Comparison of kumquat (Fortunella spp.) volatiles using various SPME fibres followed by GC/MS techniques and determination of the total phenol and antioxidant compounds

Kumquat is the smallest citrus fruit with an edible peel. It is a member of the Fortunella genus in the Rutaceae family and is native to south-eastern China. After understanding the health benefits of kumquat fruits, farmers started their plantations in Turkey. Therefore, this study was aimed to determine the aromatic profiles of volatile compounds in the peel and juice of kumquat by SPME headspace technique for CAR/PDMS/DVB, PDMS followed by GC/MS (gas chromatography-mass spectrometry) method and determine the biochemical characteristics (namely total phenolic and antioxidant compounds) of kumquat. The volatile compounds are known to contain different biochemical substances that can be classified as aldehydes, alcohols, esters, terpenic compounds, and other compounds. Kumquat juice is primarily composed of terpenoids, and its main terpene compound is d-limonene. The headspace technique led to the identification of 62 compounds, among which d-limonene was the most abundant. Moreover, a total of 5 different aldehydes, 8 esters, 15 alcohols, 2 ketones, and 32 terpenes were identified and quantified in the peel and juice of kumquats. Also, as a result of this study, the total amount of phenols determined in kumquat peel was higher than the total amount of phenols in fruit juice. On the other hand, the total antioxidant capacity determined in the juice of kumquats was higher than that in the kumquat peel.