Method of producing tea

Abstract

FIELD: food industry.SUBSTANCE: raw material used is dried, and tea stalks are used as the raw material. Tea stalks are exposed to infrared light with a wavelength of 2.5-3.5 mcm for 10-30 minutes until the surface temperature of the raw material reaches 45-50 °C. They are treated with a 0.2-0.3% solution of succinic acid salt and kept for 30-60 minutes at a temperature of 25-30 °C, fermented under anaerobic conditions in a carbon dioxide atmosphere at a temperature of 30-35 °C and relative humidity of 60-70% for 8-12 hours, dried at a temperature of up to 45 °C with a residual moisture content of no more than 6%, followed by separation and aging.EFFECT: making a drink with a soft, rich taste with fruity and spicy notes.1 cl, 1 tbl, 3 ex

Description

[0001] Technical field

[0002] The invention relates to the food industry, namely to methods for producing teas with increased antioxidant activity, obtained by improving the technology for processing tea raw materials.

[0003] Modern consumers are interested in natural, healthy drinks that are part of a modern, healthy lifestyle. One such drink is tea. According to recent research, the antioxidant activity of tea made from the leaves, stems, and petioles of Camellia sinensis has scientifically proven physiological and biochemical effects aimed at protecting the body from oxidative stress and its consequences. Therefore, special attention is being paid to the production of products rich in antioxidants and high in gamma-aminobutyric acid (GABA).

[0004] Prior Art

[0005] A known method of processing tea leaves involves withering the tea leaves to a moisture content of 50-70%, twisting and fermentation in two stages - the first under vacuum at 15-30°C for 1-12 hours, the second (aerobic) - for 0.5-12 hours and drying to a moisture content of 7%. This method allows one to obtain black tea with a fairly high content of GABA [I].

[0006] The disadvantage of this method is the insufficient specification of the parameters (wide ranges of anaerobic (1-12 h) and aerobic (0.5-12 h) fermentation times, as well as temperatures (15-30°C) are given, without specifying optimal values ​​or justifying their selection, the lack of information on humidity control during the fermentation process, the drying conditions are described fragmentarily, which is insufficient for reliable reproduction of the industrial process.

[0007] The closest in technical essence and achieved result to the claimed invention is a method for preparing tea with an increased content of amino acids, including collecting the source material for the production of tea, including stems and leaves, physically separating the stem material from the leaf material in order to obtain a tea plant with a large number of stems, processing the source material using at least one of the traditional methods of processing tea, including withering, maceration, grinding, steaming, fermentation, drying [II].

[0008] The disadvantage of this method is that it does not include preliminary stimulation of antioxidant activity, which ensures the opening of cellular structures and increases the efficiency of enzymatic conversion. Furthermore, the fermentation conditions are general and not optimized for temperature and humidity, and drying at elevated temperatures can reduce catechin levels.

[0009] The objective of this invention is to develop a method for producing tea using tea stalks, which can improve the functional properties of tea.

[0010] The technical result is an increase in the antioxidant activity and the content of gamma-aminobutyric acid in the target product.

[0011] Brief summary of the invention.

[0012] The technical result is achieved by the fact that in the method of producing tea, including withering of raw materials, fermentation and drying, tea stalks are used as raw materials, and after withering, the tea stalks are additionally exposed to infrared light with a wavelength of 2.5-3.5 μm for 10-30 minutes to a raw material surface temperature of 45-50 ° C, then treated with a 0.2-0.3% solution of succinic acid salt and kept for 30-60 minutes at a temperature of 25-30 ° C, fermentation is carried out under anaerobic conditions in an atmosphere of carbon dioxide at a temperature of 30-35 ° C and a relative humidity of 60-70% for 8-12 hours, and drying is carried out at a temperature of up to 45 ° C to a residual moisture of no more than 6%, followed by separation and aging.

[0013] The term "tea petiole" refers to the structural part of the tea plant that connects the leaf blade to the stem, although the petiole and stem are considered distinct parts of the tea plant. In traditional tea production processes, petioles are separated and discarded as waste, despite containing beneficial substances such as L-theanine, phenolic compounds, and fiber. They also contain significant amounts of glutamic acid, a precursor to GABA.

[0014] Disclosure of the claimed technical solution

[0015] The method is implemented as follows. Pre-screened tea stalks are withered on trays or drums at a temperature of at least 26°C for 10-12 hours to remove excess moisture (by 30-40%) and initiate enzymatic processes. Infrared light is irradiated in an IR chamber with a wavelength range of 2.5-3.5 μm for 10-30 minutes until the surface temperature of the raw material reaches 45-50°C (monitored with an infrared pyrometer). The raw material is then treated with a 0.2-0.3% succinic acid solution and held for 30-60 minutes at a temperature of 25-30°C. Typically, sodium succinate (food additive E363) is used and the process is carried out in a stainless steel bath with a stirring device using nozzles to evenly wet the surface of the petioles, and containing a heating and temperature maintenance system.Following this, fermentation takes place in an anaerobic fermentation chamber in a carbon dioxide atmosphere at a temperature of 30-35°C and a relative humidity of 60-70%) for 8-12 hours. The raw material is then transferred to a low-temperature drying chamber with forced ventilation for drying at a temperature no higher than 45°C to a residual moisture content of no more than 6%. From the drying chamber, the tea stalks are fed to an air separator to remove dust and unwanted particles, after which the finished product is placed in a storage silo for maturation in a ventilated area until it reaches a temperature of 18-23°C.

[0016] The withering process reduces the moisture content of tea stems to 60-65%. This increases the tissue's sensitivity to infrared treatment and enzymatic activation. Withering also stimulates oxidative stress and triggers the biosynthesis of antioxidants (catechins, flavonoids).

[0017] In plant materials, especially fibrous parts (petioles), water, pectin, and proteins actively absorb radiation in the 2.5-4.0 μm range. This is the zone of maximum absorption. IR wavelengths in the 2.5-3.5 μm range provide optimal surface heating and moderate penetration, sufficient to disrupt intercellular bonds and soften tissue without causing deep dehydration. After IR treatment, tea petioles become more susceptible to ionic diffusion (succinate penetration). However, IR treatments of less than 10 minutes result in insufficient heating, dense petiole tissue, and poor succinate penetration. IR treatments of more than 30 minutes increase the risk of dehydration, loss of volatile substances, and enzyme inactivation.At a surface temperature of 45-50°C, the cell walls of tea stalks become more permeable, succinate and sodium penetrate into the tissues, and the preservation of polyphenol oxidase and glutamate decarboxylase (an enzyme involved in the synthesis of gamma-aminobutyric acid) is observed.

[0018] Succinic acid supplements are used as metabolic correctors – they can increase stress resistance, improve neuronal energy production, and enhance antioxidant protection. Treatment with a 0.2-0.3% succinic acid solution creates metabolic conditions conducive to GABA synthesis. GABA is metabolized to succinate, which can then enter the Krebs cycle. This relationship is particularly important, as it has a multi-level effect on the body, particularly on the nervous system, energy metabolism, and anti-stress and adaptive mechanisms.

[0019] Treating tea stalks with a solution of succinic acid salt (succinate) stabilizes the pH. At pH 5.0-6.5, succinate acts as a mild buffer. Lowering the pH can inhibit fermentation by reducing the oxidation of catechins, thereby masking the flavor and enhancing the aroma with less bitterness and astringency. Furthermore, succinate is a cofactor in the regulation of energy metabolism. The use of succinates in tea processing offers the potential to enhance antioxidant and stimulating effects, both through the metabolic action of the succinates themselves and through synergy with natural tea components (caffeine and theanine).

[0020] Fermentation under anaerobic conditions in a carbon dioxide atmosphere is necessary to activate the enzyme glutamate decarboxylase, which converts glutamic acid salts into γ-aminobutyric acid, promotes the accumulation of GABA and reduces the oxidative breakdown of polyphenols, increasing the antioxidant activity of tea.

[0021] In a carbon dioxide atmosphere, the activity of oxidative enzymes is suppressed, preserving antioxidants and amino acids. Fermentation activates the flavonoid complex (especially thearubigins and theaflavins). During fermentation in an oxygen environment, enzymes such as polyphenol oxidase are active, which, conversely, oxidize catechins and other antioxidants.

[0022] A combination of optimal factors, such as a temperature of 30-35°C, a relative humidity of 60-70%, and a process duration of 8-12 hours, also provides favorable conditions for glutamic acid decarboxylase activity. At temperatures above 37°C, enzyme activity decreases.

[0023] Anaerobic conditions and slow fermentation prevent the breakdown of aromatic substances, especially theanine, linalool, geraniol and other volatile components.

[0024] Gentle drying at a temperature not exceeding 45°C allows preserving heat-labile antioxidants.

[0025] As a result, the drink acquires a soft, rich taste with fruity and spicy notes.

[0026] The claimed method for producing tea from tea stems yields tea with a high content of γ-aminobutyric acid and antioxidants. Furthermore, the claimed integrated technology of treating tea stems with infrared radiation, a solution of succinic acid salt, anaerobic fermentation, and drying releases extractive substances, enhancing the unique woody flavor and removing the specific aroma of tea stems, thereby improving the sensory characteristics of the tea. Thus, the combination of the claimed features of the invention enables the technical result to be achieved.

[0027] The author of the declared technical solution has produced experimental samples of tea from tea stalks of the "Colchis" tea variety, the production method of which is explained with examples of specific implementation.

[0028] Examples of specific implementation.

[0029] Example 1. Pre-screened tea stalks in an amount of 1000 g are withered on trays at a temperature of at least 26°C for 10 hours. Infrared light irradiation is carried out in an IR chamber with a wavelength range of 2.5 μm for 20 minutes to a surface temperature of 45°C. The raw materials are then treated with 200 ml of a 0.2% succinic acid solution in a stainless steel bath with a stirring device and kept for 60 minutes at a temperature of 25°C. After this, fermentation is carried out in an anaerobic fermentation chamber in a carbon dioxide atmosphere at a temperature of 35°C and a relative humidity of 70% for 10 hours. Then the raw materials are sent to a drying chamber for drying at a temperature of no higher than 45°C to a residual moisture content of no more than 6%. From the drying chamber, the tea stalks are fed into an air separator to remove dust and unwanted particles, after which the finished product is sent to a storage silo for storage in a ventilated area until it reaches a temperature of 23°C.

[0030] The physicochemical and sensory properties of the obtained product are given in the table.

[0031] Example 2. Pre-screened tea stalks in an amount of 1000 g are withered on trays at a temperature of at least 26°C for 12 hours. Infrared light irradiation is carried out in an IR chamber with a wavelength range of 3 μm for 10 minutes until the surface temperature of the raw material reaches 47°C. Then, the raw material is treated with 200 ml of a 0.25% succinic acid solution in a stainless steel bath with a stirring device and kept for 45 minutes at a temperature of 30°C. After this, fermentation is carried out in an anaerobic fermentation chamber in a carbon dioxide atmosphere at a temperature of 32°C and a relative humidity of 65% for 8 hours. Then the raw material is sent to a drying chamber for drying at a temperature of no higher than 42°C to a residual moisture content of no more than 6%. From the drying chamber, the tea stalks are fed into an air separator to remove dust and unwanted particles, after which the finished product is sent to a storage silo for storage in a ventilated area until it reaches a temperature of 20°C.

[0032] The physicochemical and sensory indicators of the target product are shown in the table.

[0033] Example 3. Pre-screened tea stalks (1000 g) are withered on trays at a temperature of at least 26°C for 11 hours. Infrared light is irradiated in an IR chamber with a wavelength of 3.5 μm for 30 minutes until the surface temperature of the raw material reaches 50°C. The raw material is then treated with 200 ml of a 0.3% succinic acid solution in a stainless steel bath with a stirring device and kept at a temperature of 27°C for 30 minutes. After this, fermentation is carried out in an anaerobic fermentation chamber in a carbon dioxide atmosphere at a temperature of 30°C and a relative humidity of 60% for 12 hours. Then the raw material is sent to a drying chamber for drying at a temperature of no higher than 44°C until the residual moisture content is no more than 6%. From the drying chamber, the tea stalks are fed into an air separator to remove dust and unwanted particles, after which the finished product is sent to a storage silo for storage in a ventilated area until it reaches a temperature of 18°C.

[0034] The physicochemical and sensory indicators of the target product are shown in the table.

[0035]

[0036] Industrial applicability.

[0037] The claimed technical solution is implemented using commercially available devices and materials and can be implemented at any tea processing facility. The use of tea stalks, a secondary raw material and waste product from tea harvesting and processing, allows for the production of new tea products with a high content of gamma-aminobutyric acid and antioxidant activity.

[0038] SOURCES OF INFORMATION

[0039] 1. CN Patent No. 103005020, for the invention “Red tea with a high content of gamma-aminobutyric acid (GABA) for maintaining health” (published on 03.04.2013).

[0040] 2. Patent WO 2006021317 A1 for the invention “Method for preparing tea” (published 02.03.2006).

Claims

A method for producing tea, including withering of raw materials, fermentation and drying, characterized in that tea stalks are used as raw materials, and after withering, the tea stalks are additionally subjected to irradiation with infrared light of a wavelength of 2.5-3.5 μm for 10-30 minutes until the surface temperature of the raw material reaches 45-50°C, then treated with a 0.2-0.3% solution of succinic acid salt and kept for 30-60 minutes at a temperature of 25-30°C, fermentation is carried out under anaerobic conditions in an atmosphere of carbon dioxide at a temperature of 30-35°C and a relative humidity of 60-70% for 8-12 hours, and drying is carried out at a temperature of up to 45°C until the residual moisture content is no more than 6%, followed by separation and aging.

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