GB2224920A - Manufacture of flavoured tea - Google Patents

Description

2,'--24920 A PROCESS FOR MANUFACTURING FLAVOURED TEA This invention

relates to a process for manufacturing flavoured tea from black tea. Tea varieties of all origins and grain sizes may be used.

It is known to treat tea with flavourings in order to improve its quality, but also in order to create certain nuances of flavour and thus to give the finished tea drink a particular grade.

It is known to coat leaf tea with tea which is soluble in hot water, or brought into contact therewith in the form of a slurry, in order to improve its quality. The result is a composite tea product, which has the disadvantaae of having to be manufactured in several stages of extraction, mixing, spraying and drying, and which is therefore subjected to a relatively high, particularly thermal stress. In this process, only a strengthening of the taste of the inherent flavour of the tea is achieved.

2 It is also known to use the favouring -cyclodextrin complexes in the form of granules or a suspension to flavour the tea. In this case, first of all inclusion complexes are moistened, kneaded, granulated and dried in an expensive manner and then mixed with tea leaves.

Secondly, it is possible to manufacture a suspension of inclusion complexes, fixers and water, with which the tea leaves are sprayed, optionally in a nitrogen stream. The product is dried while being constantly stirred. These known processes have the disadvantages that they need elaborate and expensive manufacture processes for the inclusion complexes, the finished product has a high proportion of impurities, and several operations are involved in the process and considerable stress, particularly thermal stress, is placed on the product. Furthermore, it is impossible completely to prevent separation of flavouring granules and tea, even when the grain size is almost uniform (which is vii:tually impossible to achieve). Therefore, expensive packaging in filter bags is necessary. It is also disadvantageous that the process.is discontinuous and cannot be carried out automatically.

In another known process, flavour-bearing granules are manufactured which are then coated with powdered tea in a rotating drum or pan granulator. This process suffers from the disadvantage that a plurality of stages are necessary to manufacture the granules, such as spraying, mixing, extraction and drying in a drying oven, and coating them (likewise, mixing, spraying, extraction, drying). In this case, the moisture content is approx. 12% and the level of impurities is excessively high. After mixing with leaf tea, separation cannot be prevented. The tea thus flavoured therefore has to be packaged in tea bags.

Yet another process is known for manufacturing flavouring granules for black tea preparations in which powdered tea of a certain grain size is mixed with lactose and caster sugar in a mixing machine, and flavouring concentrate and gelatine solution are added. The mixture is granulated, dried and graded. The granules are added to the tea and the mixture is used to fill tea bags. These are packaged in small cardboard boxes and covered in cellophane. The disadvantages of the process are based on the fact that the flavouring granules are manufactured in a sep-zrate process in several stages, with considerable stress on the raw materials (particularly thermal stress). Then they are added to the tea. In this case, separation of the tea and the flavouring, even while being transported around the factory, cannot be completely prevented. Heavy losses of flavour arise due to long periods of drying, which leads to poor quality of the product. The process requires at least one workforce and cannot be carried out continuously, leading to high energy costs.

It is also known to manufacture a suspension from flavouring concentrate and an aqueous solution of methylcellulose and/or carboxymethylcellulose, which is sprayed on to tea leaves with an atomiser by means of compressed air or an inert gas or in a pressure atomiser by means of a nozzle. A disadvantage is the inevitable use of methyl- and/or carboxymethylcellulose as a fixer, but the process is not continuous.

It is an object of the invention to provide a process for manufacturing flavoured tea in which it is possible to treat the tea continuously, adding no more than a minirrium of impurities, with an economic use cf d' - 5 flavourings and low energy consumption, thereby avoiding excessive stress on the raw materials used and any subsequent separation.

It is a particularly important feature of the present invention to evenly distribute the flavouring of the tea particles.

According to the invention, there is provided a process in which tea is allowed to trickle down continuously at normal temperature and pressure, under gravity, in the manner of a fine spray, so as to form a hollow cylinder, liquid flavourings being atomised inside this hollow cylinder and brought into contact with the tea, and then, as the tea continues to shower down, it is swirled around in the flavouring-saturated atmosphere. The quantity of flavourings relative to the tea is preferably 0.1 to 3% by weight.

The process of the invention may take place in an inert atmosphere from which atmospheric oxygen hasbeen substantially eliminated. 0.01 to 0.1% by weight -1 to the (relative to the tea) of a fixer way be adde-1.4 flavourings use's- In this process, it is possi.!:le tr, - 6 use both liquid neat flavourings as well as flavourings in aqueous solution, in which case solutions with 1 to 10% fixer are preferred. Preferred fixers include gum arabic, dextran and/or dextrin, soluble starch or hydroxyethylcellulose. With the process according to the invention, it is possible to treat te_a of any provenance and grain size by means of flavourings of liquid consistency. In this case, the product is subject to neither thermal nor any other kind of stress. Consequently, the flavour losses may be kept to a minimum, ensuring economic use of flavourings. In addition, any subsequent drying of the tea becomes superfluous, since this is in any case unnecessary for flavourings which are not water soluble, and, in the case of water-soluble flavourings, the composition is so chosen that the treated tea at the end of the flavouring process has just as much --JLsture as the required final moisture content of the tea before packing. This is easy to achieve llby atomising the flavourings, which does not constitute a direct wetting of the tea leaves. The gentle treatment achieved alsc ensures that all components of the flavourings, including the volatile ones, are retained and are StIL1 1 - 7 fully effective when the tea is brewed even after prolonged storage.

An even flavouring of the tea is ensured by the fact that the extremely finely atomised flavouring particles can diffuse well into the individual tea leaf. This also solves the problem of the separation of flavouring granules and tea leaves which has occurred hitherto. Consequently, it is possible to pack the tea, for example in soft packagings or in packages for bulk consumers. Since a number of flavourings are sensitive to oxidation, it is advantageous to create an inert atmosphere by eliminating atmospheric oxygen during the flavouring process. The process according to the invention also has the advantage that when fixers are used, a so-called granulating-on effect occurs, whereby the dust-like tea fines which are always present in tea are bonded. Thus it is possible to use the dust. The mentioned slight amount of fixer is sufficient to fix the flavouring concerned sufficiently long to the tea leaf, so that the use of impurities as an additive to the tea is reduced to a minimum.

The flavouring process is carried out according to the invention continuously, so that the expense on apparatus is also reduced. Mixers or dryers are in this case completely superfluous. Consequently, the energy costs fall quite considerably.

The device for carrying out the process has a vertical, cylindrical chute, in which is located a drivable shaft, mounted coaxially, on which is mounted a cone with its apex pointing upwards, which may have baffle plates at its widest diameter. Seen in the direction of falling, the shaft is followed by a cylindrical body, whose upper end face is formed as a centrifugal atomiser. The continuation of the cylinder casing may also have baffle plates. The process is automatically controllable via the use of moisture sensor signals.

The tea is supplied to the chute in metered quantities and slides over the cone and then forms a downward-trickling hollow cylindrical spray, until it reaches the vicinity of the centrifugal atomiser. The flavouring particles in this case atomised inside the hollow cylinder thus come into contact with the tea and are absorbed thereby.

As the tea continues to trickle down, it reaches the region of the baffle plates, where a thorough swirling of the flavouring-saturated atmosphere takes place. The chute is so formed that an inert atmosphere can be produced. Then the tea falls into a container, from which it is supplied to the packing machine.

The invention will now be described in more detail with reference to the four examples hereafter.

Example 1: (wild cherry flavoured tea) 100kg of tea base in the fines grain size range is allowed to trickle down in a hollow cylindrical fine spray. Inside the hollow space, a total of 1.5kg liquid wild cherry flavouring concentrate is centrifugally atomised to an average par-ticle diameter of 0.005mm to lmm and thus evenly applied to the tea particles. The tea thus flavoured is put into pour-on or floating tea bags in quantities of 1.5g - 2g each, packed in small cardboard boxes of 20 or 50 bags each, and the boxes are covered in cellophane. The tea thus flavoured and packed has a minimum shelf life of 6 months and is also rich in perfume and flavour.

Example 2:

kg tea base of the crumb grain size range is flavoured as in Example 1 with 1.5kg liquid mango flavouring concentrate, and packed in flat-ended bags or tubular bags made of aluminised PE-foil in quantities of 100g or 150g each. The tea thus flavoured and packed has a minimum shelf life of 1 year.

(manqo flavoured tea) Example 3: (lemon flavoured tea) kg tea base of the leaf grain size range with a moisture content of 7% is flavoured as in Example 1 with 2kg of a flavouring-bearing fixer suspension. This consists of 10% by weight of gum arabic solution, to which 50% by weight of lemon flavouring concentrate is added. The tea thus flavoured has a moisture content of 3% and is packed in tubular bags or flat-ended bags made of transparent compound foil in quantities of 100- 200 g. Packing in bags of up to 2 kg for bulk consumers is also possible.

is The tea thus flavoured and packed has a minimum shelf life of 6 months.

Example 4 As in Example 3, a flavouring-bearing fixer suspension containing 8% by weight of dextrin is used.

Claims (9)

1. A process for manufacturing flavoured tea using liquid flavourings, comprising the steps of allowing the tea to fall freely and continuously at normal temperature and pressure, in the manner of a fine spray to form a hollow cylinder, atomised liquid flavourings inside this hollow cylinder being brought into contact with the tea, and then, as the tea continues to fall, it is swirled in the atomised flavouring-saturated atmosphere.

2. A process according to claim 1 wherein the quantity of flavouring used relative to the tea -s 0.1 to 3% by weight and the flavouring process may be carried out in an inert atmosphere.

3. A process according to claim 1 or claim 2 wherein 0.01 - 0.1% by weight relative to the tea of a fixer is added to the flavouring.

4. A process according to any of claims 1 to 3, wherein both liquid neat flavourings as well as flavourings in aqueous solution are used.

5. A process according to any of claims 1 to 4, wherein solutions containing 1 - 10% by weight of fixer are used.

6. A process according to claim 1, or claims 3 and 5, wherein gum arabic, dextran and/or dextrin, soluble starch or hydroxyethylenecellulose are used as fixers.

7. A process for manufacturing flavoured tea substantially as herein described.

8. A flavoured tea manufactured in accordance with the process as claimed in any of claims 1-6.

9. A flavoured tea substantially as herein described.