Comparative investigation of the sweet and bitter orange essential oil (Citrus sinensis and Citrus aurantium)

Abstract

The volatile fraction composition of commercially produced sweet and bitter orange oil from fruit peels was studied using GC-MS. More than fifty components were identified in the oils using their mass spectra and linear retention indices. The monoterpene limonene was the most abundant component even though not in a quantity expected for a fresh orange essential oil. Aldehydes, followed by alcohols and esters, were the main components in the oxygenated fraction. Aldehydes were the major oxygenated components in the sweet orange oil, whereas alcohols and esters were present in higher amounts in the bitter orange oil. Among them, nonanal, decanal and linalool are the most important components for the flavour of sweet orange oil and carvon is the most important ketone for the flavour of bitter orange oil in combination with the other components. The amount of carvon gives a good indication about the freshness of the oil and the quantities of α-pinene and β-pinene, sabinene and myrcene give an indication about the natural or artificially changed composition of the essential oils.