Coating composition based on coloring foodstuffs

Abstract

A coating composition includes, in relation to 100% of the weight thereof: between 10 and 90 wt. % of at least one film-forming polymer selected from cellulosic polymers or derivatives of cellulosic polymers, derivatives of vinyl alcohol, derivatives of vinyl pyrrolidones, polymers of a natural origin, acrylic or methacrylic derivatives, derivatives of glycol or propylene glycol or combinations of the two substances or the copolymers of vinyl alcohol and polyethylene glycol (PEG); between 1 and 50 wt. % of at least one food colouring agent; and between 0 and 50 wt. % of at least one auxiliary coating agent selected from white opacifiers, diluents, surfactants, plasticizers, and anti-foaming agents.

Claims

1. A coating composition comprising, per 100% of the weight thereof: from 70 wt % to 82 wt % of a film-forming polymer combination of hydroxypropylmethyl cellulose and sodium carboxymethyl cellulose, wherein the hydroxypropylmethyl cellulose comprises between 59% and 69.8% and the sodium carboxymethyl cellulose comprises between 11% and 12.2%, from 12 wt % to 30 wt % of at least one coloring foodstuff, said at least one coloring foodstuff comprising concentrated black carrot or purple carrot prepared with physical processing using only water as a solvent, wherein the at least one coloring foodstuff does not contain any functional additives, wherein the at least one coloring foodstuff retains a flavor, a taste and a color of said at least one coloring foodstuff and said at least one coloring foodstuff does not consist of selective extraction of a coloring substance from said at least one coloring foodstuff, and from 0 to 6 wt % of at least one auxiliary coating agent selected from the group consisting of white opacifiers, diluents, surfactants, plasticizers and antifoams, wherein the intensity and stability, as measured by L*a*b* coordinates, of the color of the coloring foodstuff is maintained after six months in daylight by approximately at least 88%, 83%, and 75% respectively for the L*a*b* coordinates.

2. The coating composition as claimed in claim 1, wherein said at least one auxiliary coating agent is selected from the group consisting of: white opacifiers selected from the group consisting of titanium dioxide, talc, kaolin, and magnesium oxide; diluents selected from the group consisting of lactose, sucrose, mannitol, sorbitol, xylose, xylitol, isomalt, cellulose, talc, and native starches; surfactants selected from the group consisting of sorbitan esters, ethoxylated sorbitan esters, hydrogenated and ethoxylated castor oils, lecithins, sodium lauryl sulfate, ethoxylated fatty alcohols, and ethoxylated fatty acids; plasticizers selected from the group consisting of glycerin, polypropylene glycols, polyethylene glycols or derivatives thereof from condensation with a fatty acid or fatty alcohol, stearic acid and derivatives thereof, and acetylated monoglycerides; and antifoams selected from the group consisting of fatty acids and silicone derivatives.

3. The coating composition as defined in claim 1, wherein said composition is in the form of an aqueous dispersion, a powder or ready-to-use granules.

4. A process for preparing the coating composition as defined in claim 1 and which is in the form of a dry powder, comprising the following steps: a step (a) of mixing the film-forming polymer combination, coloring foodstuff and, optionally, one or more other auxiliary coating agents to form a mixture, an optional step (b) of milling the mixture arising from step (a) to form said coating composition.

5. A process for preparing a coating composition as defined in claim 1 and which is in the form of ready-to-use granules, comprising the following steps: a step (a1) of wetting a mixture of film-forming polymer combination, coloring foodstuff and, optionally, one or more other auxiliary coating agents using a binder solution, so as to obtain a wet mass containing from 30% to 60% water, a step (b1) of drying the wet mass obtained in step (a1) to obtain a dried wet mass and, optionally, a step (c1) of calibrating the dried wet mass obtained in step (b1) to obtain said coating composition.

6. A process for preparing the coating composition as defined in claim 1 and which is in the form of an aqueous dispersion, comprising the following steps: a step (a2) of dispersing, in an aqueous phase, the film-forming polymer combination, the coloring foodstuff and, optionally, one or more other auxiliary coating agents, a step (b2) of milling the dispersion obtained from step (a2) to form said coating composition.

7. A process for coating ingestible solid forms comprising coating the ingestible solid forms with an effective amount of the coating composition as defined in claim 1.

8. A process for preparing coated solid forms comprising: dispersing in an aqueous medium the coating composition as defined in claim 1; and spraying the dispersion obtained onto solid substrates to be coated.

9. The coating composition as defined in claim 1, wherein: said at least one auxiliary coating agent is a plasticizer selected from the group consisting of glycerin, polypropylene glycols, polyethylene glycols or derivatives thereof from condensation with a fatty acid or fatty alcohol, stearic acid and derivatives thereof, and acetylated monoglycerides.

10. The coating composition as defined in claim 1 wherein the stability of the intensity, as measured by L*a*b* coordinates, of the color of the coloring foodstuff is substantially greater as compared to the same composition using from 12 wt % to 30 wt % of a carotenoid natural dye instead of the at least one coloring foodstuff.

Description

EXAMPLES

Example 1

Coating Compositions, the Constituents of which are Expressed as Weight Percentages, are Formulated as Follows

(1) TABLE-US-00001 Comparative Inventive example: composition: composition A composition B Film-forming Hydroxypropylmethyl Hydroxypropylmethyl agent cellulose (HPMC): cellulose (HPMC): 69.8% 69.8% Carboxymethyl Carboxymethyl cellulose (CMC): cellulose (CMC): 12.2% 12.2% Auxiliary Acetylated Acetylated agent monoglycerides: 6% monoglycerides: 6% Coloring 12% natural dye: 12% coloring system carotenoids. foodstuff: black (β-carotene powder: carrots Fusion Red Orange P-WD. CAS number: 7235-40-7)

(2) 500 mg tablets comprising, per 100% of their weight, 49.75 wt % microcrystalline cellulose, 49.75 wt % lactose and 0.5 wt % magnesium stearate are coated with coating compositions A and B.

(3) Coating is carried out in a perforated “PILOT XT laboratory tablet coater” pan sold by Profile Automation, loaded with 2 kg of tablets.

(4) At the end of the prior coating step, the coated tablets obtained are then placed in daylight and darkness so as to measure the stability of the coloring.

(5) The color of the tablets is monitored regularly using a MEDSCAN colorimeter, sold by NEWTONE.

(6) TABLE-US-00002 L*a*b* of L*a*b* of L*a*b* of tablets tablets tablets Composition L*a*b* of after 2 after 5 after 7 coating the tablets weeks in weeks in weeks in tablet at T = 0 light light light Composition A 64.4/57.9/ 74.4/25.9/ 92.9/−0.4/ No 59.8 67.2 4.6 stability (total loss of color of tablet) Composition B 42.4/33.6/ 44.5/36.0/ 48.2/34.5/ 50.3/32.2/ −0.8 0.0 0.0 (color 0.0 of tablets (color of very close tablets to T = 0) close to T = 0)

(7) Interpretation in terms of color saturation, according to the saturation C* parameter, calculated according to the formula: C*=(a*.sup.2+b*.sup.2).sup.1/2.

(8) TABLE-US-00003 Saturation Saturation Saturation Composition C* after 2 C* after 5 C* after 7 coating the Saturation weeks in weeks in weeks in tablet C* at T = 0 light light light Composition A 83.2 72.0 4.6 No stability Composition B 33.6 36.0 34.5 32.2

(9) The coating composition B comprising the coloring foodstuff enables tablets to be obtained, the color of which remains intense and stable for at least 7 weeks in daylight.

(10) Conversely, significant loss of color is observed for the tablets coated by composition A comprising carotenoids.

Example 2

Coating Compositions, the Constituents of which are Expressed as Weight Percentages and which are More Concentrated in Dyes/Coloring Foodstuffs, were Prepared and are Formulated as Follows

(11) TABLE-US-00004 Comparative Comparative Inventive example: example: composition: composition C composition D composition E Film- Hydroxypropyl- Hydroxypropyl- Hydroxypropyl- forming methyl cellulose methyl cellulose methyl cellulose agent (HPMC): 59% (HPMC): 59% (HPMC): 59% Carboxymethyl Carboxymethyl Carboxymethyl cellulose (CMC): cellulose (CMC): cellulose (CMC): 11% 11% 11% Coloring 30% natural dye: 30% natural dye: 30% coloring carotenoids. carotenoids. food-stuffs: (β-carotene powder: (Natracol beta purple carrots. Fusion Red Orange carotene wsp. CAS P-WD. CAS number: 7235-40-7) number: 7235-40-7)

(12) 500 mg tablets comprising, per 100% of their weight, 49.75 wt % microcrystalline cellulose, 49.75 wt % lactose and 0.5 wt % magnesium stearate are coated with coating compositions C, D and E. Coating is carried out in a perforated “PILOT XT laboratory tablet coater” pan sold by Profile Automation, loaded with 2 kg of tablets.

(13) At the end of the prior coating step, the coated tablets obtained are then placed, for stability purposes, in daylight and darkness. The color of the tablets is monitored regularly using a MEDSCAN colorimeter, sold by NEWTONE.

(14) TABLE-US-00005 L*a*b* of L*a*b* of L*a*b* of L*a*b* of L*a*b* of Composition L*a*b* of tablets after tablets after tablets after tablets after tablets after coating the tablets at 2 weeks 5 weeks 5 weeks 6 months 6 months tablet T = 0 in light in light in the dark in light in the dark Composition C 58.8/53.1/52.5 67.6/47.2/55.2 84.8/−1.5/65.3 66.3/51.4/63.1 No No (loss of color stability stability of tablet) Composition D 67.8/46.9/65.1 75.5/19.6/74.0 84.4/−3.7/75.1 75.0/21.3/75.1 No No (loss of color stability stability of tablet) Composition E 58.7/50.7/28.2 62.3/46.5/23.8 62.2/46.0/19.0 62.8/48.1/22.8 66.7/42.3/19.2 62.8/47.5/21.3

(15) As above, the coating composition E according to the invention, comprising the coloring foodstuff, enables a color for the tablets to be obtained which is intense and stable for 6 months in daylight. Moreover, the L*a*b* parameters measured after 6 months in light for the tablets coated with composition E show very little difference to the L*a*b* parameters measured after 6 months in darkness.

(16) On the contrary, a rapid loss of color is observed for the tablets coated with compositions C and D, comprising carotenoids as coloring system. Therefore, the results do not depend on the amount of dye used.

(17) The parameters used to describe a color can be subsumed under three categories: hue, which characterizes the color itself (green, red, etc.) lightness, which characterizes the ability of the colored sample to reflect light to a greater or lesser extent (light color, dark color, etc.) saturation, which characterizes the intensity of color of the sample (bright color=saturated color).

(18) The CIELab 1976 system is used to mathematically represent the colorimetric coordinates of a color.

(19) This system has two modes of representation: Representation by L*a*b* coordinates in which L* represents the lightness axis, a* the red/green axis and b* the yellow/blue axis. Representation by L*C*h0 coordinates in which L* represents the lightness axis, C* the saturation axis and h0 the hue angle.

(20) In order for a color to be stable, the variation of the L*a*b* or L*C*h0 over time must be as small as possible.

(21) The L*a*b* coordinates were used for the examples of the present invention.