Photoisomerized compositions of anthocyanins and methods of making and use thereof
Disclosed herein are photoisomerized compositions comprising anthocyanins and methods of making an use thereof. For example, disclosed herein are methods of photoisomerizing a composition, the methods comprising: irradiating a composition comprising an anthocyanin dissolved in a solvent solution with UV light; wherein at least a portion of the anthocyanin is present as a trans isomer before the irradiation; wherein the solvent solution comprises ethanol and water in a ratio of ethanol to water (volume/volume) of 99:1 to 70:30; thereby converting at least a portion of trans isomer to a cis isomer via photoisomerization to produce a photoisomerized composition. In some examples, the photoisomerized composition has a more intense and stable blue color at pH 8 relative to the composition before irradiation.
1 . A method of making a photoisomerized composition, the method comprising:
irradiating a first composition comprising an anthocyanin dissolved in a solvent solution with UV light;
wherein the anthocyanin comprises cyanidin-3-p-coumaroyl-sambubioside-5-glucoside;
wherein at least a portion of the anthocyanin is present as a trans isomer before the irradiation;
wherein the solvent solution comprises ethanol and water in a ratio of ethanol to water (volume/volume) of from 90:10 to 80:20;
thereby converting at least a portion of trans isomer to a cis isomer via photoisomerization to produce the photoisomerized composition.
2 . The method of claim 1 , wherein the solvent solution comprises ethanol and water in a ratio of ethanol to water of 90:10 or 80:20.
3 . The method of claim 1 , wherein the UV light comprises light of one or more wavelengths of from 100 nm to 400 nm.
4 . The method of claim 1 , wherein the first composition is irradiated for an amount of time of from 1 minute to 60 minutes.
5 . The method of claim 1 , wherein the first composition comprises a crude extract derived from a plant dissolved in the solvent solution.
6 . The method of claim 1 , wherein the first composition comprises a crude extract derived from a raw agricultural product dissolved in the solvent solution.
7 . The method of claim 1 , wherein the first composition comprises a crude extract derived from an elderberry dissolved in the solvent solution.
8 . The method of claim 1 , wherein the anthocyanin is derived from a plant and/or a raw agricultural product.
9 . The method of claim 1 , wherein the anthocyanin is derived from an elderberry.
10 . The method of claim 1 , wherein the anthocyanin comprises an acylated anthocyanin.
11 . The method of claim 1 , wherein the anthocyanin comprises a cinnamic acid acylated anthocyanin.
12 . The method of claim 1 , wherein the first composition comprises the anthocyanin in a concentration of from 50 to 500 micromoles per liter (micromolar, μM).
13 . The method of claim 1 , wherein the cis isomer to the trans isomer are present in the photoisomerized composition in a ratio of greater than 0.5.
14 . The method of claim 1 , wherein the cis isomer is present in the photoisomerized composition in a concentration of 20 μM or more.
15 . The method of claim 1 , wherein the photoisomerized composition has improved color and stability relative to the first composition before irradiation.
16 . The method of claim 1 , wherein the photoisomerized composition has a more intense and stable blue color at pH 8 relative to the first composition before irradiation.
17 . The method of claim 1 , wherein the method further comprises making the first composition by dissolving the anthocyanin in the solvent solution.
18 . A photoisomerized composition made using the method of claim 1 .
19 . A method of use of the photoisomerized composition of claim 18 , the method comprising using the photoisomerized composition as a natural food dye, on an OTC coating, or in a cosmetic.
20 . The method of claim 1 , wherein the cis isomer to the trans isomer are present in the photoisomerized composition in a ratio of 0.65 or more.