Читать книгу Encyclopedia of Essential Oils: The complete guide to the use of aromatic oils in aromatherapy, herbalism, health and well-being. - Julia Lawless - Страница 35

In general, the term ‘essential oil’ is rather loosely applied to all aromatic products or extracts derived from natural sources, including concretes, resinoids and absolutes which contain a mixture of volatile and non-volatile components, such as wax or resin. This is not strictly accurate, since they are only partially composed of essential oils and are obtained by different methods of production, which include the use of solvents or more recently, carbon dioxide extraction. However, it is always the essential oil content in a given product that accounts for its aromatic quality.

Some plant materials, especially flowers, are subject to deterioration and should be processed as soon as possible after harvesting; others, including seeds and roots, are either stored or transported for extraction, often to Europe or America. The method of extraction which is employed depends on the quality of the material which is being used, and the type of aromatic product that is required.