EA041080B1 - SOURCE MATERIAL FOR TEA-BASED DRINK - Google Patents

Description

Technical field

The invention relates to starting materials for the preparation of tea-based beverages. In particular, the invention relates to tea granules for use in such starting materials.

State of the art

Tea consumption dates back several centuries and is popular in both developed and developing countries. Tea is the most popular drink in the world after water. The popularity of tea is due to a number of factors: it is generally considered good for health, it can be a safe alternative to untreated water, it has been linked to providing benefits such as relaxation and mental alertness, and it has a widely acceptable taste.

The health benefits of tea are mainly due to the presence of high levels of polyphenols. Both black tea and green tea are rich in polyphenols, which can include catechins, theaflavins, and thearubigins.

Tea-based beverages are traditionally made by dipping tea leaves in hot water and separating the brew from the used tea material. It is believed that tea polyphenols contribute to the organoleptic characteristics of tea leaves. Unfortunately, a significant portion of tea polyphenols does not pass into the brew and is thus discarded along with the waste tea material. Therefore, it is possible to provide a beverage preparation raw material with improved brewing efficiency.

Indian Patent No. 187547 (Hindustan Lever Limited) relates to a process for granulating tea dust with additives based on sugar to obtain a homogeneous product similar to leaf tea. The brewing efficiency of the products is not disclosed, although the samples are said to have organoleptic characteristics (e.g., taste, mouth feel, tea quality) that are comparable to those of conventional packaged tea when prepared in the traditional Indian way (boiling 1.2 liters of water with 45 g palm sugar for 3 min, adding 7.75 g of the appropriate tea sample and boiling for an additional 15 min). The granular tea product of Indian Patent No. 187547 contains palm sugar (a type of conventional cane sugar that is not centrifuged) as a binder in an amount of 30 to 85% by weight. Thus, while said granular product may be suitable for the Indian market, it is not suitable for markets where unsweetened tea beverages are preferred. In addition, since the binder is rich in sugars (the main components of palm sugar are sucrose, glucose, fructose and water), both the binder itself and the resulting granules are likely to be hygroscopic and therefore difficult to handle on a large scale. For example, the granules can aggregate into solid masses that can interfere with the operation of the production line or even lead to device failure.

At present, the health conscious consumer does not want to consume foods containing high amounts of sugar. In addition, consumers increasingly want to consume clean label products, i.e. products that contain only natural ingredients.

We have found that there is still a need to provide beverage starting materials with improved brewing efficiency that do not impart undesirable taste (eg, excessive sweetness) to the beverage and that include only natural ingredients.

Brief description of the invention

In a first aspect, the present invention relates to porous tea granules containing loose tea particles and a binder, wherein at least 50% by weight of the loose tea particles have a size of 100 to 300 microns;

the binder is a tea-based binder containing tea solids;

tea granules contain a binder in an amount of from 1 to 40% by weight of dry granules; and porous granules have D[4,3] greater than 350 µm.

Consumers often prefer teas with a quick brew and rich color. One of the objectives of the present invention is to enable consumers to prepare a beverage using less tea material and/or in a shorter time compared to conventional loose leaf tea.

Without being limited by theory, the authors of the present invention believe that the structural components and the low surface area to volume ratio of traditional leaf tea limit the efficiency of its brewing. Reducing the particle size of leaf tea is believed to improve brewing efficiency by reducing structural barriers and increasing the surface area to volume ratio. However, simply using fine leaf particles (or incorporating fine leaf particles into an existing mixture) is undesirable for several reasons. First, consumers commonly associate fine leaf particles with poor quality tea. Secondly, small leaf particles can have a negative effect on the tea leaves (for example, they can increase haze). In addition, fine leaf particles can lead to technical problems (such as

- 1 041080 increase in bag shedding) when placed in tea bags. The porous granules of the present invention have improved brewing efficiency while being sized to limit the negative aspects normally associated with fine leaf particles.

In a second aspect, the present invention relates to a beverage preparation raw material comprising porous tea granules according to the first aspect of the invention. Such a beverage preparation raw material allows the consumer to prepare the beverage in an efficient manner, for example, due to a shorter brewing time compared to conventional loose leaf tea. Additionally or alternatively, the beverage preparation raw material may be more economical, for example, it may allow the amount of beverage preparation raw material required to achieve a particular brewing efficiency to be reduced compared to conventional loose leaf tea.

In a third aspect, the present invention relates to a method for producing porous tea granules, comprising the steps:

(a) providing loose leaf tea;

(b) grinding and/or screening the leaf tea such that at least 50% by weight of the leaf tea has a particle size of 100 to 300 microns;

(c) obtaining a mixture containing the leaf tea obtained in step (b) and a binder;

(d) obtaining porous granules from the mixture by low shear granulation;

wherein the porous tea granules have a D[4,3] greater than 350 µm, and the binder is a tea-based binder containing tea solids.

The method is preferably applied to the production of porous tea granules according to the first aspect of the invention. It should be noted that steps (c) and (d) can be carried out separately or simultaneously. From the point of view of the efficiency of the method, it is preferable to carry out steps (c) and (d) simultaneously.

Brief description of the drawings

The invention is described with reference to the accompanying drawings, in which FIG. 1 is a confocal photomicrograph of traditional black leaf tea;

fig. 2 is a confocal micrograph of a porous tea bead;

fig. 3 shows the brewing curves of tea pellets in tea bags during active dipping.

Detailed description of the invention

Tea.

For the purposes of the present invention, tea means material from Camellia sinensis var. sinensis and/or Camellia sinensis var. assamica. The term leaf tea refers to the leaf and/or stem material from the tea plant in unbrewed form (ie not subjected to a solvent extraction step). Leaf tea is dried to a moisture content of less than 30% by weight. Typically, leaf tea has a moisture content of 1 to 10% by weight.

Loose tea particles.

The loose leaf tea particles may comprise green leaf tea, black leaf tea, or semi-fermented leaf tea (oolong). They may also contain a mixture of one or more types of loose tea. Green leaf tea refers to essentially unfermented leaf tea. Black leaf tea refers to essentially fermented leaf tea. Semi-fermented leaf tea refers to partially fermented leaf tea. Fermentation refers to the oxidative and hydrolytic process that tea undergoes when some exogenous enzymes and substances are combined. During this process, the colorless catechins in the leaves are converted to a complex mixture of yellow/orange to brown polyphenols.

National or regional culture often dictates consumer preferences for tea. For example, green tea drinks have been consumed in China and Japan for many hundreds of years, while black tea drinks are more popular in Europe and India.

Consumers in regions with a tradition of drinking black tea often prefer teas with a quick brew and rich color. In order for the tea granules to contribute to the production of a raw material for the preparation of a drink that meets the specified consumer need, it is preferable that the loose tea particles are black loose tea particles.

In recent years, there has been significant interest in the potentially health-beneficial compounds present in green tea (in particular, flavanols such as catechins). In order for the tea granules to contribute to these benefits, it is preferred that the loose leaf tea particles are green leaf tea particles.

Naturally, some consumers want the benefits of both types of tea. Thus, it is also envisaged that the tea granules may contain a mixture of black leaf tea particles and green leaf tea particles.

At least 50% by weight of loose leaf tea particles are between 100 and 300 microns in size. Preferably at least 65% by weight of the tea particles are of the indicated size, more preferably at least 80% by weight of the tea particles are of the indicated size, even more preferably at least 90% by weight of the tea particles are of the indicated size and most preferably at least 95% by weight of the tea particles are of this size. This particle size can be achieved in various ways. For example, by grinding or grinding loose leaf tea to a suitable size and/or sorting loose leaf tea according to particle size.

The mass fraction of particles having a certain size can be determined by sorting tea into fractions by particle size (for example, by sieving) and then weighing the fractions. When determining particle size, the leaf tea particles are in the dried state and have a moisture content of less than 30% by weight (typically 1 to 10% by weight).

The leaf tea contains material having a range of particle sizes resulting from a conventional production process. Indeed, loose leaf tea is usually sorted into different grades (eg, whole leaf tea, broken tea, chips, and dust) before being sold at auction. One of the criteria for sorting tea is the particle size. For example, loose leaf tea can be passed through a series of vibrating sieves in which different varieties are retained and collected. In this way, leaf tea particles having a size of 100 to 300 µm can be separated. For example, particles passing through a sieve having a Tyler mesh size of 48 mesh (297 microns) and being retained by a sieve having a Tyler mesh size of 150 mesh (105 microns) are of the appropriate size.

Up to 50% of the loose leaf tea particles may have a size that is not in the range of 100 to 300 microns. Typically, such tea particles are less than 100 µm in size because removal of very fine particles after grinding and/or sieving is difficult and such fine particles are of no commercial value. However, without being limited by theory, it is believed that when tea granules are brewed in hot water, partial destruction of the granules may occur. Thus, a large number of particles having a size of less than 100 µm is undesirable because they are not retained by either the tea strainer or the tea bag and can therefore lead to undesirable haze and/or sedimentation in the tea. Therefore, it is preferable that the tea granules contain loose tea particles having a size of less than 100 µm in an amount of less than 30 wt.%, more preferably less than 20 wt.%, more preferably less than 10 wt.%, and most preferably less than 5 wt.%.

Without being limited by theory, it is believed that loose tea particles larger than 300 µm are likely to have a negative effect on the brewing efficiency of porous tea pellets because they have a reduced surface area to volume ratio compared to smaller loose tea particles. Since leaf tea particles larger than 300 µm are more easily removed after grinding and/or screening, it can be guaranteed that only a small amount of particles of this size will be present in the granules. Preferably, the tea granules contain loose tea particles having a size greater than 300 µm in an amount of less than 15 wt.%, more preferably less than 10 wt.%, more preferably less than 5 wt.%, and most preferably less than 1 wt.%.

The loose tea particles are essentially insoluble. The term substantially insoluble as used herein refers to a substance that does not dissolve when immersed or soaked in an aqueous solution such as water. However, when immersed or soaked in water, the substance may release certain water-soluble substances (eg, taste and/or aroma molecules). In addition, as mentioned above, there is a possibility of partial destruction of the tea granules during their brewing.

Binder.

The binder is a tea-based binder containing tea solids. As used herein, the term tea solids refers to water-soluble solids derived from tea raw materials. The tea solids are conveniently provided by the liquid tea composition. The tea solids are preferably black tea solids, green tea solids, or a combination thereof.

For example, one particularly preferred option is the use of a tea extract as a binder. In other words, the liquid tea composition is a leaf tea extract, preferably an aqueous leaf tea extract. The tea extract can conveniently be obtained by direct extraction of leaf tea with a solvent, preferably an aqueous solvent. It may be appropriate for the liquid tea composition to be a concentrated tea extract, in which case the tea extract will be concentrated by removing the solvent therefrom. An alternative method for preparing a tea extract is to dissolve the tea powder in a solvent, preferably an aqueous solvent. Preferably the tea extract is a black tea extract, a green tea extract, or a combination thereof. Black tea extract is particularly preferred.

Another preferred option is the use of tea juice as a binder. In other words, the liquid tea composition is the squeezed tea juice. Applied in

- 3 041080 of this application, the term pressed tea juice refers to juice that is squeezed from fresh tea leaves and/or dhool (dhool) using physical force (as opposed to extracting tea solids using a solvent). Thus, squeezing includes methods such as compression, pressing, wringing, spinning, and extrusion. Fresh tea leaves refer to tea leaves and/or stems that have never been dried to a moisture content of less than 30% by weight. Dhul refers to macerated fresh tea leaves. During the pressing step, the moisture content of fresh tea leaves and/or dhula is 30 to 90% by weight, more preferably 60 to 90% by weight. Further details regarding pressed tea juice and its production can be found in, for example, WO 2009/059924 (Unilever), WO 2009/059926 (Unilever) and WO 2009/059927. Preferably the tea juice is black tea juice, green tea juice, or a combination thereof.

Tea juices tend to contain a lower proportion of gallated polyphenols than regular tea extracts. For example, black tea juice typically contains theaflavins, wherein the weight ratio of theaflavin (TF1) to theaflavin digallate (TF4) is at least 2.0, more preferably at least 3.0, more preferably at least 3.2, and most preferably from 3.5 to 5.0.

Green tea juice typically contains catechins, wherein the weight ratio of non-gallated catechins to gallated catechins is greater than 1.4:1, more preferably greater than 1.6:1, more preferably still greater than 1.8:1, and most preferably from 3 :1 to 20:1. Definitions of theaflavins and catechins, as well as suitable methods for determining the content of theaflavins and catechins in tea juice, can be found in WO 2009/059927 (Unilever).

The binder may also contain tea solids from various sources. For example, the liquid tea composition may be a combination of tea extract and tea juice.

The remainder of the binder, other than tea solids, is typically water. Preferably at least 90% by weight of the total binder solids is tea solids, more preferably at least 95%, and most preferably at least 99%.

The amount of binder in tea granules is in the range from 1 to 40% by weight of dry matter. The amount of binder should be sufficient to ensure that the loose tea particles adhere to each other to form tea granules. Therefore, the tea granules preferably contain a binder in an amount of at least 5%, more preferably at least 10%, even more preferably at least 11% and most preferably at least 12% by weight of the dry granules. Large amounts of binder may be undesirable, for example, high levels may increase cost and/or introduce flavor notes that may be perceived as too strong. Therefore, it is preferable that the tea granules contain a binder in an amount of no more than 35%, more preferably no more than 30%, even more preferably no more than 25% and most preferably no more than 20% by weight of dry matter.

Porous tea granules.

Tea granules according to the present invention are porous. Such porous granules have a more open structure compared to the natural cellular structure of a conventional loose leaf tea particle. The porous nature of the granules can be observed by microscopy. In FIG. 1 and 2 show the structural differences between conventional black leaf tea (FIG. 1) and porous tea granules according to the present invention (FIG. 2).

Fig. 1 is a confocal image of traditional black leaf tea. The cuticle and cut surface of one leaf fragment can be observed in this image, with the cuticle being a significant part of the total fragment surface.

Fig. 2 is a confocal image of a tea granule according to the present invention. The agglomeration of many smaller particles (with well-defined gaps between constituent particles) can be clearly seen in this image. The granule may have an open (porous) structure, with most of the exposed surfaces being cut surfaces rather than cuticle surfaces.

Porous tea granules have a D[4,3] greater than 350 µm. The average volumetric moment D[4,3] reflects the size of those particles that make up the bulk of the volume of the sample. The porous granules according to the present invention have a size that limits the negative aspects usually associated with small sheet particles (eg, consumer acceptance, ease of processing in the factory, etc.). For example, sizing porous granules is associated with improved consumer acceptance in terms of brew properties (eg, lower haze) and/or product appearance. To maximize these benefits, D[4,3] is preferably greater than 400 μm, more preferably greater than 450 μm, and most preferably greater than 500 μm.

A Malvern Mastersizer 2000 with Scirocco was used to determine the particle size of both loose and granulated tea. Scirocco is a dry dispersion unit with variable feed rate with vibration and dispersion pressure. For smaller particles and larger granules, a dispersion pressure of 2.0 bar and 0.5 bar, respectively, was used.

- 4 041080

The vibration feed rate was maintained at 40% in both cases. Software

The Mastersizer 2000 monitors the system during measurement and analyzes the scatter data to calculate the volumetric size distribution.

As stated above, the tea granules may contain black leaf tea particles, green leaf tea particles, or a mixture of black leaf tea particles and green leaf tea particles. In addition, the binder may contain black tea solids, green tea solids, or a combination thereof. Thus, it is to be understood that tea granules may contain any combination of the contemplated leaf tea particles and binder.

Since fast steeping and rich infusion color are generally preferred by consumers in black tea drinking countries, it is particularly preferred that the tea granules contain black leaf tea particles and the binder contains black tea solids.

Source material for the drink.

The present invention also relates to a beverage preparation starting material containing porous tea granules. The term beverage starting material as used herein refers to a manufactured composition suitable for preparing a beverage.

The beverage preparation raw material may be contacted with an aqueous solution, such as water, to form a beverage. This process is called brewing. The brewing can be carried out at any temperature, although preferably the brewing temperature is at least 40°C, more preferably at least 55°C, most preferably at least 70°C. Preferably the brewing temperature is less than 120°C, more preferably less than 100°C.

A beverage is defined as a substantially aqueous beverage composition that is suitable for human consumption. Preferably, the beverage contains at least 85 wt.% water, more preferably at least 90 wt.% water, and most preferably from 95 to 99.9 wt.% water.

As with porous tea granules, it is preferred that the beverage preparation raw material further comprises leaf tea. The meaning of the term leaf tea is set out above under the heading tea.

At least 90% by weight of loose leaf tea has a particle size of -5+30 mesh. Preferably at least 90% by weight of the loose tea has a particle size of -5+25 mesh, more preferably at least 90% by weight of the leaf tea has a particle size of -5+20 mesh.

For the purposes of the present invention, the particle size of leaf tea is characterized by the mesh size of the sieve. In this application, Tyler cell sizes are used (see Table 1). If the + symbol is present in front of the mesh size, it indicates that the particles are retained by a sieve having the specified mesh size. If the symbol - is present in front of the mesh size, it indicates that the particles are passing through a sieve having the specified mesh size. Leaf tea is usually dried before sieving. For example, if the particle size is described as -5+30 mesh, then the particles pass through a 5 mesh sieve (particles less than 4.0 mm) and are retained by a 30 mesh sieve (particles larger than 595 microns).

Table 1. Selected cell sizes according to Tyler

Tyler cell size 5 mesh 20 mesh 25 mesh 30 mesh 48 mesh 150 mesh Hole size 4.0 mm 841 µm 707 µm 595 µm 297 µm 105 µm

The beverage starting material is preferably packaged. For ease of use, it is particularly preferred that the beverage preparation raw material be packaged in an infusion bag (eg a tea bag). Such a brew bag contains a porous material. The porous material can be any material that is suitable so that water can penetrate into the pouch and insoluble contents cannot be released from the pouch. Examples of a suitable material include filter paper, nylon mesh, gauze, muslin, non-woven material, although any other similar material or fabric may also be used. Thus, if the beverage preparation raw material is packaged in an infusion bag, it is preferable that substantially all of the porous tea granules are retained within the infusion bag.

To ensure long-term storage stability, the beverage preparation starting material preferably contains less than 15 wt.% water, more preferably less than 10 wt.%, and most preferably from 0.1 to 5 wt.%. It should be understood that the quantities indicated refer to the water content before the beverage preparation starting material is used to prepare the beverage (ie, before brewing).

Other ingredients that are commonly used to flavor beverage preparation raw materials containing leaf tea (e.g., bergamot, citrus peel, etc.) may optionally be combined with tea granules and leaf tea in the beverage preparation raw material of the present invention. invention. For example, the source material for preparing a beverage may further comprise an herbal material. The term herbal material refers to a material that is commonly used as a starting material for herbal tinctures.

Preferably, the herbal material is selected from chamomile, cinnamon, elderberry, ginger, hibiscus, jasmine, lavender, lemongrass, mint, rooibos, rosehip, vanilla and verbena. The beverage starting material may additionally or alternatively contain pieces of fruit (eg, apple, blackcurrant, mango, peach, pineapple, raspberry, strawberry, etc.).

There is no particular limit to the relative amounts of porous tea granules and leaf tea in the beverage starting material. The inventors of the present invention believe that the use of a large amount of porous granules in the source material for the preparation of the drink can adversely affect the appearance and, therefore, the acceptance by the consumer of the source material for the preparation of the drink. From the viewpoint of balancing brewing efficiency and consumer acceptance, it is preferable that the mass ratio of porous tea granules to loose tea is 5:1 to 1:5, more preferably 4:1 to 1:4, more preferably 3:1 to 1: 3 and most preferably from 2:1 to 1:2.

Preferably, the weight of the beverage preparation starting material is at least 1 g, since smaller amounts are difficult to accurately portion and dose. More preferably, the mass is at least 1.2 g and most preferably at least 1.4 g. It is further preferred that the mass of the beverage starting material is less than 4 g, since large amounts lead to storage difficulties and/or processing. More preferably, the weight is less than 3 g, and most preferably, less than 2 g.

The beverage starting material can be obtained by any suitable method. For example, by combining porous tea granules according to the present invention with leaf tea, where at least 90 wt.% leaf tea has a particle size of -5+30 mesh. Said method may optionally include an additional and subsequent step of packaging the beverage preparation starting material, preferably in an infusion bag.

The term containing as used in this application includes the terms essentially consisting of and consisting of. All percentages and ratios given in this application are calculated by weight, unless otherwise indicated. It should be noted that when specifying any range of values or amounts, any specific upper value or amount may be associated with any specific lower value or amount. With the exception of examples of implementation and comparison, all numbers in the description characterizing the amount of materials, reaction conditions, physical properties of materials and/or application, should be understood as numbers with the preceding word approximately. The various features of the embodiments of the present invention that pertain to the individual sections above are applicable to other sections, mutatis mutandis, if necessary. Therefore, the distinguishing features specified in one section, if necessary, can be combined with the distinguishing features specified in other sections. The description of the invention given in this application covers all embodiments specified in the claims, which have multiple dependencies on each other. Unless otherwise indicated, all technical and scientific terms used in this application have the same meaning as commonly understood by a person skilled in the art of tea processing.

Examples

The following non-limiting examples illustrate the present invention.

Example 1

The confocal images of black leaf tea and tea granules shown in FIG. 1 and 2 were obtained as follows. Dry beads/particles were placed in 35 mm glass bottom culture dishes with 14 mm microwells and a No. 1.0 coverslip. Confocal laser imaging was performed using a Zeiss LSM-780 confocal laser scanning microscope (Carl Zeiss Ltd) with a 1x/0.45 objective. Image processing was performed using ZEN 2012 V software. Three laser excitation lines (405 nm, 488 nm, and 561 nm) were used to excite autofluorescent molecules, and emission was recorded using a PMT-based detector (from 429 to 474 nm), a detector based on based on GaAsP (from 517 to 579 nm) and a second detector based on PMT (from 650 to 758 nm). z-slice based 3D images were obtained using a pixel delay of 0.64 μs in sequential line scan mode at a magnification factor of 1.0, 2x with line average and 8 μm step on the z-axis. 3D composite fluorescent images were obtained by 3D rendering using ZEN software in maximum intensity mode.

Black leaf tea (control) was a standard grade PF1 material. It was obtained at the Kenyan plant through standard tea processing, including the standard collection, drying, maceration, fermentation, drying and sizing.

Tea granules were obtained as follows.

a) Grinding.

A 160UPZ impact mill (Hosokawa Micron UK) was used to grind standard grade PF1 material into fine particles with a wider size distribution. The device was operated at 6000 rpm and a feed rate of 60 kg/h. The crushed particles were then divided into different fractions with a narrow size distribution using the ATS600 classifier (Allgaier GmbH):

less than 150 microns, from 150 to 250 microns, from 250 to 425 microns and more than 425 microns.

b) Granulation protocol.

Granulation was carried out in an Aeromatic Fielder MP1 fluid bed granulator (GEA Process Systems). The granulation procedure can be divided into three stages, namely heating, agglomeration and drying. A mass of 1 kg of ground tea particles (particle size 150 to 250 nm) was fluidized by maintaining an air flow of 10 to 20%. The temperature of the particles of the fluidized bed was raised to 60°C-70°C before the introduction of an aqueous solution of Saint Brite instant tea (Unilever) at 0.65% w/w. through a two-fluid nozzle at a flow rate of 25 to 30 ml/min using a peristaltic pump. The addition of an aqueous solution of the binder resulted in a decrease in the temperature of the layer to about 50°C. The height of the nozzle and the pressure of the atomized air (0.75 bar) were kept constant throughout the study. During the experiment, an intermittent shock pressure of 0.5 bar was used to reintroduce any small particles into the particle bed. The drying regime was started immediately after completion of the dosing of the liquid binder, and the experiment was terminated after keeping the particles in a fluidized state at an elevated temperature (70° C.) for an additional 10-15 minutes. The granulated product was then optionally further dried in a tray dryer at 80° C. for 2-3 hours to ensure that the final product had a moisture content of less than 3% by weight. The dried granules contained 0.16% wt./wt. binder (Saint Brite instant tea) and had a particle size D[4,3] of 600 µm.

Example 2

Control material and tea granules were obtained and prepared as described in Example 1 above.

The brewing efficiency of the porous tea granules was compared with the brewing efficiency of the control tea material. More specifically, three different amounts of control material and three different samples of porous tea granules were compared. In table. 2 shows the amounts of leaf tea and tea granules that were used in each case.

table 2

Control A Control B Control C sample 1 Sample 2 Sample 3 Leaf tea 3.125 g 2.5 g 2.19 g - - - tea granules - - - 3.125 g 2.5 g 2.19 g

Brewing characteristics were determined using the dynamic method described in WO 2012/113602. The dynamic procedure (continuous dipping) is a laboratory simulation of the consumer's tea preparation process involving the stirring of a tea bag. In all cases, tea bags of the same size and geometry were used, made from the same filter material (tetrahedral tea bags). Absorbance was measured at 445 nm. The total infusion time was 120 s in a volume of 200 ml and the sampling rate was 1 sample per second.

The brewing curves are shown in Fig. 3. Sample 1 (porous granules, standard pouch weight), sample 2 (porous granules, 20% pouch weight reduction), and sample 3 (porous granules, 30% pouch weight reduction) had improved brew efficiency compared to Control A ( loose leaf tea, standard sachet weight). Each of the samples also showed an improvement in brewing efficiency compared to the respective control, ie. Sample 1 vs. Control A (standard pouch weight), Sample 2 vs. Control B (20% sachet weight reduction), Sample 3 vs. Control C (30% sachet weight reduction).

The level of soluble solids in the tea was measured at the end of the dynamic procedure. A 50 ml sample of the tea leaves was taken and weighed using an accurate balance. This sample was allowed to dry completely in an oven for 16 hours and then reweighed. The difference between the initial weight of the tea leaves and the weight of the dry sample was used to calculate the level of soluble solids in the tea leaves. The results are shown in table. 3. The level of soluble solids released into the tea leaves for samples 1 and 3 compared to their respective controls (ie controls A and C) was significantly higher.

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Claims (12)

Table 3 Control A Sample 1 Control C Sample 3 Soluble solids in tea leaves 0.473% 0.748% 0.327% 0.515% The level of soluble solids released into the porous tea granule infusion will include solids from the binder as well as solids from loose leaf tea particles. It differs from controls where the soluble solids in the brew come exclusively from the leaf tea material. To establish that the improvement in brewing efficiency was not due solely to the presence of the binder, the proportion of soluble solids extracted from the loose leaf tea particles was evaluated. For this, it was assumed that all the solids contained in the binder were released into the tea leaves. The rest of the soluble solids in the brew above this level were believed to be derived from loose leaf tea particles. For controls, the soluble solids in the brew were obtained from leaf tea. Table 4 Control A sample 1 Control C Sample 3 Fraction of soluble solids extracted from leaf component 65.1% 75.0% 67.2% 78.5% In table. 4 shows the fraction of soluble solids extracted from the leaf component (ie, leaf tea particles for samples 1 and 3, leaf tea for controls A and C). For Controls A and C, it was estimated that approximately two thirds of the soluble solids present in the leaf component were released into the tea leaves. At the same time, for samples 1 and 3, it was estimated that at least three quarters of the soluble solids present in the loose leaf tea particles are released into the infusion. This indicates that the improved brewing efficiency of porous tea pellets is not due solely to the presence of the binder. In other words, in the case of granules, more of their constituent solids are released into solution from the loose tea particles than in the case of regular (ungranulated) loose tea. CLAIM 1. Porous tea granules containing particles of leaf tea and a binder, where at least 50 wt.% particles of leaf tea have a size of from 100 to 300 microns; the binder is a tea-based binder containing tea solids; tea granules contain a binder in an amount of from 1 to 40% by weight of dry granules; and porous tea granules have D[4,3] greater than 350 µm. 2. Porous tea granules according to claim 1, characterized in that the binder is a tea extract or tea juice. 3. Porous tea granules according to claim 1 or 2, characterized in that the tea granules contain a binder in an amount of 10 to 25% by weight of dry granules. 4. Porous tea granules according to any one of claims 1 to 3, characterized in that the loose tea particles are crushed leaf tea particles. 5. Porous tea granules according to any one of claims 1 to 4, characterized in that the leaf tea having a particle size of 100 to 300 µm is black leaf tea. 6. Porous tea granules according to any one of claims 1 to 5, characterized in that the porous tea granules have a D[4,3] of more than 450 µm. 7. A tea beverage starting material comprising the porous tea granules according to any one of claims 1 to 6. 8. A tea-based beverage source material according to claim 7, characterized in that the beverage source material further comprises leaf tea, where at least 90 wt.% of the leaf tea has a particle size of 595 µm to 4.0 mm (- 5+30 mesh). 9. The starting material for a tea-based beverage according to claim 8, characterized in that the mass ratio of porous tea granules to leaf tea is from 5:1 to 1:5. 10. An infusion bag containing the tea beverage starting material according to any one of claims 7 to 9. 11. The sachet according to claim 10, characterized in that the starting material for the tea-based beverage has a mass of 1 to 4 g. 12. A method for producing porous tea granules, including the steps: (a) providing loose leaf tea; (b) grinding and/or screening the leaf tea such that at least 50% by weight of the leaf tea has a particle size of 100 to 300 microns; -