Towards a sustainable and green extraction of curcuminoids using the essential oil of Cinnamomum cassia

Abstract

A natural and sustainable alternative to conventional solvents in terms of solubilization and extraction of curcuminoids from Curcuma longa L. was investigated by examining different naturally occurring aroma compounds and cinnamon oils.

Aromas: Lovely to Smell and Nice Solvents for Polyphenols? Curcumin Solubilisation Power of Fragrances and Flavours

“…Continuing the studies of Huber et al [ 11 ], where aromas improved the solubility of curcumin even more than previously tested additives like triacetin and NADES [ 20 , 21 , 22 ], more aroma compounds were examined. Aroma compounds were compared depending on their functional groups by optical density measurements and COSMO-RS calculations.…”

“…The difference between aldehydes, citral, and citronellal is a result of the conjugation of the formyl groups and the formation of hemiacetals in ethanol. As observed with trans-cinnamaldehyde and hydrocinnamaldehyde, the C-C double bond in conjugation with the aldehyde reduced the amount of hemiacetal, which is formed [ 11 ]. The formed hemiacetal with its hydroxy group again is unfavourable for the solubilisation of curcumin.…”

“…First, sigma profiles and the Gibbs free energy are considered. In the second part, the presence of specific interactions, as found by Huber et al [ 11 ], is investigated via NMR spectroscopy.…”

“…In a recent paper [ 11 ], it was demonstrated that the extent of the solubilisation of curcumin in cinnamon-bark essential oil is strongly dependent on the cinnamon species and the nature and amount of molecules present in the essential oil. It was found that the solubilisation is linked to specific interactions between cinnamaldehyde and curcumin.…”

“…In continuation of Huber et al [ 11 ], more aroma compounds were investigated regarding their capacity to dissolve curcumin. The solubility of curcumin is a research topic of interest.…”