Method for increasing anthocyanin content in carrots
A method for obtaining an anthocyanin pigment color composition from carrot plants (preferably black carrot plants) comprising pre-harvest foliar spraying of an ethylene-releasing compound and the use of the obtained anthocyanin pigment color composition for coloring of an edible product or a pharmaceutical product.
1 . A method for obtaining an anthocyanin pigment color composition from carrot plants, comprising:
(i) foliar spraying an ethylene-releasing compound on carrot plant leaves
(ii) subsequently, harvesting the carrot plants; and
(iii) isolating anthocyanin pigments from the harvested carrot plants, thereby obtaining the anthocyanin pigment color composition
wherein the ethylene-releasing compound used in step (i) is either one or a mixture of two selected from 2-chloroethylphosphonic acid, (2-chloroethyl) methylbis (phenylmethoxy) silane; (2-chloroethyl) tris (2-methoxyethoxy) silane, and laminocyclopropane-1-carboxylic acid.
2 . The method of claim 1 , wherein the carrot plants are capable of producing anthocyanin pigments.
3 . The method of claim 1 , wherein the isolation of anthocyanin pigments of step (iii) is carried out using at least 100 different harvested carrot plants, wherein the harvested carrot plants are pre-treated by foliar spraying of ethylene-releasing compound in step (i).
4 . The method of claim 1 , wherein the amount of obtained anthocyanin pigments is at least 15% (w/w) higher than the amount of anthocyanin pigments obtained in a control experiment wherein the control experiment is in identical environmental conditions as the ethylene-releasing compound treated carrot plants except the application of ethylene-releasing compound in step (i).
5 . The method of claim 1 , wherein the amount of ethylene-releasing compound applied by foliar spraying in step (i) is from 5 g ha −1 active ingredient (a.i.) to 5000 g ha −1 a.i.
6 . The method of claim 1 , wherein the amount of Ethylene-releasing compound applied by foliar spraying in step (i) is from 50 g ha −1 a.i. to 200 g ha −1 a.i.
7 . The method of claim 1 , wherein the foliar spraying of step (1) is performed later than 2 weeks after planting of the carrot plants.
8 . The method of claim 1 , wherein the foliar spraying of step (i) is performed at least 3 times before the harvesting of step (ii) and the harvesting of step (ii) is performed later than 6 weeks after planting of the carrot plants.
9 . The method of claim 1 , wherein the isolating of step (iii) comprises extracting anthocyanin pigments from taproots of the harvested carrot plants.
10 . The method of claim 1 , wherein the anthocyanin pigment color composition obtained at step (iii) comprises one of the following:
at least 20% (w/w dry matter) or
50% (w/w dry matter) or
90% (w/w dry matter) of the isolated anthocyanin pigments.
11 . The method of claim 1 , wherein the ethylene-releasing compound used in step (i) is one of 2-chloroethylphosphonic acid, (2-chloroethyl) methylbis (phenylmethoxy) silane; (2-chloroethyl) tris (2-methoxyethoxy) silane, and laminocyclopropane-1-carboxylic acid.
12 . The method of claim 1 , wherein the ethylene-releasing compound used in step (i) is a mixture of two selected from 2-chloroethylphosphonic acid, (2-chloroethyl) methylbis (phenylmethoxy) silane; (2-chloroethyl) tris (2-methoxyethoxy) silane, and l-aminocyclopropane-1-carboxylic acid.