Anthocyanin pigments with improved heat-resistance

• US 20050181101A1
• Filed: 02/04/2005
• Published: 08/18/2005
• Est. Priority Date: 02/16/2004
• Status: Abandoned Application

• Current Assignee: Riken Vitamin Company Limited
• Original Assignee: Riken Vitamin Company Limited
• Inventors: Harada, Koichi, Hanato, Ichiyo
• Application Number:
  US11/049,650
• Publication Number:
  US 20050181101A1
• Time in Patent Office: Days
• US Class Current: 426/250
• CPC Class Codes: A23L 5/43 using naturally occurring organic dyes or pigments, their artificial duplicates or their derivatives
• CPC Class Codes: C09B 61/00 Dyes of natural origin prepared from natural sources , e.g. vegetable sources

Abstract

The present invention is to provide anthocyanin pigments with improved heat-resistance and production thereof, and a method for coloring foods with said anthocyanin pigments and foods colored with said anthocyanin pigments. Heat-resistance in anthocyanin pigments is enhanced by adjusting an aqueous anthocyanin solution to a pH range of 4.0 to 6.5 at a temperature of 40 to 100° C.

Claims

1. a method for producing an anthocyanin pigment with improved heat-resistance, which comprises adjusting the ph of an aqueous solution containing an anthocyanin pigment to within a range of 4.0 to 6.5 at 20°

C. and heating the solution at a temperature within a range of 40°

C. to 100°

C.

2. The method for producing an anthocyanin pigment according to claim 1, wherein the pH range is 5.0 to 6.0, and the heating temperature range is 80°

C. to 100°

C.

3. An anthocyanin pigment obtainable by the method according to claim 1.

4. The anthocyanin pigment according to claim 3, wherein an increasing rate of color intensity calculated by the following method is not less than 100%.

[Calculation Method for Increasing Rate of Color Intensity]

A sample is weighed out in such a manner that absorbance to be measured falls within a range of 0.5±

0.005, and Macllvaine buffer (pH 3.0) is added to accurately make up 100 ml. This solution is served as a test solution. A portion (15 mL) of the test solution is placed in a 25 mL-screw capped test tube (outer diameter 18 mm×

length 160 mm;

available from Nichiden Rika Glass Co.), and the cap of the test tube is screwed. The test tube is heated in a warm water bath of 80°

C. for 30 minutes under shading, and then cooled down to room temperature with water. Using Macllvaine buffer (pH 3.0) as a control, absorbance of the test solution at maximum absorption band of around 500 to 600 nm in a 1 cm cell is measured before heating and after heating and water cooling. The measured data are substituted into the following equation to obtain an increasing rate of color intensity (%).

Increasing rate of color intensity (%)=Absorbance of test solution after heating and water cooling/Absorbance of test solution before heating×

100

5. The anthocyanin pigment according to claim 4, wherein the increasing rate of color intensity (%) is 110 to 140%.

6. The anthocyanin pigment according to claim 4, wherein the increasing rate of color intensity (%) is 120 to 140%.

7. A food which is colored by an anthocyanin pigment described in claim 3.

8. A method for coloring a food by an anthocyanin pigment described in claim 3.

10. An anthocyanin pigment obtainable by the method according to claim 2.

11. A food which is colored by an anthocyanin pigment described in claim 4.

12. A food which is colored by an anthocyanin pigment described in claim 5.

13. A food which is colored by an anthocyanin pigment described in claim 6.

14. A method for coloring a food by an anthocyanin pigment described in claim 4.

15. A method for coloring a food by an anthocyanin pigment described in claim 5.

16. A method for coloring a food by an anthocyanin pigment described in claim 6.

9. An anthocyanin pigment, wherein an increasing rate of color intensity calculated by the following method is not less than 100%.

[Calculation Method for Increasing Rate of Color Intensity]

A sample is weighed out in such a manner that absorbance to be measured falls within a range of 0.5±

0.005, and Macllvaine buffer (pH 3.0) is added to accurately make up 100 ml. This solution is served as a test solution. A portion (15 mL) of the test solution is placed in a 25 mL-screw capped test tube (outer diameter 18 mm×

length 160 mm;

available from Nichiden Rika Glass Co.), and the cap of the test tube is screwed. The test tube is heated in a warm water bath of 80°

C. for 30 minutes under shading, and then cooled down to room temperature with water. Using Macllvaine buffer (pH 3.0) as a control, absorbance of the test solution at maximum absorption band of around 500 to 600 nm in a 1 cm cell is measured before heating and after heating and water cooling. The measured data are substituted into the following equation to obtain an increasing rate of color intensity (%).

Increasing rate of color intensity (%)=Absorbance of test solution after heating and water cooling/Absorbance of test solution before heating×

100