NZ226287A - Carbonating non-fermented milk - Google Patents

Description

22 6 287 Priority Deters}:.

Co-mr^fp Specification Flisjd: "X I ' 3.-.S& C ass: (5)...A.^t AQ.&U./aUr.^ Jub5lcatk>n Date: ........2.8.. v-'.O. Joysv?a?,^«K Patents form No 5 PATENTS ACT 1953 COMPLETE SPECIFICATION Number Dated CARBONATED MILK l/W£ MICHAEL ALOYSIUS TRACEY of 54 Rice Street, Port Sorell, Tasmania 7307, Australia, an Australian citizen do hereby declare the invention for which l/we pray that a Patent may be granted to meias, and the method by which it is to be performed, to be particularly described in and by the following statement: 1 226287 The present invention generally relates to food substances, and in particular to beverages. More particularly, the present invention relates to milk drinks which have been carbonated or aerated. Preferred embodiments of the present invention include an ultra 10 heat treated sparkling skim milk drink including combinations of all milk and all flavours of milk, all fruit juice combinations, non-diary products e.g. soya, field milk, artificial milk and the 226287 like. In addition, the present invention relates to a method of carbonating milk and packaging the carbonated milk in aseptic and non-aseptic packaging. described with particular reference to an ultra heat treated pasteurization, (HTST) and chemical pasteurization milk drink aerated with sterilized and purified carbon dioxide and to methods of carbonating the treated milk it is to be noted that the present invention 10 is not necessarily limited to this embodiment and the scope of the invention may be more extensive by including within it other beverages aerated with other gases and gas mixtures of varying ratios, such as substitute milk products, for example soya substitutes.

It is to be noted that the use of the general term milk products includes all kinds of non-fermented milk products whether natural or artificial, milk or substitute milk materials, such as for example, whole milk, low fat milk, modified milk, and milk products in general 20 including combinations with other beverage materials such as fruit juices, soy and the like. and other carbonated drinks have been increasing at the expense of other types of drinks, such as milk product drinks. In order to increase the appeal of milk as a drink and hopefully to gain an increased market share for 30 milk drinks, particularly in situations away from a refrigerator such as during out-of-home activities, it has been thought that if carbonated and/or aerated milk was available this product, because of its similarities Although the present invention will be Soft drink sales and sales of aerated and/or carbonated beverages in general have over a period of time increased so that not only are more beverages in 2 5 general being sold but the market share of soft drinks to soft drink in appeal, would be successful in view of it being perceived as a more healthy alternative to soft drinks.

Additionally, at present in many countries 5 there is an oversupply of milk and large surpluses of milk and milk products are in existence. Carbonated milk could at least alleviate these large surpluses of milk and milk products. Therefore, the present invention is an attempt to redress both problems mentioned above, (i) 10 to gain a greater market share for milk drinks and (ii) to reduce the amount of surplus milk or milk products.

Technically, there are some inherent problems which must be overcome in order to be able to carbonate milk and to package the carbonated milk in aseptic 15 packages while carbonated. Among these problems include the following two technical problems which are (a) the nature and behaviour of the product stored under aseptic refrigeration during the manufacture before packaging requires that a settling step be introduced in the 2 0 manufacture to allow the carbonated product to have the required desired properties when packaged, and (b) the excessive foaming caused by sparging with gases at lightly elevated temperatures which may require the use of anti-foam' additives. Moreover, there is the general 25 problem of the stability of milk emulsion during processing and subsequent packaging and storage which makes the carbonation of milk difficult.

Therefore, it is an aim of the present invention to provide a method for carbonating milk 3 0 products and combinations of milk products and to provide a carbonated milk product.

According to the present invention there is provided an aerated beverage comprising a milk product in general which is aerated or carbonated with a suitable - 5 - 226287 gas or mixture of gases in a suitable package whereby the milk product remains carbonated in the package for a reasonably long shelf life until opened.

According to a further aspect of the present invention there is provided a method of carbonating or aerating a non-fermented milk product to produce a final packaged product comprising the following steps: (a) cooling the milk product in a single step to a temperature of between substantially 1°C and substantially 10°C; (b) introducing substantially purified carbon dioxide, carbon dioxide containing gas or mixture of gases into the milk product, within 'the temperature range of between substantially 1°C to substantially 10°C • (c) conveying the milk product to an aseptic pressure balanced tank where it is held to settle or pacify the milk product; and (d) packaging the milk product.

Typically, the milk, product includes non-fermented milk products such as whole milk, skim milk, low fat milk, total milk solids, non-fat soy or any other product conventionally referred to as a milk or dairy product or non-dairy product or artificial milk product or milk substitute product where solid or liquid of any viscosity.

Typically, the package includes bottles, cartons of paperboard or any suitable materials, softpacks of suitable plastic materials, bottles of plastics including PET, polypropylene and mixtures thereof or the like.

The present invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 is a flow chart illustrating one embodiment of the overall method and apparatus of one form of making the product of the present invention by one method.

, , .■ X r\ ; } * ;Example 1: > v 4- ;An ultra heat treated sparkling skim milk drinJ?/. ^ c ;(a) Skim Milk Product which typically contains ^the^^y following ingredients in the following ranges: ' o ;226287 ;- 6 - ;Modified Milk ;50 ;- 95% ;Sucrose ;0 ;- 30% ;Flavours ;0 ;- 45% ;Stabilizers ;0.2 - ;- 10% ;Trisodium citrate ;.01 - ;- 2% ;Modified milk refers generally to natural milk that has been 5 filtered to remove water and to natural milk altered by the addition of total solids from which the fat has been removed ;(b) A batch of fresh whole milk is pumped from a suitable source into stainless steel holding tank 2 where its pH is adjusted to a desired level in accordance 10 with a preselected product taste usually in the range from 3.8 to 6.9 and cooled to a temperature of about 5°C where it is maintained for a suitable period until required. The milk sample is then pumped to heat exchanger 4 where it is heated to a temperature of about 15 40°C. However other temperatures may be obtained. It is preferable that indirect heat is used to raise the temperature, such as for example by using a plate heat exchanger. The heated whole milk is then separated in a separator 6 to produce a first portion which is 20 substantially skim milk and a second portion which is essentially cream having a fat content of about 40%. The second portion is pumped to a refrigerated stainless steel holding tank 8 where it is stored until required for further use. The first portion of skim milk is 25 standardized to about 1% + .5%, as required, 0 - 5%, is then pasteurized at about 72°C. After maintaining the skim milk at 72°C for the required time, such as for example for 15 seconds or other corresponding time in accordance with the approved heat holding time method, 30 the skim milk is cooled to about 2 - 10°C, preferably 4°C, and the pH is adjusted to the preselected value which is between 3.8 and 6.9 as required by adding citric acid monohydrate C^HgO^.H^O and citric acid C^HgO^ and ;- 7 - ;stored in a refrigerated stainless steel vat, mix tank or similar 10 for use as required. When required the skim milk is passed to refrigerated stainless steel mix tank 12 where additives may be added in predetermined amounts. ;5 Examples of such additives include flavours, colours, sweeteners and the like including any food grade material. In one embodiment an alcoholic additive may be used such as for example a whiskey-base flavouring. ;Thus, by this process there is produced a skim milk 10 product, optionally containing any suitable or desirable additives, suitable for subsequent processing into a drink in accordance with the present invention. ;Typically, the mixture thus produced is held at this temperature for approximately up to 1 hour, preferably 3 0 15 minutes for protein protection maturity. ;(b) Ultra heat treatment ;The skim milk sample, optionally containing any suitable, conventional or desirable additives, is pumped from the stainless steel mix tank 12 to a ultra heat 20 treatment (UHT) plant 14 where in the first stage which is the UHT preheater being a plate heat exchange 16, the skim milk is indirectly heated from a temperature of from 4°C to a temperature of about 138°C. After attaining a temperature of 138°C the milk is ultra heated from 138°C 25 to 150°C in the UHT heater 18 where it is held at a pressure of 700 kPA or an appropriate pressure for about 2.25 seconds within limits as required to kill microorganisms, pathogens, bacteria and the like. It is to be noted the precise conditions can change such as at 30 a temperature of 153° for 2.5 seconds or similar. ;Thereupon it is cooled, preferably to below 10°C/ more ;- 8 - ;preferably to 2°C immediately- Thus, at this stage in the regeneration part 20 of the UHT plant 14, there is now provided a ultra heated skim milk product. ;(c) Product carbonating 5 The ultra heated skim milk product may be carbonated in the following ways by direct injection' of sterilized, purified carbon dioxide gas into the coding chamber section of the plate heat exchange to the stainless steel holding receptacles, refrigerated in 10 aseptic modified pressurised maturing tanks. One form of the carbonator is substantially integral with the UHT and is denoted generally as 22. Another form of the carbonator may be located remote from the UHT plant 14. In the embodiment illustrated the carbonator 22 is 15 integral with the UHT plant or nearly so. ;Briefly, carbonator 22, which may be especially designed or modified for the present plant or may be a conventional carbonator either as is or modified as required comprises a carbon dioxide inlet for receiving 20 carbon dioxide or a mixture of gases, a filter and an injection nozzle (atomizer). Typically, the supply of carbon dioxide is from 11 to 56 kg per hour and is typically delivered under pressure range of from 50 kPA to 200 kPA. The carbon dioxide then passes through a 25 filter sterilizer to ensure that the carbon dioxide which is used to carbonate the skim milk is pure, sterilized and aseptic. Typically, the carbon dioxide undergoes gas filtration and sterilization to produce a substantially purified carbon dioxide. After passing through the 30 filter tihe carbon dioxide is passed to a carbon dioxide injector for actually injecting gaseous carbon dioxide into the skim milk. Typically, the injector is an adjustable or otherwise controllable carbon dioxide ;- 9 - ;226287 ;injector used in the beer-brewing and bottling industry or a modified sparger- One form of the injector is supplied by Hoistein V. Koppert GmbH of West Germany. Briefly, this injector has an adjustable needle-like 5 valve which controls the size of opening of a port which is located in a tube perpendicular to the direction of flow of the milk inside the tube. ;Typically, the amount of carbonation is about 3 vols./8 vols, and the carbon dioxide is supplied at a 10 pressure of 60 p.s.i. to the milk. The injection of the carbon dioxide takes place by sparging the milk product. ;An inlet for the carbonator is provided to admit the milk product thereto from the remainder of the UHT plant- A further inlet in the form of a conduit is 15 provided for admitting carbon dioxide under pressure into the carbonator for atomisation. Another example is a sparge pipe provided with an injector for dispersion. In one embodiment the milk product is passed through the injector. ;20 Once the skim milk has been carbonated at 2°C + ;1°C it is pumped to a pressurised carbonator holding tank 30 where the carbonated product is held under pressure in order to maintain its carbonation to fully mature and saturate. Typically, the carbonator holding tank is 25 maintained at a pressure of 450 kPA and a temperature of 2 to 6°C. Holding tank 30 is provided with a carbon dioxide sensor probe for measuring the amount of the carbonation of the milk product. One form of the carbon dioxide sensor is that provided by Canongate Technology 3 0 Limited of Scotland under the name "EMBRA" carbo-check gas monitor. ;In another embodiment carbon dioxide from the carbonator is used to carbonate the milk product in line in a manner similar to that described using an injector ;- 10 - ;but with the difference that in this case it is in-line sparger. In this embodiment the carbon dioxide is delivered at a pressure which is compatible with the filling operations, typically of about 450 kPA. The 5 carbon dioxide is cooled to about 0.2°C or thereabouts and is filtered by two Sterile Micron Filters, typically each being a 3-stage filter arrangement. The amount, quality and other characteristics of the carbon dioxide is maintained by an 'in-line' gas analyser set-up for 10 carbon dioxide, such as for example, the "Embra" gas monitor and/or analyzer. ;Control of the distribution of carbon dioxide to the in-line type modified sparger for milk is by means of a carbon dioxide Control Panel which controls the 15 amount of carbon dioxide being delivered to various locations for carbonating the milk product. Conventional gas control means are employed. ;In the event that the amount of the carbon dioxide levels or the amount of carbonation of the milk 20 product is insufficient, suitable sensors connected to the gas analyser detect this condition so that by means of the control panel the insufficiently carbonated product can be diverted to be reprocessed through the carbonator in a return loop to a holding tank to be 25 repasteurized to be within the specification. ;(d) Packaging ;After the milk is carbonated by the process described above either using a carbonator more or less integral with the UHT plant, a separate carbonator or an 30 in-line sparging pipe, it is conveyed to an aseptic pressure balanced tank which is specifically designed to settle/pacify the milk. It is then conveyed to the packaging station 40 where the carbonated milk product is ;- 11 - ;packaged into sterile containers. Prior to packaging the milk, suitable containers such as for example cans or bottles, are sterilised by dry heat such as for example using hot blasts of air heated to a temperature of 150°C 5 directed onto the cans or bottles for about 58 seconds or a chemical (cooled refrigerated) twist rinse sterilising bath suitable for bottles, including plastic bottles using ultra violet sterilization. The bottles or cans may additionally be sterilised by the injection of 10 nitrogen. The milk product is maintained at a suitable pH depending on the product, during the packaging operations. Just prior to filling, the sterilised containers are purged with sterilised purified carbon dioxide and/or nitrogen. Typically, the packages into 15 which the carbonated milk is packed are bottles, cans, plastic containers, either rigid or flexible. Additionally, the caps, tops, lids, closure means or the like are either separately or simultaneously sterilized by any suitable or convenient method. ;20 After packaging the milk product into individual containers the milk may be further sterilized by non-toxic radiation or pasteurizationation. The filling operations is by means of a modified counter pressure aseptic filler conveniently housed in a clean 25 environment, i.e. forced air pressure in super atmospheric clean surroundings. The finished packages are then pressure checked, product coded, boxed into cartons and the cartons stacked onto pellets for storage in refrigerated or chilled conditions. ;30 It is anticipated that the shelf life will be about 6 weeks. However, in UHT situations coupled with 100% aseptic filling the shelf life will be greatly extended. Under refrigeration the containers have an extended shelf life. ;- 12 - ;226287 ;The described arrangement has been advanced by explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination 5 of features hereindisclosed. ;Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described- It is understood that the 0 invention includes all such variations and modifications which fall within its spirit and scope as defined by the following claims. * 226287

Claims (17)

WHAT WE CLAIM IS;

1. A method of carbonating or aerating a non-fermented milk product to produce a final packaged product comprising the following steps: (a) cooling the milk product in a single step to a temperature of between substantially 1°C and substantially 10°C; (b) introducing substantially purified carbon dioxide, carbon dioxide containing gas or mixture of gases into the milk product within the temperature range of between substantially 1°C and substantially 10°C; (c) conveying the milk product to an aseptic pressure balanced tank where it is held to settle or pacify the milk product; and (d) packaging the milk product.

2. A method according to Claim 1, in which the milk product is whole milk, skim milk, low fat milk, total milk solids, modified milk, non-fat soy or any other non-fermented milk product either natural or artificial.

3. A method according to Claim 2 in which the skim milk product has the following formulation: Modified Milk 50 Sucrose 0 Flavours 0 95% 30% 45% r ,X. y.* & % - 14 - 226287 Stabilizers 0.2 - 10% Trisodium citrate 0.01 - 2%

4. A method according to Claim 1, in which the milk product is a skim milk and the method further comprises standardising the skim milk to 0 to 5% fat content.

5. A method according to Claim 4, further comprising standardising the skim milk to 0.5 to 1.5% fat content.

6. A method according to Claim 4 or 5 in which the skim milk is ultra heated treated skim milk.

7. A method according to Claim 6 in which the ultra heat treated skim milk is carbonated by a carbonator comprising a direct injection of sterilised, purified carbon dioxide gas or gas mixture containing carbon dioxide.

8. A method according to Claim 7 in which the carbonator is substantially integral with an ultra heat treatment apparatus.

9. A method according to claim 7 or 8 in which the carbon dioxide from the carbonator is supplied from 11 to 56kg per hour at a pressure in the range from 50 kPa to 200 kPa. - 15 - 226287

10. A method according to any one of Claims 7 to 9 in which the carbonator has an injector which is an adjustable needle-like valve.

11. A method according to claim 10 in which the injector is a tube arranged to extend substantially at right angles to the direction of flow of the milk being carbonated.

12. A method according to any one of Claims 1 to 11 in which the amount of carbonation is 3 volumes of carbon dioxide to 8 volumes of milk product.

13. A method according to any one of Claims 1 to 12 in which the carbonation takes place at 1°C to 5°C.

14. A method according to Claim 13 in which the carbonation takes place at from 1°C to 2°C.

15. A method according to any one of the previous claims in which the pressure balanced tank is maintained at a pressure of 450 kPa and a temperature of from 2 to 6°C.

16. A method according to any one of the previous claims which the carbonated milk product is packaged into sterile containers. P A T - 16 - 226287

17. An aerated or carbonated non-fermented milk product made in accordance with the method of any one of Claims 1 to 16. WEST-WALKER, McCABE per. ATTORNEYS FOR THE APPLICANT /„ 6/% Hp \o Vv > ft ~ y.