GB2398721A

GB2398721A - The use of polyphosphate in beverages to provide colour stability

Info

Publication number: GB2398721A
Application number: GB0401679A
Authority: GB
Inventors: Craig Beardmore
Original assignee: Britvic Soft Drinks Ltd
Current assignee: Britvic Soft Drinks Ltd
Priority date: 2003-01-31
Filing date: 2004-01-27
Publication date: 2004-09-01
Also published as: GB0401679D0

Abstract

A beverage comprises a colour agent and sufficient polyphosphate to provide improved colour stability over time. The polyphosphate may be a sodium, potassium or calcium polyphosphate, in particular sodium hexametaphosphate. The polyphosphate may be present at up to 3000 mg/l. The beverage may comprise fruit juice, preferably between 0.1 and 50%. The colour agent may be a natural colour agent derived from a plant or fruit, such as anthocyanin, b -carotene or betaine.

Description

239872 1

IMPROVEMENTS IN OR RELATING TO BEVERAGES

This invention relates to beverages which have improved colour stability over time and to a method of making such beverages. It is especially, but not exclusively, related to carbonated and uncarbonated soft drinks containing fruit juice.

Controlling colour stability in beverages, especially fruit juice drinks, has long been of concern to beverage manufacturers and retailers. A natural, or nature identical, colour agent, chosen on the basis of the colour to be achieved, usually imparts the colour in the beverage. For example, a derivative of black carrot or grapeskin may be used to impart colour, in particular, anthocyanines derived from black carrot or grapeskin can be used to impart a red colour to a beverage. Other suitable natural colour agents include,B-carotene and betaine. The colour agents may be provided in the fruit juice itself or added as a supplement.

Colour agents, including anthocyanines, p-carotene and betaine, are known to be unstable in many beverages, and in particular in the acidic conditions of a fruit juice beverage. In such conditions poor colour stability is observed, that is, the intensity of colour fades and browning can occur over time. This is unappetizing to the consumer.

It is believed that the loss of colour and browning arises in fruit juice containing beverages due to the action of sugars and acids on the colour agent, and is discussed in detail in The Biochemistry of Fruits and their Products, Vol. 2, edited by A C Hulme, Academic Press London and New York.

In some beverages marked browning and loss of colour can be observed within weeks, and for many product browning is visible to the naked eye within 3 months of production. This process does not appear to be temperature driven and typically the packaging used is opaque so that the effect of light exposure is minimal.

By controlling the stability of the colour in the beverage over time the shelf life of the beverage can be improved.

The present invention provides a beverage comprising a colour agent, water and an amount of polyphosphate sufficient to provide improved colour stability over time in the beverage.

Sufficient polyphosphate may be enough polyphosphate to observe a detectable improvement in colour stability over time when compared to a beverage without polyphosphate. This improvement may be detected by observing a AE of between 0.5 and 6 or more in a beverage over a period of one week to six months or more. Preferably the AE is 1 or more, more preferably the AE is 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more. Preferably the time period is one month, and more preferably 3 months.

AE is a measure of the difference in total colour observed between a beverage without polyphosphate and a beverage with polyphosphate.

Alternatively, sufficient polyphosphate may be enough polyphosphate to observe a change in 'L', 'a' or 'b' over time. Where 'L' is a measure of lightness (greyscale), 'a' is a measure of red to green colour, and 'b' is measure of blue to yellow colour. 'L', 'a' or 'b' are well known parameters to the man skilled in the art.

As a fruit juice beverage begins to 'brown' over time it may become more red and more blue in colour, as calculated on the Lab scale.

Preferably a AL of at least 0.5 to 4, or more, is observed in a beverage over a period of one week to six months or more. More preferably a AL of 0.5 to 3.5, and more preferably still of 1 to 3.5 or more, or about 1, about 2, or about 3, is observed. Preferably the time period is one month, and more preferably 3 months.

Preferably a Aa of at least, or in the order of, -0.3, or in a range defined between -0.3 and 2.0, or more, is observed in a beverage over a period of one week to six months, more preferably one month, and more preferably 3 months.

Preferably a Ab of at least, or in the order of, -3.0, or in a range defined between -3.0 and 3.0, more preferably in a range defined between 2.0 and 1.0, or more, is observed in a beverage over a period of one week to six months, more preferably one month, and more preferably 3 months.

Preferably the beverage comprises 0.1 to 50 to or more fruit juice. More preferably the beverage comprises from 7 to 15 % fruit juice, and more preferably about 105to fruit juice.

Preferably the polyphosphate is a sodium, potassium or calcium polyphosphate, most preferably sodium polyphosphate.

Preferably the sodium polyphosphate is sodium hexametaphosphate. r

The polyphosphate preferably has the formula

O

M- -P -M

O

in which n is preferably between 2 and 100, and M is a metal.

Preferably M is potassium, sodium or calcium.

Preferably the n value is between 10 and 30, more preferably about 25.

Preferably the beverage comprises up to 3000mg/1 (3000ppm) polyphosphate, Preferably, polyphosphate is in the range defined between lOOmg/1 (lOOppm) and 1500mg/1 (1500ppm). More preferably the beverage comprises polyphosphate at between 300mg/1 (300ppm) to 700mg/1 (700ppm). Preferably the beverage comprises polyphosphate at 500mg/1 (500ppm), more preferably the beverage comprises polyphosphate at 700mg/1 (700ppm).

The beverage may comprise a mix of polyphosphates comprising polymers of different lengths. The mix may comprise polyphosphate with an average chain length of n, and polyphosphate of an average chain length n2 Preferably, the mix comprises at least 10%, or more, of polyphosphate of each chain length n, and at least 10%, or more of polyphosphate of chain length n2. More preferably, the mix comprises about 20 to 30% of polyphosphate of chain length n, and about 70 to 80% of polyphosphate of chain length n2.

Preferably the chain length of n, is above 3, more preferably the chain length of n, 15 to 30.

Preferably, the chain length of n, is at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 11 more than the chain length of n2.

Preferably the chain length of n2 is 2. The chain length of n2 may be 1.

This mix may include up to 3000mg/ml of polyphosphate with an n value of at least 3, and a sufficient amount of polyphosphate with a n value of 2 to provide improved colour stability over time in the beverage. Wherein sufficient to provide improved colour stability over time' is as described above.

More preferably the beverage comprises polyphosphate, with an n of above 3 at between lOOmg/1 and 1000mg/1 or more, more preferably still the polyphosphate is provided at 100mg/1 to 280mg/1.

The effect of the polyphosphate on colour stability over time may be dose dependent: that is, the more polyphosphate added the greater the observed improvement in colour stability over time.

The effect of the polyphosphate in improving colour stability over time may be more marked in a beverage with added sugar.

Preferably by modifying the amount of polyphosphate added the colour stability can be controlled, it may be that the amount of polyphosphate needed will be determined by the sugar content of the beverage.

The colour agent in the beverage may be part of the fruit juice or may be a separate component.

Preferably the beverage comprises a colour agent which is a natural, or a nature identical, derivative of a plant or fruit. More preferably the colour agent is an anthocyanin, 3-carotene or betaine.

Preferably the beverage comprises water which has a hardness of 0.5 to 300ppm, more preferably the water has a hardness of 1 to 150ppm. The water may have a hardness of 1.7ppm, alternatively the water may have a hardness of 150ppm.

Preferably the beverage is acidic and may have a pH in the range 2 to 5, more preferably in the range 3 to 4.

The beverage may be ready to drink (i.e. does not need diluting).

Alternatively, the beverage may be a concentrate, which must be diluted before being drunk.

Preferably the beverage is a soft beverage.

The beverage may contain added sugar, or may be a no, or a low, added sugar beverage. There may be an artificial sweetener (that is not sugar).

The beverage may be still (uncarbonated) or carbonated. Preferably the beverage is carbonated by the addition of carbon dioxide under pressure to provide a carbonation level of up to 3 volumes with carbonation of 1.8 to 2.6 volumes preferred.

The beverage may contain milk. Preferably the milk content is in the range 2-6% wtw with a milk content of around 4% w/w being especially preferred. The milk may be skimmed milk.

The beverage may include other ingredients in an amount required for the purpose such as an acidity regulator(s), antioxidant(s), flavouring(s), preservative(s), thickening agent(s), stabiliser(s). Such ingredients are well known in the art and their use will be understood by those skilled in the art.

Preferably, the inclusion of polyphosphate in a beverage provides colour stability by preventing the degradation of the colour agent According to second aspect of the invention there is provided a process for preparing a beverage with improved colour stability over time, which process comprises admixing a colour agent, water and an amount of polyphosphate sufficient to provide colour stability over time in the beverage.

According to a further aspect of the invention there is provided a use of a polyphosphate in a beverage comprising a colour agent and water to provide improved colour stability over time.

According to a yet further aspect of the invention there is provided a use of polyphosphate for the production of a beverage in order to provide improved colour stability over time.

It will be appreciated that the optional features discussed in relation to the first aspect of the invention apply to all other aspects of the invention.

The present invention will now be further described with reference to the following Examples 1 to 6 and Figures/Graphs 1 to 4: In all the Examples the intensity of colour in a beverage was analysed using a Hunterlab colorflex calorimeter (available from Kirstol Instruments) set to the 'L', 'a','b' (Lab) scale (10 /D65) which is well known to those skilled in the art, and discussed in The Measurement of Appearance by Richard S Hunter, published 1975 by J Wiley and Sons.

More specifically, 'L' is a measure of lightness (greyscale), 'a' is a measure of red to green colour, and 'b' is measure of blue to yellow colour, all are well known parameters to the man skilled in the art.

AE is a measure of the difference in total colour observed between a beverage without polyphosphate and a beverage with polyphosphate, and is the sum of the squares of L, a and b.

A AE value of 1 or greater indicates a colour change which is detectable to the naked eye.

In the Examples provided the data is based on the total change in delta values for samples with polyphosphate when compared to the control sample with no added polyphosphate. Five series of samples were assessed for each variant, and the results were then compared.

In the Examples the 'description' is the visual appearance of the samples, viewed with the naked eye, in comparison to the control.

The following examples use strawberry, peach & orange, blackcurrant & apple beverages. The colour agent added to these beverages is either anthocyanin derived from grapeskins or hibiscus; or betaine derived from beetroot. In particular, the strawberry beverage comprises anthocyanines derived from hibiscus and black carrot and betaine derived from beetroot.

In the black currant and apple beverage the colour agent is anthocyanin derived from grapeskin. In the orange and peach beverage the colour agent is an anthocyanin. Some of the beverages tested have added sugar and some have no added sugar. For the purposes of the Examples the beverages were assessed separately at three month and five month intervals.

In each case, a freshly made beverage sample was subjected to a specified amount of sodium hexametaphosphate with an average chain length of 25 (where one unit chain length is one phosphate) - Omg/1, 300mg/1, 500mg/1 or 700mg/1, and stored at room temperature for three months and five months, under the same conditions of light and temperature, at the end of three and five months the colour levels (L, a and b) and the AE for each sample was determined and compared.

All the Examples use a beverage of Formulation 1, with or without added sugar and with varying amounts of added polyphosphate.

It is believed that similar results will be obtained for beverages of Formulations 2 to 6, also detailed below.

Formulation 1 A beverage comprising: about 10% fruit (made of a single fruit or two fruits, say 5% of one and 5% of the other); 300mg/litre (300ppm) potassium sorbate; 9-14 Bx sugar in an added sugar variant, and 1.4 - 1.6 Bx in a no-added, or low added, sugar variant with a blend of 0.013% w/v acesulfame K and in the region of 0.02% w/v aspartame; 0.06% xanthan gum; 200-300mg/litre (200-300ppm) each of citric acid and/or trisodium citrate and/or ascorbic acid; 80%-90% water, preferably processed water with a hardness of 1.7ppm.

Balance to include a colour, such as an anthocyanin or betaine; various flavours depending on the fruit used; and vitamins B. C and D; Formulation 2 A beverage comprising: about 10% fruit (made of a single fruit or two fruits, say 5% of one and 5% of the other); 300mg/litre (300ppm) potassium sorbate; 0.0012% oil-in-water emulsion; 9-14 Bx sugar in an added sugar variant, and 1.4 - 1.6 Bx in a no-added, or low added, sugar variant with a blend of 0.013% w/v acesulfame K and in the region of 0.02% w/v aspartame; 200-300mg/litre (200-300ppm) each of citric acid and/or trisodium citrate and/or ascorbic acid; about 0.5% weight per volume barley starch; 80%-90% water, preferably spring water with a hardness of 150ppm.

Balance to include a colour, such anthocyanin or betaine; and various flavours depending on the fruit used.

The pH in the final drink is about 3.5.

Formulation 3 A beverage comprising: 86.04% w/w water; 5.03% w/w apple (11.1 Bx) (Juice); 4.06% w/w skimmed milk; 2.55,0 w/w strawberry (6.8 Bx) (juice); 0.37% w/w stabiliser (total) - pectin; 0.23% w/w citric acid anhydrous E330; and 0.12% w/w calcium chloride E509; Balance to include: acidity regulator; flavouring; preservative; artificial sweeteners, antioxidant; and colour.

The beverage having a final pH of 3 to 4.

Formulation 4 A beverage comprising: 85.94% w/w water; 5.02% w/w apple (11.1 Bx) (juice); 4.05% w/w skimmed milk; 2.32% w/w orange (6.8 Bx) (juice); 0.37% w/w stabiliser (total) - pectin; 0.19% w/w citric acid anhydrous E330; and 0.12% w/w calcium chloride E509.

Balance to include: acidity regulator; flavouring; preservative; artificial sweeteners, antioxidant; and colour.

The beverage having a final pH of 3 to 4.

Formulation 5 about 15% fruit (juice); 300mg/litre (300ppm) potassium sorbate; 9-14 Bx of sugar in an added sugar variant, and 1.4 - 1.6 Bx of Sugar in a no-added, or low added, sugar variant with a blend of 0.013% w/v acesulfame K and in the region of 0.02% w/v aspartame; 0.06% xanthan gum; 200-300mg/litre (200-300ppm) each of citric acid and/or trisodium citrate and/or ascorbic acid; 80-90% water, preferably water with a hardness of 0.1 to 150ppm.

Balance to include a colour, such as an anthocyanin or betaine; various flavours depending on the fruit used; and vitamins B. C and D; Formulation 6 about 14% fruit (juice); 300mg/litre (300ppm) potassium sorbate; 9-14 Bx of sugar in an added sugar variant, and 1.4 - 1.6 Bx of Sugar in a no-added, or low added, sugar variant with a blend of 0.013% w/v acesulfame K and in the region of 0.02% w/v aspartame; about 0.5% weight per volume barley starch; 200-300mg/litre (200-300ppm) each of citric acid and/or trisodium citrate and/or ascorbic acid; 80%-90% water, preferably water with a hardness of 0.1 to 150ppm.

Balance to include a colour, such as an anthocyanin or betaine; various flavours depending on the fruit used; and vitamins B. C and D; Example 1 Strawberry Beverage with no added sugar Data after 3 months:

Polyp h osp hate Description L a b AL Aa Ab AE

O /le(d ontrol) 44.48 9.12 23.84 = = = 700mg/l Lighter, 45.58 8.74 23.55 1.10 -0.38 -0.29 1.21 less red, less yellow 500mg/l Lighter, 45.86 8.50 23.54 1.38 -0.62 -0.3 1.55 less red, less yellow 300mg/l Lighter, 44.96 9.11 23.65 0.56 -0.01 -0.19 0.76 less red, less yellow The table shows that a significant difference in colour, AK, was observed between the control beverage (with no polyphosphate) and those with polyphosphate. This difference is most marked in beverage samples comprising levels of 500mg/l and 700mg/l polyphosphate. In all samples containing polyphosphate the visual description demonstrates that beverages with polyphosphate are less brown and lighter in colour than the control.

Data after 5 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/1 (control) 47.66 6.59 22.89 700mg/1 Lighter, 49.93 5.97 22.94 2.27 0.62 -0.05 2.35 less red, less yellow 500mg/1 Lighter, 49.05 6.57 23.58 1.39 0.69 1.57 less red, 0.02 less yellow 300mg/1 As light, 47.90 7.27 23.90 0.24 0.68 1.01 1.29 redder, yellower After 5 months the samples with polyphosphate still show a significant difference in colour when compared to the control beverage (with no polyphosphate). Again the most marked difference was seen in samples comprising 500mg/1 and 700mg/1 of polyphosphate. However, even at 300mg/1 this difference is visible to the naked eye. The samples with polyphosphate were still observed to be less brown and brighter than the control.

Graph 1 is a spectral plot (optical density) and Graph 2 is a 3D spectral plot (reflectance) of all 4 samples of Strawberry Beverage with no added sugar after 3 months. The wavelength in the visible range is plotted against L (the greyscale). These results show that the effect of polyphosphate on beverage colour occurs across the visible spectrum.

Example 2 - Strawberry Beverage with added sugar Data after 3 months:

Polyphosphate Description L A B AL Aa Ab AE added

Og/1 (control) 49.42 7.15 21.18 700mg/1 Lighter, 51.50 5.91 19.91 2.08 -1.16 -1.27 2.73 Less red, Less yellow 500mg/1 Darker,redder, 49.31 7.71 21.00 -0.11 0.56 -0.18 0.65 less yellow 300mg/1 Darker,redder, 49.17 7.65 21.21 -0.25 -0.50 0.03 0.59 less yellow The beverage with 700mg/1 of polyphosphate shows the most marked improvement in colour stability when compared to the control beverage.

The samples comprising 500mg/1 polyphosphate show a smaller difference in colour when compared to the control. Those comprising 300mg/1 polyphosphate show a slightly greater decrease in colour stability. This would seem to indicate that the stabilising effect of the polyphosphate in a strawberry based beverage with added sugar is dose dependent and requires a higher dosage than the no added sugar beverage of Example 1.

Data after 5 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/l(control) 50.52 5.13 21.75 700mg/1 Lighter, 51.67 4.88 21.38 1.15 -0.25 -0.37 1.30 less red, less yellow 500mg/1 As light, 50.67 5.81 21.99 0.15 0.68 0.24 0.83 redder, Blue 300mg/1 lighter, 51.68 5.28 21.31 1.16 -0.15 -0.44 1.29 less red, less yellow After 5 months the samples with polyphosphate still show a difference in colour between the control beverage (with no polyphosphate), Graph 3 is a spectral plot (optical density) and Graph 4 is a 3D spectral plot (reflectance) of all 4 samples of Strawberry Beverage with added sugar at 3 months. Again, the wavelength in the visible range is plotted against L (the greyscale), and the results show that the effect of polyphosphate on beverage colour occurs across the visible spectrum. l

Example 3 - Orange & Peach Beverage with no added sugar Data after 3 months:

Polyphosphate Description L a b AL Aa Ab AE added

Og/1 (control) 49.60 3.40 24.23 700mg/1 Lighter, 52.62 1.96 22.50 3.02 -1.44 - 1.73 2.60 less red, Less yellow 500mg/1 Lighter, 50.84 2.88 24.02 1.24 -0.52 -0.21 1.17 less red, Less yellow 300mg/1 Darker, 48.89 4.36 24.54 0.71 0.96 0.21 0.85 redder, yellower The results for this set of samples showed a clear increase in stability with increased dosage of polyphosphate. Beverage dosed at 300mg/1 showed a slight darkening, but those dosed at 500mg/1 showed a noticeable improvement in colour stability. The colour stability was more noticeable for those dosed at 700mg/1 with samples showing a decrease in browning compared to the standard.

Data after 5 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/1 (control) 51.02 4.70 23.63 _ 700mg/1 Lighter, 51.59 2.59 23.80 0.57 -2.11 0.17 3.61 less red, less yellow 500mg/1 Lighter, 50.10 4.54 25.08 -0.92 -0.16 1.45 0.72 less red, less yellow 300mg/1 Darker, 48.45 5.25 25.43 -2.57 0.55 1.80 0.70 redder, yellower Again, an increase in stability compared to the control was seen with increased dose of polyphosphate. Those dosed at 300mg/1 show a noticeable darkening, those dosed with 500mg/1 show an improvement in colour stability with only slight darkening. The stability is more noticeable in samples does with 700mg/1 which show a decrease in browning compared to the control.

Example 4 - Orange & Peach Beverage with added sugar Data after 3 months:

Polyphosphate Description L a B AL Aa Ab AE

added _ 0g/1 (control) 53.32 0.55 20.85 =_ 700mg/l Lighter, 55.82 -0.28 18.91 2.50 0.83 - 1.94 4.04 less red, less yellow 500mg/l Lighter, 55.44 -0.20 20.07 2.12 0.75 -0.78 2.94 less red, less yellow 300mg/1 Lighter, 54.43 0.31 21.39 1.11 0.54 1.28 less red, 0.24 less yellow All of the samples tested showed an improvement in stability compared to the control (with no polyphosphate). For this beverage the effect was also dose dependent, with those samples dosed at 500mg/l and 700mg/l polyphosphate showing the greatest stability in colour over time. These samples did not show as strong a browning effect as those dosed at 300mg/l, and seemed overall to be more stable than the no added sugar Orange & Peach samples.

Data after 5 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/1 (control) 54.02 0.43 21.72 700 mg/1 Lighter, 55.29 -0.04 20.04 1.27 -0.47 -0.68 3.82 less red, less yellow 500 mg/1 Lighter, 54.89 0.09 21.19 0.87 -0.34 -0.53 2.34 less red, less yellow 300mg/1 darker, 53.77 0.72 22.44 -0.25 0.29 0.82 1.65 redder, yellower Again, all the samples tested showed an improvement in stability compared to the control. For this group the effect was also dose dependent with those samples dosed at 500mg/1 and 700mg/l polyphosphate showing the greatest stability in colour over time. l

Example 5 - Blackcurrant & Apple Beverage with no added su.gar Data after 3 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/1 (control) 32.22 18.89 16.59 700mg/1 Darker, 31.63 18.00 17.97 -O.59 -O.89 1.38 1.75 less red, yellower 500mg/1 Darker, 31.36 18.09 17.72 -0.84 -0.80 1.13 1.79 less red, yellower 300mg/1 Darker, 32.18 17.87 17.87 -O.04 -1.03 1.28 1.64 less red, yellower All samples show an improvement in colour stability over the control.

The effect was again dose dependent.

Data after 5 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/1 (control) 33.53 16.84 18.01 = 700mg/1 Darker, 31.57 17.50 18.64 -1.96 0.66 0.63 2.23 less red, yellower 500mg/1 Darker, 31.67 17.48 18.72 -1.86 0.64 0.71 2.11 redder, yellower 300mg/1 Darker, 32.56 16.87 18.89 -0.97 0.03 0.88 1.32 less red, yellower Again all samples show an improvement in colour stability over time, and this effect again appears to be dose dependent.

Example 6 - Blackcurrant & Apple Beverage with added sugar Data after 3 months:

Polyphosphate Description L A B AL Aa Ab AE added

Og/1 (control) 32.32 20.52 16.64 700mg/1 Lighter, 33.50 19.61 16.71 1.18 -0.91 0.07 1.97 less red, less yellow 500mg/1 Lighter, 32.86 20.41 16.47 0.54 -0.11 1.44 less red, 0.17 less yellow 300mg/1 Lighter, 33.04 19.74 17.18 0.62 -0.78 0.48 1.03 less red, yellower These results are consistent with those for the other variants. The improvement in stability was greatest in those samples dosed at 700mg/1.

Data after 5 months:

Polyphosphate Description L a b AL Aa Ab AE added

Omg/1 (contol) 33.35 18.48 17.70 700mg/1 Lighter, 34.49 17.74 18.38 1.14 -0.74 0.68 1.97 less red, less yellow 500mg/1 Lighter, 33.97 18.45 18.17 0.62 -0.03 0.47 1.04 less red, less yellow 300mg/1 Lighter, 33.14 18.10 18.60 -0.21 -0.38 1.44 less red, 0.90 yellower Again, the results were consistent with those for the other variants. The improvement in stability was greatest in those samples dosed at 700mg/1.

Overall, the results demonstrate that polyphosphate provides improved colour stability in fruit juice containing beverages. It appears that the improvement in stability seen in the samples tested was greatest where the amount of polyphosphate added was greatest. The examples also appear to display a dose dependent effect, that is, the more polyphosphate added the more marked the improvement in colour stability over time.

It is thought that the effect of the polyphosphate in the beverage may be to bind to sugar and to thereby reduce condensation of the colour agents and it is this condensation which may cause the browning. Typically, the colour agents are polyphenols which on condensation produce tannins which discolour the beverage. r

This reaction may explain the difference seen between beverages with and without added sugar. Typically, the effect with added sugar is more pronounced than in beverages without added sugar.

In some embodiments the addition of other colour stabilisers or other compounds to enhance the polyphosphates colour stabilising properties are not used. More particularly, flavanols or antioxidants are not included in the formulation. Alternatively ascorbic acid or ethylenediaminetetraacetic acid are not included in the formulation.

Preferably the formulation does not include a tannin.

Claims

1. A beverage comprising a colour agent, water and an amount of polyphosphate sufficient to provide improved colour stability over time in the beverage.

2. A beverage as claimed in Claim 1 comprising 0.1 to 50% or more fruit juice.

3. A beverage as claimed in Claim 2 comprising 7 to 15o fruit juice.

4. A beverage as claimed in any of the preceding claims wherein the polyphosphate has the formula: OR 1

M- -P -M )

in which n is between 2 and 100, and M is a metal.

5. A beverage as claimed in any of the preceding claims wherein the polyphosphate is a sodium, potassium or calcium polyphosphate.

6. A beverage as claimed in Claim 5 wherein the polyphosphate is a sodium hexametaphosphate.

7. A beverage as claimed in Claim 4, 5 or 6 wherein the polyphosphate has an n value of 10 to 30.

8. A beverage as claimed in any of the preceding claims comprising up to 3000mg/1 of polyphosphate.

9. A beverage as claimed in Claim 8 comprising polyphosphate in the range defined between lOOmg/1 and 1500mg/1.

10. A beverage as claimed in Claim 8 or Claim 9 comprising polyphosphate at between 300mg/1 to 700mg/1.

11. A beverage as claimed in any of the preceding claims comprising a mix of polyphosphates comprising polymers of different lengths.

12. A beverage as claimed in Claim 11 wherein the mix of polyphosphates comprises a first polyphosphate with an average chain length of n, and a second polyphosphate of an average chain length n2

13. A beverage as claimed in Claim 12 wherein the mix comprises at least 10'7o, or more, of polyphosphate of each chain length n, and at least logo or more of polyphosphate of chain length n2.

14. A beverage as claimed in Claim 13 wherein the mix comprises about 20 to 30% of polyphosphate of chain length n' and about 70 to 80o of polyphosphate of chain length nz.

15. A beverage as claimed in any of Claims 12 to 14 wherein the chain length of n, is above 3.

16. A beverage as claimed in any of Claims 12 to 15 wherein the chain length of n, is at least 4, at least 5, at least 6 at least 7, at least 8, at least 9 at least 10, at least 11 more than the chain length of n2.

17. A beverage as claimed in any of Claims 12 to 15 wherein the chain length of n2 is 2.

18. A beverage as claimed in any of Claims 12 to 17 comprising between 100mg/l and 1000mg/l or more of a polyphosphate with chain length n,.

19. A beverage as claimed in Claim 18 comprising 100 to 280mg/1 of polyphosphate with chain length nl.

20. A beverage as claimed in any of the preceding claims wherein the effect of the polyphosphate on colour stability over time is dose dependent.

21. A beverage as claimed in any preceding claim with a natural colour agent derived from a plant or fruit.

22. A beverage as claimed in any of the preceding claims wherein the colour agent is an anthocyanin, p-carotene or betaine.

23. A beverage as claimed in any of Claim 1 to 20 and 22 wherein the colour agent is nature identical to a derivative from a plant or fruit.

24. A beverage as claimed in any of the preceding claims wherein the water has a hardness of 0.5 to 300ppm.

25. A beverage as claimed in Claim 24 wherein the water has a hardness of 1 to 150ppm.

26. A beverage as claimed in any of the preceding claims with a pH in the range 2 to 5.

27. A beverage as claimed in any of the preceding claims which is ready to drink.

28. A beverage as claimed in any of Claims 1 to 26 in which the beverage is a concentrate.

29. A beverage as claimed in any of the preceding claims which is still.

30. A beverage as claimed in any of Claims 1 to 28 which is carbonated.

31. A beverage as claimed in any of the preceding claims which comprises milk in the range 2-6% w/w.

32. A beverage as claimed in any preceding claim which includes one or more of the ingredients, in an amount required for the purpose, selected from the list comprising an acidity regulator(s); antioxidant(s); flavouring(s); preservative(s); thickening agent(s); and stabiliser(s).

33. A process for preparing a beverage with improved colour stability over time, which process comprises admixing a colour agent, water and an amount of polyphosphate sufficient to provide improved colour stability over time in the beverage.

34. A use of a polyphosphate in a beverage comprising a colour agent and water to provide improved colour stability over time.

35. A use of polyphosphate for the production of a beverage in order to provides improved colour stability over time.