How Vanilla Conquered the World – Science Meets FoodScience Meets Food

According to old legends told by the indigenous Totonac “Jaguar” people of Mexico, in a time before vanilla was cultivated, there lived the beautiful princess Tzacopontziza of the Totonocopan kingdom [1]. One day, a young prince by the name of Zkatan-Oxga saw her picking flowers for a temple offering, and overcome with passion, he whisked her away into the depths of the lush forest. But before they reached their destination, they were stopped by the temple priests, and executed on the spot for their transgressions. After several months, the tendrils of a young, fragile green vine grew from the spot on which the two had been executed and grew many feet tall in a few days. From the vine came green pods that opened and released a fragrant scent that perfumed the entire rainforest. The legend identifies vanilla as the plant that grew on the grave of the beautiful princess. It was from the death of the beautiful princess that gave birth to vanilla.

While the myth of Tzacopontziza is but one of many stories that riddle the oral histories of the Totonac Indians about the origin of vanilla, the Totonacas all agree that the fruit of the Tlilxochitl vine, the vanilla pod, was an incredible gift bestowed upon their tribe.  Tantalizing yet delicate, the flavor and aromas of vanilla have been prized by the Totonac natives for generations, and the pods of the vanilla plant continued to be cultivated by the Totonaca people until the 19th century.  During the 15th century, the Aztecs developed a taste for vanilla after conquering the Totonocopan region, forcing the Totonacas to pay tribute with their vanilla pods.  The Aztecs were fond of a drink that combined cocoa beans with vanilla (chocolatl), which we now know as a predecessor to hot chocolate.  The taste of vanilla expanded to Europe after the Spanish conquered the Aztecs and brought back the chocolatl drink to Spain. After its arrival in Europe, Queen Elizabeth I’s royal apothecary – Hugh Morgan –transformed vanilla from an additive to chocolate to a flavoring in its own right, and vanilla became a court favorite. [2].

Birth of an Industrial Flavor

Once vanilla made its way into the gustatory consciousness of the Western world, the uses for vanilla began to expand exponentially.  Demand for vanilla continued to rise as vanilla appeared in recipes for confections, pastries, beverages, candies, and ice cream.  Vanilla became and continues to be one of the most important flavoring agents in the world.  However, the places in which the vanilla orchid can thrive and bear fruit are primarily localized in the tropical regions of the world that are subject to tumultuous environmental conditions such as rainstorms, deforestation, and fluctuating harvests.  The most commercially significant of these production areas were Mexico, Tahiti, the West Indies, and Madagascar.  On top of that, vanilla harvesting methods were labor intensive, requiring laborers to manually pollinate the orchid flowers prior to fruiting as well as collect mature vanilla pods every day, as each pod ripens at its own pace [3].  These factors together were largely responsible for the high cost of vanilla, making natural vanilla the second most expensive flavor in the world, behind saffron.  Saffron, similarly, is expensive because of the extreme levels of labor that goes into harvesting the flower.

The high cost of natural vanilla harvesting created a push for alternative sources of vanilla flavor and became the impetus for manufacturing synthetic vanilla.  In 1858, French pharmacist Nicolas-Theodore Gobley isolated pure vanillin crystals from the extracts of vanilla bean and determined vanillin to be the principle flavor compound found in vanilla [4].  Two enterprising German chemists, Ferdinand Tiemann and Wilhelm Haarmann, followed suit and deduced the chemical structure of vanillin, allowing them to conduct the first synthesis of vanillin using a readily available glucoside of isoeugenol, coniferin, a product of pine tree sap [5].  Vanillin is prepared by first oxidizing coniferin (1) to cleave the hydroxyl substituent and give glucovanillin (2), followed by cleavage of the sugar glucoside to give the desired phenol characteristic of vanillin (3).

Together, they started a vanillin production plant to commercialize this process, but surprisingly did not achieve financial success. Within in a few short years after opening, Karl Reimer and Ferdinand Tiemann devised a second synthesis of vanillin by utilizing guaiacol, a less expensive product of wood and coal pyrolysis, and subjecting it to the action of warm chloroform and alkali to install an aldehyde group on the molecule, followed by an acidification step to produce vanillin as the final product. Now known as the Reimer-Tiemann reaction for the preparation of phenolic aldehydes [6], the synthesis became commercially successful and led to the formation of the Harmann & Reimer Company.

With a new commercial production process, and accompanying lower price, uses for vanilla flavor spread like wild fire.  The low cost afforded by the new method of vanillin synthesis led to mass production of many popular treats, confections, baked goods, sweets, and drinks (alcoholic and otherwise), normally reserved for the wealthy upper class.  At one point, vanilla made its way into the age-old frozen dessert, ice cream, popularized in the United States by Thomas Jefferson, himself [7].  Vanilla also found use in the perfumery industry as a base note, where its unique ability to enhance sweet scents and round out stronger notes became an important feature, exemplified by the strong, oriental vanillin notes of Guerlain’s Shalimar perfume of 1925. The changing economic landscape around vanilla also created a new opportunity for food entrepreneurs.  In 1886, Coca-Cola arrived on the market, whose original formula called for the use of vanilla, and vanilla flavor production rose to meet the new escalating demand [8].  The economic future of the vanilla enterprise seemed secured.

The Evolution of Synthetic Vanilla

The growing vanilla industry expanded efforts to develop new methods in the synthesis of vanillin and continued driving down costs.  Clove oil became an important feedstock for vanillin synthesis after another pathway was discovered and the reduced cost of clove oil at the time made the method economical.  The main component of clove oil, eugenol, is structurally similar to coniferin and the same approach is taken to convert the eugenol to vanillin.  The clove oil process eventually fell out of favor by the 1920s after low-cost synthetic guaiacol became available following the meteoric rise of the petrochemical industry.  A more efficient pure petrochemical process of vanillin synthesis was developed in the 1970s by Solvay and in current use commercially.  Here, guaiacol is first reacted with another petrochemical product, glyoxylic acid, to form vanillylmandelic acid.  This intermediate is acidified and oxidized by atmospheric oxygen to form vanillin…

Source: How Vanilla Conquered the World – Science Meets FoodScience Meets Food