Vanilla orchids are a genus of over 100 species within the orchid family. The flat-leaved vanilla, Vanilla planifolia, is the source of natural vanilla flavoring, the key constituent of which is vanillin.
Vanillin (C8H8O3) is a phenolic aldehyde, derivative of the aromatic organic compound phenol. It was first noticed from cultivation of Vanilla plants in pre-Columbian Mesoamerica, and first isolated as a pure substance in 1858. The chemical structure of vanillin was identified in 1874 by German scientists, and was first synthesized from compounds typically found in wood. In the 1980s 60% of the world’s synthetic vanillin, derived from lignin wastes, was the result of a single paper mill. Today, most synthetic vanilla is synthesized from guaiacol and glyoxylic acid.
Vanilla extract in its natural form not only contains vanillin but also include several hundered other compounds that contribute to its aroma and flavor. Cured vanilla seed pods, which can only result from either natural or manually pollinating each orchid flower, are about 2% vanillin by dry weight, and can be visible on the surface of pods as a white crystalline dust on the exterior. To cure the seed pods they are first blanched in hot water, then over the course of two weeks they are laid out in the sun during the day and then wrapped in cloth and stored in airtight boxes to sweat at night. This process leads to the pods becoming dark brown, and the enzymes in the pod breaking down non-aromatic β-D-glucoside of vanillin into free molecules of vanillin. The pods are then allowed to dry and age for several months to further develop the flavors. Natural vanilla extract is created by macerating and percolating vanilla pods with a solution of ethanol and water, and can only be called pure by FDA standards if the solution contains a minimum of 35% alcohol and 100 grams of vanilla beans per liter. Natural vanilla flavoring is also derived from vanilla beans, while containing <2-3% alcohol.
The labor intensive methods required to produce natural vanilla flavoring combined with the high demand for vanilla flavoring drives the synthesis of artificial vanilla, but other than the difference in source of raw materials, the natural vs. industrial chemical process, and the lack of complexity that the numerous other compounds in vanilla beans would normally impart, both are chemically identical.
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