be crucial for variety screening and selection for use in flavour or fragrance creation and application