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, the present invention provides a liquid tea product comprising: a. tea solids; b. a compound comprising a flavylium cation; and, c. a reducing agent, wherein i) the structure of the flavylium cation is : formula (I), ii) the compound comprising flavylium cation belongs to the group of anthocyanins, iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine or mixtures thereof, and; iv) the pH of the product is less than 6.

Description

[0001] P0001022 CPL

[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-d rink 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 and either 15 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] The ready-to-drink format is gaining popularity in today's world. It seems that consumers 20 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 teas, iced teas are very popular worldwide. Although they are available in liquid and ready-to- 25 drink format, the color 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] JP3032153 (2000, ASAHI BEER INRIYOU SEIZO KK) describes a red-coloured liquid 30 tea product with green tea.

[0012] 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. P0001022 CPL

[0013] 2

[0014] WO 2023 / 187034 (2023, EKATERRA RES AND DEVELOPMENT UL LIMITED) describes a process of producing a tea product. More particularly the present invention relates to a process of producing a cold-water infusible leaf tea product with rich red 5 colour. Accordingly, the present invention provides a process for producing a tea product comprising the steps of contacting tea leaves with 0.1 to 10 percent by weight of a base for about 30 minutes to 6 hours.

[0015] CN 104782814 (2015, WU 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] 15 There is also non-patent literature which describes purple tea and anthocyanins.

[0017] "The inhibitory action of purple tea on in vivo starch digestion compared to other Camellia sinensis teas" by DASILVA TAMIRES ET AL. (FOOD RESEARCH INTERNATIONAL, vol. 150, 1 December 2021 (2021-12-01), page 110781) describes the inhibitory action 20 of purple tea on in vivo starch digestion compared to other Camellia sinensis teas.

[0018] "Characterization of anthocyanins in Kenyan teas: Extraction and identification" by KERIO L C ET AL. (FOOD CHEMISTRY, ELSEVIER LTD, NL,

[0019] vol. 131, no. 1, 2 August 2011 (2011-08-02), pages 31-38) describes characterization 25 and quantification of anthocyanins in selected tea cultivars which processed into black (aerated) and green (unaerated) tea products.

[0020] "Identification and Quantification of Anthocyanin and Catechin Compounds in Purple Tea Leaves and Flakes" by ABDEL-AAL EL-SAYED M. ET AL. (MOLECULES, vol. 27, no.

[0021] 30 19, 7 October 2022 (2022-10-07), page 6676) describes identification and quantification of anthocyanin and catechin compounds in purple tea leaves and flakes. In particularly it describes a process of preparing both green and black teas from purple tea cultivars of Canadian origin. P0001022 CPL

[0022] 3

[0023] One of the problems associated with the colored iced tea is that the colour of the product deteriorates on storage. A pink or red coloured iced tea loses its colour on storage.

[0024] It is therefore an object of the present invention to provide a liquid tea product.

[0025] 5

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

[0027] 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.

[0028] The present inventors while working on the problem have surprisingly found that a liquid tea product with a coloured compound when combined with a reducing agent solve the problem thereby satisfying one or more of the above-mentioned objects.

[0029] 15

[0030] Summary of the invention

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

[0032] a. tea solids;

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

[0034] 20 c. a reducing agent;

[0035] wherein,

[0036] i) the structure of the flavylium cation is:

[0037]

[0038] ii) the compound comprising flavylium cation belongs to the group of anthocyanins,

[0039] 30 iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine or mixtures thereof, and;

[0040] iv) the pH of the product is less than 6. P0001022 CPL

[0041] 4

[0042] 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 and a reducing agent together followed by a step of heat treatment, wherein,

[0043] 5 i) the structure of the flavylium cation is:

[0044]

[0045] ii) the compound comprising flavylium cation belongs to the group of anthocyanins,

[0046] iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, 15 sodium metabisulphite, selenocysteine or mixtures thereof, and;

[0047] iv) the pH of the product is less than 6.

[0048] 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 20 avoidance of doubt, any feature of one aspect of the present invention may 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 25 those examples perse. Similarly, all 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 understood as modified by the word “about”. Numerical ranges expressed in the format 30 "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. P0001022 CPL

[0049] 5

[0050] Detailed description of the invention

[0051] The present invention provides a liquid tea product comprising:

[0052] a. tea solids;

[0053] b. a compound comprising flavylium cation; and

[0054] 5 c. a reducing agent.

[0055] wherein,

[0056] i) the structure of the flavylium cation is:

[0057]

[0058] ii) the compound comprising flavylium cation belongs to the group of anthocyanins,

[0059] 15 iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine or mixtures thereof, and

[0060] iv) the pH of the product is less than 6.

[0061] 20 Liquid tea as mentioned herein preferably means a ready- to-d rink 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 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.

[0062] 25

[0063] A beverage precursor in concentrated from, e.g. as dried powder or liquid concentrate is also preferably within the scope of the present invention.

[0064] The term ready- to-d rink format preferably means a format which does not need many 30 efforts at the consumer end for preparing a beverage and most of the cases consumer can directly consume as it is. P0001022 CPL

[0065] 6

[0066] The liquid tea product of the invention comprises tea solids. The amount of tea solids preferably in the range from 0.01 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.

[0067] 5 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 produced through processes like withering, maceration, fermentation, and drying. It has distinct characteristics and organoleptic properties compared to green tea, which is nonfermented. Green tea is made from fresh tea leaves that undergo withering followed by 10 drying (steaming or pan firing) to stop enzymatic activities. Oolong tea is semifermented, with fresh tea leaves undergoing withering and maceration, but the fermentation period is shorter than that of black tea.

[0068] Other than the tea solids, the liquid tea product of the present invention also comprises a compound comprising flavylium cation.

[0069] Flavylium cation represented by the following structure:

[0070]

[0071] 20

[0072] Flavylium cation is found in many of the pigment compound. One of such preferable pigment compounds are anthocyanins which belongs to flavonoids family. It is responsible for providing various colours e.g. red, purple, blue based on the pH level.

[0073] 25 Anthocyanins are very well known. It is a group of compounds which are very easily soluble in water. The colored 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: P0001022 CPL

[0075]

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

[0077] Preferably, the source of anthocyanins used in the invention are from natural sources.

[0078] 5 However, any other source such as synthetically prepared are also within the scope of the present invention.

[0079] 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, 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 15 or metal ions.

[0080] 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 20 contains elevated levels of these natural pigments, 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 colored 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, 25 making it an attractive ingredient for innovative beverage formulations.

[0081] 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 potential antioxidant benefits. P0001022 CPL

[0082] 8

[0083] 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.

[0084] 5 Although anthocyanins are available in different sources, the composition of different anthocyanins varies from one source to another, e.g. in case of purple 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.

[0085] The amount of the compound comprising flavylium cation is preferably in the range from 0.0001 to 0.1% by weight of the liquid tea 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.

[0086] 15 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.

[0087] The present inventors while working on the coloured liquid tea product have found that 20 the colour of the compounds tends to degrade over time. They surprisingly found that addition of a selected reducing agent able to stabilize the colour of the product.

[0088] Hence, the composition of the present invention also includes a reducing agent.

[0089] 25 The reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulphite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine and mixtures thereof. The most preferred reducing agent is sodium metabisulphite, sodium sulphite and L-Cysteine.

[0090] 30 The amount of reducing agent in the product is preferably in the range from 0.0001 to 5% by weight, more preferably from 0.001 to 2% by weight, furthermore preferably from 0.01 to 1% by weight and most preferably from 0.01 to 0.5% by weight.

[0091] The product may further comprise an acidulant to maintain the pH of the product. P0001022 CPL

[0092] 9

[0093] The preferred pH of the product is less than 6, more preferably 2 to 5, furthermore preferably in the range from 2.5 to 4.5 and most preferably in the range from 2.5 to 4.

[0094] 5 The product of the present invention may also additionally comprise an antioxidant.

[0095] The product of the present invention may also comprise a buffer.

[0096] The present invention also provides a process for producing the product of the invention. The method comprising the steps of mixing tea solids, a compound comprising flavylium cation and a reducing agent together followed by a step of heat treatment, wherein

[0097] i) the structure of the flavylium cation is:

[0098]

[0099] ii) the compound comprising flavylium cation belongs to the group of anthocyanins,

[0100] 20 iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine or mixtures thereof, and;

[0101] iv) the pH of the product is less than 6.

[0102] 25 Preferably the heat treatment step is required to make the product microbiologically stable. The most preferred heat treatment step is pasteurization.

[0103] Examples

[0104] The examples are intended to illustrate the invention and are not intended to limit the 30 invention to those examples perse.

[0105] Effect of reducing agents with fixed amount of anthocyanin:

[0106] Different formulation was prepared based on the following Table 1, with varied amount and type of reducing agent. P0001022 CPL

[0107] 10

[0108] Table 1:

[0109]

[0110] For the above, oolong tea was procured from Damin from China batch No:

[0111] 5 DM04222237, Purple sweet Potato Extract was procured from Givaudan from China Variant and Batch no: Vegebrite Raspberry Shade PWS C0306320.

[0112] The following Table 2 represents the varying amount and types of reducing agent.

[0113] 10 Table 2

[0114]

[0115] Sodium metabisulphite P0001022 CPL

[0116] 11

[0117] 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.

[0118] 5 After 7 days the samples were taken out of the storage and colour measurement was performed using the following method.

[0119] The colour (CIE L*a*b* values) of the liquid tea samples was measured using Hunter colorimeter Vis model using D65 illuminant and 10° observer angle. The machine was 10 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.

[0120] 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 connotes to blue colour. The higher the a* value the redder is the infusion.

[0121] 20

[0122] The results of the measurements are summarized below in Table 3.

[0123] Table 3

[0124]

[0125] P0001022 CPL

[0126] 12

[0127] From the above results it is evident that the examples (1 to 8) within the scope of the present invention can stabilize the red colour of the liquid tea products, it is very clear that a* value of the products with inclusions of reducing agents much higher when 5 compared to control Example A where reducing agent is absent.

[0128] Effect of anthocyanin concentration with fixed amount of reducing agents:

[0129] In these set of examples same formulation as mentioned is Table 1 was used. The difference is the concentration of anthocyanin, and the reducing agent was varied as per Table 4.

[0130] The colour was also measured using the same method as disclosed above, after 7 days of hot and dry storage condition. Table 4 summarizes the variations, and the colour 15 measurements results together.

[0131] Table 4

[0132]

[0133] From the above Table 4, it is evident that with the varied concentration of anthocyanin 20 same trend was observed. Examples 9 and 10 provides much higher red colour when compared with example B. Similarly, Examples 11 and 12 provides much higher red colour when compared with example C.

[0134] From the description and the example it is apparent that, by way of present invention it 25 is now possible to provide a red / pink coloured liquid tea product the colour of which is stable on storage.

Claims

P0001022 CPL13Claims1. A liquid tea product comprising:a. tea solids;b. a compound comprising flavylium cation; and,c. a reducing agent,whereini) the structure of flavylium cation is:ii) the compound comprising flavylium cation belongs to the group of anthocyanins,iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine or mixtures thereof, and;iv) the pH of the product is less than 6.

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

3. A product according to any one of the preceding claims further comprises an acidulant.

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

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

6. A product according to any one of the preceding claims wherein the amount of tea solids in the product is in the range from 0.1 to 10% by weight of the product.P0001022 CPL147. A process of producing a liquid tea product comprising the steps of mixing tea solids, a compound comprising flavylium cation and a reducing agent together followed by a step of heat treatment,whereini) the structure of flavylium cation is:ii) the compound comprising flavylium cation belongs to the group of anthocyanins,iii) the reducing agent is selected from L-Cysteine, glutathione, formic acid, sorbic acid, glucose, sodium sulfite, sodium bisulfite, sodium dithionite, sodium metabisulphite, selenocysteine or mixtures thereof, and;iv) the pH of the product is less than 6.

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