ORIGANUM

Chemical properties

Herbaceous plant, widespread throughout all continents; it grows wild in sunny spots or is cultivated. It reaches 30 to 80 cm (12 to 32 in.) in height and exhibits an oblique rhizome, erect flower-bearing stalks with lateral sterile stalks, opposite leaves and purple or white flowers (July to August) that form terminal spikes. The flowering tops are the only part used. Origanum has a fresh, herbaceous odor and a warm, burning flavor. The oil is obtained by steam distillation from the dried, flowering herb of various origanum species with yields of less than 1%. Confusion abounds regarding the identities of the sources of marjoram, origanum and thyme. A number of genera and species associated with these plants are identified. Details of species considered commercially important are summarized by Burdock (1997). A number of botanical sources are classified under the name “origans.” These species differ considerably in both odor and flavor characteristics. The so-called “wild marjoram” is the common herb Origanum vulgare, which is cultivated all over the world. The commercially known “oil of wild marjoram” is distilled from the plant Thymus martichina, which grows wild in the mountainous areas of central Spain. The latter, in turn, should not be confused with “Spanish origanum” (Thymus capitatus), which yields an essential oil with a high (about 50%) carvacrol content. The flavor of oregano is similar to that of majoram, but slightly less sweet.

Essential oil composition

Thymol comprises the major portion of the phenols in some varieties, while others contain mainly carvacrol.