MODIFIED ANTHOCYANIN COLORING AGENT

Abstract

An anthocyanin-based coloring agent having a lower max and thus a reduction in blueness and an increase in yellowness, with increased chroma, hue and redness is formed by combining the aqueous-based anthocyanin coloring agent with an aqueous sorghum extract. The ratio of anthocyanin to sorghum extract in terms of color unit can be from 35:1 to 1:5. This can be used in a wide variety of edible products including foods, nutraceuticals and pharmaceutical products and formulations, wherever an aqueous-based coloring agent is preferred.

Claims

1. An food coloring agent comprising a combination of an aqueous anthocyanin solution and an aqueous sorghum extract.

2. The coloring agent claimed in claim 1 where the ratio of anthocyanin solution to sorghum extract based on color units is from 35:1 to 1:5.

3. The coloring agent claimed in claim 1 having a pH of 1.5 to 6.

4. The coloring agent claimed in claim 1 having a pH of 2 to 5.

5. The coloring agent claimed in claim 1 having a pH of 2.5 to 4.

6. The coloring agent claimed in claim 1 having a max of less than 513.

7. The coloring agent claimed in claim 1 wherein said sorghum extract is a black sorghum extract.

8. The coloring agent claimed in claim 7 wherein said sorghum extract is a sorghum bran extract.

9. A powdered food coloring agent comprising a dried blend of an aqueous anthocyanin solution and an aqueous sorghum extract.

10. A method of modifying the chroma and hue of an aqueous anthocyanin solution comprising adding to said anthocyanin solution an aqueous sorghum extract in an amount effective to increase said chroma and hue and decrease said max.

Description

DETAILED DESCRIPTION

[0013] In the present invention, color content is expressed in color units. The color content of clear extracts is determined by suitably diluting the extract with 2.2 molar pH 3 citrate buffers and reading absorbance at max, with a UV-visible spectrophotometer. The color units are then equal to max minus 700 multiplied by a dilution factor. The max, in turn, is the wavelength at the highest absorbance. The present invention is a combination of an aqueous solution of anthocyanin, preferably extracted from a plant, in combination with an aqueous extract of sorghum, such as black and red sorghum.

[0014] The source of the anthocyanin can be virtually any known anthocyanin extract. These can, for example, be extracted from elderberries, purple corn, purple potato, black carrot, radish, currants, red cabbage and many other generally red or purple plants. The extract is obtained by simply grinding the source material and combining this with water, with or without the aid of acid and at elevated temperature. Extracts of anthocyanins from various plant sources are commercially available.

[0015] The sorghum extract is extracted from either sorghum bran or sorghum whole-grain, generally using an acidic aqueous medium. For example, 20 grams of sorghum bran can be extracted with 400 mL of 1% phosphoric acid at 80 C. for sixty minutes. This can be filtered and centrifuged and decanted to provide a clear extract. The clear extract may be further concentrated.

[0016] To form the modified anthocyanin of the present invention, the sorghum extract is combined with the anthocyanin with mixing. The ratio in color units of anthocyanin to sorghum can be from 35 to 1; 33 to 1; 25 to 1; 20 to 1; 15 to 1; 10 to 1; 5 to 1; 1 to 1; 1 to 1.5 or 1 to 2; 1; 3 to 1; 4 to 1; 5.

[0017] Once mixed, the pH of the mix is adjusted, generally to an acidic pH of 1.5 to 6 or 2 to 5, or 2.5 to 4. This is then allowed to stand during which period the color of the mix changes from purple-red to orange-red/red and the chroma increases significantly. The blend can stand at a temperature of 55 F. to 140 F. for a period of 1 to 24 hours to develop its final color. The coloring agent can be incorporated into an aqueous or alcohol-based syrup or concentrate or can be dried to form a powder. The edible coloring agent can be added to foods and beverages at any stage of production of the food or beverage. It can be used as a potential replacement for FD&C Red #40. The invention will be further appreciated in the following detailed examples.

Example 1

[0018] An elderberry extract was combined with sorghum extract at a ratio or color units of 1 to 1. The sorghum extract increased the hue from 25.18 to 52.05, and the chroma from 62.97 to 93.73. Similarly, a sorghum extract was combined with a purple corn extract at a ratio of 1 to 1. This increased the hue from 21.98 to 44.7 and the chroma from 53.84 to 82.13. The sorghum extract had an initial hue of 69.01, and a chroma of 62.98. The following Table 1 shows a comparison of the individual elderberry and purple corn extracts with the extracts in combination with the sorghum extract.

TABLE-US-00001 TABLE 1 L a b C h Elderberry Extract EB) 64.01 56.99 26.8 62.97 25.18 Elderberry Extract (EB) + 59.27 57.59 73.94 93.73 52.09 Sorghum Extract Purple Corn Extract PCE) 60.66 49.92 20.15 53.84 21.98 Purple Corn Extract PCE) + 52.09 58.28 57.77 82.13 44.7 Sorghum Extract

[0019] Table 2 shows the max at a pH of 3 of the individual anthocyanin extracts, as well as the anthocyanin extracts in combination with the sorghum extract.

TABLE-US-00002 TABLE 2 Absorption Maximum nm (max) at pH 3.0 Elderberry Extract EB) 513 Elderberry Extract (EB) + 496.5 Sorghum Extract Purple Corn Extract PCE) 513 Purple Corn Extract PCE) + 504 Sorghum Extract

[0020] Thus, the max of the anthocyanin is reduced to either 504 nm or 496.5 nm from 513 nm on addition of sorghum extract.

Example 2

[0021] To determine the effect of pH on chroma and hue, elderberry extract in water was combined with sorghum extract a ratio of 1:1 color units. The pH of the blend was adjusted with 0.1 normal hydrochloric acid or with diluted 50% potassium hydroxide. The various blends were allowed to stand at ambient temperature for 24 hours. Chroma and hue are then determined by Hunter calorimeter. The results are shown in Table 3.

TABLE-US-00003 TABLE 3 Chroma Hue pH 2.52 85.88 47.55 2.86 81.32 46.49 3.11 76.05 43.67 3.55 63.99 36.99 4.15 46.99 30.82 4.5 40.07 29.3 Elderberry extract only @ pH 3.0 62.97 25.18 Sorghum extract only @ pH 3 62.98 69.01

[0022] Accordingly, the present invention provides an edible coloring agent which can be added to food or beverages at any desired concentration to color the food red. Generally the food or beverage will have an acid pH. The present invention provides a color with increased chroma and hue. Further, it provides a color which is stable over a wide range of pHs.

[0023] This has been a description of the present invention, along with a preferred method of practicing the present invention, however, the invention itself should only be defined by the appended claims wherein we claim: