A liquid tea product

Abstract

The present invention relates to a liquid tea product. More particularly the present invention relates to a ready-to-drink liquid tea product. Accordingly, a liquid tea product comprising: a. a tea extract; and, b. a compound comprising a flavylium cation; wherein the total polyphenol content in the product is less than 0.04% by weight, and further wherein i) the structure of the flavylium cation is: formula (I); ii) the compound comprising flavylium cation belongs to the group of anthocyanins; and, iii) the pH of the product is less than 6.

Description

[0001] P0001023

[0002] 1

[0003] A LIQUID TEA PRODUCT

[0004] Field of the invention

[0005] The present invention relates to a liquid tea product. More particularly the present 5 invention relates to a ready-to-drink liquid tea product.

[0006] Background of the invention

[0007] Tea is one of the most consumed non-alcoholic beverages in the world. There are various types of tea products, such as green tea, black tea, oolong tea, and white tea. These teas can be consumed either as hot or cold beverages.

[0008] These teas are also available in different formats, such as leaf tea, ready-to-drink, or in a form that can be easily reconstituted into a beverage. In the case of leaf tea, consumers need to prepare the tea beverage using either hot or cold water 15 and either boiling the tea leaves or dunking the tea bags several times in hot water. In some regions, people also add milk and / or sugar to it. In the case of ready-to-drink format, consumers just need to open the pack and consume it directly.

[0009] 20 The ready-to-drink format is gaining popularity in today's world. It seems that consumers do not want to spend much time on preparing tea beverages and at the same time they want to enjoy tea as a beverage.

[0010] One of the most consumed ready-to-drink teas is in liquid format. Among liquid 25 teas, iced teas are very popular worldwide. Although they are available in liquid and ready-to-drink format, the colour of iced teas is mostly brown to black. To enhance the visual and sensorial appeal, the tea industry started preparing liquid tea in attractive colours. One of the colours is red and / or pink.

[0011] 30 JP3032153 (2000, ASAHI BEER INRIYOU SEIZO KK) describes a red-coloured liquid tea product with green tea. P0001023

[0012] 2

[0013] JP2007028933 (2007, ASAHI BREWERIES LTD) describes a tea beverage containing anthocyanin, having 500-550 nm of maximal absorption of visible light, and taking on colour ranging from red to pink.

[0014] 5

[0015] CN 104782814 (2015, Wil QINGQUAN) describes a purple sweet orange tea drink, characterized by the following raw materials in parts by weight: purple sweet potato 118-120, distilled 239-245, a - amylase 0.8-1, 1.2-1.6 glucoamylase, citrus 35-40, 8-10 oolong tea, ginger 80-85, Radix 5-6, 3-4 bellflower, Atractylodes 2-3, 2-3 sage, heterophylla 3 -4, sugar powder 25-30, citric 0.05-0.08 and water.

[0016] There is also non-patent literature which describes purple tea and anthocyanins.

[0017] 15 “The Effect of pH and Color Stability of Anthocyanin on Food Colorant” by Wahyuningsih S ET AL (IOP Conference Series: Materials Science and Engineering, vol. 193, 1 April 2017 (2017-04-01), page 012047).

[0018] “Processing of Herbal Tea from Roselle (Hibiscus sabdariffa L.) and effects of 20 Drying Temperature and Brewing Condition on Total Soluble Solid, Phenolic Content, Antioxidant Capacity and Sensory Quality” by Nguyen Quang Vinh ET AL (Beverages, vol. 6, no. 1, 2 January 2020 (2020-01-02), page 2).

[0019] “The Dark -Purple Tea Cultivar ‘Ziyan’ accumulates a Large Amount of 25 Delphinidin-Related Anthocyanins” by Lai Yun-Song ET AL (Journal of Agricultural and Food Chemistry, vol. 64, no. 13, 25 March 2016 (2016-03-25), pages 2719-2726)

[0020] “Sustainable and effective approach to recover antioxidant compounds from 30 purple tea (Camellia sinensis var. assamica cv. Zijuan) leaves” by DE MOURA P0001023

[0021] 3

[0022] CRISTIANE ET AL (FOOD RESEARCH INTERNATIONAL ELSIVIER, AMSTERDAM, NL, vol. 164, 31 December 2022 (2022-12-31)).

[0023] “Anthocyanins: Factors Affecting Their Stability and Degradation” by ENARU 5 BIANCA ET AL (ANTIOXIDANTS, vol. 10, no. 12, 9 December 2021 (2021-12- 09), page 1967).

[0024] One of the problems associated with the coloured iced tea is that the colour of the product deteriorates on storage. A pink- or red-coloured iced tea loses its colour on storage.

[0025] It is therefore an object of the present invention to provide a liquid tea product.

[0026] It is another object of the present invention to provide a liquid tea product with intense red / pink colour.

[0027] 15

[0028] It is yet another object of the present invention to provide a red / pink coloured liquid tea product, the colour of which is stable on storage.

[0029] The present inventors while working on the problem have surprisingly found that 20 a liquid tea product with a coloured compound when formulated with a particular amount of polyphenols in the tea solve the problem thereby satisfying one or more of the above-mentioned objects.

[0030] Summary of the invention

[0031] 25 In a first aspect, the present invention provides a liquid tea product comprising:

[0032] a. a tea extract; and,

[0033] b. a compound comprising a flavylium cation;

[0034] wherein the total polyphenol content in the product is less than 0.04% by weight, and further wherein

[0035] 30 i) the structure of the flavylium cation is: P0001023

[0036]

[0037] ii) the compound comprising flavylium cation belongs to the group of anthocyanins; and

[0038] iii) the pH of the product is less than 6.

[0039] 5

[0040] In a second aspect, the present invention provides a process of producing a liquid tea product comprising the steps of mixing tea solids, a compound comprising flavylium cation together followed by a step of heat treatment wherein the total polyphenol content in the product is less than 0.04% by weight,

[0041] 10 and further wherein

[0042] i) the structure of the flavylium cation is:

[0043]

[0044] ii) the compound comprising flavylium cation belongs to the group of anthocyanins; and

[0045] iii) the pH of the product is less than 6.

[0046] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description. For the avoidance of doubt, any feature of one aspect of the present invention may 20 be utilized in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of’ or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all P0001023

[0047] percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be 5 understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

[0048] Detailed description of the invention

[0049] The present invention provides a liquid tea product comprising:

[0050] a. tea solids; and,

[0051] b. a compound comprising a flavylium cation;

[0052] wherein the total polyphenol content in the product is less than 0.04% by weight 15 and further wherein

[0053] i) the structure of the flavylium cation is:

[0054]

[0055] ii) the compound comprising flavylium cation belongs to the group of anthocyanins; and

[0056] 20 iii) the pH of the product is less than 6.

[0057] Liquid tea as mentioned herein preferably means a ready-to-drink format of tea in liquid form. Most preferably the liquid tea product of the invention is served as iced tea, i.e. a liquid tea beverage served in chilled condition. The temperature 25 of the iced tea is preferably in the range from 0°C to 15°C, preferably from 0°C to 10°C and most preferably from 0°C to 6°C. P0001023

[0058] 6

[0059] A beverage precursor in concentrated form, e.g. as dried powder or liquid concentrate is also preferably within the scope of the present invention.

[0060] The term ready-to-drink format preferably means a format which does not need 5 many efforts at the consumer end for preparing a beverage, and most of the cases consumer can directly consume as it is.

[0061] The liquid tea product of the invention comprises tea solids. The amount of tea solids preferably in the range from 0.001 to 10%, more preferably 0.01 to 5%, furthermore preferably 0.01 to 3% and most preferably 0.1 to 3% by weight of the composition.

[0062] Tea solids can preferably be selected from various types of teas, such as black tea, oolong tea, green tea, or their mixtures. Black tea is a fermented tea 15 produced through processes like withering, maceration, fermentation, and drying.

[0063] It has distinct characteristics and organoleptic properties compared to green tea, which is non-fermented. Green tea is made from fresh tea leaves that undergo withering followed by drying (steaming or pan firing) to stop enzymatic activities. Oolong tea is semi-fermented, with fresh tea leaves undergoing withering and 20 maceration, but the fermentation period is shorter than that of black tea.

[0064] Preferably the tea solids sourced from Camellia sinensis plant, e.g. Camellia sinensis var. sinensis and / or Camellia sinensis var. assamica. Most preferrably Camellia sinensis var. assamica.

[0065] 25

[0066] The polyphenols content of the tea solids is preferably below 25% by weight, more preferably below 20% by weight, furthermore preferably below 15% by weight and most preferably below 10% by weight.

[0067] 30 Other than the tea solids, the liquid tea product of the present invention also comprises a compound comprising flavylium cation. P0001023

[0068] Flavylium cation represented by the following structure:

[0069]

[0070] 5

[0071] Flavylium cation is found in many of pigment compounds. One group of such preferable pigment compounds are anthocyanins, which belongs to the flavonoids family. They are responsible for providing various colours, e.g. red, purple, blue - based on the pH level.

[0072] 10

[0073] Anthocyanins are very well known. They are a group of compounds which are very easily soluble in water. The coloured anthocyanin pigments have been traditionally used as a natural food colorant.

[0074] The structure of the pigments belongs to the group of anthocyanins is as follow:

[0075]

[0076] Where R1 and R2 is preferably selected from, H, OH and OCH3.

[0077] 20

[0078] Preferably, the source of anthocyanins used in the invention are from natural sources. However, any other source such as synthetically prepared are also within the scope of the present invention. P0001023

[0079] 8

[0080] There are several types of anthocyanins, each differing in their chemical structure and the specific substitutions on their core flavylium cation. The most common anthocyanins found in nature include cyanidin, delphinidin, pelargonidin, 5 peonidin, petunidin, and malvidin. These compounds vary mainly in the number and position of hydroxyl and methoxy groups attached to the flavylium backbone, which influence their colour expression and stability. The diversity among anthocyanins results in a wide range of hues, from red and purple to blue, depending on the pH and the presence of co-pigments or metal ions.

[0081] One of the examples of plants containing anthocyanins is purple tea. It is a unique variety of tea derived from the Camellia sinensis plant, distinguished by its vibrant purplish leaves and high anthocyanin content. Unlike traditional black or green teas, purple tea contains elevated levels of these natural pigments, 15 which not only contribute to its striking colour but also offer potential antioxidant benefits. The anthocyanins present in purple tea are similar to those found in berries and other deeply coloured fruits, imparting a subtle floral taste and a mild, smooth flavor profile. This rare tea is cultivated primarily in Kenya and is gaining popularity for its distinctive appearance and health-promoting properties, making 20 it an attractive ingredient for innovative beverage formulations.

[0082] In addition to purple tea as sources of anthocyanins, sweet potatoes are also excellent sources of these vibrant pigments. Purple sweet potatoes are especially rich in anthocyanins, imparting their characteristic hue as well as 25 potential antioxidant benefits. These root vegetables not only enhance the colour of food and beverage products, but also provide a subtle sweetness and a creamy texture, making them a versatile ingredient in food / beverage formulations.

[0083] Although anthocyanins are available in different sources, the composition of 30 different anthocyanins varies from one source to another, e.g. in case of purple P0001023

[0084] 9

[0085] tea peonidin to cyanidin ratio is less than 1. Whereas, in case of sweet potatoes the ratio of peonidin to cyanidin ratio is greater than 1.

[0086] The amount of the compound comprising flavylium cation is preferably in the 5 range from 0.0001 to 0.1 % by weight of the product, more preferably in the range from 0.009 to 0.01% by weight, furthermore preferably in the range from 0.007 to 0.003% by weight and most preferably 0.006 to 0.002% by weight.

[0087] Preferably the product flavylium cation is present in the product in the form of anthocyanins. Most preferably in those anthocyanins the ratio of peonidin to cyanidin ratio is greater than 1.

[0088] The present inventors while working on the coloured liquid tea product have found that the colour of the compounds tends to degrade over time. They surprisingly 15 found that use of selected tea solids with a particular polyphenol content able to stabilize the colour of the product.

[0089] Without wishing to be bound by theory, it is believed that presence of sufficiently high amounts of polyphenol (preferably more than 25% by weight) in tea solids 20 interacts with the flavylium cation belongs to the group of anthocyanins at low pH (preferably below 6) leading to colour instability on storage.

[0090] The polyphenol content in the end product is less than 0.04% by weight of the composition, preferably less than 0.035% by weight, more preferably less than 25 0.03 by weight and most preferably 0.028% by weight.

[0091] Preferably the polyphenol content is in the range from 0.038 to 0.001 % by weight of the composition, more preferably 0.028 to 0.001% by weight, furthermore preferably 0.025 to 0.001% by weight and most preferably 0.020 to 0.001% by 30 weight. P0001023

[0092] 10

[0093] This polyphenol content in the final product is preferably achieved by using tea solids with total polyphenol content in the range from 1 % to 50% by weight of tea solids. More preferably the polyphenol content in the tea solids is in the range from 1 to 40%, furthermore preferably in the range from 1 to 35% and most 5 preferably in the range from 3 to 35% by weight of tea solids. Furthermore, to achieve very low polyphenol content (less than 0.04% by weight) in the final product, it is preferable that the tea solids employed in the present invention are passed through a resin, ideally a polyamide resin, to selectively remove polyphenols and isolate only the polyphenol poor fraction which is then converted into tea solids. These tea solids are preferably utilised in the preparation of the product described herein. Polyphenol poor fraction preferably means a fraction having a polyphenol content of less than 5% by weight.

[0094] The product may further comprise an acidulant to maintain the pH of the product.

[0095] 15

[0096] The preferred pH of the product is less than 6, more preferably 2 to 5 and most preferably in the range from 2.5 to 4.5.

[0097] The most preferred acidulant is ascorbic acid.

[0098] 20

[0099] Preferably the weight ratio of polyphenols to ascorbic acid in the product is 1 :4 or less, more preferably 1 :3 or less and most preferably 1 :2.5 or less.

[0100] Preferably the weight ratio of caffeine to total polyphenol in the product is more 25 than 1 , more preferably more than 1.2, further more preferably more than 1.5 and most preferably more than 1.7.

[0101] The product of the present invention may also additionally comprise an antioxidant.

[0102] 30

[0103] The product of the present invention may also comprise a buffer. P0001023

[0104] 11

[0105] The present invention also provides a process of producing a liquid tea product comprising the steps of mixing tea solids, a compound comprising flavylium cation together followed by a step of heat treatment wherein the total polyphenol 5 content in the product is less than 0.04% by weight.

[0106] Preferably the heat treatment step is required to make the product microbiologically stable. The most preferred heat treatment step is pasteurization.

[0107] Preferably the tea solids are pretreated with a resin before using them in the process of the present invention. The most preferred resin is a polyamide resin. This step is preferably done to reduce the polyphenol content in the tea solids. Regular tea contains high amount of polyphenols (preferably greater than 15%, 15 more preferably 20% by weight).

[0108] Now the invention will be demonstrated with the help of following non-limiting examples.

[0109] 20 Examples

[0110] The examples are intended to illustrate the invention and are not intended to limit the invention to those examples perse.

[0111] Effect of reducing agents with fixed amount of anthocyanin:

[0112] 25 Different formulations were prepared based on the following Table 1, with oolong tea solids having varied amounts of polyphenols. P0001023

[0113] 12

[0114] Table 1:

[0115]

[0116] For the above, oolong tea was procured from Damin from China batch No: DM04222237, with total polyphenol (PP) content of about 35% by weight, Purple 5 sweet Potato Extract was procured from Givaudan from China Variant and Batch no: Vegebrite Raspberry Shade PWS C0306320.

[0117] The above procured oolong tea (with about 35% of polyphenol content) first passed through a polyamide resin to obtain a polyphenol poor fraction with a 10 polyphenol content of about 3% by weight. This fraction was used in preparing the products.

[0118] For preparing the products, oolong tea solids were added at a fixed concentration of 0.12% in all the formulations. Only the PP content in the tea solids were varied. Three formulations were prepared based on the PP content in the tea solids which are as follows:

[0119] i) Example A: polyphenol content about 35% (oolong tea as procured) by dry weight of the tea solids,

[0120] 20

[0121] ii) Example 1 : polyphenol content 13% (a mix of oolong tea with 3% PP and 35% PP) by dry weight of the tea solids; and, P0001023

[0122] 13

[0123] iii) Example 2: polyphenol content about 3% (oolong tea as obtained after polyamide treatment) by dry weight of the tea solids.

[0124] The amount of polyphenols in the final tea products was calculated as follows:

[0125] Amount of tea solids added in the product x polyphenol content of the tea solids 5

[0126] 100

[0127] After the formulations were prepared, it was transferred to a Schott Duran glass bottle (100 mL) they and kept under hot and dry storage chamber maintained at 40 ± 2° C for 7 days.

[0128] After 7 days the samples were taken out of the storage and colour measurement was performed using the following method.

[0129] The colour (CIE L*a*b* values) of the liquid tea samples was measured using 15 Hunter colorimeter Vis model using D65 illuminant and 10° observer angle. The machine was calibrated using white tile, black trap and black card. The sample cuvette size was 0.8 cm. The anthocyanins stability was calculated indirectly using absorbance at 530 nm using the same instrument.

[0130] 20 The L*a*b* values were measured at room temperature (25°C). The maximum value for L* is 100, which represents a perfect reflecting diffuser. The minimum is L*=0, which represents black. The a* and b* axis have no specific numerical limits. Positive a* connotes to red colour and negative a* connotes to green. Similarly, positive b* value connotes yellow colour and negative b* value 25 connotes to blue colour. The higher the a* value the redder is the infusion.

[0131] The results of the measurements are summarized below in Table 2. P0001023

[0132] 14

[0133] Table 2

[0134]

[0135] From the above results it is evident that the Examples (1 and 2) within the scope of the present invention can stabilize the red colour of the liquid tea products. It 5 is very clear that a* value of the products with the polyphenol concentration within the scope of the present invention is much higher than the a* value of the control Example A.

[0136] From the description and the example, it is apparent that, by way of present 10 invention it is now possible to provide a red / pink coloured liquid tea product, the colour of which is stable on storage.

Claims

P0001023Claims1. A liquid tea product comprising:a. tea solids; and,5 b. a compound comprising a flavylium cation;wherein the total polyphenol content in the product is less than 0.04% by weight, and further whereinthe structure of the flavylium cation is:ii) the compound comprising flavylium cation belongs to the group of anthocyanins; and,iii) the pH of the product is less than 6.

2. A product according to claim 1 wherein anthocyanins are sourced from a 15 natural material.

3. A product according to claim 1 wherein the amount of polyphenol in the product is in the range from 0.0001 to 0.4% by weight.20 4. A product according to claim 3 wherein the amount of polyphenol in the product is in the range from 0.009 to 0.035% by weight.

5. A product according to any one of the claims 1 to 4 further comprises an acidulant.

256. A product according to claim 5 wherein the acidulant is ascorbic acid.P0001023167. A product according to claim 6 wherein the ratio of polyphenols to ascorbic acid in the product is 1 :4 or less.

8. A product according to any one of the preceding claims further comprises 5 an antioxidant.

9. A product according to any one of the preceding claims further comprises a buffer.

10. A product according to any one of the preceding claims wherein the amount of tea solids in the product is in the range from 0.001 to 10% by weight of the product.

11. A process of producing a liquid tea product comprising the steps of mixing 15 tea solids, a compound comprising flavylium cation together followed by a step of heat treatment, wherein the total polyphenol content in the product is less than 0.04% by weight, and further whereini) the structure of the flavylium cation is:20 ii) the compound comprising flavylium cation belongs to the group of anthocyanins; and,iii) the pH of the product is less than 6.

12. A process as claimed in claim 11 wherein the tea solids are pretreated with 25 a resin.

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