Enzymatic lipophilization is an important process to extend the use of anthocyanins in lipidic media. In this work delphinidin 3-O-sambubioside (Dp3sam) isolated from Hibiscus sabdariffa L. flower was esterified with octanoic acid using Candida antarctica lipase B. The physical-chemical properties of the new lipophilic pigment were studied by UV-vis spectroscopy. Dp3sam with chloride, acetate and formate as counter ions were employed to study the lipophilization reaction. The hydrolysis of the reagent was avoided with a formate counter ion and the expected product was achieved with a noteworthy change of solubility. 1D and 2D NMR characterization of Dp3sam-C8 confirmed that the lipophilization took place at the primary alcohol of the glucoside moiety. Overall, the Dp3sam-C8 ester presents a stabilization of the quinoidal base (blue color) at neutral or moderate alkaline pH, which foresees a potential use of this pigment as a broad kind of industries on lipo-soluble formulations.
Keywords: Chemical equilibria; Color stability; Disaccharide anthocyanin; Fatty acid; Lipophilization.
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