almond, oil of

Fixed oil obtained from the dried ripe kernel of both sweet and bitter almond trees, but more usually from the latter as the residual cake is of more value. It has a yellowish colour and slight characteristic odour; it consists mainly of glyceryl oleate, and is used in cosmetics and medicine.

Oil of bitter almonds is obtained by maceration and distillation from bitter almond cake. It is a volatile, almost colourless oil, and has a characteristic odour. The odour is due to benzaldehyde, which constitutes about 90% of the whole and is formed together with benzaldehyde-cyanhydrin, hydrocyanic acid and a glucoside, gentiobiose, by the action of the enzyme emulsin (synaptase) on amygdalin during maceration. Benzaldehyde is often called ‘oil of bitter almonds’ and is used for flavouring purposes, and in perfumery and dyestuffs.