Novel green production of natural-like vanilla extract from curcuminoids

Abstract

The demand for natural vanilla extract, and vanillin in particular, by far exceeds the current production, as both the cultivation of vanilla beans and the extraction of vanillin are laborious. For this purpose, most vanillin used today is produced synthetically, contrary to the general trend toward bio-based products. The present study deals with the synthesis of nature-based vanillin, starting with the more accessible rhizomes of the plant Curcuma longa. Besides vanillin, vanillic acid and p-hydroxybenzaldehyde are synthesized that way, which are also found in the natural vanilla bean. The extraction of the curcuminoids and, finally, their conversion to the flavors are performed using visible light and food-grade chemicals only. A binary mixture of ethanol and triacetin, as well as a surfactant-free microemulsion consisting of water, ethanol, and triacetin, are investigated in this context. The results exceed the literature values for Soxhlet extraction of vanilla beans by a factor > 7.

Keywords: Curcumin; Curcumin I (PubChem CID 969516); Curcumin II (PubChem CID 5469424); Curcumin III (PubChem CID 5315472); Ethanol (PubChem CID 702); Ferulic acid (PubChem CID 445858); Flavor; Green Chemistry; Nature-Based; Photoreaction; Tetraacetyl riboflavin (PubChem CID 9915369); Triacetin (PubChem CID 5541); Vanillic acid (PubChem CID 8468); Vanillin; Vanillin (PubChem CID 1183); p-Hydroxybenzaldehyde (PubChem CID 126).