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Processing, extraction and purity
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Chapter 4
Processing, extraction and purity
Extraction From Natural Products When considering quality and composition of an essential oil the method of extraction plays a crucial role. An essential oil is that oil extracted from plant material that is volatile at room temperature, but there are a number of other products whose nature and means of production need to be clarified – absolutes, resinoids, tinctures, floral waters, etc. (see Fig. 4.1). The descriptions and definitions given here are only a brief summary and for further detail more specialized texts can be consulted. Essential oils are extracted from different parts of the plant – petals, leaves, fruits, roots, barks, etc. – and this should be known when considering an oil. The efficiency and yield of oil will depend on the method used and is usually reflected in price.
Aromafact The time of year and even time of day the material is harvested can be crucial; for example, jasmine should be picked in the evening, rose in the morning before the dew goes off it. When the oil is found deep in plant tissue, the tissues need breaking up or powdering before extraction is possible; for example, cedarwood essential oil is extracted from wood chips or sawdust.
Distillation Distillation is the most commonly used method for the extraction of essential oils. There are two techniques of distillation: water and steam.
Water distillation The distillation apparatus, commonly called a ‘still’, consists of a vessel for plant material and water, a condenser to cool and condense the vapour produced and a method of collection, or ‘receiver’. Material from the appropriate
Chapter 4
Processing, extraction and purity
Extraction From Natural Products When considering quality and composition of an essential oil the method of extraction plays a crucial role. An essential oil is that oil extracted from plant material that is volatile at room temperature, but there are a number of other products whose nature and means of production need to be clarified – absolutes, resinoids, tinctures, floral waters, etc. (see Fig. 4.1). The descriptions and definitions given here are only a brief summary and for further detail more specialized texts can be consulted. Essential oils are extracted from different parts of the plant – petals, leaves, fruits, roots, barks, etc. – and this should be known when considering an oil. The efficiency and yield of oil will depend on the method used and is usually reflected in price.
Aromafact The time of year and even time of day the material is harvested can be crucial; for example, jasmine should be picked in the evening, rose in the morning before the dew goes off it. When the oil is found deep in plant tissue, the tissues need breaking up or powdering before extraction is possible; for example, cedarwood essential oil is extracted from wood chips or sawdust.
Distillation Distillation is the most commonly used method for the extraction of essential oils. There are two techniques of distillation: water and steam.
Water distillation The distillation apparatus, commonly called a ‘still’, consists of a vessel for plant material and water, a condenser to cool and condense the vapour produced and a method of collection, or ‘receiver’. Material from the appropriate