FIELD OF THE INVENTION

The present invention relates to a composition for coloring foods, beverages, animal feeds, cosmetics or drugs, in particular the coloring of cheese.

BACKGROUND OF THE INVENTION

Beta-carotene is a useful cheese coloring agent because it is naturally present in milk. Beta-carotene gives cheese a color which appeals to the customer and it does not produce off-flavors during the ripening of the cheese.

However, beta-carotene preparations face the problem that a large amount of color is lost in the whey during the cheese making process. This loss negatively impacts the suitability of the whey for its further processing to infant nutrition.

WO201 0/069889 to Cybercolors relates to a composition for coloring cheese curd comprising a combination of an oil phase comprising an effective amount of paprika, an effective amount of a carotenoid, and a fat, and an aqueous phase comprising a caseinate. However, no native casein is disclosed as first hydrocolloid nor second hydrocolloid.

EP2717720 to Chr. Hansen Natural Colors A/S describes a liquid coloring composition comprising: a) an oil-in-water emulsion comprising a carotenoid dissolved in an oil phase, wherein the oil phase is emulsified in an aqueous phase using a suitable emulsifier and wherein the oil phase is present in an amount of between 5% w/w to 40% w/w of the oil-in-water emulsion; and b) a formulation of water dispersible carotenoid particles encapsulated with a second hydrocolloid, wherein the suitable hydrocolloid is present in an amount of at least 0.5% w/w of the formulation; wherein the ratio of a):b) is between 1 :100 to 100:1 and wherein the total carotenoid content of a) and b) is between 0.1 % w/w to 15% w/w of the resulting liquid coloring composition. The suitable emulsifier, called first hydrocolloid, preferably is selected from the group consisting of lecithin, caseinate and a combination thereof. However, no native casein is disclosed as first hydrocolloid nor second hydrocolloid.

LIS20190254302 to Cornell University discloses microcapsules comprising a core comprising a coloring agent such as a carotenoid dispersed in a gel matrix such as 2lginate; a proteolytically-cleavable outer polymer shell surrounding said core; and an enzymat- ically-cleavable lipid layer such as glycerol between said core and said shell.

UK2248170 to Hoffmann-La Roche describes a beta-carotene emulsion composition for coloring cheese curd comprising beta-carotene, a fat, a caseinate and an aqueous solution of gelatin.

US2020/178564 to Deutsches Institut fur Lebensmitteltechnik describes a process in which casein micelles are suspended in an aqueous medium and treted with pulsed electric fields in order to produce casein micelles which contain at least one lipophilic compound as a preparation which is suspended in the aqueous medium.

Thus, there is a need for alternative, beta-carotene coloring compositions perceived as natural that prevent coloration of the whey.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide an improved pigment composition using a carotenoid for coloring of foods, such as cheeses. Especially, it is an aim of the present invention to provide an improved coloring composition comprising beta-carotene which is capable meeting consumer expectations in respect of natural compounds. Moreover, the present invention aims at preventing the coloration of the whey. Finally, the present invention aims at providing natural solution to calcium caseinate described in EP2717720. The inventors surprisingly found that native casein can replace casein derivatives such as calcium caseinate whilst providing a very good coloration of cheese and reducing the coloration of the whey.

Accordingly, a first aspect of the invention is a liquid coloring composition comprising: a) an oil-in-water emulsion comprising a carotenoid dissolved in an oil phase, wherein the oil phase is emulsified in an aqueous phase using a first hydrocolloid and wherein the oil phase is present in an amount of between 5% w/w to 25% w/w of the oil-in-water emulsion and wherein the first hydrocolloid is present in an amount from about 1 % w/w to about 20% w/w of the oil-in- water emulsion; and b) a formulation of water dispersible carotenoid particles encapsulated with a second hydrocolloid, wherein the second hydrocolloid is present in an amount of at least 2% w/w of the formulation; wherein the ratio of a) : b) is between 1 : 10 to 10: 1 ; wherein the total carotenoid content of a) and b) is between 0.1 % w/w to 15 % w/w, preferably between 1 % w/w to 5 % w/w of the resulting liquid coloring composition; and wherein the first hydrocolloid is native casein.

In one aspect, the first hydrocolloid is native casein and the second hydrocolloid is calcium caseinate. In another aspect of the liquid coloring composition, both the first hydrocolloid and the second hydrocolloid are native casein.

In another aspect, the liquid coloring composition, and in particular oil-in-water emulsion, is substantially free of casein derivatives, caseinate, such as calcium caseinate. In one embodiment, no calcium caseinate is present in the liquid coloring composition in an amount sufficient to serve as first hydrocolloid for the carotenoid.

In another aspect of the liquid coloring composition, the oil phase is present in an amount of between about 10% w/w to about 20% w/w of the oil-in-water emulsion a).

In another aspect of the liquid coloring composition, the ratio of the oil-in-water emulsion a) to the formulation of water dispersible carotenoid particles encapsulated with a second hydrocolloid b) is between about 10:1 to about 1 :10, preferably from 1 :5 to about 5:1 , or from about 4:1 to about 1 :4, or from to about 3:1 to about 1 :3, or from about 1 :2 to about 2:1.

In another aspect, the carotenoid is selected from the group consisting of beta-carotene, alpha-carotene, gamma-carotene, zeaxanthin, lutein, apocarotenal, cis/trans isomers thereof and combinations thereof.

In another aspect, the carotenoid is beta-carotene.

In another aspect, the first hydrocolloid is native casein.

In another aspect, the first hydrocolloid further comprises lecithin, citric acid esters, mono/di-glycerides, poly-oxyethylene sorbitan fatty acid esters, milk proteins, pea proteins, acacia gum and combinations thereof.

In another aspect, the oil phase comprises a fat selected from the group consisting of lard, oils and combinations thereof.

In another aspect of the liquid coloring composition the fat is an oil selected from sunflower seed oil, com oil, soybean oil, olive oil, coconut oil, palm oil, palm kernel oil, groundnut oil, cottonseed oil, grapeseed oil, rapeseed oil, medium-chain triglyceride oils, and combinations thereof.

In another aspect, the second hydrocolloid is selected from the group consisting of nonmodified starch, modified starch, milk protein, native casein, pea protein, beet pectin and combinations thereof.

A further aspect of the present invention is a method for preparing a liquid coloring composition comprising the steps of:

■ preparing an oil-in-water emulsion of a dissolved carotenoid using a first hydrocolloid by:

■ preparing an aqueous phase;

■ preparing an oil phase by heating a fat comprising the carotenoid to a temperature suitable for dissolving the carotenoid; and

■ mixing the oil phase in the aqueous phase;

■ preparing a formulation of carotenoid particles encapsulated in a second hydrocolloid by milling; and ■ mixing the oil-in-water emulsion of a) with the encapsulated carotenoid particle formulation of b) in a ratio of between 1 : 10 to 10: 1 ; wherein the first hydrocolloid is native casein.

In another aspect, the temperature suitable for dissolving the carotenoid is between about 140°C to 180°C in the oil-in-water emulsion.

A further aspect is a method of coloring cheese comprising the steps of:

■ adding a starter culture, rennet and the liquid coloring composition according to any of claims 1 to 10 to milk;

■ incubating the mixture under conditions favorable to the generation of curd and whey fractions; and

■ separating the curds from the whey.

A further aspect is a food product, a cheese, a beverage, an animal feed, a cosmetic or a drug comprising the liquid coloring composition of the invention.

A further aspect of the invention is the use of the liquid coloring composition of the invention as a colorant for a food product, a cheese, a beverage, an animal feed, a cosmetic or a drug.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

The term “pigment” relates to a material that changes the color of light it reflects as the result of selective color absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which the material itself emits light.

The term “carotenoid” as used herein comprises carotenes or structurally related polyene compounds, such as xanthophylls, which can be used as a colorant for foods, beverages, animal feeds, cosmetics or drugs. Examples of such carotenoids are alpha- or beta-carotene, 8’-apo-beta-carotenal, 8’-apo-beta-carotenoic acid esters such as ethyl ester, canthaxanthin, astaxanthin, lycopene, lutein, zeaxanthin or crocetin, or mixtures thereof. As already mentioned, the preferred carotenoid is beta-carotene.

The term “native casein” describes a mixed complex of phosphoproteins isolated from mammal milk and in particular from cow milk as colloidally dispersed micelles from 50 to 600 nanometers in diameter. The variable-sized micelles comprise spherical subunits of 10 to 20 nm, containing 25 to 30 casein molecules. Casein may be separated from the whey proteins of milk for example by gel-filtration or high-speed centrifugation.

The term “casein derivative” describes compounds that are obtained by chemical or structural (other than separation by filtration or centrifugation) modification of native casein, for example acidification. Examples of casein derivatives are caseinate, such as calcium caseinate.

The term “calcium caseinate” describes a derivative of native casein. Calcium caseinate is produced by adding an alkali to acid casein. Calcium caseinate is currently used in stabilizing color formulations in cheese production. However, some of the color pigments may still migrate to the whey. Consequently, the whey becomes less suitable for further processing to powdered milk for infant nutrition. Therefore, it is an object of the invention to reduce this migration of color pigments into the whey.

Implementation and aspects of the invention

The liquid coloring composition of the present invention is made up of 2 main fractions: a) an emulsified carotenoid (oil-in-water emulsion) formulation and b) a formulation with water dispersible carotenoid particles encapsulated with a hydrocolloid.

In a preferred embodiment of the present invention the ratio of a):b) is between about 1 :100 to about 100:1 , such as between about 1 :10 to about 10: 1 , such as between about 1 :5 to about 5:1.

Carotenoids from natural sources as well as their nature-identical counterparts may be used. In a preferred embodiment of the present invention, the coloring composition is made with the following carotenoids: beta-carotene, alpha-carotene, gamma-carotene, ze- axanthin, lutein, cis/trans isomers and combinations thereof.

In an even more preferred embodiment the carotenoid is beta-carotene.

The first hydrocolloid preferably is native casein. The first hydrocolloid may further comprise lecithin, citric acid esters, mono/di-glycerides, poly-oxyethylene sorbitan fatty acid esters, milk proteins, pea proteins, acacia gum and combinations thereof.

The amount of first hydrocolloid used in the oil-in-water emulsion is from about 1 % weight per weight to about 20% weight per weight, such as from about 2% weight per weight to about 15% weight per weight.

The second hydrocolloid preferably is native casein. The second hydrocolloid may further comprise lecithin, citric acid esters, mono/di-glycerides, poly-oxyethylene sorbitan fatty acid esters, milk proteins, pea proteins, acacia gum and combinations thereof.

Ascorbyl palmitate may be added to regenerate antioxidants present at the emulsion interface.

Other ingredients in the water phase may include sugar, starches and organic acids.

Preferably, the oil phase comprises a fat selected from the group consisting of lard, or a vegetable oil, such as sunflower seed oil, com oil, soybean oil, olive oil, coconut oil, palm oil, palm kernel oil, groundnut oil, cottonseed oil, grapeseed oil, rapeseed oil or medium-chain triglyceride oil, and combinations thereof.

The amount of fat used in the oil-in-water emulsion may be between about 5% weight per weight to about 25% weight per weight, preferably about 10% weight per weight to about 20% weight per weight. Antioxidants, preferable alpha-tocopherol or mixed tocopherols, may be added to the oil phase in order to protect carotenoids during heating and subsequently stabilize the final color formulation against oxidative degradation.

Antimicrobials such as organic acids or salts thereof, e.g. sorbic acid, benzoic acid, may be used to inhibit growth of microorganisms during storage. Preferably, the composition further comprises an emulsion carrier. Suitably, the emulsion carrier may be selected from the group consisting of maltodextrin, sucrose, glucose, fructose, lactose, maltose, invert sugar, and combinations thereof.

The carotenoid particles may comprise amorph carotenoid as well as crystalline carotenoid. Preferably, the carotenoid particles comprise 100% crystalline carotenoid.

In a preferred embodiment the amount of hydrocolloid in the milled fraction is at least about 0.5% weight per weight, such as at least about 2% weight per weight.

Preferably, the total beta-carotene pigment content is from about 0.1 % weight per weight to about 15% weight per weight, more preferably from about 0.5% weight per weight to about 10% weight per weight.

The process of preparing the coloring composition comprises three steps: An oil-in- water emulsion of a dissolved carotenoid is prepared using a first hydrocolloid by i) preparing an aqueous phase; ii) preparing an oil phase by heating a fat comprising the carotenoid to a temperature suitable for dissolving the carotenoid; and iii) mixing the oil phase in the aqueous phase by stirring;

The term “a temperature suitable for dissolving the carotenoid” refers to a temperature in a range from about 120°C to about 230°C, at which temperature the carotenoid can be dissolved in the fat during the process of preparing the oil-in-water emulsion.

In a preferred embodiment, the temperature suitable for dissolving the carotenoid is between about 140°C to about 180°C, preferably form about 150°C to about 180°C.

The two phases are mixed using high speed propeller stirring, and the subsequent processing step is an emulsification by homogenization. A particle size distribution with an average particle size in the range 0.25 - 2.50 pm is obtained following the emulsification of this fraction.

A fraction containing water-dispersible, encapsulated particles of carotenoid is produced by milling the carotenoid particles either in dry form or as a water suspension with a hydrocolloid, such as native casein, non-modified starch or modified starch, milk or pea protein or beet pectin, thereby stabilizing the suspension of the encapsulated carotenoid in aqueous phase and avoiding slow dissolution of particles in presence of oily phases. Moreover, the colorimetric properties may be improved in the cheese application.

The suspension is heated moderately, e.g. to 55°C, while mixing by high speed propeller stirring and a pre-emulsification. The suspension is thereafter submitted to ball mill step in order to increase the surface area of the particles while simultaneously ensuring coverage of particles with stabilizing hydrocolloid.

The final step is to mix the emulsion fraction and the milled fraction by stirring. It is also possible to mix ratios that ensure a desired reddish shade in the final application.

As mentioned above, an aspect of the present invention relates to a food product, a beverage, an animal feed, a cosmetic or a drug comprising the coloring composition according to the present invention.

In a preferred embodiment, the food product is a cheese, such as a traditional cheese or a processed cheese.

The coloring composition of the present invention may find use as a colorant for cheese, such as traditional cheese or processed cheese.

The coloring composition of the present invention may find use as colorant not only for cheese but also for other foods, beverages, animal feeds, cosmetic and drugs.

As will be appreciated by the skilled person, the coloring composition of the present invention may be added either as an aqueous stock solution or a pre-blend with other suitable food ingredients according to the specific application. Mixing may be carried out e.g. using a low shear mixer, a high pressure homogenizer or a high shear mixer depending on the formulation of the final application. Mixing procedure and amount of oily or aqueous ingredients may impact the color of the final application. As will be readily apparent such technicalities are within the skill of the expert.

Embodiments of the present invention are described below, by way of non-limiting examples. EXAMPLES

Process

Emulsified fraction:

The emulsified part is processed with a homogenizer APV lab 1000 from SPX.

All emulsions were prepared with the following order of addition and process:

1 ) Prepare the aqueous phase by adding water, native casein.

2) Prepare the oil phase by adding oil, carotene. Heat until a fully dissolution of pigment.

3) Transfer the oil phase into the water phase

4) Homogenize

5) Pasteurize

Milled fraction:

The milled fraction is milled with a ball mill from WAB.

All encapsulations were prepared with the following order of addition and process:

1 ) Prepare the water phase by adding water, and native casein.

2) Add carotene

4) Pasteurize

5) Mill the suspension on a ball mill

As a final step, a simple mixing of the emulsion fraction and the milled fraction by stirring while adding ratios that ensure the desired reddish shade in the final application.

Analysis

The Malvern Zetasizer Nano-S is used to determine the Z-average (Zave) particle size and PDI (polydispersity index) when the size is from 1 nm to 1 pm. One drop of the liquid color is added in 40 mL of demineralized water. This solution is put in the Zetasizer. A laser passes through the solution and the intensity fluctuations due to Brownian movements is measured and converted to size. The pigment contents in the two parts and blend are determined with a UV-spectro- photometer UV-1800 from Shimadzu by dissolving the formulation in water and then acetone at appropriate dilution. The extinction coefficient used to determine the concentration of beta-carotene (w w %) is 2559 at a A = 452 nm.

The lightness, chroma and hue are obtained with a Datacolor 650 in reflexion. All samples are analyzed in milk 3.5%fat.

Lab Cheese

Color Evaluations

Color measurements are performed on the colorimeter Probe4Light

The Cheese was produced as follows. For 200 g of milk following compounds were added in following order while stirring and following process steps were carried:

1 ) Add Culture: 4g of pre-blend of 2.5 g culture to 125 g milk

2) Add CaCI2: 4 drops of 10% CaCI2

3) Fermentation for 45 minutes at 32°C

4) Add 1 wt% or less, preferably 0,1 wt% or less, here 0,1 w% of liquid color composition, 15 minutes before end of fermentation time.

5) Add rennet: 400 microliters pre-blend produced by adding 1000 microliters to 7 g water.

6) Renneting for 45 minutes at 32°C.

7) Cutting

8) Pre-stirring for 15 minutes

9) Scalding for 15 minutes at 40°C with slow stirring

10) Final stirring for 7 minutes

11 ) Whey off

Example 1

To determine the content of native casein suitable for our purpose, different emulsions and encapsulations were performed containing water and native casein at different ratios. Then, in cheese application, they were compared to the reference of each part (emulsified or milled) based on calcium caseinate.

Formulation recipes:

All recipes were processed following the different steps as described above. The pro- cess was stopped when expected shade and particle size were reached.

All ratios of native casein in the emulsified and the milled portions have led to a liquid bulk similar to the references. Surprisingly, it was possible to increase and decrease the level of casein without interfering with the viscosity and stabilization. Application test and whey analysis:

All formulations based on native casein surprisingly exhibit less beta-carotene color into the whey. Indeed, the chroma value of sample A is lower than the reference for emulsified product and hue is higher compared to the reference. Consequently, a lower amount of pigment has migrated from the curd into the whey resulting in a whiter whey.

Regarding the milled fraction where there is native casein, there is the same coloration and whey performance as calcium caseinate whilst being more acceptable to consumers that are interested in natural solutions.

Example 2

A blend between the emulsified and milled parts was, therefore, produced at a fraction 55/45, respectively based on example 1. Formulation recipes: Application test and whey analysis:

The blend was compared to the reference based on calcium caseinate and same ratios between emulsified and milled parts. Surprisingly, a reduction of beta-carotene transfer was observed in the blend containing native casein compared to the reference based on calcium caseinate. The emulsified part has an unexpected synergic effect with the milled portion leading, when blended, to a significant decrease of pigment migration from the curd to the whey. Example 3: Addition of hydrocolloids in emulsified part

A hydrocolloid was added to the emulsified part in recipes containing native casein. All recipes were processed following the different steps as described above. Process was stopped when good shade and particle size were reached.

Formulation recipes:

Application test and whey analysis:

The addition of a hydrocolloid has, surprisingly, lead to a better retention of the beta- carotene in the curd. Indeed, the transfer of pigment is lower when a hydrocolloid is added. The chroma value of samples A and B is lower than the reference for emulsified product and hue is higher compared to the reference. The native casein and the additional hydrocolloid have a synergic effect leading to an unexpected better stabilization of the pigment. Comparative example 1 : Use of emulsifier in emulsified part

An emulsifier was used instead of native casein to stabilize the emulsified part. All recipes were processed following the different steps as described above. Process was stopped when good shade and particle size were reached.

Formulation recipes:

Application test and whey analysis:

The use of citrem instead of casein leads to a high migration of beta-carotene from the curd to the whey. An unexpected very intense whey was observed with an important chroma due to a significant pigment transfer.

Comparative example 2: Use of a hydrocolloid in emulsified part

An hydrocolloid was used instead of native casein to stabilize the emulsified part. All recipes were processed following the different steps above. Process was stopped when expected shade and particle size were reached.

Formulation recipes:

Application test and whey analysis:

Gum arabic instead of native casein did not retain the beta-carotene in the cheese curd and by consequence, highly colored the whey. A very high chroma and low hue were obtained demonstrating an orange shade of the whey due to a significant transfer of pigment.