Tea extract soluble in cold water

FIELD: food industry.

SUBSTANCE: tea product is suggested which is soluble in cold water and its production method. Method includes extraction of the material with water to produce tea extract and removal of tea leaves from the tea extract. The tea extract without tea leaves is then concentrated, the extract is cooled, tea cream is removed from the tea extract to produce tea cream fraction and decreamed tea fraction. After that the tea cream fraction is dissolved in water at 40-100°C foolwed by ultrafiltration causing formation of permeate and retentate and extraction of permeate.

EFFECT: tea product obtained is soluble in cold water, has good colour characteristics and the method suggested does not depend on adding any chemicals and provides acceptable yield of the product.

6 cl, 5 tbl, 2 ex

The invention relates to a method of obtaining a concentrated tea product, soluble in cold water, from which you can prepare tea drink good transparency and satisfactory color.

Black tea is traditionally produced by oxidation and drying recently plucked green tea leaves. This tea is usually soaked in hot water, then used the tea leaves are removed, and the resulting hot drink, to which may be added other ingredients, widely consumed in most countries.

When the hot water infusions rough leaf tea, it was found that infusion contains substances that are soluble in hot water but insoluble in cold water, and such substances tend to be precipitated during cooling of the infusion. Substances insoluble in cold water, include complexes such as polyphenol-protein-caffeine (also called tea "cream"), and usually their number is 20-20% of the total dry substance content contained in the infusion. In addition, many of the substances contained in the leaves, giving the drink a unique organoleptic properties, only partially soluble in cold water.

In this regard, it is desirable to develop a concentrated tea products, soluble in cold water, you could make China the drinks with good organoleptic properties, since this operation is very popular because of the convenience in use. Such systems can also be used to make iced tea, and this drink is very popular in some countries. Concentrated tea products, soluble in cold water can be a liquid or may be dried to obtain powders.

It was suggested several ways to obtain soluble in cold water or instant tea. One of the most common ways described in the description of U.S. patent 3163539 (Standard Brands Inc), includes the extraction of the leaves of black tea, alkaline treatment, intended for dissolution of particulate tea material, and centrifugation to remove any remaining particulate tea material, insoluble in cold water. These powders, when dissolved in water give a good colour of the solution, which is a transparent system.

However, the alkaline treatment process involves the addition of unwanted chemicals and significantly reduces the content of flavonoid antioxidants. In this regard, the industry attempts to replace the alkaline process. But used alternative solutions involve adding chemicals or do not provide sufficient yield of useful solid comp the components of tea.

In EP 198209 AND described by way of concentration and cooling of the tea extract to a temperature of 5-15°With the purpose of obtaining insoluble in cold water fractions of tea "cream" (dark) and soluble in cold water (light) fraction, from which tea cream removed. Faction of tea "cream" is separated and then dissolved in warm water to obtain a second fraction of tea "cream" and the second fraction, from which tea cream removed. Two such fractions, of which tea cream removed, mixed together and dried to obtain tea powder, soluble in cold water. The second faction of tea "cream" throw. Only ingredients that are soluble in cold water, which together are deposited at the first separation, extracted in the second extraction. Thus, during the second stage, only a small increase in output.

In U.S. patent 4639375 (Procter & Gamble) describes the processing of black tea with tannate, together with other enzymes that digest the cell wall, with the aim of obtaining tea powders, quickly soluble in cold water.

In EP 391468 (Unilever) describes a method for the tea powder, soluble in cold water, and this method includes a process using tannase, but with additional ultrafiltration treatment of the extract. This treatment further reduces p is mutenye extract, but still requires the use of tannase.

In EP 464919 (Unilever) indicated that the separation process of the tea extract to the dark faction of tea "cream" and the light fraction from which tea cream removed at a temperature below 5°C, the destruction of the tea "cream" results in the obtaining of a tea extract, soluble in cold water. However, even at such a low temperature process was that the faction of tea "cream" contains a large amount of useful natural ingredients of tea, which, therefore, lost.

In EP 699393 AND (Nestle) described an improved method according to EP 198209 AND in which tea cream solubilizing not only in water but also with used tea leaves from the first stage extraction or separately received green tea. Thus, in the second stage extraction extracted additional solids of tea, and soosazhdenie ingredients, soluble in cold water, while also improving product yield. However, the output remains low.

In WO 02/100184 (Unilever) proposed a method including mixing the extract of the tea material with anionic colloidal material, resulting in a gain concentrated tea product, soluble in cold water.

Thus, the objective of the invention is to create a method of producing a tea extract, process is imago in cold water, having good color characteristics and with a slight haze or no haze, and the proposed method does not depend on the addition of any chemical substances and ensures a good yield of product.

The inventors have found that the way in which a concentrated tea extract is divided into faction and the faction of tea "cream"from which tea cream removed, while the fraction of tea "cream" separately dissolved in water and subjected to ultrafiltration, can solve all the above technical problems.

Thus, the invention provides a method of obtaining a tea product, soluble in cold water, comprising the extraction step of the tea material with water to obtain a tea extract, remove from the extract of the tea leaves, the concentration of the obtained tea extract, cooling, extract, remove from the concentrated extract of tea "cream" with the aim of obtaining fractions of tea "cream" and the faction from which tea "cream" are removed, the dissolution of the faction of tea "cream" in water at a temperature of 40-100°C With subsequent ultrafiltration treatment of the dissolved fraction of tea "cream", resulting in a gain of permeate and retentate, and the selection of the permeate.

Accordingly, in the method according to the invention do not want to add any substance p is obtained not from the tea.

In addition, the present invention also provides tea products, soluble in cold water, received and/or obtained by the method according to the invention.

The term "tea"used in the description, denotes a sheet material obtained from tea plants such as Camellia sinensis var. Sinensis or Camellia sinensis var. assamica. This term also includes tea "Rooibos", derived from Aspalathus linearis, although this material is a poor source of endogenous fermentation enzymes. The term "tea" also includes the product of mixing two or more teas.

The term "tea material" refers to plant material. Such material may be a freshly picked tea leaves, and may include black tea, Chinese (yellow) tea or green tea, low-grade leaf tea, or a mixture thereof.

The term "soluble in cold water" refers mainly to enough cold water, for example water with a temperature of about 4°C.

The term "tea beverage" refers to a drink containing tea, in form suitable for consumption by a consumer.

All parts, unless otherwise noted, are given in mass terms.

With the exception of information contained in the working and comparative examples, or details of a particular as, otherwise, all numeric values listed in the description relating to share what you or concentrations of material, should be treated as values, providing for the use of the word "about".

To avoid ambiguity, the term "containing, including" includes the expression "consisting of" or "formed from". In other words, the above stage or options should not be regarded as fully satisfactory.

The treated extract

Concentrated tea products, soluble in cold water can be a liquid that can be diluted with obtaining a tea drink good clarity and color. According to other variant concentrated tea products, soluble in cold water, can be dried with getting tea, soluble in cold water, or ready-to-drink tea powder, soluble in cold water, which can be obtained tea drink good clarity and color.

Extraction

The tea material is extracted in hot water. Tea material preferably is a newly produced leaf tea. However, you can get a concentrated tea good quality product, soluble in cold water, using tea lower grades, such as chopped mixed crowns (tops) (funnings) black tea. The tea material is preferably extracted in water at the same time is the temperature value of 60-100°C, especially at 90°C for at least 5 minutes. This operation is conveniently carried out in a vessel with steam jacket while stirring the contents.

Leaf removal

After extraction from the tea extract removes leaves, i.e. outside sheet material, such as stems. Such an operation can be performed using a screw press, followed by passing a hot fluid through a centrifuge to remove small particles.

Concentration

Tea extract, devoid of leaves, contains 2-4% of the dissolved solids of the tea material. In practice it is better to concentrate the extract, devoid of leaves, to the content of solid material 8-20% (concentrated tea extract). This significantly decreases the amount of fluid required for processing. Any suitable known devices or processes may be used for this purpose, for example a heat exchanger with solenoi surface in the form of a falling film.

Separation

At this stage, the extract must be at a low temperature (for example, less than 35°C, more preferably below 31°C, and optimally less than 15°C) to remove insoluble in cold water, the material was deposited and caused turbidity. However, when an excessively low temperature, the final output of the faction from which tea "cream" deleted too mA is. In this regard, preferably, the extract was divided at temperatures above 1°C, more preferably above 5°C.

Next extract, concentrated at low temperature, centrifuged for separation of the precipitate on the fraction of tea "cream" and the faction without tea "cream". The fraction of liquid without tea "cream", soluble in cold water, gives a slight turbidity. It is physically separated from the tea "cream".

According to another variant of the separation fraction tea "cream" and phase without it can be done (i) the freezing of the extract to a temperature below -5°C at a rate of 0.5-5°C/min, or (ii) cooling the extract at a temperature below 5°C, for at least 5 hours.

Re-dissolution

Next faction of tea "cream" is again dissolved in water preferably at a temperature of 40-100°C. it is Preferable to use water with a temperature close to the boiling point. The quantity and temperature of water should be sufficient to ensure dissolution of all tea "cream" to get Nemunas fluid. It is best to dissolve the tea cream to the dry matter content of 1-15 wt.%.

Ultrafiltration

The dissolved fraction of tea "cream" later served on the stage ultrafiltration. The preferred temperature dissolved tea "cream" was 40-100°C. As was discovered later, perme the t this stage not cloudy when cooled to room temperature. Next, the resulting permeate, before or after drying and concentration, can be combined with the faction without tea "cream". According to another variant, in connection with various chemicals, permeate can be used for dispensing in some special products.

Retentate may be subjected to an optional re-dissolve and directed on stage filtration to obtain a second permeate, which is extracted from the system.

In the preferred stage ultrafiltration using a filter with srednemolekularna-mass cutoff of 5000 daltons, more preferably at least 20000 daltons, even more preferably at least 50000 daltons. The preferred point of exclusion (clipping) is not too high, since otherwise large, visible particles can pass through the filter. Thus, it is preferable that the filter was characterized by the value srednemolekularna-mass cut-off less of 500,000 daltons, more preferably less than 300000, and most preferably less than 200000 daltons.

Examples

Example 1

Received 2.4 kg tea extract, soluble in hot water containing 10 wt.% the tea material on dry substance. The resulting system was centrifuged at 30°C with getting 2,17 kg light transparent faction, is the Oh top and 0.23 kg of a dark faction of tea "cream"at the bottom. Faction of tea "cream" was separated from the light fraction by physical removal. The obtained fraction tea "cream" was then dissolved in 2,71 kg of boiling water. The result has been 2,94 kg of a solution containing particulate tea material in a quantity 2,545 wt.%. Dissolved tea cream was passed through the ultrafiltration membrane at a temperature of 45°C. the ultra-filter belonged to the class of filters 100 daltons. Received 2.6 kg of permeate with a good color that is slightly Motel when cooled to room temperature.

The permeate is mixed with the light fraction not containing tea "cream", in the ratio 15:85 per dry weight. The resulting mixture had a good color, was characterized by a slight haze and a sufficient content of polyphenols, tea flavins, caffeine and catechins. The chemical composition of the different samples were analyzed by the method GHUR on the content of tea flavins, catechins and caffeine. To determine the total content of polyphenols used the method of Folin-Ciocalteu.

The total content of the polyphenols

The polyphenols contained the following ingredients: tea rubigen, tea are the catechins, Gallic acid, teocalli, chlorogenic acid.

The measurements were expressed in mg/g of frozen dry powder.

* A mixture of permeate with the above-described light fraction from which tea "cream" are removed in the ratio of 15:85.

Standard hot extract was obtained by hot extraction of tea low grade, removal of leaves and hot clarification received the drink, concentration and spray drying.

Tea flavins

The measurements were expressed in mg/g of lyophilized powder.

Tea flavin, tea flavin-3-mangalat, tea flavin-3^,-mangalat, tea flavin digallate.

The total content of catechins

The measurements were expressed in mg/g of lyophilized powder.

You can see that the compounds which can be appreciated in relation to the availability of useful tea solids.

Color

Various samples were analyzed for color characteristics and levels of turbidity at room temperature (20°C) using a HunterLab Colorquest^TMXE, working in the following conditions: the transfer mode, CIE color space, With illuminant, the angle of 2° and a length of 50 mm.

From the presented data shows that adding a certain amount subjected to ultrafiltration tea "drain is to" back in the faction, not containing tea "cream", provides improved color properties (e.g., dark and red shades)that is not accompanied by blushing.

Example 2

The example demonstrates the advantages of the method using ultrafiltration compared with the method similar to that described in EP 0 198209 A2 that uses centrifugation.

A sample And

Pre-cooked tea extract, soluble in hot water, was dissolved in water at 95°C. when the content of tea solids material 10 wt.%. The resulting system was centrifuged at 30°C To produce fractions of tea "cream" and the faction from which tea cream removed. Then, the resulting nericcio tea "cream" liofilizirovanny to get sample A.

Sample

Pre-cooked tea extract, soluble in hot water, was dissolved in water at 95°C. when the content of tea solids material 10 wt.%. The resulting system was centrifuged at 30°C To produce fractions of tea "cream" and the faction from which tea cream removed. The obtained fraction tea "cream" was dissolved in water at 95°C before cooling to a temperature of 30°C and subjected to centrifugation with the formation of the second faction of tea "cream" and the second fraction, from which tea cream removed. Then the second nericcio tea "cream" life who was seravalli to get sample Century.

Sample

Pre-cooked tea extract, soluble in hot water, was dissolved in water at 95°C. when the content of tea solids material 10 wt.%. The resulting system was centrifuged at 30°C To produce fractions of tea "cream" and the faction from which tea cream removed. The obtained fraction tea "cream" was dissolved in water at 95°C before cooling to a temperature of 45°C and passed through the ultrafiltration membrane at a temperature of 45°C. was Used ultra-filter class 100 daltons. The resulting permeate liofilizirovanny with the formation of the sample S.

Color

Each of samples a, b and C was dissolved in boiling water to ensure complete dissolution of all dry materials and then diluted to a concentration of 1.4 g·l^-1using water at room temperature (~20°C). Each of the samples kept at 4°C for 7 days and then analyzed their color properties and the ability to turbidity. Color numbers were obtained using a Minolta^TMCT-310 (illuminant, color space L*a*b*, the path length 1 cm), and non opacities were obtained using NASN^TMR of turbidimetry (automatic switching measurement modes, the diameter of the cell is ~ 2 cm).

From these data we can see that the use of ultrafiltration (Sample) significantly reduces the turbidity compared using centrifugation (sample), this delivers improved color characteristics.

1. The method of obtaining tea product, soluble in cold water, comprising the extraction step of the tea material with water to obtain a tea extract, removing the sheet material from the tea extract, the concentration of the tea extract, not containing sheet material, cooling the extract, the destruction of the tea "cream" from the concentrated tea extract with obtaining fractions of tea "cream" and pracc and, from which tea "cream" are removed, the dissolution of the faction of tea "cream" in the water with subsequent ultrafiltration, resulting in the formation of the permeate and retentate, and the allocation of permeate.

2. The method according to claim 1 that does not include adding any chemical, not derived from tea.

3. The method according to claim 1 or 2, in which the permeate re-unite with the faction from which tea "cream" removed.

4. The method according to claim 1 or 2, in which retentate subjected to additional re-dissolve and subjected to filtration to obtain a second permeate, which is separated from the system.

5. The method according to claim 1 or 2, in which the ultra-filter used at the stage of ultrafiltration has a cutoff at an average molecular weight of at least 5000 Yes.

6. Tea product, soluble in cold water, obtained by the method according to any preceding paragraph.