Reprocessing method for improving quality of oolong tea byproduct
Through the method of steaming, twisting, and drying the oolong tea "pornographic tablets", the problem of low quality of "pornographic" is solved, which significantly improves its flavor quality and utilization rate, making it a sellable drink.
Patent Information
- Application Number
- CN202411773480.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-01-24
AI Technical Summary
The by-product "yellow slices" produced during the processing of oolong tea is poor in appearance and content, poor taste and aroma, resulting in low utilization and serious waste of resources.
Use steps such as steam fumigation, twisting, and drying, and then process the "pornographic" of the oolong tea. Specific steps include fumigation under high-pressure steam, light-heavy-light pressure-lightly twisting, static setting and drying through the twisting machine.
By softening tea, increasing cell crushing rate, and fixed tea quality, it has significantly improved the flavor and quality of oolong tea "pornographic", makes its aroma obvious and mellow, has become a sellable drink, which improves the utilization rate of by -product.
Smart Images
Figure CN119344381A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of agricultural product processing, and particularly relates to a reprocessing method for improving the quality of oolong tea by-products. Background Art
[0002] As a specialty tea in my country, oolong tea is deeply loved by consumers for its rich floral and fruity aroma and mellow and sweet flavor. However, in the process of oolong tea processing, loose and thick tea flakes, tea stems and other by-products are inevitably produced, collectively referred to as "yellow flakes". According to surveys, the output of oolong tea raw tea has exceeded 270,000 tons in the past five years, of which "yellow flakes" account for about 20% to 30% of the total raw tea. Oolong tea "yellow flakes" are usually sold in bulk at low prices or used as fertilizer to cover the rows of tea trees due to their poor appearance and proportion of internal substances, poor taste and aroma. The utilization rate is low, which is a great waste of oolong tea resources. Therefore, it is urgent to improve the quality of oolong tea "yellow flakes", enhance the value of oolong tea "yellow flakes", and make it a marketable beverage to meet the diversified needs of consumers.
[0003] In order to improve the utilization rate of oolong tea by-products, the present invention studies and designs a reprocessing method for improving the quality of oolong tea by-products. Summary of the invention
[0004] The purpose of the present invention is to provide a reprocessing method for improving the quality of oolong tea byproducts. The present invention uses oolong tea byproducts as raw materials to reprocess oolong tea byproducts, including steam fumigation, rolling, and drying steps.
[0005] To achieve the above object, the present invention adopts the following technical solutions: A reprocessing method for improving the quality of oolong tea by-products comprises the steps of steam fumigation, rolling and drying.
[0006] A reprocessing method for improving the quality of oolong tea by-products comprises the following specific steps: (1) Steam fumigation: The loose and coarse tea leaves and tea stem byproducts selected from the raw oolong tea, collectively referred to as "yellow leaves", are fumigated under high-pressure steam of 0.3-0.4 Pa for 5-7 minutes; (2) Kneading: Place the “yellow sheet” treated in step (1) in a medium-sized kneading machine and knead it for 10-12 minutes in a light-heavy-light pressure mode; (3) Standing to set: Place the "yellow flakes" treated in step (2) in a wrapping towel, lift the four corners of the cloth towel to form a tea bag, turn it over and place it on another tea towel, cover it with a pad, grab the four corners of the other tea towel and place it on a speed packaging machine for packaging. After 30 to 60 seconds, the tea bag will be in a pumpkin shape. Let it stand for 15 to 20 minutes; (4) Drying: The "yellow flakes" treated in step (3) are placed in a roaster and roasted twice. The first roasting temperature is 120-125°C and lasts for 45-60 min. The second roasting temperature is 120-125°C and roasted until the moisture content of the tea leaves reaches 4%-6%. Reprocessed oolong tea "yellow flakes" are obtained.
[0007] Preferably, the high-pressure steam fumigation pressure in step (1) is 0.3 Pa.
[0008] Preferably, the high-pressure steam fumigation time in step (1) is 5 minutes.
[0009] Preferably, the kneading time in step (2) is 10 minutes.
[0010] Preferably, the standing time in step (3) is 15 minutes.
[0011] Preferably, the first baking temperature in step (4) is 120°C.
[0012] Preferably, the first baking time in step (4) is 45 minutes.
[0013] Preferably, the second baking temperature in step (4) is 120°C.
[0014] Preferably, in step (4), the second baking is performed until the moisture content of the tea leaves reaches 5%.
[0015] The invention discloses a reprocessed oolong tea byproduct prepared by the method.
[0016] The advantages of the present invention are: steam fumigation is used to soften the "yellow flakes" of oolong tea, which is helpful for the formation of tea leaves. Through the rolling process, the cell breakage rate is increased, the full transformation of the substances contained in the "yellow flakes" of oolong tea is promoted, and the flavor quality of the finished product "yellow flakes" of oolong tea is improved. Finally, the quality of the tea leaves is fixed by drying. By comparison, the "yellow flakes" of oolong tea have low fragrance, light taste and low quality. The reprocessed oolong tea "yellow flakes" prepared by this method have obvious floral and fruity fragrance and mellow taste, which significantly improves the flavor quality of the "yellow flakes" of oolong tea. The present invention increases the reprocessing process flow of the "yellow flakes" of oolong tea, and improves the flavor quality of the "yellow flakes" of oolong tea by optimizing the reprocessing process parameters, making it a marketable beverage, which has a significant effect on improving the utilization rate of oolong tea by-products. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the reprocessing process of the present invention; Figure 2 This is a graph showing the characteristic non-volatile metabolite content differences of Huang Guanyin "Yellow Tablets" after primary processing and reprocessing; Figure 3This is a graph showing the content of newly generated aroma compounds in the "yellow slices" of Huang Guanyin after reprocessing. DETAILED DESCRIPTION
[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the present invention is further described in detail below in conjunction with the accompanying drawings and preferred embodiments. Example
[0019] A reprocessing method for improving oolong tea by-products comprises the following steps: (1) Steam fumigation: Fresh leaves of Huang Guanyin, a tea variety suitable for making oolong tea, are used as raw materials. Raw tea is made in accordance with the Technical Specification for Oolong Tea Processing (GB / T 35863-2018). The "yellow leaves" (loose, coarse tea leaves, tea stems, etc.) selected from the Huang Guanyin raw tea are fumigated under 0.3 Pa high-pressure steam for 5 min.
[0020] (2) Kneading: Place the "yellow sheet" after step (1) in a kneading machine and knead it for 10 minutes in a light-heavy-light pressure mode.
[0021] (3) Standing to set: Place the "yellow sheet" after step (2) in a wrapping towel, lift the four corners of the cloth towel to form a tea bag, turn it over and place it on another tea towel, cover it with a pad, grab the four corners of the other tea towel and place it on a speed packaging machine for packaging. After 30 to 60 seconds, the tea bag will be in a pumpkin shape. Let it stand for 15 minutes; (4) Drying: Place the "yellow flakes" after step (3) in a roaster and roast them twice. The first roasting temperature is 120°C and lasts for 45 min. The second roasting temperature is 120°C and roasted until the moisture content of the tea leaves reaches 5%. Reprocessed oolong tea "yellow flakes" are obtained.
[0022] The sensory evaluation comparison of Huang Guanyin "Yellow Slices" after primary processing and reprocessing is shown in Table 1.
[0023] Table 1. Comparison of sensory evaluation of Huang Guanyin “Yellow Slices” after primary processing and reprocessing It can be seen from Table 1 above that the quality (appearance and internal quality) of the "yellow slices" of Huang Guanyin prepared by the reprocessing process in the embodiment of the present invention is better than that of the primary Huang Guanyin "yellow slices", the strips are tighter, the floral and fruity aroma is obvious, and the taste is especially mellower and more astringent than the primary "yellow slices".
[0024] Non-volatile compound detection: Sample preparation: Accurately weigh an appropriate amount of sample into a 2 mL centrifuge tube, add 600 µL methanol containing 2-chloro-L-phenylalanine (4 ppm), vortex for 30 s; add steel beads, put into a tissue grinder, grind at 55 Hz for 60 s; ultrasonicate at room temperature for 15 min; centrifuge at 12000 rpm at 4 ℃ for 10 min, take the supernatant and filter it through a 0.22 μm membrane, add the filtrate to the detection bottle for LC-MS detection.
[0025] Chromatographic conditions: Thermo Vanquish (Thermo Fisher Scientific, USA) ultra-high performance liquid chromatography system, using an ACQUITY UPLC® HSS T3 (2.1×100 mm, 1.8 µm) (Waters, Milford, MA, USA) column, a flow rate of 0.3 mL / min, a column temperature of 40 °C, and an injection volume of 2 μL. In positive ion mode, the mobile phases were 0.1% formic acid in acetonitrile (B2) and 0.1% formic acid in water (A2), and the gradient elution program was: 0-1 min, 8% B2; 1-8 min, 8%-98% B2; 8-10 min, 98% B2; 10-10.1 min, 98%-8% B2; 10.1-12 min, 8% B2. In negative ion mode, the mobile phase was acetonitrile (B3) and 5 mM ammonium formate water (A3), and the gradient elution program was: 0-1 min, 8% B3; 1-8 min, 8%-98% B3; 8-10 min, 98% B3; 10-10.1 min, 98%-8% B3; 10.1-12 min, 8% B3. Mass spectrometry conditions: Thermo Q Exactive Focus mass spectrometer (Thermo Fisher Scientific, USA), electrospray ion source (ESI), data acquisition in positive and negative ion modes. The positive ion spray voltage was 3.50 kV, the negative ion spray voltage was -2.50 kV, the sheath gas was 40 arb, and the auxiliary gas was 10 arb. The capillary temperature was 325 °C, the primary full scan was performed at a resolution of 70000, the primary ion scan range was 100-1000 m / z, and HCD was used for secondary fragmentation, the collision energy was 30 eV, the secondary resolution was 17500, the first 3 ions of the acquisition signal were fragmented, and dynamic exclusion was used to remove unnecessary MS / MS information.
[0026] After identification and analysis, non-volatile substances with VIP>1, P<0.05 and fold change ≥2 or ≤0.5 were screened as characteristic differential metabolites between the reprocessed and primary Huang Guanyin "Yellow Tablets". A total of 55 differential metabolites were identified, which can be divided into different categories, mainly including 8 amino acids and their derivatives, 9 flavonoids, 6 organic acids and their derivatives, 7 terpenes, 4 phenols, 4 oxygen-containing organic compounds, 3 phenolic acids, 4 lipids and lipid molecules, and 4 alkaloids. Among them, the total content of amino acids and their derivatives and flavonoids accounted for the highest proportion and increased significantly after reprocessing. Most amino acids have a fresh taste, and flavonoids have a certain astringency. As the main secondary metabolites in tea, these substances are closely related to the quality of tea, forming a rich taste and unique flavor of tea. This may be the main reason for the significant improvement of the thickness and astringency of the taste of the reprocessed Huang Guanyin "Yellow Tablets" and the improvement of the brewing resistance. The total content of organic acids and their derivatives was significantly reduced. These substances may be involved in the formation and transformation of tea aroma. Figure 2 .
[0027] Volatile compound detection: Extraction of aroma components: Take out the samples from the -80 ℃ refrigerator and grind them with liquid nitrogen. Vortex mix them evenly. Weigh 100 mg of each sample into a headspace bottle and add 10 μL (10 μg / mL) of internal standard solution. Then, oscillate and balance for 5 min at 75 ℃. Insert the 50 / 30 μm DVB / CWR / PDMS extraction head into the sample headspace bottle. Perform headspace extraction for 45 min. Decompose at 250 ℃ for 5 min. Then perform GC-MS separation and identification.
[0028] Chromatographic conditions: SH-PolarWax column (30 m × 250 μm × 0.25 μm), carrier gas was high-purity helium (purity ≥ 99.999%), constant flow rate was 1.2 mL / min, injection port temperature was 250 °C, splitless injection was performed, and solvent delay was 3 min. Program temperature rise: 50 °C for 3.5 min, then increase to 100 °C at 4 °C / min, and hold for 3 min, then increase to 120 °C at 3 °C / min, and hold for 2 min, then increase to 150 °C at 2 °C / min, and hold for 2 min, then increase to 180 °C at 3 °C / min, and hold for 2 min, then increase to 190 °C at 5 °C / min, and hold for 2 min, and finally increase to 230 °C at 10 °C / min, and hold for 2 min.
[0029] Mass spectrometry conditions: electron impact ion source (EI), ion source temperature 250 °C, interface temperature 280 °C, mass spectrometry interface temperature 280 °C, electron energy 70 eV, scanning mode selected ion detection mode (SIM), qualitative and quantitative ion precise scanning.
[0030] A total of 70 volatile compounds were identified in the Huang Guanyin "Yellow Tablets" after primary processing and reprocessing, of which 20 were newly generated aroma substances after reprocessing of Huang Guanyin "Yellow Tablets", including heterocyclic compounds (63.2%), terpenes (18.4%), hydrocarbons (14.6%), alcohols (2.2%) and aldehydes (1.6%). Heterocyclic compounds usually have roasted and nutty aromas, and terpenes mainly present floral and fruity aromas. Under the high temperature conditions during the reprocessing process, the Maillard reaction accelerates the chemical transformation of the components with strong catalytic activity, thereby generating more heterocyclic compounds. After reprocessing, the aroma of Huang Guanyin "Yellow Tablets" changes from fresh fragrance to floral and fruity fragrance. Among the newly generated aroma substances, the aroma components showing floral and fruity aromas include bergamotol, trans-2,4-decadienal, neophytadiene, α-ionone, phyton, lauryl aldehyde, β-cyclohomocitral, etc. These newly generated aroma compounds make the Huang Guanyin "Huang Pian" have rich aroma layers and distinct floral fragrance. Figure 3 .
[0031] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.
Claims
1. A reprocessing method for improving the quality of oolong tea by-products, characterized in that: The specific steps include: (1) Steam fumigation: The loose and coarse tea leaves and tea stem byproducts selected from the raw oolong tea, collectively referred to as "yellow leaves", are fumigated under high-pressure steam of 0.3-0.4 Pa for 5-7 minutes; (2) Kneading: Place the "yellow sheet" treated in step (1) in a medium-sized kneading machine and knead it for 10-12 minutes in a light-heavy-light pressure mode; (3) Standing to set: Place the "yellow flakes" treated in step (2) in a wrapping towel, lift the four corners of the cloth towel to form a tea bag, turn it over and place it on another tea towel, cover it with a pad, grab the four corners of the other tea towel and place it on a speed packaging machine for packaging. After 30 to 60 seconds, the tea bag will become a pumpkin shape. Let it stand for 15 to 20 minutes; (4) Drying: Place the "yellow flakes" treated in step (3) in a roaster and roast them twice. The first roasting temperature is 120-125°C and lasts for 45-60 min. The second roasting temperature is 120-125°C and roasted until the moisture content of the tea leaves reaches 4%-6%. Reprocessed oolong tea "yellow flakes" are obtained.
2. The method according to claim 1, characterized in that: In step (1), the high-pressure steam fumigation pressure is 0.3 Pa.
3. The method according to claim 1, characterized in that: The high-pressure steam fumigation time in step (1) is 5 minutes.
4. The method according to claim 1, characterized in that: The kneading time in step (2) is 10 minutes.
5. The method according to claim 1, characterized in that: The standing time in step (3) is 15 min.
6. The method according to claim 1, characterized in that: The first baking temperature in step (4) is 120°C.
7. The method according to claim 1, characterized in that: The first baking time in step (4) is 45 minutes.
8. The method according to claim 1, characterized in that: The second baking temperature in step (4) is 120°C.
9. The method according to claim 1, characterized in that: In step (4), the second baking is performed until the moisture content of the tea leaves reaches 5%.
10. A reprocessed oolong tea by-product prepared by the method of claim 1.