Lemon juice volatiles

Lemon peel oil is much more valuable than its juice therefore, extensive research efforts have been expended to determine its natural composition as a way to detect adulteration as well as to determine quality factors [6, 31, 32]. However, a few studies on lemon juice volatiles can be found [33-35]. Lemon oils are notable for possessing relatively low levels of limonene (more than 70%) and relatively high levels of a-pinene (1-2%), -pinene (6-13%), sabinene (1-2%) and y-terpinene (8-10%) [32]. The relatively high concentration of -pinene is thought to instil the green peely odour of lemon oil. The concentrations of aliphatic and monoterpenic aldehydes, (especially citral) as well as those of esters and alcohols are critical components in the perceived quality of the oil. As lemon oil is unstable, quality can deteriorate with improper storage, resulting in... 

Expression is good for the top notes, e.g. in bergamot and lemon esssential s Nhlc p very volatile owing to being high in monoterpenes. Many of these would be lost in distillation because of the high temperatures. It is also a cheap method, using by-products from the juice industry. 

Lemon Oil, Distilled, occurs as a colorless to pale yellow liquid with the characteristic odor of fresh lemon peel. It is the volatile oil obtained by distillation from the fresh peel or juice of the fruit of Citrus limon L. Burmann filius (Fam. Rutaceae), with or without the previous separation of the juice, pulp, and peel. It is soluble in most fixed oils, in mineral oil, and in alcohol (with haze). It is insoluble in glycerin and in propylene glycol. It may contain a suitable antioxidant. 

Allegrone G, Belliardo F, Cabella P (2006) Comparison of volatile concentrations in hand-squeezed juices of four different lemon varieties. JAgric Food Chem 54 1844-1848. 

---