A low-caffeine tea beverage and its processing method

Abstract

The invention discloses a low-caffeine tea beverage and a processing method thereof. Through a gradient elution process, high-temperature rinsing is performed first and low-temperature extraction is performed, so that the most suitable tea beverage ingredients for drinking are selected, the loss of nutrients and the attenuation of product flavor caused by multiple processing are reduced, the original flavor of the tea beverage is ensured, and a low-caffeine product is obtained at the same time. The high-temperature rinsing process in the previous process can stimulate the fragrance of the tea beverage, change the phenomenon of insufficient fragrance in the cold-brewed tea beverage technology, and greatly optimize the flavor characteristics of the product. The invention has a simple process, does not require auxiliary reagents, strains and enzymes, is green and environmentally friendly, has a short processing time, can reduce the growth of microorganisms in the processing process, and the prepared product has good product sensory characteristics, economic rationality and ease of operation, and is suitable for large-scale promotion.

Description

Technical Field

[0001] The invention belongs to the technical field of tea beverages, and in particular relates to a low-caffeine tea beverage and a processing method thereof. Background Art

[0002] Low-caffeine beverages have received more and more attention and demand in recent years. As people pursue a healthy lifestyle, they are more concerned about caffeine intake. Some groups, such as pregnant women, children, the elderly or people with specific diseases, prefer low-caffeine beverages. In addition, some people may choose low-caffeine beverages because they need to sleep at night or are sensitive to caffeine.

[0003] At present, the research on low-caffeine tea beverages mainly focuses on the following aspects:

[0004] 1) Tea cultivation: The caffeine content in tea can be reduced by adjusting the planting conditions and cultivation techniques of tea trees.

[0005] 2) Processing technology: Using specific tea processing technology, such as steam treatment and control of the fermentation process, can reduce the extraction of caffeine in tea.

[0006] 3) Caffeine degradation: Caffeine in tea can be decomposed or converted into other substances using enzyme, microbial or chemical methods.

[0007] That is, the existing technology for low-caffeine tea beverages has many limitations, mainly including the need to select raw materials and use organic solvents for processing, which results in significant changes in product properties, complex product processes, easy introduction of impurities, high processing costs, etc. The complex process also leads to significant loss of product flavor and poor product sensory perception. Therefore, there is an urgent need for a new low-caffeine tea beverage processing method that can overcome the current technical defects and produce tea beverages with low caffeine content while meeting people's quality requirements for tea beverages. Summary of the invention

[0008] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0009] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0010] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a method for processing a low-caffeine tea beverage.

[0011] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0012] After the tea leaves are pretreated, they are rinsed at high temperature, and the filtered tea leaves are immediately cooled with liquid nitrogen;

[0013] The cooled tea leaves are then subjected to low temperature extraction to obtain an extract;

[0014] The extract is sequentially subjected to coarse filtration, fine filtration, blending, sterilization and canning to obtain a low-caffeine tea beverage.

[0015] As a preferred solution of the processing method of the low-caffeine tea beverage of the present invention, wherein: the high-temperature rinsing, wherein the rinsing temperature is 70-100° C., and the rinsing time is 20-120 seconds.

[0016] As a preferred solution of the processing method of the low-caffeine tea beverage of the present invention, the material-liquid ratio in the high-temperature rinsing process is 1:10-100.

[0017] As a preferred embodiment of the processing method of the low-caffeine tea beverage of the present invention, the low-temperature extraction comprises the following steps: the extraction temperature is 0 to 30° C., and the extraction time is 10 to 300 min.

[0018] As a preferred solution of the processing method of the low-caffeine tea beverage of the present invention, the material-liquid ratio in the low-temperature extraction process is 1:10-300.

[0019] As a preferred embodiment of the processing method of the low-caffeine tea beverage of the present invention, the coarse filtration is performed by filtering through a disc centrifuge with a rotation speed of 5000 to 10000 r / min, and the fine filtration is performed by filtering through a filter screen with a mesh size of 100 to 1600.

[0020] As a preferred embodiment of the processing method of the low-caffeine tea beverage of the present invention, the blending includes blending the filtered extract with one or more of an antioxidant and a sweetener.

[0021] As a preferred solution of the processing method of the low-caffeine tea beverage of the present invention, the sterilization is a high-temperature instantaneous sterilization at 135° C. for 5 seconds.

[0022] Another object of the present invention is to overcome the deficiencies in the prior art and provide a low-caffeine tea beverage, wherein the caffeine content of the tea beverage is less than 20 mg / kg and the aroma is strong.

[0023] Beneficial effects of the present invention:

[0024] (1) The present invention adopts a gradient elution process, first high-temperature rinsing and then low-temperature extraction, to select the most suitable tea beverage ingredients for drinking, thereby reducing the loss of nutrients and the attenuation of product flavor caused by multiple processing, ensuring the original flavor of the tea beverage while obtaining a low-caffeine product. The high-temperature rinsing process in the previous step can stimulate the aroma of the tea beverage, changing the phenomenon of insufficient aroma in cold-brewed tea beverage technology, and greatly optimizing the flavor characteristics of the product.

[0025] (2) The process of the present invention is simple, does not require auxiliary reagents, strains, and enzymes, is green and environmentally friendly, has a short processing time, can reduce the growth of microorganisms during the processing, and the product has good product sensory properties, economic rationality, and simple operation, and is suitable for large-scale promotion. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0029] The tea variety used in the present invention is Zhengshan Xiaozhong black tea leaves;.

[0030] Determine the caffeine content according to GB / T5009.139;

[0031] Reference: GB / T21733-2008 Determination of sensory quality of tea beverages;

[0032] The chromaticity was measured using a benchtop transmission and reflection spectrophotometer (JMCM-828N).

[0033] Example 1

[0034] This embodiment provides a method for processing a low-caffeine tea beverage, specifically:

[0035] 1) Tea pretreatment: artificially remove foreign matter, tea leaves of different colors and other impurities attached to the tea leaves;

[0036] 2) High temperature rinsing: rinsing is performed according to the ratio of tea leaves to deionized water of 1:10, the rinsing temperature is 85°C, and the rinsing time is 35 seconds;

[0037] 3) The tea leaves obtained after rinsing and filtering are immediately cooled by liquid nitrogen;

[0038] 4) Low-temperature extraction: The tea leaves treated in step 3) are extracted at a material-water ratio of 1:200, at an extraction temperature of 3° C., for an extraction time of 70 min, to obtain an extract;

[0039] 5) Coarse filtration: The obtained extract is coarsely filtered through a disc centrifuge at a speed of 5000 r / min;

[0040] 6) Fine filtration: The extract after coarse filtration is then filtered through a 1200 mesh filter cloth;

[0041] 7) Preparation: The finely filtered tea beverage is prepared with 0.1% sodium ascorbate;

[0042] 8) Sterilization canning: The above-mentioned prepared liquid is sterilized at 135°C for 5 seconds and then aseptically canned.

[0043] Example 2

[0044] This example is used to explore the effect of different high-temperature rinsing conditions on the quality of the tea beverage obtained. The difference from Example 1 is that the rinsing time in step 2) is adjusted to 20s, 35s, and 50s, and the rinsing temperature is 55°C, 70°C, 85°C, and 100°C. The process parameters of the remaining steps are the same as those in Example 1. The relevant qualities of the tea beverage products obtained are measured, and the results are shown in Tables 1 and 2, respectively.

[0045] Table 1 Effect of different high temperature rinsing time on the quality of tea beverages

[0046]

[0047] Table 2 Effect of different high temperature rinsing temperatures on tea beverage quality

[0048]

[0049] (Note: L* value represents black and white (0-100), the larger the L* value, the brighter it is, and the smaller the L* value, the darker it is; b* value represents yellow and blue, "+" is bluer, and "-" is yellower)

[0050] As can be seen from Table 1 and Table 2, the high-temperature rinsing process has a significant impact on the quality of tea beverages. The high-temperature rinsing step in the scheme of the present invention can stimulate the aroma of tea beverages, and at the same time, by controlling the rinsing parameters, some caffeine can be dissolved in the rinsing step. If the rinsing time is too short and the temperature is too low, substances such as caffeine and tea polyphenols in the tea leaves will undergo oxidation reactions, and the aroma in the tea leaves cannot be effectively stimulated, resulting in poor sensory quality of the tea soup obtained by subsequent extraction, and caffeine cannot be precipitated; while if the rinsing time is too long and the temperature is too high, the nutrients in the tea leaves will be over-stimulated, and the tea soup will lose a large amount of nutrients in the rinsing step, and the caffeine in the subsequent extraction process will be more easily dissolved in the tea soup, resulting in an increase in the caffeine content in the tea beverage. Therefore, selecting a suitable high-temperature rinsing process can effectively promote the release and dissolution of substances in the tea drink, and will not lose a large amount of nutrients in the rinsing stage, and can control the amount of caffeine dissolved in the subsequent extraction process, while avoiding excessive oxidation, and obtaining tea soup with good sensory quality.

[0051] Example 3

[0052] This example is used to explore the effect of different low-temperature extraction conditions on the quality of the tea beverage obtained. The difference from Example 1 is that the time of low-temperature extraction in step 4) is adjusted to 30 min, 60 min, 90 min, and 120 min, and the extraction temperature is 0°C, 3°C, 5°C, and 10°C. The process parameters of the remaining steps are the same as those in Example 1. The relevant qualities of the tea beverage product obtained are measured, and the results are shown in Table 3.

[0053] Table 3 Effect of different low-temperature extraction times on the quality of tea beverages

[0054]

[0055] (Note: L* value represents black and white (0-100), the larger the L* value, the brighter it is, and the smaller the L* value, the darker it is; b* value represents yellow and blue, "+" is bluer, and "-" is yellower)

[0056] Table 4 Effect of different low-temperature extraction temperatures on the quality of tea beverages

[0057]

[0058]

[0059] (Note: L* value represents black and white (0-100), the larger the L* value, the brighter it is, and the smaller the L* value, the darker it is; b* value represents yellow and blue, "+" is bluer, and "-" is yellower)

[0060] It can be seen from the data in Tables 3 and 4 that the low-temperature extraction process has a significant impact on the quality of tea beverages. When the extraction time is too short and the temperature is too low, the aroma and other flavor substances in the tea cannot be fully dissolved, the flavor of the tea soup is bland, and the nutritional content is low; when the extraction time is too long and the temperature is too high, tea polyphenols and other components in the tea are easily affected by oxidation reactions, causing the color of the tea to darken, the taste to become bitter, and the quality to decline. In addition, due to the increase in temperature, the dissolution rate of caffeine increases. As the extraction time is extended, the amount of caffeine dissolved continues to increase, resulting in an increase in the caffeine content in the tea soup, and the low-caffeine tea beverage required by the present invention cannot be obtained.

[0061] Comparative Example 1

[0062] This comparative example prepares a tea beverage only by high-temperature rinsing, specifically:

[0063] This embodiment provides a method for processing a low-caffeine tea beverage, specifically:

[0064] 1) Tea pretreatment: artificially remove foreign matter, tea leaves of different colors and other impurities attached to the tea leaves;

[0065] 2) High temperature rinsing: rinsing is performed according to the ratio of tea leaves to deionized water of 1:10, the rinsing temperature is 85°C, and the rinsing time is 35 seconds;

[0066] 3) Coarse filtration: The rinsed tea soup is coarsely filtered through a disc centrifuge at a speed of 5000r / min;

[0067] 4) Fine filtration: The extract after coarse filtration is then filtered through a 1200 mesh filter cloth;

[0068] 5) Preparation: The finely filtered tea beverage is prepared with 0.1% sodium ascorbate;

[0069] 6) Sterilization canning: The above-mentioned prepared liquid is sterilized at 135°C for 5 seconds and then aseptically canned.

[0070] Comparative Example 2

[0071] This comparative example only prepares tea beverages by low-temperature extraction, specifically:

[0072] 1) Tea pretreatment: artificially remove foreign matter, tea leaves of different colors and other impurities attached to the tea leaves;

[0073] 2) Low-temperature extraction: The pretreated tea leaves were extracted at a material-water ratio of 1:200, at an extraction temperature of 3°C, for an extraction time of 70 min, to obtain an extract;

[0074] 3) Coarse filtration: The obtained extract is coarsely filtered through a disc centrifuge at a speed of 5000 r / min;

[0075] 4) Fine filtration: The extract after coarse filtration is then filtered through a 1200 mesh filter cloth;

[0076] 5) Preparation: The finely filtered tea beverage is prepared with 0.1% sodium ascorbate;

[0077] 6) Sterilization canning: The above-mentioned prepared liquid is sterilized at 135°C for 5 seconds and then aseptically canned.

[0078] Table 5 Effects of different processing technologies on the quality of tea beverages

[0079]

[0080] It can be seen from the data in Table 5 that only using high-temperature rinsing or low-temperature extraction process has a significant impact on the taste and caffeine content of tea beverages. Only using the same high-temperature rinsing process parameters as in Example 1, the aroma substances and influencing components in the tea leaves are effectively stimulated, but due to the lack of a subsequent extraction process, the nutrients in the tea leaves have not yet dissolved into the tea soup, while the caffeine has dissolved into the tea soup, resulting in a low nutrient content in the obtained tea beverage, a weak aroma, and a high caffeine content.

[0081] By only using the same low-temperature extraction process parameters as in Example 1, the aroma substances in the tea leaves are not effectively stimulated, and caffeine is not lost. Within the same extraction time, the amount of dissolved nutrients and aroma components is low, while at the same extraction temperature, the amount of caffeine dissolved increases, resulting in the prepared tea beverage also having the problems of low nutrient content, weak aroma, and high caffeine content.

[0082] Comparative Example 3

[0083] This comparative example provides a method for preparing a tea beverage with low caffeine content by eluting with ethanol in a current process, specifically:

[0084] 1) Water extraction: put the tea leaves into a distillation kettle, add 80℃ water, extract at this temperature for 30 minutes to separate the solid and liquid, cool to 30℃ and filter with a 1000 mesh filter to obtain the extract;

[0085] 2) Adsorption: The extract is washed with water on a column containing resin, the water flow rate is 5m / h, and the adsorption resin is H103;

[0086] 3) First ethanol elution: add 2 times the volume of water to the product after water washing to dilute it, and then add 4 times the weight of ethanol to elute it 4 times, wherein the ethanol concentration is 20%;

[0087] 4) Second ethanol elution: After the first ethanol elution treatment, the product obtained was eluted again twice with a certain concentration of ethanol, and the ethanol concentration was 60%.

[0088] 5) Crude extract treatment: The product after the second ethanol elution is concentrated and dried to obtain a crude extract, which is then dissolved in a 15% ethanol aqueous solution 6 times its weight, and filtered to obtain sample I;

[0089] 6) Polyamide column chromatography: Sample I was loaded at a column volume ratio of 6:1 and eluted with a gradient of ethanol and water solution. The pH value of the eluent was adjusted to pH 3 with glacial acetic acid. The eluents were water (2BV), 20% ethanol (3BV), and 30% ethanol (4BV). The eluents were collected step by step, and the eluents without EGCG-adjacent impurities were combined and concentrated for standby use to obtain a concentrated solution.

[0090] 7) Self-made MCC column chromatography: using the concentrate in step 6) as the raw material, diluting it with 3 times the volume of water, loading it with a column volume ratio of 25:1, using a 7% ethanol solution as the eluent, and separating the solution with a weight percentage content of EGCG of more than 95%;

[0091] 8) Concentration and drying: Concentrate and dry the products of each stage, freeze and store them to obtain the final product, tea beverage.

[0092] Comparative Example 4

[0093] This comparative example provides a method for preparing a tea beverage with low caffeine content by physical adsorption in an existing process, specifically:

[0094] The volume of the tea concentrate was controlled to be 1000 L, the solid content to be 8%, and the temperature to be 40°C;

[0095] The concentrated liquid was adsorbed by 70 L of HPD-100 macroporous adsorption resin, and the flow rate of the effluent after the resin adsorption was controlled to be 200 L / h; the concentrated liquid was sent to a vacuum freeze-drying device for drying to obtain instant tea powder with low caffeine content.

[0096] In summary, the existing technologies for low-caffeine tea beverages have many limitations, mainly including the need to select the best raw materials and use organic solvents for processing, which results in significant changes in product properties, complex product processes, easy introduction of impurities, high processing costs, etc. In addition, the complex process leads to a significant loss of product flavor and poor product sensory perception.

[0097] Under the existing technical background, the present invention proposes a novel method for preparing low-caffeine tea beverages, which can break the current technical defects and meet people's quality requirements for products. Through high-temperature and short-time treatment, the release of aroma and nutrients in tea leaves can be stimulated. Under high temperature, the chemical reaction rate in tea cells is accelerated, which helps to stimulate the chemical substances in the tea leaves. This can increase the aroma components in the tea leaves in the subsequent low-temperature extraction process, such as volatile substances, aromatic alcohol substances, etc., thereby enhancing the aroma of the tea beverage.

[0098] Low-temperature extraction allows the substances in the tea leaves to dissolve into the tea soup. Under low-temperature conditions, the caffeine in the tea leaves is released slowly, while the other flavors and nutrients in the tea leaves are released quickly. This can reduce the caffeine content in the tea beverage, while extracting other flavors and nutrients in the tea leaves, making the tea beverage softer and more mellow in taste.

[0099] Through the gradient process of high-temperature rinsing combined with low-temperature extraction, the caffeine content in tea beverages can be effectively reduced while maintaining the release of the aroma and nutrients in the tea leaves. High-temperature rinsing strengthens the release of aroma components, and low-temperature extraction reduces the solubility of caffeine, making the tea beverage have a lower caffeine content and a richer taste.

[0100] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for processing a low-caffeine tea beverage, Features: include, After the tea leaves are pretreated, they are rinsed at high temperature, and the tea leaves filtered after rinsing are immediately cooled by liquid nitrogen, wherein the rinsing temperature of the high temperature rinsing is 70-85°C, and the rinsing time is 20-50s; The cooled tea leaves are then subjected to low temperature extraction to obtain an extract, wherein the extraction temperature of the low temperature extraction is 0-10°C and the extraction time is 30-90 minutes; The extract is sequentially subjected to coarse filtration, fine filtration, blending, sterilization and canning to obtain a low-caffeine tea beverage, wherein the caffeine content of the low-caffeine tea beverage is less than 20 mg / kg and the aroma is rich.

2. The method for processing the low-caffeine tea beverage according to claim 1, Features: The material-liquid ratio during the high-temperature rinsing process is 1:10-100.

3. The method for processing the low-caffeine tea beverage according to claim 1, Features: The material-liquid ratio during the low-temperature extraction process is 1:10-300.

4. The method for processing a low-caffeine tea beverage according to claim 1, Features: The coarse filtration is carried out by filtering through a disc centrifuge with a rotation speed of 5000-10000 r / min, and the fine filtration is carried out by filtering through a filter screen with a mesh size of 100-1600.

5. The method for processing the low-caffeine tea beverage according to claim 1, Features: The preparation includes preparing one or more of antioxidants and sweeteners with the filtered extract.

6. The method for processing the low-caffeine tea beverage according to claim 1, Features: The sterilization is high temperature instantaneous sterilization at 135° C. for 5 seconds.

7. A low-caffeine tea beverage obtained by the processing method according to any one of claims 1 to 6.

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