Fermented black tea containing purple perilla component and preparation process thereof

Abstract

The present invention relates to the field of black tea preparation processes, and discloses a fermented black tea containing a perilla frutescens component and a preparation process thereof, the preparation process comprises the following steps: (a) primary fermentation of tea leaves: staged fermentation is performed in an environment with the temperature of 20-25 DEG C and the humidity of 75-80%, the first-stage fermentation temperature is 20 DEG C, the humidity is 75%, and the time is 1 hour; the second-stage fermentation temperature is 25 DEG C, the humidity is 80%, and the time is 2-3 hours; (b) pretreatment of perilla leaves: withering and pre-fermentation are performed in sequence, the withering stage is performed in an environment with the temperature of 25-30 DEG C and the humidity of 50-70% for 3 hours, and the pre-fermentation stage is performed in an environment with the temperature of 30-35 DEG C and the humidity of 80-85% for 1-2 hours; and (c) performing compound fermentation on the tea leaves and the perilla leaves: mixing the treated tea leaves and the perilla leaves according to the weight ratio of 3: 7. By selecting Yunnan big-leaf tea growing in soil with trace element content and reasonably controlling fermentation process conditions, the fermented black tea containing the purple perilla component is rich in trace elements, achieves the effect of balanced nutrition and meets the requirements of consumers for trace elements.

Description

Technical Field

[0001] The invention relates to the field of black tea preparation technology, in particular to a fermented black tea containing perilla components and a preparation technology thereof. Background Art

[0002] As one of the most widely consumed teas in the world, black tea is deeply loved by consumers for its rich aroma and unique fermented flavor. The production process of traditional black tea mainly includes withering, rolling, fermentation and drying, and the aroma and flavor of the tea leaves are stimulated through the fermentation process. However, the content of trace elements in ordinary black tea is low, which cannot meet consumers' demand for trace element products.

[0003] Selenium is an important trace element that has health benefits such as anti-oxidation, enhancing immunity, and preventing various diseases. In particular, plants grown in soils with high trace element content have higher trace element content. Therefore, in recent years, tea has gradually become the focus of market attention. The usual method of making tea with high trace element content is to increase the application of selenium fertilizer or select soil with high trace element content during the planting stage, but there are certain limitations to increasing the trace element content only by this method, and in subsequent processing, the loss of selenium is also more significant.

[0004] In addition, modern consumers have increasing requirements for the nutritional content and flavor of tea. Studies have shown that blending plants rich in natural aroma components (such as perilla leaves) with tea can enhance the complex aroma and antioxidant function of tea, meeting people's dual needs for health and taste. However, currently, tea products rarely combine tea with plants rich in antioxidant components such as perilla for fermentation. This process still has room for improvement in stabilizing the content of trace elements and improving aroma and nutrition.

[0005] Therefore, how to optimize the process conditions, scientifically mix tea leaves and perilla leaves, and perform compound fermentation, so that the finished tea leaves are rich in selenium, have a strong compound aroma and rich antioxidant components, has become a technical demand in the field of black tea processing. Based on the above demand, the present invention provides a fermented black tea with trace element content containing perilla ingredients and a preparation process thereof, so as to achieve a comprehensive improvement in the nutritional value, aroma level and quality of black tea with trace element content. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a fermented black tea containing perilla ingredients and a preparation process thereof, which solves the problems in the prior art of unstable trace element content, single aroma and insufficient antioxidant ingredients in tea.

[0007] To achieve the above objectives, the present invention is implemented through the following technical scheme: a fermented black tea containing perilla ingredients, the fermented black tea includes tea leaves and perilla leaves, which are mixed in a weight ratio of 3:7, the tea leaves are subjected to primary fermentation treatment, and the perilla leaves are subjected to withering and pre-fermentation treatment, and then processed through a composite fermentation process.

[0008] Preferably, the tea leaves are Yunnan large-leaf tea, planted in soil rich in trace elements.

[0009] A process for preparing fermented black tea containing perilla ingredients comprises the following steps:

[0010] (a) Primary fermentation of tea leaves: fermentation is carried out in stages in an environment of 20-25°C and 75%-80% humidity, with the first stage fermentation temperature being 20°C and 75% humidity for 1 hour; the second stage fermentation temperature being 25°C and 80% humidity for 2-3 hours;

[0011] (b) pretreatment of the perilla leaves: withering and pre-fermentation are performed in sequence, the withering stage is performed in an environment of 25-30° C. and a humidity of 50%-70% for 3 hours, and the pre-fermentation stage is performed in an environment of 30-35° C. and a humidity of 80%-85% for 1-2 hours;

[0012] (c) Compound fermentation of tea leaves and perilla leaves: the treated tea leaves and perilla leaves were mixed in a weight ratio of 3:7, and compound fermented for 2-3 hours in an environment of 35-40° C. and 85% humidity, with the mixture being stirred every 30 minutes;

[0013] (d) Drying: The mixture after composite fermentation is subjected to preliminary drying and low-temperature drying, the preliminary drying temperature is 50-55° C., the time is 1 hour; the low-temperature drying temperature is below 40° C., and the duration is 1 hour, and the moisture content of the final product is finally controlled to be below 5%.

[0014] Preferably, the withering of the perilla leaves is divided into two stages, the first stage is at a temperature of 25° C. and a humidity of 50%-55%, which lasts for 1 hour; the second stage is at a temperature of 30° C. and a humidity of 65%-70%, which lasts for 2 hours.

[0015] Preferably, the composite fermentation process includes two fermentation stages, the first stage is at a temperature of 35° C., a humidity of 85%, and a fermentation time of 1 hour; the second stage is at a temperature of 40° C., a humidity of 85%, and a fermentation time of 2 hours.

[0016] Preferably, the drying process includes two stages: preliminary drying and variable temperature drying, and the variable temperature drying gradually reduces the temperature to below 40° C. for 1 hour.

[0017] Preferably, the dried product is naturally cooled in an environment of 35° C. for 2 hours.

[0018] Preferably, the finished product after cooling is sterilized by ultraviolet light for 15-20 minutes.

[0019] Preferably, the finished product is stored by vacuum nitrogen-filled packaging.

[0020] Preferably, the aroma components of the finished product are detected by gas chromatography-mass spectrometry, and the trace element content is above 0.25 mg / kg.

[0021] The present invention provides a fermented black tea containing perilla ingredients and a preparation process thereof. It has the following beneficial effects:

[0022] 1. The present invention selects Yunnan large-leaf tea grown in soil with high trace element content and reasonably controls fermentation process conditions. The fermented black tea containing perilla components of the present invention contains rich trace elements (achieving a nutritionally balanced effect) and meets consumers' needs for trace elements.

[0023] 2. The present invention adopts a scientific blending ratio of tea leaves and perilla leaves (3:7), and uses a composite fermentation process with segmented temperature and humidity control to blend the aroma of tea leaves and perilla leaves, so that the aroma of the finished tea is strong and rich in layers. The aroma cooling step further consolidates the composite aroma, making the aroma of the finished product more lasting and stable.

[0024] 3. The perilla leaves of the present invention contain abundant natural antioxidant components such as polyphenol compounds. Through appropriate perilla leaf ratio and fermentation conditions, the antioxidant content of the finished tea leaves is significantly improved, which has a good antioxidant health care effect on the human body.

[0025] 4. The composite fermentation of the present invention fully combines the flavors of tea leaves and perilla leaves, and the finished tea has a mellow taste and diverse layers. It not only retains the sweetness of black tea, but also adds the fragrance of perilla, satisfying consumers' taste requirements for high-quality black tea.

[0026] 5. The present invention adopts low-temperature ozone treatment and ultraviolet sterilization technology to effectively remove microorganisms on the surface of tea leaves and perilla leaves, while avoiding the destruction of nutrients and aroma by high-temperature sterilization, ensuring the hygiene and safety of the finished product, and being suitable for long-term storage and circulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1:

[0030] Please refer to the attached Figure 1 The embodiment of the present invention provides a fermented black tea containing perilla ingredients and a preparation process thereof, comprising the following steps:

[0031] Tea Selection

[0032] In this embodiment, the tea leaves are selected from Yunnan large-leaf tea grown in soil with high trace element content at high altitude in Yunnan. The tea leaves grow in soil with high altitude and trace element content, which is conducive to the accumulation of its natural trace element content. At the same time, the tea leaves are thick and have good texture, which is suitable for fermentation.

[0033] In this embodiment, the freshly picked tea leaves are strictly screened to ensure that the leaves are intact, free of damage and pests, and to remove impurities. The screened tea leaves will better maintain the trace element content characteristics and nutritional components in the subsequent process, laying a foundation for the preparation of fermented black tea with trace element content.

[0034] Selection of Perilla Leaves

[0035] In this embodiment, the selection criteria of the perilla leaves include bright green color, no mold, no odor, and complete leaves, so as to ensure that the aroma and antioxidant components of the perilla in the finished black tea are fully retained.

[0036] In order to further remove impurities and possible microorganisms, the present embodiment performs low-temperature ozone disinfection on the perilla leaves, the ozone concentration is controlled at 2-3ppm, and the treatment time is 5 minutes. Low-temperature ozone treatment can effectively kill bacteria and fungi on the surface, avoid the generation of bad flavors due to the influence of miscellaneous bacteria during the subsequent fermentation process, and ensure that the antioxidant components inside the perilla leaves remain stable.

[0037] Cleaning

[0038] In this embodiment, the screened tea leaves and basil leaves are washed with flowing clean water to remove surface dust and impurities. Mechanical kneading is avoided during the washing process to maintain the natural state of the leaves and prevent the loss of nutrients and aroma components.

[0039] After washing, the perilla leaves need to be dried naturally in a sterile environment to avoid oxidation and discoloration of the leaves or loss of aroma due to excessive humidity.

[0040] Primary fermentation of tea leaves

[0041] In this embodiment, the initial fermentation of tea leaves is divided into two stages to gradually release its natural aroma and some nutrients, and at the same time prepare for the subsequent composite fermentation with perilla leaves:

[0042] The first stage of low-temperature fermentation: Place the tea leaves in a constant temperature fermentation room, control the temperature at 20°C, and the humidity at 75% for 1 hour. This stage of fermentation is a low-temperature preliminary fermentation, which is mainly to gradually adapt the tea leaves to the fermentation environment, ensure the stability of intracellular substances, and avoid excessive oxidation due to high temperature.

[0043] The second stage of high temperature fermentation: the fermentation temperature is raised to 25°C, the humidity is increased to 80%, and the fermentation time is extended to 2-3 hours. Under this temperature and humidity condition, the cell wall of the tea leaves gradually breaks down, and some phenolic compounds and aroma components are released. This process not only gives the tea leaves a preliminary aroma, but also lays the foundation for the subsequent fusion with the perilla leaves.

[0044] Pretreatment of Perilla Leaves

[0045] In this embodiment, the pretreatment of the perilla leaves includes two stages: withering and pre-fermentation, so as to stimulate the aromatic components and antioxidant substances in the perilla leaves and ensure that they reach a state suitable for fermentation.

[0046] Withering: The withering of shiso leaves is carried out in two stages to gradually remove some of the water and release the aroma components:

[0047] The first stage of withering: Place the perilla leaves in an environment of 25°C and 50%-55% humidity for 1 hour to initially remove some of the moisture and keep the leaf structure intact.

[0048] The second stage of withering: the humidity is gradually increased to 65%-70%, the temperature is increased to 30℃, and the withering is continued for 2 hours. The increase in humidity at this stage helps release the aromatic substances in the perilla leaves, while reducing excess water, creating a suitable environment for subsequent fermentation.

[0049] Pre-fermentation: The withered perilla leaves are pre-fermented in a fermentation room at 30-35°C and 80%-85% humidity for 1-2 hours. During this process, the leaves are turned over every 30 minutes to ensure uniform fermentation. The pre-fermentation further releases the aromatic and antioxidant components in the perilla leaves, providing a good aroma and nutritional basis for the subsequent compound fermentation with tea leaves.

[0050] Blending Proportions and Mixing

[0051] In this embodiment, tea leaves and perilla leaves are blended at a weight ratio of 3:7 to ensure that the aroma of perilla is fully integrated into the tea leaves, while ensuring that the trace element content of the tea leaves meets the standard requirements. The selection of a ratio of 3:7 can add the unique aroma of perilla on the basis of maintaining the main flavor of the tea leaves. In order to achieve uniform mixing, the blended raw materials are placed in a light vibration device and slightly vibrated to evenly mix the tea leaves and perilla leaves to avoid affecting the subsequent fermentation effect due to uneven distribution of ingredients.

[0052] Compound fermentation process

[0053] In this embodiment, the blended tea leaves and perilla leaves mixture is placed in a fermentation chamber for composite fermentation. The fermentation is carried out in two stages, and the temperature and humidity conditions are controlled in each stage to gradually release and integrate the aroma and nutrients of the two:

[0054] The first stage of compound fermentation: the temperature is set at 35℃, the humidity is 85%, and the fermentation time is 1 hour. This stage initially stimulates the aromatic substances of perilla, allowing its aroma to penetrate into the tea leaves and begin to form a compound aroma.

[0055] Second stage of compound fermentation: raise the temperature to 40℃, maintain the humidity at 85%, and extend the fermentation time to 2 hours. The temperature increase at this stage further promotes the in-depth integration of tea leaves and perilla leaf ingredients, and releases a richer aroma. To ensure a uniform fermentation process, turn the mixture every 30 minutes so that the leaves at different levels are more evenly heated and humidified, avoiding problems such as uneven fermentation or excessive concentration of local ingredients.

[0056] After the above-mentioned segmented composite fermentation, the aroma components and nutrients in the tea leaves and perilla leaves achieve mutual penetration and fusion, laying a good foundation for the next drying process.

[0057] Initial drying

[0058] In this embodiment, the mixture after composite fermentation is first subjected to preliminary drying. The fermented tea leaves and perilla leaf mixture is placed in a drying device, the temperature is controlled at 50-55°C, and the drying time is 1 hour. The preliminary drying at this stage quickly removes part of the water through a higher temperature to ensure that the mixture will not cause microbial growth or deterioration due to excessive humidity, but will not cause excessive volatilization of the aroma components in the leaves.

[0059] Low temperature drying

[0060] After the initial drying, low-temperature drying is performed to further reduce the moisture content of the mixture and maintain the stability of the aroma and nutrients. In this embodiment, the temperature is gradually reduced to below 40°C, and the drying is continued for 1 hour until the moisture content of the mixture is controlled below 5%. The low-temperature drying condition can effectively prevent the destruction of the aroma and nutrients by high temperature, and ensure that the effective ingredients in the leaves are well preserved.

[0061] Final moisture control

[0062] After two stages of preliminary drying and low-temperature drying, the final moisture content of the mixture of tea leaves and perilla leaves in this embodiment is controlled below 5%. This is not only conducive to the long-term storage of the product, but also provides an ideal foundation for the next cooling and aroma process.

[0063] Titian

[0064] In this embodiment, the mixture of tea leaves and perilla leaves after drying is placed in an environment of 35°C for aroma treatment for 2 hours. The aroma treatment is carried out at a relatively constant temperature to ensure that the aromatic components in the tea leaves and perilla leaves are gradually stabilized and released to achieve the effect of full fusion of aroma. During this process, no forced wind blowing or stirring is performed to avoid excessive dissipation of aroma, ensuring that the final product has a complex and rich aroma.

[0065] Natural cooling

[0066] In this embodiment, after the aroma is extracted, the mixture is gradually cooled to room temperature, i.e., below 20° C., by a cooling fan. The natural cooling process can prevent the oxidation of components under high temperature and help lock the aromatic components of tea leaves and perilla leaves. During the cooling process, the environment is kept well ventilated, but strong wind is not used to prevent the loss of aroma components.

[0067] Aroma Consolidation

[0068] After the aroma enhancement and natural cooling steps, in this embodiment, the aroma of the mixture of tea leaves and perilla leaves is consolidated and the ingredients are stable, which lays a foundation for the next step of ultraviolet sterilization treatment and sealed packaging.

[0069] Use of ultraviolet disinfection equipment

[0070] In this embodiment, the mixture of Titian tea leaves and perilla leaves after cooling is treated with an ultraviolet sterilization device. The sterilization device is set to non-contact ultraviolet irradiation to avoid physical damage that may be caused by direct contact. The wavelength range of ultraviolet rays is set at 253.7 nanometers, which is a wavelength range with a better microbial killing effect.

[0071] Sterilization conditions

[0072] In this embodiment, the irradiation time of ultraviolet sterilization is set to 15-20 minutes, which ensures the sterilization effect without affecting the internal components of tea leaves and perilla leaves. By continuously irradiating within this time range, the total number of bacterial colonies on the surface of the product can be effectively reduced, and the levels of microorganisms such as coliform bacteria, mold and yeast can be controlled.

[0073] Consolidation of treatment effects

[0074] After the sterilization is completed, the product enters the subsequent packaging process. In this embodiment, the ultraviolet sterilization step further improves the hygienic safety of the finished product, provides suitable conditions for the subsequent vacuum nitrogen packaging, and ensures that the finished product maintains stable quality throughout the storage and circulation process.

[0075] Vacuum nitrogen filling packaging equipment

[0076] In this embodiment, a vacuum nitrogen filling packaging device is used to seal and package the sterilized tea leaves and perilla leaves mixture. The device first extracts the air in the package and then fills it with nitrogen to form an oxygen-free environment, thereby reducing the impact of oxidation reactions on the finished product. The vacuum nitrogen filling operation is carried out in a dust-free workshop to ensure that the entire packaging process meets hygiene standards.

[0077] Packaging material selection

[0078] In this embodiment, the packaging material is a double-layer composite structure, the inner layer is a moisture-proof and anti-oxidation film, and the outer layer is an aluminum foil bag. The inner layer material can effectively block moisture and oxygen to keep the product dry; the outer layer of aluminum foil has excellent light-shielding properties to prevent light from affecting the tea ingredients. The choice of this composite material helps to further maintain the aroma and quality of the finished product.

[0079] Packaging environment and sealing control

[0080] In this embodiment, the packaging temperature is controlled at room temperature (below 20°C) to prevent the temperature from being too high and affecting the sealing of the packaging. After the vacuum nitrogen-filled packaging bags are sealed, they need to be checked bag by bag to ensure that there is no leakage. By controlling the above packaging conditions, the tea is not easily affected by the external environment during storage and transportation, and the product quality can be kept stable for a long time.

[0081] Storage requirements

[0082] In this embodiment, the packaged products are stored in a constant temperature warehouse, the storage temperature is controlled below 15°C, and the humidity is controlled at 50%-55%. This storage condition further ensures the stability of the aroma, trace element content and nutritional components of the finished product during the storage period, providing good quality assurance for subsequent sales and use.

[0083] Trace element content detection

[0084] In this embodiment, atomic fluorescence spectroscopy is used to detect the trace element content of the packaged finished black tea. The detection process is carried out in a constant temperature laboratory to ensure the detection accuracy. The trace element content must meet the standard requirements of more than 0.25 mg / kg to meet the positioning of black tea with trace element content.

[0085] Aroma component detection

[0086] In this embodiment, a gas chromatography-mass spectrometer (GC-MS) is used to detect the aroma components of the product. This test can accurately analyze the aromatic components formed by tea leaves and perilla leaves during the composite fermentation and drying process to verify the level and stability of the aroma of the finished product. Through the test, it is ensured that the aroma of perilla and black tea is evenly integrated.

[0087] Antioxidant ingredient testing

[0088] In this embodiment, the antioxidant components in tea leaves are quantitatively detected, mainly the content of polyphenol compounds. The antioxidant component detection is carried out in an anaerobic environment to prevent sample oxidation from affecting the test results. Through this test, it is confirmed that the antioxidant components of perilla leaves are retained in the product, which meets the nutritional value requirements of the product.

[0089] Microbiological testing

[0090] In this embodiment, microbial tests for total bacterial count, coliform group, mold and yeast are performed in a laboratory that meets sterile standards to ensure that the packaged products meet food hygiene standards and meet safety requirements for circulation and sales. Only after the microbial test is qualified can the product enter the market circulation link.

[0091] Through the above series of tests, this embodiment ensures that the trace element content of the fermented black tea containing perilla ingredients meets the expected standards in terms of ingredient content, aroma characteristics, nutritional function and sanitary safety, providing full guarantee for the quality of the finished product.

[0092] Embodiment 2:

[0093] The preparation process of this embodiment is basically the same as that of the first embodiment, except that the blending ratio of tea leaves to perilla leaves in this embodiment is adjusted to 4:6 instead of 3:7 in the first embodiment. The remaining process conditions, steps and detection methods are kept consistent, so as to compare the effects of the changes in the blending ratio on the aroma, trace element content, nutritional components and other indicators of the finished product.

[0094] Specific process steps

[0095] Selection and processing of tea leaves and perilla leaves

[0096] The tea we choose is Yunnan large-leaf tea grown in Yunnan's high-altitude soil with rich trace elements. It is strictly screened, cleaned and removed to ensure that the leaves are intact and free of pests.

[0097] The perilla leaves were screened, cleaned and sterilized with low-temperature ozone at a concentration of 2-3 ppm for 5 minutes.

[0098] Primary fermentation and pretreatment

[0099] The tea leaves are initially fermented with two stages of temperature and humidity control (20°C, 75% humidity for 1 hour; 25°C, 80% humidity for 2-3 hours).

[0100] The perilla leaves are subjected to withering and pre-fermentation treatments (withering is carried out in an environment of 25-30° C., 50%-70% humidity, for 3 hours; pre-fermentation is carried out in an environment of 30-35° C., 80%-85% humidity, for 1-2 hours).

[0101] Blending and complex fermentation

[0102] Mix tea leaves and perilla leaves in a weight ratio of 4:6, and shake the equipment to mix evenly. The compound fermentation is divided into two stages to control temperature and humidity (the first stage: 35℃, humidity 85%, time 1 hour; the second stage: 40℃, humidity 85%, time 2 hours), and turn it over every 30 minutes.

[0103] Drying and fragrance

[0104] The mixture after composite fermentation is subjected to preliminary drying (50-55° C., time 1 hour) and low-temperature drying (temperature drops to below 40° C., time 1 hour), and the final moisture content is controlled below 5%.

[0105] Aroma enhancement and natural cooling: Naturally enhance the aroma for 2 hours in a 35℃ environment, and cool to below 20℃ to ensure the aroma is stable.

[0106] Ultraviolet sterilization and vacuum nitrogen packaging

[0107] Non-contact ultraviolet sterilization (253.7 nanometer wavelength, 15-20 minutes) ensures the hygiene and safety of the finished product.

[0108] Vacuum nitrogen-filled packaging, the packaging materials are moisture-proof and anti-oxidation film and aluminum foil bags, and the packaging environment is controlled below room temperature 20°C.

[0109] Finished product testing

[0110] Trace element content detection: Trace element content is detected by atomic fluorescence spectrometry.

[0111] Aroma component detection: Use gas chromatography-mass spectrometry (GC-MS) to analyze the aroma of the finished product.

[0112] Antioxidant component detection: quantitative detection of polyphenolic compound content.

[0113] Microbiological testing: total colony count, coliform bacteria, mold, yeast and other microbiological testing to ensure compliance with food hygiene standards.

[0114] Comparative analysis of results

[0115] By testing the trace element content, aroma components, antioxidant components, etc. of the finished products of Example 1 (tea leaves and perilla leaves ratio of 3:7) and Example 2 (tea leaves and perilla leaves ratio of 4:6), the following comparative results were obtained:

[0116] Trace element content The trace element content of Example 1 is higher than that of Example 2, which meets the trace element content positioning standard of black tea (above 0.25 mg / kg), while the trace element content of Example 2 is slightly lower, close to the lower limit of the standard.

[0117] Aroma concentration and stability

[0118] Since the proportion of perilla leaves in Example 1 is higher, the aroma component detection results show that the aroma concentration is stronger and richer, and the aroma persistence is better than that in Example 2. In Example 2, the proportion of perilla leaves is lower, the tea aroma is dominant, and the composite aroma is slightly insufficient.

[0119] Antioxidant content

[0120] The test result of antioxidant components (such as polyphenol compounds) in Example 1 is higher than that in Example 2, which is related to the natural antioxidant components brought by the higher proportion of perilla leaves. In Example 2, the antioxidant components are slightly lower due to the relatively reduced content of perilla leaves.

[0121] Sensory evaluation

[0122] The first embodiment is superior to the second embodiment in terms of complex aroma and taste levels, having a softer taste and richer aroma levels, while the aroma of the second embodiment is slightly single.

[0123] The above results show that the formula of Example 1 (3:7 ratio) is better than that of Example 2 (4:6 ratio), having higher trace element content, richer compound aroma and richer antioxidant components. Therefore, the selection of a blending ratio of 3:7 is more effective in the preparation process of the fermented black tea containing trace element content of perilla components of the present invention, and can better meet the quality requirements of high trace element content and compound aroma.

[0124] Embodiment three:

[0125] The preparation process of this embodiment is basically the same as that of the first embodiment, except that the compound fermentation temperature in this embodiment is adjusted: the temperature of the first compound fermentation is reduced to 30° C., and the temperature of the second compound fermentation is reduced to 35° C. The remaining process conditions, blending ratios and detection methods are consistent with those of the first embodiment, so as to compare the effects of the change in fermentation temperature on the aroma, trace element content, nutritional components and other indicators of the finished product.

[0126] Specific process steps

[0127] Selection and processing of tea leaves and perilla leaves

[0128] We select Yunnan large-leaf tea grown in the soil with high trace element content at high altitudes in Yunnan, and screen, wash and remove impurities to ensure that the leaves are intact.

[0129] After screening and washing, the perilla leaves are sterilized with low-temperature ozone at an ozone concentration of 2-3ppm for 5 minutes to remove surface impurities and microorganisms.

[0130] Primary fermentation and pretreatment

[0131] The tea leaves were initially fermented according to the two-stage temperature and humidity conditions of Example 1 (20° C., 75% humidity, 1 hour; 25° C., 80% humidity, 2-3 hours).

[0132] The withering and pre-fermentation treatments of the perilla leaves remained unchanged (withering stage: 25-30° C., humidity 50%-70%, time 3 hours; pre-fermentation: 30-35° C., humidity 80%-85%, time 1-2 hours).

[0133] Blending and complex fermentation

[0134] Tea leaves and basil leaves are blended in a weight ratio of 3:7 and mixed evenly using a light-vibrating device.

[0135] The compound fermentation is adjusted to the following two stages of temperature and humidity control:

[0136] The first stage of compound fermentation: the temperature is set to 30°C, the humidity is 85%, and the time is 1 hour.

[0137] The second stage of compound fermentation: the temperature is set to 35°C, the humidity is 85%, and the time is 2 hours.

[0138] Stir the mixture every 30 minutes to ensure even heating and humidity treatment of the mixture.

[0139] Drying and fragrance

[0140] The mixture after composite fermentation is subjected to preliminary drying (temperature 50-55° C., time 1 hour) and low-temperature drying (temperature drops to below 40° C., lasting for 1 hour), and finally the moisture content is controlled to be below 5%.

[0141] Carry out aroma extraction at 35℃ for 2 hours and gradually cool down naturally to below 20℃.

[0142] Ultraviolet sterilization and vacuum nitrogen packaging

[0143] After non-contact ultraviolet sterilization (253.7 nanometer wavelength, time 15-20 minutes), vacuum nitrogen packaging equipment is used for sealed packaging, and the packaging environment temperature is controlled below 20°C.

[0144] Finished product testing

[0145] Atomic fluorescence spectrometry is used to detect the content of trace elements to ensure that it reaches above 0.25 mg / kg.

[0146] Gas chromatography-mass spectrometry (GC-MS) was used to detect aroma components and analyze the aromatic levels of the finished products after compound fermentation and aroma extraction.

[0147] The antioxidant component detection and microbial detection are the same as those in Example 1 to ensure product hygiene and nutritional quality.

[0148] Comparative analysis of results

[0149] By testing the trace element content, aroma components, antioxidant components, etc. of the finished products of Example 1 (composite fermentation temperature: 35°C / 40°C) and Example 3 (composite fermentation temperature: 30°C / 35°C), the following comparative results were obtained:

[0150] Trace element content

[0151] The trace element contents of Example 1 and Example 3 are not much different, both reaching above 0.25 mg / kg, which meets the standard of black tea for trace element content.

[0152] Aroma concentration and stability

[0153] The aroma concentration and level of Example 1 are significantly better than those of Example 3. In Example 3, due to the low compound fermentation temperature, the aroma components are not released enough, resulting in a slightly insufficient aroma concentration of the finished product, and the compound aroma effect is not as good as that of Example 1.

[0154] Antioxidant content

[0155] The antioxidant component detection result of Example 3 is lower than that of Example 1. The reason may be that the lower fermentation temperature fails to fully stimulate the antioxidant components in the perilla leaves, thereby affecting the antioxidant level of the finished product.

[0156] Sensory evaluation

[0157] The first embodiment is superior to the third embodiment in terms of aroma and taste. The finished product has a strong aroma and rich layers, while the aroma of the third embodiment is relatively thin, and the unique flavor brought by the composite fermentation is not as good as that of the first embodiment.

[0158] The above results show that Example 1 (composite fermentation temperature 35°C / 40°C) is better than Example 3 (composite fermentation temperature 30°C / 35°C), and performs better in terms of aroma concentration, antioxidant content and sensory level of the finished product. Therefore, the higher fermentation temperature used in Example 1 is more suitable for the preparation process of the fermented black tea with trace element content containing perilla components of the present invention, which can better achieve aroma fusion and nutritional improvement of the finished product.

[0159] Table 1 Comparison table of experimental data of embodiment

[0160]

[0161]

[0162] Example 1 performs best in terms of trace element content, aroma concentration, aroma level and antioxidant content, and is suitable for meeting the demand for high-aroma and high-nutrition black tea.

[0163] The content of trace elements in Example 2 is slightly lower, the fragrance of Perilla is not obvious enough, and the content of antioxidant components is also lower than that in Example 1.

[0164] In Example 3, due to the lower fermentation temperature, the aroma concentration and layering are insufficient, the content of antioxidant components is relatively low, and the aroma and taste are relatively simple in terms of sensory perception.

[0165] The above data show that the ratio and fermentation temperature conditions of Example 1 are the most suitable and are the best embodiment of the present invention.

[0166] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fermented black tea containing perilla ingredients, characterized in that: The fermented black tea comprises tea leaves and perilla leaves, which are mixed in a weight ratio of 3:

7. The tea leaves are subjected to primary fermentation treatment, and the perilla leaves are subjected to withering and pre-fermentation treatments and then processed through a composite fermentation process.

2. The fermented black tea containing perilla ingredients according to claim 1, characterized in that: The tea leaves are large-leaf tea from Yunnan, grown in soil rich in trace elements.

3. A process for preparing fermented black tea containing perilla, according to the fermented black tea containing perilla as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: (a) Primary fermentation of tea leaves: fermentation is carried out in stages in an environment of 20-25°C and 75%-80% humidity, with the first stage fermentation temperature being 20°C and 75% humidity for 1 hour; the second stage fermentation temperature being 25°C and 80% humidity for 2-3 hours; (b) pretreatment of the perilla leaves: withering and pre-fermentation are performed in sequence, the withering stage is performed in an environment of 25-30° C. and a humidity of 50%-70% for 3 hours, and the pre-fermentation stage is performed in an environment of 30-35° C. and a humidity of 80%-85% for 1-2 hours; (c) Compound fermentation of tea leaves and perilla leaves: the treated tea leaves and perilla leaves were mixed in a weight ratio of 3:7, and compound fermented for 2-3 hours in an environment of 35-40° C. and 85% humidity, with the mixture being stirred every 30 minutes; (d) Drying: The mixture after composite fermentation is subjected to preliminary drying and low-temperature drying, the preliminary drying temperature is 50-55° C., the time is 1 hour; the low-temperature drying temperature is below 40° C., and the duration is 1 hour, and the moisture content of the final product is finally controlled to be below 5%.

4. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The withering of the perilla leaves is divided into two stages. The first stage is at a temperature of 25° C. and a humidity of 50%-55% and lasts for 1 hour. The second stage is at a temperature of 30° C. and a humidity of 65%-70% and lasts for 2 hours.

5. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The composite fermentation process includes two stages of fermentation, the first stage is at a temperature of 35° C., a humidity of 85%, and a time of 1 hour; the second stage is at a temperature of 40° C., a humidity of 85%, and a time of 2 hours.

6. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The drying process includes two stages: preliminary drying and variable temperature drying. The variable temperature drying gradually reduces the temperature to below 40° C. for 1 hour.

7. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The dried product was naturally cooled in an environment of 35° C. for 2 hours.

8. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The finished product after cooling is sterilized by ultraviolet light for 15-20 minutes.

9. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The finished product is stored in vacuum nitrogen-filled packaging.

10. The process for preparing fermented black tea containing perilla ingredients according to claim 3, characterized in that: The aroma components of the finished product are detected by gas chromatography-mass spectrometry, and the content of trace elements is above 0.25 mg / kg.

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