A forsythia leaf tea, juglans ailanthoides composite fu tea and a preparation method thereof

Abstract

The present application belongs to the technical field of composite Fu tea, and particularly relates to a forsythia suspense leaf tea, walnut branch wood composite Fu tea and a preparation method thereof. The forsythia suspense leaf tea, walnut branch wood composite Fu tea is prepared by adding composite strains to forsythia suspense leaf tea, black tea and branch wood silk after steam softening, and then performing two-stage fermentation and finally microwave treatment. The mass ratio of the forsythia suspense leaf tea, black tea, branch wood silk and composite strains is 40-70:20-50:10-30:0.5-1. The composite strains are prepared by mixing Eurotium cristatum liquid, Lactobacillus plantarum liquid and Aspergillus niger liquid at a mass ratio of 5-7:2-4:1. The two-stage fermentation is primary fermentation at 32-35 DEG C for 10-14 hours, and then secondary fermentation at 24-28.5 DEG C for 19-21 days. The forsythia suspense leaf tea, walnut branch wood composite Fu tea has a golden flower density of greater than 2.0*10 5 CFU / g dry tea, high forsythiaside retention rate, weak bitterness, strong aroma and good taste.

Description

Technical Field

[0001] This invention belongs to the field of compound Fu brick tea technology, specifically relating to a compound Fu brick tea made from forsythia leaf tea and walnut septum wood, and its preparation method. Background Technology

[0002] Forsythia tea is made from forsythia leaves and flowers through steps such as cooling, washing, blanching, rolling, and drying. Forsythia tea can enhance the body's antiviral capabilities and inhibit various viruses in the body. It can also eliminate bacilli, cocci, and streptococci in the body. The trace elements and amino acids contained in forsythia leaf tea can form a protective layer on the surface of the liver, reducing the damage to the liver caused by drugs and irritants. It can also repair damaged liver cells, lower transaminase levels, and promote glycogen synthesis, maintaining stable liver function and reducing the incidence of hepatitis and liver cancer. Forsythia leaf tea has a bidirectional regulatory effect on blood pressure and promotes blood circulation. As a cooling health tea, forsythia leaf tea can also relieve headaches, fever, and coughs. It has a preventative effect against internal heat.

[0003] Fu brick tea is made from black tea leaves through processes such as piling, fermentation, shaping, and fermentation. The caffeine, vitamins, amino acids, and phospholipids in Fu brick tea aid digestion and regulate fat metabolism. The stimulating effect of caffeine increases gastric juice secretion, thus improving appetite and aiding digestion. Fu brick tea contains higher levels of fat-decomposing enzymes than any other type of tea, possessing strong functions in relieving greasiness and aiding digestion. Fu brick tea promotes diuresis by increasing the filtration rate of water in urine through the kidneys. The bladder-stimulating effect of caffeine also assists in diuresis, while theophylline exerts a significant diuretic effect by dilating renal microvessels and inhibiting the reabsorption of water in the renal tubules. Diuresis also helps to sober up and relieve the harmful effects of alcohol. Because Fu brick tea contains tea polyphenols, long-term consumption can strengthen capillary resilience and prevent microvascular rupture. In Japan and South Korea, Fu brick tea is known as "slimming tea" and "beauty tea." Long-term consumption of Fu brick tea can promote and regulate metabolism, enhance physical fitness, and delay aging.

[0004] Walnut septum is the dried, woody septum inside the walnut kernel, appearing in thin flakes. According to the *Chinese Pharmacopoeia*, walnut septum is bitter, astringent, and neutral in nature. It enters the spleen and kidney meridians. It astringes semen, reduces urination, stops bleeding and leukorrhea, and stops diarrhea and dysentery. It is used for seminal emission, frequent urination, enuresis, metrorrhagia, leukorrhea, diarrhea, and dysentery. It is particularly effective for insomnia caused by spleen and kidney deficiency. For men suffering from sexual dysfunction or frequent urination at night, drinking walnut septum infused water can also have certain health benefits. Walnut septum also has a certain effect on promoting qi circulation, invigorating blood, and replenishing blood. Therefore, women with menstrual disorders or hematuria can also use walnut septum infused water to better improve their symptoms. Drinking walnut septum infused water regularly can strengthen the body, replenish qi, enhance physical constitution, and improve immunity, allowing the body to recover health more quickly.

[0005] Currently, forsythia leaf tea has a rather bitter taste. Walnut septum is mostly used in tea bags, such as CN110810592A, but it has a high tannin content (≥12%). Adding forsythia leaves and walnut septum directly to Fu brick tea during fermentation will intensify the bitterness. Furthermore, the significant difference in fiber structure between forsythia leaves and walnut septum leads to uneven microbial colonization during mixed fermentation, resulting in a low rate of walnut flower formation in Fu brick tea.

[0006] In summary, combining forsythia leaves and septum wood with Fu brick tea currently exacerbates bitterness and results in a low success rate of developing the flowering process. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a compound tea of ​​forsythia leaf and walnut septum, and a method for preparing the same.

[0008] The purpose of this invention is to provide a compound Fu tea made from forsythia leaf tea and walnut septum, which is made by steaming forsythia leaf tea, black tea and walnut septum fibers, adding compound bacteria and fermenting in two stages, and finally microwave treatment.

[0009] The mass ratio of the forsythia leaf tea, black tea, wood septum, and compound microbial strain is 40~70:20~50:10~30:0.5~1.

[0010] The compound microbial strain is prepared by mixing *Aspergillus cristatus* liquid, *Lactobacillus plantarum* liquid, and *Aspergillus niger* liquid in a mass ratio of 5-7:2-4:1.

[0011] The two-stage fermentation involves primary fermentation at 32℃~35℃ for 10h~14h, followed by secondary fermentation at 24℃~28.5℃ for 19 days~21 days.

[0012] Preferably, the mass ratio of the forsythia leaf tea, black tea, wood septum, and compound microbial strain is 50:40:20:0.8.

[0013] Preferably, the mass ratio of the *Aspergillus cristatus* solution, *Lactobacillus plantarum* solution, and *Aspergillus niger* solution is 6:3:1.

[0014] Preferably, the viable count of *Aureobasidium tricornutum* in the *Aureobasidium tricornutum* solution is 8 × 10⁻⁶. 6 CFU / g ~1.2×10 7 CFU / g.

[0015] The viable count of *Lactobacillus plantarum* in the *Lactobacillus plantarum* solution is 3 × 10⁻⁶. 5 CFU / g ~5×10 5 CFU / g.

[0016] The viable count of Aspergillus niger in the Aspergillus niger solution was 8 × 10⁻⁶. 3 CFU / g ~1.1×10 4 CFU / g.

[0017] The second objective of this invention is to provide a method for preparing a compound Fu brick tea made from forsythia leaf tea and walnut septum, comprising the following steps.

[0018] The septum of the wood is steamed, shredded, and sun-dried to obtain wood septum fibers. A mixture of *Aspergillus cristatus*, *Lactobacillus plantarum*, and *Aspergillus niger* in the specified mass ratio is then used to obtain a compound microbial strain. This mixed strain enhances the degradation of lignocellulose and the generation of flavor precursors.

[0019] Forsythia leaf tea, black tea, and walnut septum fibers are mixed and softened by steaming at 100℃~120℃ for 6-8 minutes. After cooling to 40℃~42℃, a compound microbial culture is added, and primary fermentation is carried out at 32℃~35℃ and 75%~80% humidity for 10-14 hours. Secondary fermentation is then carried out at 24℃~28.5℃ and 75%~80% humidity for 19-21 days to obtain the fermented mixed tea. The fermented mixed tea is then microwaved at 350W~400W for 3-5 minutes and dried until the moisture content is less than or equal to 8%, yielding a compound Fu brick tea of ​​forsythia leaf tea and walnut septum fibers.

[0020] Primary fermentation promotes the decomposition of pectin and cellulose in forsythia leaves and septum. Secondary fermentation selectively enriches *Aureobasidium aureum* and synthesizes Fu tea glycoside 18. The fermented tea mixture is then microwaved and dried to a moisture content of ≤8% to obtain compound Fu tea. Microwave pretreatment and heat pump drying inhibit unwanted microorganisms while preserving volatile aromas.

[0021] Preferably, the steam softening temperature is 110°C and the time is 7 minutes.

[0022] Preferably, the cooling temperature is 41°C.

[0023] Preferably, the cooking time is 28 to 30 minutes. The width of the split wood fibers is 1.8 mm to 2.2 mm, and the moisture content is less than or equal to 7%.

[0024] Preferably, the temperature of the primary fermentation is 34°C and the time is 12 hours.

[0025] Preferably, the secondary fermentation is carried out at a temperature of 26°C for 20 days.

[0026] Preferably, the drying temperature is 35℃~40℃ and the humidity is 14%~16%.

[0027] Preferably, the drying method is heat pump drying.

[0028] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention relates to a compound Fu brick tea made from forsythia leaf tea and walnut septum, which is produced by steam softening forsythia leaf tea, black tea, and walnut septum fibers, followed by two-stage fermentation with the addition of compound microbial cultures, and finally microwave treatment. The steam softening process promotes the transformation of internal substances, activates enzyme activity in the tea leaves, and accelerates subsequent fermentation, causing preliminary transformation of substances such as tea polyphenols and amino acids, laying the foundation for subsequent aging or fermentation. It also kills harmful microorganisms; the high-temperature steam can kill some bacteria and mold on the surface of the tea leaves. Furthermore, it improves the aroma by volatilizing some low-boiling-point grassy odor substances, resulting in a purer aroma and reduced astringency. The two-stage fermentation increases the rate of flower formation, resulting in a golden flower density greater than 2.0 × 10⁻⁶. 5 CFU / g dry tea. Microwave pretreatment and heat pump drying can inhibit miscellaneous bacteria and retain volatile aromas, such as increasing the content of β-ionone and linalool by 35%, and the content of Fu tea catechin A is greater than or equal to 0.6 mg / g. This invention solves the problems of bitter taste and low flowering rate of Fu tea prepared from forsythia leaf tea and walnut septum by combining steam softening, two-stage fermentation and microwave treatment, so that the golden flower density is greater than 2.0 × 10 5 CFU / g dry tea.

[0029] In this invention, the mass ratio of Forsythia leaf tea, black tea, walnut septum fibers, and compound microbial strain in the compound Fu tea made from Forsythia leaf tea and walnut septum is 40-70:20-50:10-30:0.5-1. The compound microbial strain is prepared by mixing *Aspergillus cristatus* liquid, *Lactobacillus plantarum* liquid, and *Aspergillus niger* liquid in a mass ratio of 5-7:2-4:1. The two-stage fermentation involves primary fermentation at 32-35℃ for 10-14 hours, followed by secondary fermentation at 24-28.5℃ for 19-21 days. Primary fermentation promotes the decomposition of pectin and cellulose in the Forsythia leaf and walnut septum. Secondary fermentation selectively enriches *Aureobasidium aureum* and synthesizes Fu tea glycosides. The retention rate of forsythosidesin in the compound Fu tea made from Forsythia leaf tea and walnut septum of this invention is 92%, which is more than 50% higher than that of traditional processes. The septum is de-astringent, with a tannin degradation rate of greater than or equal to 70%, and the sensory score for bitterness and astringency is reduced to 1.2 points after de-astringency. The compound microbial strain achieves highly efficient flower development, with a golden flower density greater than or equal to 8 × 10⁻⁶. 4CFU / g. Flavonoids in the wood septum, such as quercetin and forsythoside, synergistically enhance antioxidant activity, resulting in a DPPH scavenging rate of ≥90% for the compound Fu brick tea.

[0030] Therefore, the forsythia leaf tea and walnut septum compound Fu tea of ​​the present invention have a high forsythoside retention rate, mild bitterness and astringency, strong aroma, good taste and high sensory score.

[0031] 2. The preparation method of the Forsythia Leaf Tea and Walnut Septum Composite Fu Tea of ​​the present invention involves steaming, slicing, and sun-drying the septum fibers to obtain septum fibers. A mixture of *Aspergillus cristatus* liquid, *Lactobacillus plantarum* liquid, and *Aspergillus niger* liquid in the stated mass ratio is used to obtain a composite microbial strain. The mixed microbial strain enhances the degradation of lignocellulose and the generation of flavor precursors. The Forsythia Leaf Tea, black tea, and septum fibers are mixed and softened by steam at 100℃~120℃ for 6-8 minutes, cooled, and the composite microbial strain is added. Primary fermentation is carried out at 32℃~35℃ and 75%~80% humidity for 10-14 hours; followed by secondary fermentation at 24℃~28.5℃ and 75%~80% humidity for 19-21 days to obtain fermented mixed tea. The fermented mixed tea is then microwaved at 350W~400W for 3-5 minutes and dried until the moisture content is less than or equal to 8%, yielding the Forsythia Leaf Tea and Walnut Septum Composite Fu Tea. The preparation method of the compound Fu tea made from forsythia leaf tea and walnut septum of the present invention reduces the content of bitter substances in the septum through fermentation with mixed strains, enriches the synthesis of Fu tea glycosides by golden flower fungus, and retains the volatile aroma of the fermented mixed tea. Detailed Implementation

[0032] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the following detailed description, in conjunction with preferred embodiments, provides a clear and complete description of the technical solutions of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that all technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0034] The main materials used in this invention are forsythia leaves, tea leaves, and septum of *Aspergillus cristatus*, *Lactobacillus plantarum*, and *Aspergillus niger*.

[0035] The forsythia leaves were purchased from Luonan County Hongtai Honeysuckle Professional Cooperative Company as Grade A forsythia leaf tea. The tea leaves were purchased from Shaanxi Hongfei Fuyun Tea Industry Co., Ltd. as Grade A black tea. *Aspergillus cristatus*, *Lactobacillus plantarum*, and *Aspergillus niger* were all purchased from Shaanxi Hongfei Fuyun Tea Industry Co., Ltd.

[0036] 1. Detection methods for the main components of compound Fu brick tea The forsythosides in the compound Fu tea of ​​this invention were detected by high performance liquid chromatography, the tannins were detected by ferrous tartrate spectrophotometry, and the golden flower fungus was detected by microscopic counting and culture identification methods.

[0037] 2. Sensory and Evaluation Methods The standard experimental method and evaluation factors for sensory evaluation of the compound Fu brick tea of ​​the present invention are as follows.

[0038] 2.1 Evaluation Core Standards and Experimental Environment National Standard: Mainly based on GB / T 23776-2018 "Sensory Evaluation Methods for Tea".

[0039] Judging tools: standard judging tray, judging cup, judging bowl, spoon, balance, timer, leaf base plate, etc.

[0040] Environmental requirements: bright and even lighting, no odor, quiet and clean.

[0041] 2.2 Core Process of Sensory Evaluation The evaluation of Fu brick tea is based on five factors: appearance, liquor color, aroma, taste, and infused leaves.

[0042] 2.2.1 Appearance Evaluation method: Place 100g of dry tea in an evaluation tray, and separate the tea into three layers (upper, middle, and lower) by shaking and rotating the tray, and observe the tea in each layer.

[0043] Evaluation factors: Color: Observe the abundance and color of the "golden flowers". High-quality Fu brick tea has abundant golden flowers, large particles, and a bright golden color. Tea bricks or loose tea have an overall dark brown and oily luster.

[0044] Uniformity: Whether the surface of the tea brick is flat, whether the edges and corners are distinct, and whether there is any damage.

[0045] Stem content: Fu brick tea needs tea stems to form gaps inside the brick, which is conducive to the formation of golden flowers.

[0046] Commonly used descriptive terms: Superior: Abundant golden flowers, dark brown and oily color, flat brick shape, and moderate tightness.

[0047] Inferior: Sparse gold flecks, whitish or greenish color, dull luster, cracked brick body, too tight or too loose.

[0048] 2.2.2 Soup color Method: Weigh 3g of tea sample, put it into a 150mL standard tasting cup, pour in boiling water, cover and let stand for 5 minutes, then pour the tea into the tasting bowl.

[0049] Evaluation factors: mainly the color and clarity of the tea soup.

[0050] Commonly used descriptive terms: Excellent: Orange-yellow or orange-red, bright and clear. This is a sign of good fermentation in Fu brick tea.

[0051] Medium: Orange-red but dark, or yellow but not bright enough.

[0052] Inferior: Dark red and turbid, or with sediment.

[0053] 2.2.3 Aroma a) Hot Smell: Smell the aroma from the lid and inside the teacup immediately after pouring. Judge the purity of the aroma and whether there are any off-odors.

[0054] b) Warm Smell: When the tea soup temperature drops to about 45℃, smell the aroma of the tea soup in the bowl. This is the best time to judge the type and grade of the aroma.

[0055] c) Cold Smell: After the tea soup has cooled, smell the aroma of the tea leaves. Assess the persistence of the aroma.

[0056] Evaluation factors: Fungal fragrance: This is the core aroma of Fu brick tea, a unique fragrance brought by the golden flowers formed by the fungus *Aspergillus cristatus*, resembling the fragrance of mushrooms and traditional Chinese medicine.

[0057] Purity: Whether there are any off-odors such as musty, sour, or burnt smells.

[0058] Commonly used descriptive terms: Superior: The aroma of the fungus is rich and pure, with a sweet or aged fragrance, free of any off-flavors, and still retains its fragrance when smelled cold.

[0059] Medium: The aroma of fungi is distinct but faint, or it may have a coarse or aged smell.

[0060] Inferior: It has an unpleasant odor such as musty, sour, or earthy smell.

[0061] 2.2.4 Taste Method: Use a spoon to take an appropriate amount of tea soup and sip it into your mouth. Use your tongue to circulate it around in your mouth, allowing the tea soup to fully contact different parts of your tongue and experience its flavor.

[0062] Evaluation factors: Smoothness: Whether it is smooth and mellow on the palate with minimal irritation.

[0063] Mushroom flower flavor: Does the flavor exhibit a unique "mushroom flower" flavor?

[0064] Aftertaste: Does a sweet and moist sensation occur in the mouth and throat after swallowing?

[0065] Commonly used descriptive terms: Superior: Smooth and mellow, with a pronounced floral aroma, a sweet aftertaste, and no astringent or sour taste.

[0066] The flavor is fairly mellow, but the aroma of mushrooms and flowers is rather weak, or there may be a slightly rough and astringent taste.

[0067] Inferior: Bland taste, or has a musty, sour, or severely bitter taste.

[0068] 2.2.5 Leaf base The tea leaves after brewing refer to the wet tea residue. The evaluation method for the tea leaves is as follows: Pour all the tea leaves from the tasting cup onto the tea leaf tray, spread them out with your fingers, and observe their tenderness, color, and uniformity.

[0069] Evaluation factors: Color: Dark brown, uniform, and oily.

[0070] Tenderness and activity: The leaves are soft and elastic, and do not easily break when squeezed.

[0071] Traces of "golden flowers": Golden flower mycelium can be seen adhering to the tea leaves.

[0072] Commonly used descriptive terms: Superior: Dark brown and uniform, leaves are soft and glossy, with good activity.

[0073] Inferior: The leaves are mottled, carbonized, hard and brittle, or feel soft and mushy to the touch.

[0074] III. Comprehensive Evaluation and Scoring In professional reviews, different weights are usually assigned to the five factors, and then scores are given.

[0075] Appearance, 25 points: including color, uniformity, etc.

[0076] The color of the soup, 10 points: the brightness and clarity of the color.

[0077] Aroma, 25 points: purity, concentration and persistence of aroma.

[0078] Taste, 30 points: This is the most important factor, directly determining the quality.

[0079] Leaf base, 10 points: used as an auxiliary judgment.

[0080] Final evaluation: The total score is calculated based on the scores and weights of each item, and a comprehensive evaluation is given.

[0081] Example 1 A method for preparing a compound Fu brick tea made from forsythia leaf tea and walnut septum includes the following steps: The septum was steamed for 30 minutes, cut into 2mm shreds, and sun-dried for 2 hours to obtain septum shreds. The viable count of *Eurotium cristatum* was 1.2 × 10⁻⁶. 7 The viable count of *Eurotium cristatum* culture (CFU / g) and *Lactobacillus plantarum* was 5 × 10⁻⁶. 5 The viable count of *Lactobacillus plantarum* and *Aspergillus niger* in CFU / g solution was 1.1 × 10⁻⁶. 4 A compound strain of Aspergillus niger with CFU / g was obtained by mixing the two strains at a mass ratio of 6:3:1.

[0082] 40 kg of Forsythia suspensa leaf tea, 50 kg of black tea, and 10 kg of walnut septum fibers were mixed and softened by steaming at 100℃ for 8 minutes. After cooling to 41℃, 0.5 kg of compound microbial inoculum was added and mixed. Primary fermentation was carried out at 35℃ and 80% humidity for 12 hours. Secondary fermentation was then carried out at 24℃ and 75% humidity for 21 days to obtain the fermented mixed tea. The fermented mixed tea was microwaved at 400W for 4 minutes and dried at 40℃ using a heat pump until the moisture content was 8%, yielding a compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers. The obtained compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers had a forsythoside content of 0.06%, a tannin content of 7%, and a golden flower density of 8.0 × 10⁻⁶. 5 CFU / g dry tea, sensory score of 95 points. The forsythia leaf tea and walnut septum compound Fu tea have good fermentation of golden flowers, excellent tea flavor, with the unique aroma of Fu tea, no bitterness or astringency, and are top-grade tea.

[0083] Example 2 A method for preparing a compound Fu brick tea made from forsythia leaf tea and walnut septum includes the following steps: The septum was steamed for 29 minutes, cut into 2mm shreds, and sun-dried for 2 hours to obtain septum shreds. The viable count of *Eurotium cristatum* was 1×10⁻⁶. 7 The viable count of *Eurotium cristatum* culture (CFU / g) and *Lactobacillus plantarum* was 4 × 10⁻⁶. 5 The viable count of *Lactobacillus plantarum* and *Aspergillus niger* in CFU / g solution was 1×10⁻⁶. 4 A compound strain of Aspergillus niger with CFU / g was obtained by mixing the two strains at a mass ratio of 7:4:1.

[0084] 40 kg of Forsythia suspensa leaf tea, 40 kg of black tea, and 20 kg of walnut septum fibers were mixed and softened by steam at 120℃ for 8 minutes. After cooling to 42℃, a compound microbial culture was added. Primary fermentation was carried out at 35℃ and 80% humidity for 14 hours. Secondary fermentation was then carried out at 28.5℃ and 80% humidity for 21 days to obtain fermented mixed tea. The fermented mixed tea was microwaved at 400W for 5 minutes and dried at 40℃ using a heat pump until the moisture content was 6%, resulting in a compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers.

[0085] The obtained forsythia leaf tea and walnut septum compound Fu tea had a forsythoside content of 0.08%, a tannin content of 11%, and a golden flower density of 4×10⁻⁶. 5 The tea leaves (CFU / g dry tea) received a sensory score of 81. The Forsythia Leaf Tea and Walnut Septum Fu Brick Tea had a low density of golden flowers, which improved the tea flavor, but the aftertaste was astringent with tannins, resulting in a mediocre overall taste.

[0086] Example 3 A method for preparing a compound Fu brick tea made from forsythia leaf tea and walnut septum includes the following steps: The septum was steamed for 30 minutes, cut into 2.2 mm filaments, and sun-dried for 2 hours to obtain septum filaments. The viable count of *Eurotium cristatum* was 1.2 × 10⁻⁶. 7 The viable count of *Eurotium cristatum* culture (CFU / g) and *Lactobacillus plantarum* was 5 × 10⁻⁶. 5 The viable count of *Lactobacillus plantarum* and *Aspergillus niger* in CFU / g solution was 1.1 × 10⁻⁶. 4 A compound strain of Aspergillus niger with CFU / g was obtained by mixing the two strains at a mass ratio of 6:3:1.

[0087] 70 kg of Forsythia suspensa leaf tea, 20 kg of black tea, and 10 kg of walnut septum fibers were mixed and softened by steam at 110℃ for 7 minutes. After cooling to 41℃, a compound microbial culture was added. Primary fermentation was carried out at 34℃ and 77% humidity for 12 hours. Secondary fermentation was then carried out at 26℃ and 77% humidity for 20 days to obtain a fermented mixed tea. The fermented mixed tea was then microwaved at 370W for 4 minutes and dried at 37℃ using a heat pump until the moisture content was 8%, yielding a compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers. The mass fraction of forsythoside in the obtained compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers was 0.11%, the mass fraction of tannin was 7.8%, and the density of golden flowers was 3.0 × 10⁻⁶. 5 The tea has a CFU / g dry tea volume and a sensory score of 86. The fermentation of the golden flowers in this compound Fu brick tea made from forsythia leaf tea and walnut septum is average, resulting in a slightly bitter taste, but it possesses the unique aroma of Fu brick tea. It is considered a medium-grade tea.

[0088] Example 4 A method for preparing a compound Fu brick tea made from forsythia leaf tea and walnut septum includes the following steps: The septum was steamed for 28 minutes, cut into 1.8 mm filaments, and sun-dried for 2 hours to obtain septum filaments. The viable count of *Eurotium cristatum* was 8 × 10⁻⁶. 6 The viable count of *Eurotium cristatum* broth and *Lactobacillus plantarum* was 3 × 10⁻⁶ CFU / g. 5 The viable counts of *Lactobacillus plantarum* and *Aspergillus niger* in the CFU / g solution were 8 × 10⁻⁶. 3 A compound strain of Aspergillus niger with CFU / g was obtained by mixing the two strains at a mass ratio of 5:2:1.

[0089] 50 kg of Forsythia suspensa leaf tea, 20 kg of black tea, and 30 kg of walnut septum fibers were mixed and softened by steam at 100℃ for 6 minutes. After cooling to 40℃, a compound microbial culture was added. Primary fermentation was carried out at 32℃ and 75% humidity for 10 hours. Secondary fermentation was then carried out at 24℃ and 75% humidity for 19 days to obtain a fermented mixed tea. The fermented mixed tea was then microwaved at 350W for 3 minutes and dried at 35℃ using a heat pump until the moisture content was 7%, yielding a compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers. The obtained compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum fibers had a forsythoside content of 0.12%, a tannin content of 11%, and a golden flower density of 2×10⁻⁶. 5 CFU / g dry tea, sensory score of 81 points.

[0090] The sensory score of the Forsythia leaf tea and walnut septum composite Fu brick tea prepared in Example 1 was 95 points, higher than the 82 points of the traditional process. The Forsythia leaf tea and walnut septum composite Fu brick tea and its preparation method of this invention combine the important characteristics of Forsythia and walnut septum with the health benefits of Fu brick tea, maximizing performance and showing commercial potential.

[0091] Comparative Example 1 A method for preparing a compound Fu brick tea made from forsythia leaf tea and walnut septum includes the following steps: The septum was steamed for 30 minutes, cut into 2.2 mm filaments, and sun-dried for 2 hours to obtain septum filaments. The viable count of *Eurotium cristatum* was 1.2 × 10⁻⁶. 7 The viable count of *Eurotium cristatum* culture (CFU / g) and *Lactobacillus plantarum* was 5 × 10⁻⁶. 5 The viable count of *Lactobacillus plantarum* and *Aspergillus niger* in CFU / g solution was 1.1 × 10⁻⁶. 4 A compound strain of Aspergillus niger with CFU / g was obtained by mixing the two strains at a mass ratio of 6:3:1.

[0092] 70 kg of Forsythia suspensa leaf tea and 30 kg of walnut septum shavings were mixed and softened by steam at 110℃ for 7 minutes. After cooling to 41℃, a compound microbial culture was added. Primary fermentation was carried out at 32℃ and 80% humidity for 12 hours. Secondary fermentation was then carried out at 26℃ and 80% humidity for 21 days to obtain a fermented mixed tea. The fermented mixed tea was then microwaved at 400W for 5 minutes and dried at 40℃ using a heat pump until the moisture content was 8%, yielding a compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum shavings. The resulting compound Fu brick tea of ​​Forsythia suspensa leaf tea and walnut septum shavings had a low density of *Gynostemma pentaphyllum*, a bitter taste, and a strong tannin astringency, resulting in a poor taste and a sensory score of 56 points.

[0093] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described in this invention to avoid redundancy. Although preferred embodiments of this invention have been described, those skilled in the art, once they understand the inventive concept of this invention, can make other changes and modifications to these embodiments, and all such changes and modifications fall within the scope of this invention.

[0094] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If such modifications and variations fall within the scope of equivalents of this invention, then this invention is also intended to include such modifications and variations.

Claims

1. A compound Fu brick tea made from forsythia leaf tea and walnut septum, characterized in that, It is made by steaming and softening forsythia leaf tea, black tea and wood septum, adding compound bacteria and fermenting in two stages, and finally microwave treatment. The mass ratio of the forsythia leaf tea, black tea, wood septum, and compound microbial strain is 40~70:20~50:10~30:0.5~1. The compound microbial strain is prepared by mixing *Aspergillus cristatus* liquid, *Lactobacillus plantarum* liquid, and *Aspergillus niger* liquid in a mass ratio of 5-7:2-4:

1. The two-stage fermentation involves primary fermentation at 32℃~35℃ for 10h~14h, followed by secondary fermentation at 24℃~28.5℃ for 19 days~21 days.

2. The compound Fu brick tea made from forsythia leaf tea and walnut septum as described in claim 1, characterized in that, The mass ratio of the forsythia leaf tea, black tea, wood septum, and compound microbial strain is 50:40:20:0.

8.

3. The compound Fu brick tea made from forsythia leaf tea and walnut septum as described in claim 1, characterized in that, The mass ratio of the *Aspergillus cristatus* solution, *Lactobacillus plantarum* solution, and *Aspergillus niger* solution is 6:3:

1.

4. The compound Fu brick tea made from forsythia leaf tea and walnut septum as described in claim 1, characterized in that, The viable count of *Aureobasidium tricuspidatum* in the *Aureobasidium tricuspidatum* solution was 8 × 10⁻⁶. 6 CFU / g ~1.2×10 7 CFU / g; The viable count of *Lactobacillus plantarum* in the *Lactobacillus plantarum* solution was 3 × 10⁻⁶. 5 CFU / g ~5×10 5 CFU / g; The viable count of Aspergillus niger in the Aspergillus niger solution was 8 × 10⁻⁶. 3 CFU / g ~1.1×10 4 CFU / g.

5. The preparation method of a compound Fu brick tea made from forsythia leaf tea and walnut septum according to claim 1, characterized in that, Includes the following steps: The septum was steamed, shredded, and dried to obtain septum shreds; the *Aspergillus cristatus*, *Lactobacillus plantarum*, and *Aspergillus niger* were mixed in the mass ratio described above to obtain a compound strain; Forsythia leaf tea, black tea, and walnut septum fibers are mixed and steamed at 100℃~120℃ for 6 to 8 minutes. After cooling to 40℃~42℃, a compound microbial culture is added, and primary fermentation is carried out at 32℃~35℃ and 75%~80% humidity for 10 to 14 hours. Then, secondary fermentation is carried out at 24℃~28.5℃ and 75%~80% humidity for 19 to 21 days to obtain fermented mixed tea. The fermented mixed tea is then microwaved at 350W~400W for 3 to 5 minutes and dried until the moisture content is less than or equal to 8% to obtain Forsythia leaf tea and walnut septum compound Fu brick tea.

6. The preparation method of a compound Fu brick tea made from forsythia leaf tea and walnut septum according to claim 5, characterized in that, The steam softening temperature is 110°C and the time is 7 minutes.

7. The preparation method of a compound Fu brick tea made from forsythia leaf tea and walnut septum according to claim 5, characterized in that, The cooking time is 28 min to 30 min; the width of the split wood fibers is 1.8 mm to 2.2 mm, and the moisture content is less than or equal to 7%.

8. The preparation method of a compound Fu brick tea made from forsythia leaf tea and walnut septum according to claim 5, characterized in that, The primary fermentation temperature was 34°C and the time was 12 hours.

9. The preparation method of the Forsythia Leaf Tea-Walnut Septum Composite Fu Tea according to claim 5, characterized in that, The secondary fermentation was carried out at a temperature of 26°C for 20 days.

10. The preparation method of a compound Fu brick tea made from forsythia leaf tea and walnut septum according to claim 5, characterized in that, The drying temperature is 35℃~40℃.