Previous and recent advances in pyranoanthocyanins equilibria in aqueous solution

•Pyranoanthocyanin pigments equilibrium forms studies in aqueous solution are reviwed.•Pyranoanthocyanins present higher colour stabilization with the increase of pH when compared to the anthocyanin precursors.•The absence of hydration reactions in pyranoanthocyanins were confirmed using NMR techniques.

Pyranoanthocyanins are anthocyanin-derived compounds found in nature that present a vast palette of colours ranging from yellow to turquoise blue. Studies in aqueous solutions of these pigments by UV–Visible spectroscopy revealed their higher colour stability when compared to their anthocyanin precursors. Through Nuclear Magnetic Resonance (NMR) techniques it was possible to confirm the absence of hydration reactions in pyranoanthocyanins, contrarily to anthocyanins, which helps explaining their higher colour stability with the increase of the pH.

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