GB2486702A

GB2486702A - Edible ink for screen printing onto edible substrates

Info

Publication number: GB2486702A
Application number: GB1021813.9A
Authority: GB
Inventors: Susan Margaret Clarke; John Russell; Karl Richard Miller
Original assignee: Culpitt Ltd
Current assignee: Culpitt Ltd
Priority date: 2010-12-23
Filing date: 2010-12-23
Publication date: 2012-06-27
Also published as: GB201021813D0

Abstract

An edible ink base composition suitable for screen printing onto edible substrates such as cakes comprises; 40-90% water, 0.1-20% humectant, 5-10% modified cellulose, 0-8% alcohol, 0-4% glycerine. The humectant may be monopropylene glycol, the alcohol may be ethanol and the glycerine may be vegetable glycerine. In a second embodiment the ink base may comprise fondant icing sugar, water, emulsifier, alcohol and glycerine. An ink composition comprising one of said ink bases and a natural colour is also disclosed, as is an edible decorative article comprising said ink.

Description

NATURAL EDIBLE INK COMPOSITIONS SUITABLE FOR SCREEN

PRINTING

The present invention relates to natural edible ink compositions suitable for screen printing onto edible substrates, ink bases suitable for natural colours, and to decorative edible products containing said inks.

For some time now there has been demand for cakes and confectionaries bearing decorative images. Such images can be representations of Christmas or Easter scenes or representative of other holidays and occasions, or can be representations of media personalities, cartoon brands, sporting badges etc. Bakeries and manufacturers have used a number of techniques to print images onto the sugarpaste icing on cakes or on other confectionaries such as biscuits or chocolate with varying degrees of success.

One printing option that is suitable for relatively large scale manufacturing of printed confectionary and cakes is screen printing. When using a screen printing process, an artwork design is either supplied from a customer or generated internally and is broken down into a reasonable number of colours (usually 4 or 5 colours) to produce a positive image.

Using this positive image, print screens are exposed and then the print screen is cured and washed. A first colour of an edible ink is then deposited onto a screen and then forced through said screen onto a surface of a substrate, typically an icing sheet, to form a part of the image on the surface of the substrate. The icing sheet is then dried and the step is then repeated until the multi-colour image is formed on the surface of the substrate. The images can then be punched out using a fixed cutter to provide the decorative element.

When this process was first used with edible inks, the inks used were based on synthetic colourings which could be developed to have particularly suitable qualities for screen printing e.g. they provide strong, stable colours and only very small amounts of the colour is required in the ink composition. However, there has been a move away from the use of synthetic colouring, particularly in products directed to children, and consumer demand is for natural products which use only natural colourings.

One difficulty with natural colours is that there is currently no legal definition of natural colours in many jurisdictions including the UK and Europe. There is also some confusion between natural colours and nature identical compounds. FSA guidance states that "natural" means essentially that the product is comprised of natural ingredients, e.g. ingredients produced by nature, not the work of man or interfered with by man. It is misleading to use the term to describe foods or ingredients that employ chemicals to change their composition or comprise the products of new technologies, including additives and flavourings that are the product of the chemical industry or extracted by chemical processes. Generally the term can be taken to describe permitted food additives obtained from recognised food sources by appropriate physical processing (including distillation and solvent extraction) or traditional food preparation processes.

Examples of natural colours include; Anthocyanins, E163 Beetroot Red, E162 Carminic acid, E120 Chlorophylls, E140 Cu Chlorophyllin, E141 Carotenoids, E160 and E161 Curcumin, E100 Riboflavin, ElOl Carbon Black, E153 Caramels, E150 Titanium Dioxide, E171 Iron Oxides, E172 There is a colour used by some manufacturers extracted from Spirulina which gives a strong blue colour. This is an example of a currently non-approved natural colour.

Whilst consumer demand is for natural colours, this does result in a number of difficulties when producing edible images on icing sheets or other sugarpaste substrates. In particular, natural colours tend to be fainter, making strong colours difficult to produce and are often sensitive to pH changes (this is especially true of anthocyanins). They also have a reduced shelf life for the finished product. Another significant problem for printing is that the natural colours are usually water soluble so are subject to migration. Significant issues also arise as the carrier composition can affect the natural ink pigment.

It can be seen that it would be beneficial to produce an edible ink composition, or a base for producing the same, which comprises, or is suitable for use with, natural colours.

In this application, all percentages are by weight unless otherwise indicated According to a first aspect of the present invention there is provided an ink base for use for screen printing onto an edible substrate, said ink base comprising; Water -40% -90% Humectant-0.1% -20% Modified Cellulose (E464) -5% -10% Alcohol -0% -8% Glycerine -0% -4% Preferably the humectant is monopropylene glycol (E1520).

Preferably the alcohol is ethanol (E1510).

Preferably the glycerine is vegetable glycerine (E422) According to a second aspect of the present invention there is provided an ink base for use for screen printing onto an edible substrate, said ink base comprising; Fondant icing sugar (sugar 89%, glucose syrup 11 %) -20% -70% Water -10% -30% Emulsifier -3% -7% Alcohol -2% -5% Glycerine -0.3% -5% Preferably the ink base further comprises; Maize starch -20 -25% Preferably the emulsifier is lecithin.

More preferably the emulsifier is soya lecithin (E322).

Alternatively, the emulsifier is sunflower lecithin.

Preferably the alcohol is isopropyl alcohol.

Preferably the glycerine is vegetable glycerine (E422).

The vegetable glycerine acts as a humectant.

The ink base is a combination of materials which together keep the ink liquid enough to be printable, but also control how the ink dries. Solvents must evaporate sufficiently slowly that the ink does not dry in the screen, but once the ink is printed, those solvents must dry sufficiently quickly so that drying time doesn't slow down production. There are other elements that provide body to the ink and help the pigment to adhere to the substrate. The ink base undergoes changes as the ink dries.

According to a third aspect of the present invention there is provided an edible ink for use for screen printing onto an edible substrate, said edible ink comprising; The ink base of the first aspect or the second aspect; and At least one natural colour Generally the natural colour is used at 1% -30%.

Natural colours can be used legally at quantum satis (in sufficient quantities to achieve the desired effect, but no more), in the majority of, but not all, cases this is the amount at which the natural colour is used.

Optionally the natural colour is selected from the list comprising; Anthocyanins, E163 Beetroot Red, E162 Carminic acid, E120 Chiorophylls, E140 Cu Chiorophyllin, E141 Carotenoids, E160 and E161 Curcumin, E100 Riboflavin, ElOl Carbon Black, E153 Caramels, E150 Titanium Dioxide, E171 Iron Oxides, E172 Where the natural colour is Carminic acid it is included at up to SOOppm.

Where the natural colour is a Carotenoid it is included at up to SOOppm.

Where the natural colour is Curcumin it is included at up to SOOppm.

Most preferably the natural colour is selected from the list comprising; Optionally the natural colour is selected from the list comprising; Anthocyanins, E163 -15% Beetroot Red, E162 -30% Carotenes, E160a -4% Curcumin, E100 -9% Riboflavin, ElOl -1% Carbon Black, E153 -4% Preferably, the edible ink has a viscosity, at ambient conditions, of about 2000 to about 50000 centipoise (cp), more preferably about 10000 to about 30000 cp, as measured by a number 2 aperture Zahn cup at 25°C.

Preferably the edible ink is formulated as an aqueous composition.

According to a fourth aspect of the present invention there is provided an edible decorative article comprising a substrate onto which an edible ink design has been applied, said edible ink design being formed from the edible ink of the third aspect.

Preferably the substrate is an edible substrate.

Preferably the edible substrate is a layer of sugarpaste.

In order to provide a better understanding of the present invention, embodiments will now be described by way of example only. These embodiments are indicative of the invention but should not be considered as limiting.

Throughout this document the term screen printing is used to refer to a printing technique that uses a rnh and ink-blocking jjjcH. The stencil and mesh combine to form open areas of mesh that allow the transfer of ink or other printable materials which can be pressed through the mesh as a sharp-edged image onto a substrate. A tQjjffr or squeegee is moved across the screen stencil, forcing or pumping ink past the threads of the An embodiment will now be described wherein an image is applied to a sugarpaste strip using screen printing. This embodiment is particularly useful when printing on glazed surfaces, for example on icing/sugarpaste which has a shellac glaze on its surface. The first step is the image or artwork that is to be applied to the sugarpaste is generated with a limited number of colours appropriate for the screen printing process and a positive is produced. Print screens are exposed from the positives and the print screens are cured and washed. The mesh size can be varied depending on the images required but generally are between 60 and 140 threads per inch (e.g. 60, 80, 110, 130 or 140 threads per inch).

The screen is then set up on an automated printing machine such as a Mascoprint® machine such that a squeegee can be used to effectively push the ink through the mesh. The squeegee carries out two main functions. It deflects the stencil and brings it into contact with the substrate. During the printing action the squeegee is moved across the stencil, creating a pressure wave in the ink.

Prior to printing an optional glaze step can be included. This glaze is commonly a shellac resin (E904) glaze where shellac has been dissolved in a solvent e.g. an alcohol.

The edible ink is prepared using an ink base and one or more natural colours. The edible ink is prepared such that it has a viscosity and a density sufficient to keep the ink liquid enough to be printable but thick enough that it doesn't just run through the mesh without the application of the squeegee.

In this embodiment the ink base comprises deionised water (40% -90%) which acts as a solvent; monopropylene glycol (0.1% -20%) which acts as a humectants; modified Cellulose (E464) (5% -10%) which acts as both a thickener and emulsifier; ethanol (0% -8%) which acts as both a solvent but also a wetting agent which evaporates and helps the ink to dry quickly once applied to the icing strip; and vegetable glycerine (0% -4%) which acts as a humectant. Although the ink base is suitable for use with synthetic colours it allows natural colour components in greater proportions than would be used with synthetic colours.

To provide an appropriate coloured image, the edible natural ink is included in a sufficient concentration to provide the required pigment density. This can require a significant amount of natural pigment (1%- 30% for example) c.f. synthetic colours where much less pigment is required.

The modified cellulose enhances viscosity, acts as a pigment carrier and additionally enhances the release properties of the ink.

Suitable alternative humectants include, for example, glycerine, sorbitol and mannitol however the amount must be carefully controlled.

SPECIFIC EXAMPLES

Example I

Cellulose Membrane base

_________ _______________ ______ ______ ______ _______

RM Num: Generic Supplier: E No: Qty: Percent: _________ Name: ______ _____ ______ _______ DIWATER Deionised Culpitt Ltd 20.0000 89.93% ________ Water _____ _____ KG_____ ______ 31103 Modified Food Ing E464 2.1600 9.71% _________ Cellulose Tech _____ KG______ ______ 31104 Monopropylene Thew 80.0000 0.36% _________ Glycol (MPG) Arnott _____ G ________________ Mix Instructions: Store membrane in lidded container in cool place for 7 days maximum.

Dispose of any out of date product.

1. Weigh out 10 kg of water into 2 x 5 kg bowls. Heat each bowl for approx minutes in microwave until temp reaches 75 deg C. 2. Add the hot water to a large container and add the methocel. Disperse for 2 minutes using hand-blender until homogenous solution is formed.

3. Add the remaining water cold, and the MPG. Mix using hand-blender for mm or until solution becomes clear.

4. Mark container with batch details and use by date: standard shelf life is days 5. Store overnight in a cool place before use to ensure hydration -if possible store in chiller.

Example 2

Cellulose membrane base CELL-Ui RM Num: Generic Supplier: E No: Qty: Percent: _________ Name: ______ _____ __________ _______ DIWATER Deionised Culpitt 5.9300 KG 59.30% _________ Water Ltd ______ _____ __________ _______ M0007 Monopropylene Brenntag E1520 2.0000 KG 20.00% Glycol (MPG) UK _________ _______________ Limited _____ ___________ _______ 31103 Modified Food Ing E464 870.0000G 8.70% _________ Cellulose Tech _____ __________ _______ M0019 Ethanol Albion E1510 800.0000 8.00%

________ ____________ _____ ____ G ______

31188 Vegetable Thew E422 400.0000 4.00% _________ Glycerine Arnott _____ G _______ Mix Instructions: 1. Mix glycerine and MPG by pouring one into the other.

2. Add HPMC to above mix and stir gently.

3. Add alcohol to water and pour together into the above mix while stirring rapidly by hand.

4. Place container under the mixer (ensuring it is free from colours) and mix for 5 mm at 1800 rpm.

5. Place lid on container and store overnight before use to allow air bubbles to disperse.

6. Label container CELLOI, with batch number and BBE -normally 7 days.

Example 3

Yellow Process Ink -using the Cellulose base CELL-UI (as described in

example 2).

RM Num: Generic Supplier: E No: Qty: Percent: Name: CELL-UI Cellulose Sugarfayre 750.0000 91.24% Base Mix C

CELL-UI

39363 Curcumin Sensient EI00 72.0000 8.76%

C

The prepared ink is then deposited onto the screen and a flood coater spreads ink across the screen. A squeegee then forces ink through the screen onto the sugarpaste strip.

The sheet is then dried and the processes repeated for another colour until the complete image is formed.

Following printing the sugarpaste strips are allowed to dry and the printed images are punched out using a fixed cutter. The excess paste is then stripped away.

The image layer should preferably become substantially dry to the touch in about 45 minutes in air, under suitable transfer and drying conditions.

Suitable transfer and drying conditions for the image layer are about 25% to 50% relative humidity.

In an alternative embodiment, that is a particularly useful base for natural colours and allows for natural colours which appear particularly vivid substantially the same process is followed, however an alternative ink base is used which comprises; fondant icing sugar (sugar 89%, glucose syrup 11 %)(20% -70%) which is a thickener and base for the pigments/natural colour; deionised water (10% -30%)which acts as a solvent; soya lecithin (or sunflower lecithin) (3% -7%) which acts as an emulsifier and a slight humectant; isopropyl alcohol (2% -5%) which acts as a solvent/wetting agent; vegetable glycerine (0.3% -5%) which acts as a humectants; and maize starch (20% -25%) acts as a thickener and also helps the ink to dry.

SPECIFIC EXAMPLES

Example 4

Magenta Ink -using fondant base RM Num: Generic Supplier: E No: Qty: Percent: Name: 31040 Fondant Napier 1.0000 51.12% Icing Sugar Brown KG 39326 Beetroot Overseal E162 600.0000 30.67% Red Liquid G DIWATER Deionised Culpitt Ltd 200.0000 10.22% Water G 31185 Topcithin Thew E322 100.0000 5.11% (LeciTAs Arnott G 4980) 31118 Isopropyl Albion 50.0000 2.56% Alcohol C 31188 Vegetable Thew E422 6.0000 C 0.31% Glycerine Arnott Mix Instructions: Use only Coloured Water CW-MAG-12 if required.

1. Weigh the beetroot juice concentrate into a bowl.

2. Add water and glycerine and STIR well.

3. Add fondant icing sugar and BLEND well for 5 minutes.

4. Add IPA and lecithin.

5. BLEND all together for 5 minutes -make sure all ingredients are blended well.

Example 5

Cyan Ink -using fondant base RM Num: Generic Supplier: E No: Qty: Percent: Name: DI WATER Deionised Culpitt Ltd 325.0000 28.76% Water C 31130 Maize Thew 250.0000 22.12% Starch Arnott C 31040 Fondant Napier 250.0000 22.12% Icing Sugar Brown C 39362 Anthocyanin Culpitt Ltd E163 175.0000 15.49% Powder C 31185 Topcithin Thew E322 80.0000 7.08% (LeciTAs Arnott C 4980) 31188 Vegetable Thew E422 50.0000 4.42% Glycerine Arnott G Mix Instructions: Use only Coloured Water CW-CYN-15 if required.

1. Weigh Deionised Water into a bowl.

2. Add Anthocyanins and stir in.

3. Add Vegetable Glycerine and stir in.

4. Add Fondant Icing Sugar and stir in.

5. Add Maize Starch and stir in.

6. Blend with hand blender for 5 minutes.

7. Add Lecithin and stir in.

8. Blend with hand blender for 5 minutes.

It can be seen that there is a significant advantage to providing edible inks free from synthetic pigments or colourings but which are suitable for screen printing and have a commercially acceptable shelf life. The above examples indicate how this can be done using specific ink bases to carry the natural colours, however one skilled in the art will appreciate that alternative natural colours could also be used and that the quantities of the ink base constituents would be altered to suit the natural colour of interest.