Sour tea with hypoglycemic effect and preparation method thereof

Abstract

The invention provides sour tea with a hypoglycemic effect and a preparation method thereof, and the preparation method comprises the following steps: S1, preparing an organic fertilizer, and planting tea seedlings by using the organic fertilizer; s2, after the tea tree grows to be mature, picking fresh leaves with one bud and two leaves or one bud and three leaves and uniform in size; s3, the picked fresh leaves are subjected to withering, fixation and rolling in sequence, and tea leaves are obtained; s4, mixing the tea leaves obtained in the step S3 with brown sugar, and performing anaerobic fermentation in a closed environment; and S5, tedding and airing the tea leaves subjected to anaerobic fermentation to obtain the sour tea. According to the method, the tea leaves and the brown sugar are mixed and then subjected to anaerobic fermentation, in the anaerobic fermentation process, the brown sugar serves as an important nutrient substance, fermentation substrates are increased, energy is provided for mass propagation of microorganisms, rapid fermentation of the microorganisms is promoted, effective microbial communities are generated, the nutritional quality of the sour tea is further improved, and the prepared sour tea has a certain hypoglycemic effect.

Description

Technical Field

[0001] The invention belongs to the technical field of sour tea preparation, and relates to sour tea with blood sugar lowering effect and a preparation method thereof. Background Art

[0002] Sour tea is a traditional food of ethnic minorities in Yunnan Province, my country, and the majority of them are the De'ang and Bulang people. The De'ang people have many ways to make and drink tea, and the most distinctive one is the sour tea of ​​the De'ang people. There are two techniques: one is the earth pit method. Before humans invented the use of pottery, after picking fresh tea leaves and returning home, they wrapped the tea leaves with fresh banana leaves and buried them in a deep pit dug in advance for about 7 days. Then the tea leaves were taken out and rubbed in the sun and dried for 2 days. When the tea leaves were slightly dry, they were wrapped and put back into the deep pit for 3 days. They were taken out and dried before brewing. Boiling water is used for brewing. It tastes sour and bitter, has the effect of cleaning the mouth, clearing away heat and relieving summer heat, and is an original green health drink. The sauerkraut used for cooking should be appropriately left for a few more days in the second process, and then taken out and crushed in a mortar and dried. When eating, soak it in water and mix it cold. It tastes sour and astringent, which increases people's appetite. The second is the pottery method. After the invention of pottery, sour tea was directly pickled in pottery jars.

[0003] However, the preparation process of sour tea is complicated and the fermentation cycle is long, usually several months or even years. Summer and autumn tea has a high catechin content and low amino acid and aromatic substances content due to high temperature and strong light. The finished tea has a strong bitter taste and poor aroma. Therefore, the sour tea prepared by the current preparation process can no longer meet people's edible and health needs. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a sour tea with hypoglycemic effect and a preparation method thereof. The present invention mixes tea leaves with brown sugar and then performs anaerobic fermentation. During the anaerobic fermentation process, brown sugar, as an important nutrient, increases the fermentation substrate, provides energy for the massive reproduction of microorganisms, promotes their rapid fermentation, produces beneficial bacteria, and further improves the nutritional quality of the sour tea. The prepared sour tea has a certain hypoglycemic effect.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a sour tea having a blood sugar lowering effect, the preparation method comprising:

[0007] S1, preparing organic fertilizer, and using the organic fertilizer to plant tea seedlings;

[0008] S2, after the tea trees grow and mature, pick fresh leaves of uniform size, one bud and two leaves or one bud and three leaves;

[0009] S3, withering, killing and rolling the picked fresh leaves in sequence to obtain tea leaves;

[0010] S4, mixing the tea leaves obtained in step S3 with brown sugar and placing them in a closed environment for anaerobic fermentation;

[0011] S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

[0012] The present invention can increase the organic matter content in the soil and improve the life activities of microorganisms in the soil by applying biological organic fertilizer on the tea seedling planting soil, achieve the purpose of improving the ecological conditions of the soil, and reduce the soil bulk density by applying organic fertilizer, the soil becomes loose and porous, the internal space increases, and can be dug to about 120cm, the soil is soft and the roots are rich, which is conducive to improving the absorption efficiency of nutrients by the tea seedlings and promoting the nutrient absorption of the tea seedlings; in comparison, after applying commercially available organic fertilizer, the soil is severely compacted, and can only be dug to about 40cm, and the roots are less. In addition, the biological organic fertilizer prepared by the present invention needs to be fermented, and plant growth regulators such as multiple growth hormones, gibberellins, and secondary metabolites such as amino acids and vitamins will be produced during the fermentation process, and these substances rich in multiple physiological activities can effectively stimulate the growth and development of tea seedlings and produce biodiversity.

[0013] The present invention mixes tea leaves and brown sugar and then performs anaerobic fermentation. In the anaerobic fermentation process, brown sugar, as an important nutrient, increases fermentation substrate, provides energy for large-scale reproduction of microorganisms, promotes rapid fermentation, produces beneficial bacteria, further improves the nutritional quality of sour tea, and the prepared sour tea has a certain blood sugar lowering effect.

[0014] As a preferred technical solution of the present invention, in step S1, the organic fertilizer is prepared by the following method:

[0015] The method comprises the following steps: mixing sheep manure, pig manure, cow manure, bagasse, composite modified biochar, humic acid, bean dregs, brown sugar and water uniformly to obtain a fermentation stock solution; sending the fermentation stock solution into a fermentation tank for anaerobic fermentation to obtain a fermentation product; adding nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer to the fermentation product, and mixing them uniformly to obtain the organic fertilizer.

[0016] The invention mixes poultry and livestock manure, bagasse, composite modified biochar, humic acid, bean dregs, brown sugar and water for anaerobic fermentation, then adds nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer to adjust the content of nitrogen, phosphorus and potassium, and finally prepares organic fertilizer for planting tea seedlings.

[0017] There are a lot of organic matter in livestock and poultry manure such as sheep manure, pig manure and cow manure. In the process of composting and fermentation, organic matter is the main source of nutrients. When fertilizers containing organic matter are applied to the soil, they can improve the physical properties of the soil, improve the soil's fertilizer retention capacity and buffering performance; in addition, organic matter and nutrients such as nitrogen, phosphorus and potassium in livestock and poultry manure can be applied to the soil as part of organic fertilizer to improve soil fertility and improve soil fertilizer efficiency. It can not only replace the use of chemical fertilizers, but also solve the problem of livestock and poultry manure treatment, and achieve the purpose of resource utilization of manure waste. Composite modified biochar, as a carrier of probiotics, provides a rich growth and reproduction space for probiotics, so that probiotics can expand more rapidly, form a strong dominant bacterial community, inhibit the growth and reproduction of harmful bacterial communities, and eliminate most pathogenic bacterial communities. Humic acid has good physiological activity, can reduce the loss of nitrogen during the fermentation process, and can eliminate the odor problem during the fermentation process, reduce environmental pollution, and can inhibit or even kill the growth and reproduction of pathogens and eggs in livestock and poultry manure. Adding dregs can rapidly increase the temperature of the fermentation solution during the fermentation process, thereby improving the fermentation efficiency. Adding brown sugar can provide sufficient energy for the growth, development and reproduction of soil microorganisms, probiotics and enzymes in the fermentation solution.

[0018] The present invention mixes and ferments a variety of raw materials to make the prepared organic fertilizer rich in nitrogen, phosphorus, potassium and a variety of nutrients, greatly improving the fertilizer efficiency of the organic fertilizer. The anaerobic fermentation can fully decompose the protein, cellulose and the like in the raw materials, and kill parasites and their eggs, as well as some infectious pathogenic bacteria, thereby improving the fertilizer efficiency and nutrition of the organic fertilizer. In addition, the carbon dioxide released in the anaerobic fermentation process is used as a carbon source, and the odor released from livestock manure is used as an electron donor to provide a nutritional environment for anaerobic ammonium oxidizing bacteria for absorption and utilization. The anaerobic ammonium oxidizing bacteria converts the absorbed odor into nitrogen through a physiological mechanism for removal, thereby preventing the odor generated by the organic fertilizer in the fermentation process from polluting the environment and playing a role in purifying the air.

[0019] As a preferred technical solution of the present invention, based on 100 parts by weight of the fermentation stock solution, it includes the following components in parts by weight:

[0020]

[0021] Among them, the weight parts of sheep manure can be 15 parts, 15.5 parts, 16 parts, 16.5 parts, 17 parts, 17.5 parts or 18 parts, the weight parts of pig manure can be 14 parts, 14.2 parts, 14.4 parts, 14.6 parts, 14.8 parts, 15 parts, 15.2 parts, 15.4 parts, 15.6 parts, 15.8 parts or 16 parts, and the weight parts of cow dung can be 23 parts, 23.5 parts, 24 parts, 24.5 parts, 25 parts, 25.5 parts, 26 parts, 26.5 parts, 27 parts, 27.5 parts or 28 parts, the weight parts of bagasse can be 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts or 32 parts, and the weight parts of composite modified biochar can be 7.0 parts, 7.1 parts, 7.2 parts, 7.3 parts, 7.4 parts, 7.5 parts, 7.6 parts , 7.7, 7.8, 7.9 or 8.0 parts by weight, the weight portion of humic acid can be 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9 or 6.0 parts, the weight portion of bean dregs can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8 parts, the weight portion of brown sugar can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8 parts, the weight portion of water can be 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable.

[0022] The present invention particularly limits the amount of sheep manure, pig manure and cow manure. When the amount of various livestock manure is lower than the lower limit of the range defined by the present invention, due to the low organic matter content, the heat generated during the fermentation and decomposition process cannot meet the temperature required in the organic fertilizer fermentation process, resulting in low fertilizer efficiency of the produced organic fertilizer, thereby affecting its use effect. When the amount of various livestock manure exceeds the upper limit of the range defined by the present invention, it will affect the ventilation effect during the composting fermentation process, resulting in the fermentation process being mainly anaerobic fermentation, which is prone to emitting foul odors and polluting the environment.

[0023] Water is one of the essential conditions for the growth of microorganisms. The present invention specifically limits the amount of water to 1 to 2 parts. When the amount of water is less than 1 part, the water content of the fermentation solution is too low, and the demand of the microorganism growth process cannot be met during the fermentation process, resulting in difficulty in decomposing livestock manure and slow fertilizer fermentation. When the amount of water exceeds 2 parts, the water content of the fermentation solution is too high, and the temperature of the fermentation solution rises slowly or even fails to rise during the fermentation process; at the same time, when there is too much water in the fermentation solution, the ventilation effect of the fermentation solution will deteriorate, making the fermentation process mainly anaerobic, prone to emitting foul odors and polluting the environment.

[0024] In some optional examples, the fermentation temperature of the anaerobic fermentation is 45-55°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C or 55°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] During the composting fermentation process, temperature is one of the important conditions that affect the final fermentation effect of the fertilizer. The present invention specifically limits the fermentation temperature of anaerobic fermentation to 45-55°C. When the fermentation temperature is lower than 45°C, the livestock manure in the fermentation solution cannot be degraded normally, resulting in a long fertilizer maturation time; when the fermentation temperature is higher than 55°C, it will have a harmful effect on the microorganisms in the fermentation solution.

[0026] In some optional examples, the fermentation time of the anaerobic fermentation is 6 to 8 days, for example, 6 days, 7 days or 8 days, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] In some optional examples, the ratio of the mass of the nitrogen fertilizer to the total mass of sheep manure, pig manure and cow manure in the fermentation stock solution is 1:(9-10), for example, it can be 1:9.0, 1:9.1, 1:9.2, 1:9.3, 1:9.4, 1:9.5, 1:9.6, 1:9.7, 1:9.8, 1:9.9 or 1:10.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] In some optional examples, the ratio of the mass of the phosphate fertilizer to the total mass of sheep manure, pig manure and cow manure in the fermentation stock solution is 1:(9-10), for example, it can be 1:9.0, 1:9.1, 1:9.2, 1:9.3, 1:9.4, 1:9.5, 1:9.6, 1:9.7, 1:9.8, 1:9.9 or 1:10.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In some optional examples, the ratio of the mass of the potash fertilizer to the total mass of the sheep manure, pig manure and cow manure in the fermentation stock solution is 1:(8-9), for example, it can be 1:8.0, 1:8.1, 1:8.2, 1:8.3, 1:8.4, 1:8.5, 1:8.6, 1:8.7, 1:8.8, 1:8.9 or 1:9.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In some optional examples, the nitrogen fertilizer includes ammonium bicarbonate and / or diammonium phosphate.

[0031] In some optional examples, the phosphate fertilizer includes superphosphate and / or diammonium phosphate.

[0032] In some optional examples, the potash fertilizer includes potassium chloride and / or potassium sulfate.

[0033] As a preferred technical solution of the present invention, the composite modified biochar is prepared by the following method:

[0034] (a) mixing crop straw and bagasse, drying, crushing and sieving in sequence to obtain a raw material powder, mixing the raw material powder with a phosphoric acid solution, and wet ball milling to obtain a raw material mixture; placing the raw material mixture in a tubular vacuum furnace, and pyrolyzing and carbonizing it under a nitrogen atmosphere to obtain modified biochar;

[0035] (b) mixing the modified biochar with the sodium silicate solution and placing the mixture in a shaker for shaking, performing solid-liquid separation after the shaking, drying the solid obtained after the separation and placing the mixture in a tubular vacuum furnace for high-temperature calcination under a nitrogen atmosphere to obtain the composite modified biochar.

[0036] The present invention performs composite modification on biochar, and the specific surface area and porosity of the biochar after composite modification are significantly improved, and the types and quantities of groups are significantly increased. The change of its own properties can improve the adsorption capacity of harmful substances to a certain extent. On the one hand, when the composite modified biochar is mixed with livestock excrement such as sheep manure, pig manure and cow manure, it will carry more negative charges, and the electrostatic attraction between the harmful substances and the composite modified biochar will be greatly increased, so as to achieve the purpose of removing harmful substances in livestock excrement; on the other hand, compared with unmodified biochar, the specific surface area and pore structure of the composite modified biochar are more developed, and the composite modified biochar in livestock excrement can be removed by physical adsorption. Therefore, the modified biochar has a better application effect in composting than the biochar before modification.

[0037] The composting fermentation process of livestock manure is complex, including the active metabolic process of bacteria and viruses in microorganisms and the transformation process of various elements in the fermentation stock solution. In the early and middle stages of the fermentation stock composting fermentation, the microorganisms in the fermentation stock solution begin to decompose organic matter, the temperature of the fermentation stock solution rises rapidly, and the microorganisms can quickly utilize the more easily decomposable small molecular organic matter in the fermentation stock solution. Therefore, the livestock manure in the fermentation stock solution decomposes faster; in the later stage of the fermentation stock composting fermentation, the temperature of the fermentation stock solution begins to drop, the small molecular substances are fully decomposed, and there are relatively more difficult-to-decompose substances in the fermentation stock solution, which slows down the degradation rate of livestock manure. After the composite modified biochar prepared by the present invention is added to the compost, the developed specific surface area and morphological structure of the composite modified biochar itself can provide a larger living space for the survival and reproduction of microorganisms, thereby regulating the activities of various bacterial species in the fermentation stock solution, affecting the changing state of other reactions in the fermentation stock solution, and can extend the high temperature period of the composting fermentation process by 3 to 5 days. The extension of the high temperature period can significantly shorten the overall time of the composting fermentation, achieving a better composting effect.

[0038] The present invention can effectively retain the nutrients in the fermentation solution by adding composite modified biochar to the fermentation solution, and improve the content of nitrogen, phosphorus and potassium in the organic fertilizer obtained after composting fermentation. In the process of composting fermentation, with the decomposition of poultry and livestock feces, the humic acid in the fermentation solution and the inorganic phosphorus in the phosphorus element will form a complex, affecting the content of the phosphorus element; the potassium element in the fermentation solution mainly exists in the form of potassium oxide, and the effective potassium content is increased after being applied to the soil, which can promote the circulation of soil potassium and enhance the microbial activity in the soil; in the early stage of composting fermentation, the microbial activity is vigorous, and the nitrogen element is converted into ammonia and ammonium nitrogen, so that the content of the nitrogen element is reduced and the carbon-nitrogen ratio is reduced. The present invention can effectively retain the phosphorus element, potassium element and nitrogen element in the fermentation solution by adding composite modified biochar. As the composting fermentation proceeds, the organic matter, cellulose and other substances in the fermentation solution are fully degraded, resulting in a concentration effect inside the fermentation solution, so that the phosphorus element, potassium element and nitrogen element in the organic fertilizer obtained after the composting fermentation are effectively retained.

[0039] Silicon modification allows the surface of the composite modified biochar to have more hydroxyl groups or other oxygen-containing functional groups. These functional groups can improve the surface activity of the composite modified biochar, thereby providing more adsorption sites and enhancing the polarity, hydrophilicity and surface chemical activity of the composite modified biochar. The increase of oxygen-containing functional groups can enhance the adsorption capacity of composite modified biochar for polar pollutants, because these functional groups can interact with target pollutants through hydrogen bonds, ion exchange or complexation. Specific functional groups have higher selectivity for certain pollutants. For example, carboxyl groups can better adsorb heavy metal ions, while hydroxyl groups can better adsorb organic pollutants. Enhancing hydrophilicity is conducive to improving the adsorption capacity of composite modified biochar for nitrogen and phosphorus in water.

[0040] In addition, silicon modification can also increase the specific surface area of ​​biochar. The increase in specific surface area means that the number of sites available for adsorption on the biochar surface increases, which directly increases the adsorption capacity and efficiency of biochar, enabling it to quickly adsorb more pollutant molecules. Silicon modification allows biochar to have more micropores and an improved pore structure. On the one hand, small molecule pollutants are more likely to enter the micropores and be adsorbed by the surface functional groups in the micropores. Therefore, the increase in the number of micropores can provide more adsorption sites for small molecule pollutants, thereby increasing the selective adsorption of small molecule pollutants and limiting the diffusion of large molecule pollutants. On the other hand, the increase in the number of micropores will cause more adsorption to occur on the surface of biochar rather than inside the pores, thereby enhancing the surface adsorption of the composite modified biochar, which is more conducive to improving the adsorption capacity of the composite modified biochar for nitrogen and phosphorus.

[0041] In some optional examples, in step (a), the mesh size of the sieve is 100 to 200 mesh, for example, it can be 100 mesh, 110 mesh, 120 mesh, 130 mesh, 140 mesh, 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh or 200 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] In some optional examples, the mass fraction of the phosphoric acid solution is 10-15wt%, for example, it can be 10wt%, 10.5wt%, 11wt%, 11.5wt%, 12wt%, 12.5wt%, 13wt%, 13.5wt%, 14wt%, 14.5wt% or 15wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In some optional examples, the mixing ratio of the crop straw, bagasse and phosphoric acid solution is 1g:(0.7-0.8)g:(8-10)mL, for example, it can be 1g:0.7g:8mL, 1g:0.71g:8.2mL, 1g:0.72g:8.4mL, 1g:0.73g:8.6mL, 1g:0.74g:8.8mL, 1g:0.75g:9mL, 1g:0.76g:9.2mL, 1g:0.77g:9.4mL, 1g:0.78g:9.6mL, 1g:0.79g:9.8mL or 1g:0.8g:10mL, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] In some optional examples, the ball milling speed of the wet ball milling is 400-500 rpm, for example, it can be 400 rpm, 410 rpm, 420 rpm, 430 rpm, 440 rpm, 450 rpm, 460 rpm, 470 rpm, 480 rpm, 490 rpm or 500 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] In some optional examples, the wet ball milling time is 15 to 25 min, for example, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min or 25 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] In some optional examples, the heating rate of the pyrolysis carbonization is 10 to 20°C / min, for example, it can be 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min, 15°C / min, 16°C / min, 17°C / min, 18°C / min, 19°C / min or 20°C / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In some optional examples, the heating temperature of the pyrolysis carbonization is 700-800°C, for example, it can be 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C or 800°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] The temperature of pyrolysis and carbonization of biochar will affect the formation and number of surface functional groups. The present invention specifically limits the heating temperature of pyrolysis and carbonization to 700-800°C. When the pyrolysis and carbonization temperature is within the range defined by the present invention, more oxygen-containing functional groups, such as carboxyl and hydroxyl groups, can be retained. These functional groups can enhance the adsorption of ammonia nitrogen through hydrogen bonding or ion exchange. At the same time, the appropriate heating temperature will lead to an increase in the specific surface area of ​​the biochar, optimize the pore structure of the biochar, thereby increasing the number of adsorption sites and enhancing its adsorption capacity for ammonia nitrogen. When the pyrolysis and carbonization temperature exceeds 800°C, the number of oxygen-containing functional groups will decrease, and the pore structure of the biochar will be excessively damaged, thereby reducing its adsorption performance.

[0049] In some optional examples, the holding time of the pyrolysis carbonization is 2 to 3 hours, for example, it can be 2.0h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In some optional examples, in step (b), the mass ratio of the modified biochar to the sodium silicate solution is 1:(8-12), for example, it can be 1:8.0, 1:8.5, 1:9.0, 1:9.5, 1:10.0, 1:10.5, 1:11.0, 1:11.5 or 1:12.0, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] The present invention specifically limits the mass ratio of modified biochar to sodium silicate solution to 1:(8-12), and the adsorption amount of ammonia nitrogen by the composite modified biochar increases first and then decreases with the increase of the amount of sodium silicate solution used. When the amount of sodium silicate solution used exceeds the upper limit of the range defined by the present invention, the excessive reaction of sodium silicate on the surface of biochar will form excessive functional groups, and these functional groups will interact with each other, such as aggregation or cross-linking, thereby reducing the number of effective adsorption sites on the surface of the composite modified biochar, and at the same time blocking the pores of the biochar, resulting in a gradual decrease in the adsorption effect of the composite modified biochar on ammonia nitrogen.

[0052] In some optional examples, the mass fraction of the sodium silicate solution is 5 to 10 wt%, for example, it can be 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, 9.5 wt% or 10.0 wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] In some optional instances, the oscillation speed of the shaker is 150-200 r / min, for example, it can be 150 r / min, 155 r / min, 160 r / min, 165 r / min, 170 r / min, 175 r / min, 180 r / min, 185 r / min, 190 r / min, 195 r / min or 200 r / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] In some optional examples, the oscillation time of the shaker is 2 to 3 hours, for example, it can be 2.0 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours or 3.0 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] In some optional examples, the heating temperature of the high temperature calcination is 550-650°C, for example, it can be 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C or 650°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] In some optional examples, the heating time for high temperature calcination is 2 to 3 hours, for example, it can be 2.0h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0057] As a preferred technical solution of the present invention, in step S1, the tea seedling planting process includes:

[0058] (I) 2 to 3 months before planting tea seedlings, clean up the dead branches and fallen leaves on the surface of the planting soil;

[0059] (II) deep plowing the planting soil once, the depth of deep plowing once is 30-40 cm, removing grass roots, tree roots and stones turned up during the deep plowing process, and applying a soil conditioner to the soil after the deep plowing, the soil conditioner comprising 50-60 parts of dolomite powder, 20-30 parts of quicklime, 10-15 parts of peat and 5-10 parts of potassium chloride, and the application amount of the soil conditioner is 20-30 kg per mu;

[0060] The depth of deep tillage can be 30cm, 31cm, 32cm, 33cm, 34cm, 35cm, 36cm, 37cm, 38cm, 39cm or 40cm, the weight of marble powder can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts or 60 parts, the weight of marble powder can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts or 30 parts, and the weight of marble powder can be 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, 12. 5, 13, 13.5, 14, 14.5 or 15 parts by weight, the weight of marble powder can be 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5 or 10.0 parts, and the application rate of soil conditioner can be 20kg per mu, 21kg per mu, 22kg per mu, 23kg per mu, 24kg per mu, 25kg per mu, 26kg per mu, 27kg per mu, 28kg per mu, 29kg per mu or 30kg per mu, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0061] (III) 5 to 10 days after applying the soil conditioner, deep plowing the planting soil for a second time, the depth of the second deep plowing being 20 to 30 cm, and applying the organic fertilizer described in step S1 to the soil after the second deep plowing, the amount of the organic fertilizer applied being 1800 to 2000 kg per mu;

[0062] The depth of the secondary deep tillage can be 20 cm, 21 cm, 22 cm, 23 cm, 24 cm, 25 cm, 26 cm, 27 cm, 28 cm, 29 cm or 30 cm, and the amount of organic fertilizer applied can be 1800 kg per mu, 1820 kg per mu, 1840 kg per mu, 1860 kg per mu, 1880 kg per mu, 1900 kg per mu, 1920 kg per mu, 1940 kg per mu, 1960 kg per mu, 1980 kg per mu or 2000 kg per mu, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0063] (IV) Ridge the soil. In September and October of each year and 5 to 8 days after fertilization, transplant the tea seedlings with soil to the ridges. After the tea seedlings are planted, they are regularly fertilized, pruned, watered, and pest-controlled, and the weeds on the soil surface are removed.

[0064] As a preferred technical solution of the present invention, in step S3, the withering process includes:

[0065] (1) Blowing air: Put the picked fresh leaves into the withering trough, shake them loose and flatten them, so that the flattened leaf layer is fluffy, and blow air into the withering trough through an axial flow fan;

[0066] (2) Shaking: After blowing air for a period of time, the axial flow fan is turned off, and the fresh leaves in the withering trough are thrown up and then naturally fall to shake. The shaken fresh leaves are flattened again and left to stand for a period of time. After the standing period, the axial flow fan is turned on to blow air into the withering trough again;

[0067] (3) Repeat steps (1) and (2) at least five times until the leaf stems bend, the leaves shrink and the surface loses its luster, thus completing the withering treatment and obtaining withered leaves.

[0068] In some optional embodiments, in step (1), the thickness of the leaf layer after the fresh leaves are flattened is 5 to 8 cm, for example, it can be 5.0 cm, 5.5 cm, 6.0 cm, 6.5 cm, 7.0 cm, 7.5 cm or 8.0 cm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0069] In some optional embodiments, the axial flow fan has an air volume of 1800 to 2000 m 3 / h, for example, it can be 1800m 3 / h、1820m 3 / h、1840m 3 / h、1860m 3 / h、1880m 3 / h、1900m 3 / h、1920m 3 / h、1940m 3 / h、1960m 3 / h、1980m 3 / h or 2000m 3 / h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0070] In some optional instances, the temperature of the air blown in by the axial flow fan is 25-35°C, for example, it can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0071] In some optional instances, the relative humidity of the air blown in by the axial flow fan is 50-60%, for example, it can be 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59% or 60%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0072] In some optional embodiments, in step (2), the axial flow fan is turned off after blowing for 0.5 to 1.5 hours, and the fresh leaves are shaken. For example, it can be 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours, 1.0 hours, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours or 1.5 hours, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0073] In some optional examples, the height to which the fresh leaves are thrown when they are turned over and shaken is 10 to 20 cm, for example, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm, 15 cm, 16 cm, 17 cm, 18 cm, 19 cm or 20 cm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0074] In some optional examples, the standing time of the fresh leaves after shaking is 10 to 20 minutes, for example, it can be 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0075] In some optional embodiments, in step (3), the total time of the withering treatment is 10 to 15 hours, for example, it can be 10 hours, 10.5 hours, 11 hours, 11.5 hours, 12 hours, 12.5 hours, 13 hours, 13.5 hours, 14 hours, 14.5 hours or 15 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0076] In some optional instances, the moisture content of the withered leaves is 60-70%, for example, it can be 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69% or 70%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0077] As a preferred technical solution of the present invention, in step S3, the fixing process includes:

[0078] The withered leaves obtained after withering treatment are steam-sterilized; then, the steam-sterilized withered leaves are sent to a microwave chamber for a microwave heating, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then the heating is stopped, and the withered leaves are thrown up in the microwave chamber and then fall naturally to cool the withered leaves; finally, the withered leaves are evenly flattened and subjected to a second microwave heating to obtain withered leaves.

[0079] Amino acid is an important component of tea leaves, and is also an important factor affecting the color, freshness and aroma of tea soup. Steam sterilization can maximize the amino acid content in tea leaves. This is because, during the steam sterilization process, the temperature rise process of the withered leaves is from the outside to the inside and is relatively slow. During this process, proteins can be fully hydrolyzed into amino acids; but condensed water will be produced during the steam sterilization process, and water-soluble substances will be lost more, resulting in a low content of water extracts in the tea leaves. For this reason, the present invention performs microwave sterilization again after steam sterilization. The microwave sterilization tea leaves are heated for a short time, the sterilization efficiency is high, and the degradation degree of the nutrients in the tea leaves is low under hot and humid conditions. In addition, a synergistic effect can be produced by combining steam sterilization and microwave sterilization. This is because the steam sterilization process can increase the moisture content on the surface of the withered leaves. During the microwave sterilization process, the moisture on the surface of the withered leaves can be used to prevent the oxidation of the nutrients in the withered leaves, so that the nutrients in the tea leaves are retained to the greatest extent.

[0080] In some optional examples, the steam temperature for steam killing is 90-100°C, for example, it can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0081] In some optional examples, the steam flow rate for steam killing is 150-200kg / h, for example, it can be 150kg / h, 155kg / h, 160kg / h, 165kg / h, 170kg / h, 175kg / h, 180kg / h, 185kg / h, 190kg / h, 195kg / h or 200kg / h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0082] In some optional examples, the steam pressure of the steam fixing is 0.03-0.05 MPa, for example, it can be 0.03 MPa, 0.032 MPa, 0.034 MPa, 0.036 MPa, 0.038 MPa, 0.04 MPa, 0.042 MPa, 0.044 MPa, 0.046 MPa, 0.048 MPa or 0.05 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0083] In some optional examples, the steam killing time is 1 to 2 minutes, for example, it can be 1.0 min, 1.1 min, 1.2 min, 1.3 min, 1.4 min, 1.5 min, 1.6 min, 1.7 min, 1.8 min, 1.9 min or 2.0 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] In some optional examples, before the steam-sterilized withered leaves are fed into the microwave chamber, the microwave chamber is preheated to 100-150°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C or 150°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0085] In some optional examples, the microwave power of the primary microwave heating is 1200-1300 W, for example, it can be 1200 W, 1210 W, 1220 W, 1230 W, 1240 W, 1250 W, 1260 W, 1270 W, 1280 W, 1290 W or 1300 W, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0086] In some optional examples, the time for one microwave heating is 3 to 5 minutes, for example, it can be 3.0 minutes, 3.2 minutes, 3.4 minutes, 3.6 minutes, 3.8 minutes, 4.0 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes or 5.0 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0087] In some optional examples, the terminal temperature of cooling the withered leaves is 45-55°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C or 55°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0088] In some optional examples, the microwave power of the secondary microwave heating is 1500-1800 W, for example, it can be 1500 W, 1550 W, 1600 W, 1650 W, 1700 W, 1750 W or 1800 W, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0089] In some optional examples, the time for the secondary microwave heating is 30 to 40 s, for example, 30 s, 31 s, 32 s, 33 s, 34 s, 35 s, 36 s, 37 s, 38 s, 39 s or 40 s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0090] As a preferred technical solution of the present invention, in step S3, the kneading process includes:

[0091] The withered leaves are fed into a rolling machine, and are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is less than the rolling pressure of the medium rolling and less than the rolling pressure of the heavy rolling; subsequently, the withered leaves after the heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying to obtain rolled leaves.

[0092] The invention uses the rolling processes of light rolling, medium rolling, heavy rolling, primary drying, secondary rolling and secondary drying, and controls the temperature, time and pressure of each process link, so as to effectively control the water content of tea leaves, avoid the problem of uneven rolling of tea leaves, and effectively ensure the color and taste of tea leaves.

[0093] In some optional examples, the light kneading pressure is 50-60N, for example, it can be 50N, 51N, 52N, 53N, 54N, 55N, 56N, 57N, 58N, 59N or 60N, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0094] In some optional examples, the light kneading time is 10 to 20 minutes, for example, it can be 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0095] In some optional examples, the moderate kneading pressure is 70-80N, for example, 70N, 71N, 72N, 73N, 74N, 75N, 76N, 77N, 78N, 79N or 80N, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0096] In some optional examples, the moderate kneading time is 30 to 40 minutes, for example, it can be 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes or 40 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0097] In some optional examples, the heavy kneading pressure is 100-120N, for example, it can be 100N, 102N, 104N, 106N, 108N, 110N, 112N, 114N, 116N, 118N or 120N, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0098] In some optional examples, the heavy kneading time is 15 to 25 minutes, for example, it can be 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes or 25 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0099] In some optional examples, the heating temperature for the primary drying is 30-40°C, for example, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0100] In some optional examples, the heating time for one drying is 3 to 5 minutes, for example, it can be 3.0 minutes, 3.2 minutes, 3.4 minutes, 3.6 minutes, 3.8 minutes, 4.0 minutes, 4.2 minutes, 4.4 minutes, 4.6 minutes, 4.8 minutes or 5.0 minutes, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0101] In some optional examples, the kneading pressure of the secondary kneading is 90-100N, for example, it can be 90N, 91N, 92N, 93N, 94N, 95N, 96N, 97N, 98N, 99N or 100N, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0102] In some optional examples, the kneading time of the secondary kneading is 5 to 8 minutes, for example, it can be 5.0 minutes, 5.5 minutes, 6.0 minutes, 6.5 minutes, 7.0 minutes, 7.5 minutes or 8.0 minutes, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0103] In some optional examples, the heating temperature of the secondary drying is 90-100°C, for example, it can be 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0104] In some optional instances, the heating time for the secondary drying is 8 to 10 min, for example, it can be 8.0 min, 8.2 min, 8.4 min, 8.6 min, 8.8 min, 9.0 min, 9.2 min, 9.4 min, 9.6 min, 9.8 min or 10.0 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0105] As a preferred technical solution of the present invention, in step S4, the mass fraction of brown sugar in the mixture of tea leaves and brown sugar is 5-10wt%, for example, it can be 5.0wt%, 5.5wt%, 6.0wt%, 6.5wt%, 7.0wt%, 7.5wt%, 8.0wt%, 8.5wt%, 9.0wt%, 9.5wt% or 10.0wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0106] In some optional examples, the temperature of the anaerobic fermentation is 25-35°C, for example, it can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C or 35°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0107] In some optional examples, the anaerobic fermentation time is 55 to 65 days, for example, it can be 55 days, 56 days, 57 days, 58 days, 59 days, 60 days, 61 days, 62 days, 63 days, 64 days or 65 days, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0108] In a second aspect, the present invention provides a sour tea with blood sugar lowering effect, wherein the sour tea is prepared by the preparation method described in the first aspect.

[0109] Compared with the prior art, the present invention has the following beneficial effects:

[0110] The present invention can increase the organic matter content in the soil and improve the life activities of microorganisms in the soil by applying biological organic fertilizer on the tea seedling planting soil, achieve the purpose of improving the ecological conditions of the soil, and reduce the soil bulk density by applying organic fertilizer, the soil becomes loose and porous, the internal space increases, and can be dug to about 120cm, the soil is soft and the roots are rich, which is conducive to improving the absorption efficiency of nutrients by the tea seedlings and promoting the nutrient absorption of the tea seedlings; in comparison, after applying commercially available organic fertilizer, the soil is severely compacted, and can only be dug to about 40cm, and the roots are less. In addition, the biological organic fertilizer prepared by the present invention needs to be fermented, and plant growth regulators such as multiple growth hormones, gibberellins, and secondary metabolites such as amino acids and vitamins will be produced during the fermentation process, and these substances rich in multiple physiological activities can effectively stimulate the growth and development of tea seedlings and produce biodiversity.

[0111] The present invention mixes tea leaves and brown sugar and then performs anaerobic fermentation. In the anaerobic fermentation process, brown sugar, as an important nutrient, increases fermentation substrate, provides energy for large-scale reproduction of microorganisms, promotes rapid fermentation, produces beneficial bacteria, further improves the nutritional quality of sour tea, and the prepared sour tea has a certain blood sugar lowering effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Figure 1 A flow chart of the method for preparing sour tea provided in Examples 1-5 of the present invention;

[0113] Figure 2 The infrared spectra of the modified biochar and the composite modified biochar prepared in Example 1 of the present invention;

[0114] Figure 3 This is a scanning electron microscope image of the modified biochar prepared in Example 1 of the present invention;

[0115] Figure 4 This is a scanning electron microscope image of the composite modified biochar prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0116] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0117] Example 1

[0118] This embodiment provides a method for preparing a sour tea having a hypoglycemic effect, such as Figure 1 As shown, the preparation method specifically comprises the following steps:

[0119] S1. Preparation of organic fertilizer:

[0120] S1.1. Mix crop straw and bagasse, and then dry, crush and sieve through a 100-mesh sieve to obtain a raw material powder. Mix the raw material powder with a 10 wt% phosphoric acid solution and then wet-mill it. The mixing ratio of crop straw, bagasse and phosphoric acid solution is 1 g: 0.7 g: 8 mL. The ball milling speed is 400 rpm. The ball milling time is 25 min. After ball milling, a raw material mixture is obtained. The raw material mixture is placed in a tubular vacuum furnace, heated to 700 ° C at a heating rate of 10 ° C / min in a nitrogen atmosphere and kept warm for 3 hours to complete pyrolysis carbonization to obtain modified biochar.

[0121] S1.2, the modified biochar was mixed with 5wt% sodium silicate solution in a mass ratio of 1:8 and placed in a shaker for oscillation at a speed of 150r / min for 3h. After the oscillation, solid-liquid separation was performed. The solid obtained after separation was dried and placed in a tubular vacuum furnace, heated to 550°C in a nitrogen atmosphere and kept warm for 3h to complete high-temperature calcination to obtain a composite modified biochar;

[0122] S1.3. Mix 15 parts of sheep manure, 15 parts of pig manure, 23 parts of cow manure, 32 parts of bagasse, 7 parts of composite modified biochar, 6 parts of humic acid, 0.2 parts of bean dregs, 0.8 parts of brown sugar and 1 part of water to obtain a fermentation solution; send the fermentation solution into a fermentation tank for anaerobic fermentation, the fermentation temperature of the anaerobic fermentation is 45°C, the fermentation time is 8 days, and a fermentation product is obtained after the fermentation is completed; add ammonium bicarbonate, superphosphate and potassium chloride to the fermentation product, the ratio of the mass of ammonium bicarbonate to the total mass of sheep manure, pig manure and cow manure is 1:9, the ratio of the mass of superphosphate to the total mass of sheep manure, pig manure and cow manure is 1:9, and the ratio of the mass of potassium chloride to the total mass of sheep manure, pig manure and cow manure is 1:8, and mix them evenly to obtain organic fertilizer.

[0123] S2. Tea tree planting and fresh leaf picking:

[0124] S2.1. Two months before planting tea seedlings, clean up the dead branches and fallen leaves on the surface of the planting soil;

[0125] S2.2. Deep plow the planting soil once, the depth of deep plowing is 30cm, remove the grass roots, tree roots and stones turned up during the deep plowing, and apply soil conditioner to the soil after deep plowing. The soil conditioner includes 50 parts of dolomite powder, 30 parts of quicklime, 10 parts of peat and 10 parts of potassium chloride. The application rate of soil conditioner is 20kg per mu;

[0126] S2.3. Five days after applying the soil conditioner, deep plowing was performed on the planting soil for the second time. The depth of deep plowing was 20 cm. The organic fertilizer prepared in step S1 was applied to the soil after deep plowing. The amount of organic fertilizer applied was 1800 kg per mu.

[0127] S2.4. Ridge the soil. In September of each year and 5 days after fertilization, transplant the tea seedlings with soil to the ridge. After the tea seedlings are planted, they are regularly fertilized, pruned, watered, and pest-controlled, and weeds on the soil surface are removed. When the tea trees grow to maturity, fresh leaves of uniform size, one bud and two leaves or one bud and three leaves, are picked.

[0128] S3, withering, killing and rolling:

[0129] S3.1. Put the picked fresh leaves into the withering trough and shake them to make the leaf layer fluffy. The thickness of the leaf layer is 5 cm. Blow air into the withering trough through an axial flow fan. The blowing volume of the axial flow fan is 1800m 3 / h, the air temperature is 25℃, the relative humidity is 50%; after blowing for 0.5h, turn off the axial flow fan, throw the fresh leaves in the withering trough up and let them fall naturally for shaking, the throwing height during shaking is 10cm, flatten the fresh leaves after shaking and let them stand for 10min, turn on the axial flow fan after standing, and blow air into the withering trough again; repeat blowing and shaking 8 times until the leaf stems bend, the leaves shrink and the surface loses its luster, that is, the withering treatment is completed, and the withered leaves with a moisture content of 60% are obtained. The total time of withering treatment is 15h;

[0130] S3.2, steam sterilize the withered leaves obtained after withering treatment, the steam temperature is 90 ℃, the steam flow rate is 200kg / h, the steam pressure is 0.03MPa, and the steam sterilization time is 2min; then, preheat the microwave chamber to 100 ℃, send the steam sterilized withered leaves into the microwave chamber for a microwave heating, the microwave power of the microwave heating is 1200W, the microwave heating time is 5min, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then stop heating, throw the withered leaves in the microwave chamber and let them fall naturally, and cool the withered leaves to 45 ℃; finally, evenly flatten the withered leaves, and perform a second microwave heating, the microwave power of the second microwave heating is 1500W, the second microwave heating time is 40s, and the sterilized leaves are obtained after the second microwave heating;

[0131] S3.3, the fixed leaves are sent into a rolling machine, and the fixed leaves are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is 50N, and the rolling time is 20min, the rolling pressure of the medium rolling is 70N, and the rolling time is 40min, and the rolling pressure of the heavy rolling is 100N, and the rolling time is 25min; then, the fixed leaves after heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying, wherein the heating temperature of the primary drying is 30°C, and the heating time is 5min, the rolling pressure of the secondary rolling is 90N, and the rolling time is 8min, the heating temperature of the secondary drying is 90°C, and the heating time is 10min, and the rolled leaves are obtained after the secondary drying;

[0132] S4, mixing the tea leaves obtained in step S3 with brown sugar to obtain a mixture, wherein the mass fraction of brown sugar in the mixture is 5wt%, and placing the mixture in a closed environment for anaerobic fermentation at a temperature of 25° C. for 65 days;

[0133] S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

[0134] Figure 2 The infrared spectra of the modified biochar and the composite modified biochar prepared in this example show that the absorption peak of the modified biochar is not obvious, while the composite modified biochar has obvious absorption peaks in many places, among which 1428cm -1 and 874cm -1 CO3 2- The absorption peak is 1022cm -1 The antisymmetric stretching vibration absorption peak of Si-O-Si is 420cm -1 The peaks at 1565cm are the bending vibration absorption peaks of Si-O bonds, which indicate the presence of SiO2 in the composite modified biochar. -1The C=C bond absorption peak is at 495cm -1 The C—C bond absorption peak is 708 cm -1 The peak at the center is the stretching vibration absorption peak of Si-C. The introduction of Si-C bonds can increase the stability of the composite modified biochar, prevent the oxidation of organic fertilizer, and is beneficial to soil carbon fixation.

[0135] Figure 3 and Figure 4 The scanning electron microscope images of the modified biochar and the composite modified biochar prepared in this embodiment are respectively. It can be seen from the figure that the modified biochar has a certain pore structure, a rough surface, and a small amount of small particles attached to it. The pore structure of the composite modified biochar is richer, and a large number of particles of different shapes are attached to the surface, which greatly improves its specific surface area and porosity.

[0136] Example 2

[0137] This embodiment provides a method for preparing a sour tea having a hypoglycemic effect, such as Figure 1 As shown, the preparation method specifically comprises the following steps:

[0138] S1. Preparation of organic fertilizer:

[0139] S1.1. Mix crop straw and bagasse, and then dry, crush and sieve through a 120-mesh sieve in sequence to obtain a raw material powder, mix the raw material powder with an 11wt% phosphoric acid solution, and then wet-ball mill the raw material powder, wherein the mixing ratio of crop straw, bagasse and phosphoric acid solution is 1g:0.72g:8.5mL, the ball milling speed is 420rpm, the ball milling time is 22min, and a raw material mixture is obtained after ball milling; the raw material mixture is placed in a tubular vacuum furnace, heated to 720°C at a heating rate of 12°C / min in a nitrogen atmosphere, and kept warm for 2.8h to complete pyrolysis carbonization to obtain modified biochar;

[0140] S1.2, the modified biochar was mixed with 6wt% sodium silicate solution in a mass ratio of 1:9 and placed in a shaker for oscillation at a speed of 160r / min for 2.8h. After the oscillation, solid-liquid separation was performed. The solid obtained after separation was dried and placed in a tubular vacuum furnace, heated to 580°C in a nitrogen atmosphere and kept warm for 2.8h to complete high-temperature calcination to obtain composite modified biochar;

[0141] S1.3. Mix 16 parts of sheep manure, 14 parts of pig manure, 28 parts of cow manure, 26 parts of bagasse, 8 parts of composite modified biochar, 5 parts of humic acid, 0.4 parts of bean dregs, 0.6 parts of brown sugar and 2 parts of water to obtain a fermentation solution; send the fermentation solution into a fermentation tank for anaerobic fermentation, the fermentation temperature of the anaerobic fermentation is 48°C, the fermentation time is 7 days, and a fermentation product is obtained after the fermentation is completed; add ammonium bicarbonate, superphosphate and potassium chloride to the fermentation product, the ratio of the mass of ammonium bicarbonate to the total mass of sheep manure, pig manure and cow manure is 1:9.2, the ratio of the mass of superphosphate to the total mass of sheep manure, pig manure and cow manure is 1:9.2, the ratio of the mass of potassium chloride to the total mass of sheep manure, pig manure and cow manure is 1:8.2, and mix them evenly to obtain organic fertilizer.

[0142] S2. Tea tree planting and fresh leaf picking:

[0143] S2.1. Two months before planting tea seedlings, clean up the dead branches and fallen leaves on the surface of the planting soil;

[0144] S2.2. Deep plow the planting soil once, the depth of deep plowing is 32cm, remove the grass roots, tree roots and stones turned up during the deep plowing, and apply soil conditioner to the soil after deep plowing. The soil conditioner includes 52 parts of dolomite powder, 23 parts of quicklime, 15 parts of peat and 10 parts of potassium chloride. The application rate of soil conditioner is 22kg per mu;

[0145] S2.3. Six days after applying the soil conditioner, deep ploughing was performed on the planting soil for the second time. The depth of deep ploughing was 22 cm. The organic fertilizer prepared in step S1 was applied to the soil after deep ploughing. The amount of organic fertilizer applied was 1850 kg per mu.

[0146] S2.4. Ridge the soil. In September of each year and 6 days after fertilization, transplant the tea seedlings with soil to the ridge. After the tea seedlings are planted, they are regularly fertilized, pruned, watered, and pest-controlled, and weeds on the soil surface are removed. When the tea trees grow to maturity, fresh leaves of uniform size, one bud and two leaves or one bud and three leaves, are picked.

[0147] S3, withering, killing and rolling:

[0148] S3.1. Put the picked fresh leaves into the withering trough and shake them to make the leaf layer fluffy. The thickness of the leaf layer is 6 cm. Blow air into the withering trough through an axial flow fan. The air volume of the axial flow fan is 1850m 3 / h, the temperature of the blown air is 28°C and the relative humidity is 52%; after blowing for 0.8h, the axial flow fan is turned off, the fresh leaves in the withering trough are thrown up and then naturally fall down for shaking, the throwing height during shaking is 12cm, the fresh leaves after shaking are flattened again and left to stand for 12min, after the standing period, the axial flow fan is turned on, and air is blown into the withering trough again; the blowing and shaking are repeated 7 times until the leaf stems are bent, the leaves are wrinkled and the surface loses its luster, that is, the withering treatment is completed, and the withered leaves with a moisture content of 62% are obtained. The total time of the withering treatment is 13h;

[0149] S3.2, steam sterilization of the withered leaves obtained after withering treatment, the steam temperature is 92 ° C, the steam flow rate is 180kg / h, the steam pressure is 0.035MPa, and the steam sterilization time is 1.8min; then, the microwave chamber is preheated to 110 ° C, the steam sterilized withered leaves are sent into the microwave chamber for a microwave heating, the microwave power of the microwave heating is 1220W, the microwave heating time is 4.5min, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then the heating is stopped, the withered leaves are thrown up in the microwave chamber and then fall naturally, and the withered leaves are cooled to 48 ° C; finally, the withered leaves are evenly flattened and subjected to a second microwave heating, the microwave power of the second microwave heating is 1600W, the second microwave heating time is 38s, and the sterilized leaves are obtained after the second microwave heating;

[0150] S3.3, the fixed leaves are sent into a rolling machine, and the fixed leaves are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is 52N, and the rolling time is 18min, the rolling pressure of the medium rolling is 72N, and the rolling time is 38min, and the rolling pressure of the heavy rolling is 105N, and the rolling time is 22min; then, the fixed leaves after heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying, wherein the heating temperature of the primary drying is 32°C, and the heating time is 4.5min, the rolling pressure of the secondary rolling is 92N, and the rolling time is 7min, the heating temperature of the secondary drying is 92°C, and the heating time is 9.5min, and the rolled leaves are obtained after the secondary drying;

[0151] S4, mixing the tea leaves obtained in step S3 with brown sugar to obtain a mixture, wherein the mass fraction of brown sugar in the mixture is 6wt%, and placing the mixture in a closed environment for anaerobic fermentation, wherein the temperature of the anaerobic fermentation is 28° C., and the time of the anaerobic fermentation is 62 days;

[0152] S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

[0153] Example 3

[0154] This embodiment provides a method for preparing a sour tea having a hypoglycemic effect, such as Figure 1 As shown, the preparation method specifically comprises the following steps:

[0155] S1. Preparation of organic fertilizer:

[0156] S1.1. Mix crop straw and bagasse, and then dry, crush and sieve through a 150-mesh sieve in sequence to obtain a raw material powder, mix the raw material powder with a 12 wt% phosphoric acid solution, and then wet-ball mill the mixture, wherein the mixing ratio of crop straw, bagasse and phosphoric acid solution is 1 g: 0.75 g: 9 mL, the ball milling speed is 450 rpm, the ball milling time is 20 min, and a raw material mixture is obtained after ball milling; the raw material mixture is placed in a tubular vacuum furnace, heated to 750 ° C at a heating rate of 15 ° C / min in a nitrogen atmosphere and kept warm for 2.5 h to complete pyrolysis carbonization to obtain modified biochar;

[0157] S1.2, the modified biochar was mixed with 7wt% sodium silicate solution in a mass ratio of 1:10, and then placed in a shaker for oscillation at a speed of 170r / min for 2.5h. After the oscillation, solid-liquid separation was performed, and the solid obtained after separation was dried and placed in a tubular vacuum furnace, heated to 600°C in a nitrogen atmosphere and kept warm for 2.5h to complete high-temperature calcination to obtain composite modified biochar;

[0158] S1.3. Mix 17 parts of sheep manure, 15 parts of pig manure, 26 parts of cow manure, 28 parts of bagasse, 7 parts of composite modified biochar, 5 parts of humic acid, 0.5 parts of bean dregs, 0.5 parts of brown sugar and 1 part of water to obtain a fermentation solution; send the fermentation solution into a fermentation tank for anaerobic fermentation, the fermentation temperature of the anaerobic fermentation is 50°C, the fermentation time is 7 days, and a fermentation product is obtained after the fermentation is completed; add ammonium bicarbonate, diammonium dihydrogen phosphate and potassium sulfate to the fermentation product, the ratio of the mass of ammonium bicarbonate to the total mass of sheep manure, pig manure and cow manure is 1:9.5, the ratio of the mass of diammonium dihydrogen phosphate to the total mass of sheep manure, pig manure and cow manure is 1:9.5, the ratio of the mass of potassium sulfate to the total mass of sheep manure, pig manure and cow manure is 1:8.5, and mix them evenly to obtain organic fertilizer.

[0159] S2. Tea tree planting and fresh leaf picking:

[0160] S2.1. Two months before planting tea seedlings, clean up the dead branches and fallen leaves on the surface of the planting soil;

[0161] S2.2. Deep plow the planting soil once, the depth of deep plowing is 35cm, remove the grass roots, tree roots and stones turned up during the deep plowing, and apply soil conditioner to the soil after deep plowing. The soil conditioner includes 55 parts of dolomite powder, 25 parts of quicklime, 12 parts of peat and 8 parts of potassium chloride. The application rate of soil conditioner is 25kg per mu;

[0162] S2.3, 7 days after applying the soil conditioner, the planting soil is deep plowed for the second time, the depth of the second deep plowing is 25 cm, and the organic fertilizer prepared in step S1 is applied to the soil after the second deep plowing, and the amount of organic fertilizer applied is 1900 kg per mu;

[0163] S2.4. Ridge the soil. In September of each year and 7 days after fertilization, transplant the tea seedlings with soil to the ridge. After the tea seedlings are planted, they are regularly fertilized, pruned, watered, and pest-controlled, and weeds on the soil surface are removed. When the tea trees grow and mature, pick fresh leaves of uniform size, one bud and two leaves or one bud and three leaves.

[0164] S3, withering, killing and rolling:

[0165] S3.1. Put the picked fresh leaves into the withering trough and shake them to make the leaf layer fluffy. The thickness of the leaf layer is 7 cm. Blow air into the withering trough through an axial flow fan. The blowing volume of the axial flow fan is 1900m 3 / h, the air temperature is 30℃, the relative humidity is 55%; after blowing for 1h, the axial flow fan is turned off, the fresh leaves in the withering trough are thrown up and then fall naturally to be shaken, the throwing height during shaking is 15cm, the fresh leaves after shaking are flattened again and left to stand for 15min, after the standing period, the axial flow fan is turned on, and air is blown into the withering trough again; the blowing and shaking are repeated 6 times until the leaf stems are bent, the leaves are wrinkled and the surface loses its luster, that is, the withering treatment is completed, and the withered leaves with a moisture content of 65% are obtained. The total time of the withering treatment is 12h;

[0166] S3.2, steam sterilization of the withered leaves obtained after withering treatment, the steam temperature is 95 ℃, the steam flow rate is 170kg / h, the steam pressure is 0.04MPa, and the steam sterilization time is 1.5min; then, the microwave chamber is preheated to 120℃, and the steam sterilized withered leaves are sent into the microwave chamber for a microwave heating, the microwave power of the microwave heating is 1250W, the microwave heating time is 4min, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then the heating is stopped, the withered leaves are thrown up in the microwave chamber and then fall naturally, and the withered leaves are cooled to 50℃; finally, the withered leaves are evenly flattened and subjected to a second microwave heating, the microwave power of the second microwave heating is 1600W, the second microwave heating time is 35s, and the sterilized leaves are obtained after the second microwave heating;

[0167] S3.3, the fixed leaves are sent into a rolling machine, and the fixed leaves are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is 55N, and the rolling time is 15min, the rolling pressure of the medium rolling is 75N, and the rolling time is 35min, and the rolling pressure of the heavy rolling is 110N, and the rolling time is 20min; then, the fixed leaves after heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying, wherein the heating temperature of the primary drying is 35°C, and the heating time is 4min, the rolling pressure of the secondary rolling is 95N, and the rolling time is 7min, the heating temperature of the secondary drying is 95°C, and the heating time is 9min, and the rolled leaves are obtained after the secondary drying;

[0168] S4, mixing the tea leaves obtained in step S3 with brown sugar to obtain a mixture, wherein the mass fraction of brown sugar in the mixture is 7wt%, and placing the mixture in a closed environment for anaerobic fermentation at a temperature of 30° C. for 60 days;

[0169] S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

[0170] Example 4

[0171] This embodiment provides a method for preparing a sour tea having a hypoglycemic effect, such as Figure 1 As shown, the preparation method specifically comprises the following steps:

[0172] S1. Preparation of organic fertilizer:

[0173] S1.1. Mix crop straw and bagasse, and then dry, crush and sieve through a 180-mesh sieve in sequence to obtain a raw material powder, mix the raw material powder with a 13wt% phosphoric acid solution, and then wet-ball mill the raw material powder, wherein the mixing ratio of crop straw, bagasse and phosphoric acid solution is 1g:0.78g:9.5mL, the ball milling speed is 480rpm, the ball milling time is 18min, and a raw material mixture is obtained after ball milling; the raw material mixture is placed in a tubular vacuum furnace, heated to 780°C at a heating rate of 18°C / min under a nitrogen atmosphere, and kept warm for 2.2h to complete pyrolysis and carbonization to obtain modified biochar;

[0174] S1.2, the modified biochar was mixed with 8wt% sodium silicate solution in a mass ratio of 1:11, and then placed in a shaker for oscillation at a speed of 180r / min for 2.2h. After the oscillation, solid-liquid separation was performed, and the solid obtained after separation was dried and placed in a tubular vacuum furnace, heated to 620°C in a nitrogen atmosphere and kept warm for 2.2h to complete high-temperature calcination to obtain composite modified biochar;

[0175] S1.3. Mix 17 parts of sheep manure, 16 parts of pig manure, 23 parts of cow manure, 30 parts of bagasse, 7 parts of composite modified biochar, 5 parts of humic acid, 0.8 parts of bean dregs, 0.2 parts of brown sugar and 1 part of water to obtain a fermentation solution; send the fermentation solution into a fermentation tank for anaerobic fermentation, the fermentation temperature of the anaerobic fermentation is 52°C, the fermentation time is 6 days, and a fermentation product is obtained after the fermentation is completed; add ammonium bicarbonate, diammonium dihydrogen phosphate and potassium sulfate to the fermentation product, the ratio of the mass of ammonium bicarbonate to the total mass of sheep manure, pig manure and cow manure is 1:9.8, the ratio of the mass of diammonium dihydrogen phosphate to the total mass of sheep manure, pig manure and cow manure is 1:9.8, the ratio of the mass of potassium sulfate to the total mass of sheep manure, pig manure and cow manure is 1:8.8, and mix them evenly to obtain organic fertilizer.

[0176] S2. Tea tree planting and fresh leaf picking:

[0177] S2.1. Three months before planting tea seedlings, clean up the dead branches and fallen leaves on the surface of the planting soil;

[0178] S2.2. Deep plow the planting soil once, the depth of deep plowing is 38cm, remove the grass roots, tree roots and stones turned up during the deep plowing, and apply soil conditioner to the soil after deep plowing. The soil conditioner includes 58 parts of dolomite powder, 27 parts of quicklime, 10 parts of peat and 5 parts of potassium chloride. The application rate of soil conditioner is 28kg per mu;

[0179] S2.3, 8 days after applying the soil conditioner, the planting soil is deep plowed for the second time, the depth of the second deep plowing is 28 cm, and the organic fertilizer prepared in step S1 is applied to the soil after the second deep plowing, and the amount of organic fertilizer applied is 1950 kg per mu;

[0180] S2.4. Ridge the soil. In October of each year and 7 days after fertilization, transplant the tea seedlings with soil to the ridge. After the tea seedlings are planted, they are regularly fertilized, pruned, watered, and pest-controlled, and weeds on the soil surface are removed. When the tea trees grow and mature, pick fresh leaves of uniform size, one bud and two leaves or one bud and three leaves.

[0181] S3, withering, killing and rolling:

[0182] S3.1. Put the picked fresh leaves into the withering trough and shake them to make the leaf layer fluffy. The thickness of the leaf layer is 7 cm. Blow air into the withering trough through an axial flow fan. The air volume of the axial flow fan is 1950m 3 / h, the air temperature is 32℃, the relative humidity is 58%; after blowing for 1.2h, turn off the axial flow fan, throw the fresh leaves in the withering trough up and let them fall naturally for shaking, the throwing height during shaking is 18cm, the fresh leaves after shaking are flattened again and left to stand for 18min, after the standing, turn on the axial flow fan, and blow air into the withering trough again; repeat the blowing and shaking for 6 times until the leaf stems bend, the leaves shrink and the surface loses its luster, that is, the withering treatment is completed, and the withered leaves with a moisture content of 68% are obtained, and the total time of the withering treatment is 11h;

[0183] S3.2, steam sterilize the withered leaves obtained after withering treatment, the steam temperature is 98 ℃, the steam flow rate is 160kg / h, the steam pressure is 0.045MPa, and the steam sterilization time is 1.2min; then, preheat the microwave chamber to 130 ℃, send the steam sterilized withered leaves into the microwave chamber for a microwave heating, the microwave power of the microwave heating is 1280W, the microwave heating time is 3.5min, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then stop heating, throw the withered leaves in the microwave chamber and let them fall naturally, and cool the withered leaves to 52 ℃; finally, evenly flatten the withered leaves, and perform a second microwave heating, the microwave power of the second microwave heating is 1700W, the second microwave heating time is 32s, and the sterilized leaves are obtained after the second microwave heating;

[0184] S3.3, the fixed leaves are sent into a rolling machine, and the fixed leaves are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is 58N, and the rolling time is 12min, the rolling pressure of the medium rolling is 78N, and the rolling time is 32min, and the rolling pressure of the heavy rolling is 115N, and the rolling time is 18min; then, the fixed leaves after heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying, wherein the heating temperature of the primary drying is 38°C, and the heating time is 3.5min, the rolling pressure of the secondary rolling is 98N, and the rolling time is 6min, the heating temperature of the secondary drying is 98°C, and the heating time is 8.5min, and the rolled leaves are obtained after the secondary drying;

[0185] S4, mixing the tea leaves obtained in step S3 with brown sugar to obtain a mixture, wherein the mass fraction of brown sugar in the mixture is 8wt%, and placing the mixture in a closed environment for anaerobic fermentation at a temperature of 32° C. for 58 days;

[0186] S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

[0187] Example 5

[0188] This embodiment provides a method for preparing a sour tea having a hypoglycemic effect, such as Figure 1 As shown, the preparation method specifically comprises the following steps:

[0189] S1. Preparation of organic fertilizer:

[0190] S1.1. Mix crop straw and bagasse, and then dry, crush and pass through a 200-mesh sieve in sequence to obtain a raw material powder, mix the raw material powder with a 15wt% phosphoric acid solution, and then wet-ball mill, wherein the mixing ratio of crop straw, bagasse and phosphoric acid solution is 1g:0.8g:10mL, the ball milling speed is 500rpm, the ball milling time is 15min, and a raw material mixture is obtained after ball milling; the raw material mixture is placed in a tubular vacuum furnace, heated to 800°C at a heating rate of 20°C / min in a nitrogen atmosphere, and kept warm for 2h to complete pyrolysis carbonization to obtain modified biochar;

[0191] S1.2, the modified biochar was mixed with 10wt% sodium silicate solution in a mass ratio of 1:12, and then placed in a shaker for oscillation at a speed of 200r / min for 2h. After the oscillation, solid-liquid separation was performed, and the solid obtained after separation was dried and placed in a tubular vacuum furnace, heated to 650°C in a nitrogen atmosphere and kept warm for 2h to complete high-temperature calcination to obtain a composite modified biochar;

[0192] S1.3. Mix 18 parts of sheep manure, 14 parts of pig manure, 26 parts of cow manure, 25 parts of bagasse, 8 parts of composite modified biochar, 6 parts of humic acid, 0.5 parts of bean dregs, 0.5 parts of brown sugar and 2 parts of water to obtain a fermentation solution; send the fermentation solution into a fermentation tank for anaerobic fermentation, the fermentation temperature of the anaerobic fermentation is 55°C, the fermentation time is 6 days, and a fermentation product is obtained after the fermentation is completed; add ammonium bicarbonate, diammonium dihydrogen phosphate and potassium sulfate to the fermentation product, the ratio of the mass of ammonium bicarbonate to the total mass of sheep manure, pig manure and cow manure is 1:10, the ratio of the mass of diammonium dihydrogen phosphate to the total mass of sheep manure, pig manure and cow manure is 1:10, and the ratio of the mass of potassium sulfate to the total mass of sheep manure, pig manure and cow manure is 1:9, and mix them evenly to obtain organic fertilizer.

[0193] S2. Tea tree planting and fresh leaf picking:

[0194] S2.1. Three months before planting tea seedlings, clean up the dead branches and fallen leaves on the surface of the planting soil;

[0195] S2.2. Deep plow the planting soil once, the depth of deep plowing is 40cm, remove the grass roots, tree roots and stones turned up during the deep plowing, and apply soil conditioner to the soil after deep plowing. The soil conditioner includes 60 parts of dolomite powder, 20 parts of quicklime, 10 parts of peat and 10 parts of potassium chloride. The application rate of soil conditioner is 30kg per mu;

[0196] S2.3, 10 days after applying the soil conditioner, the planting soil is deep plowed for the second time, the depth of the second deep plowing is 30 cm, and the organic fertilizer prepared in step S1 is applied to the soil after the second deep plowing, and the amount of organic fertilizer applied is 2000 kg per mu;

[0197] S2.4. Ridge the soil. In October of each year and 8 days after fertilization, transplant the tea seedlings with soil to the ridge. After the tea seedlings are planted, they are regularly fertilized, pruned, watered, and pest-controlled, and weeds on the soil surface are removed. When the tea trees grow and mature, pick fresh leaves of uniform size, one bud and two leaves or one bud and three leaves.

[0198] S3, withering, killing and rolling:

[0199] S3.1. Put the picked fresh leaves into the withering trough and shake them to make the leaf layer fluffy. The thickness of the leaf layer is 8 cm. Blow air into the withering trough through an axial flow fan. The air volume of the axial flow fan is 2000m 3 / h, the air temperature is 35℃, the relative humidity is 60%; after blowing for 1.5h, turn off the axial flow fan, throw the fresh leaves in the withering trough up and let them fall naturally for shaking, the throwing height during shaking is 20cm, flatten the fresh leaves after shaking and let them stand for 20min, turn on the axial flow fan after the standing, and blow air into the withering trough again; repeat the blowing and shaking for 5 times until the leaf stems bend, the leaves shrink and the surface loses its luster, that is, the withering treatment is completed, and the withered leaves with a moisture content of 70% are obtained. The total time of the withering treatment is 10h;

[0200] S3.2, steam sterilize the withered leaves obtained after withering treatment, the steam temperature is 100 ℃, the steam flow rate is 150kg / h, the steam pressure is 0.05MPa, and the steam sterilization time is 1min; then, preheat the microwave chamber to 150℃, send the steam sterilized withered leaves into the microwave chamber for a microwave heating, the microwave power of the microwave heating is 1300W, the microwave heating time is 3min, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then stop heating, throw the withered leaves in the microwave chamber and let them fall naturally, and cool the withered leaves to 55℃; finally, evenly flatten the withered leaves, and perform a second microwave heating, the microwave power of the second microwave heating is 1800W, the second microwave heating time is 30s, and the sterilized leaves are obtained after the second microwave heating;

[0201] S3.3, the fixed leaves are sent into a rolling machine, and the fixed leaves are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is 60N, and the rolling time is 10min, the rolling pressure of the medium rolling is 80N, and the rolling time is 30min, and the rolling pressure of the heavy rolling is 120N, and the rolling time is 15min; then, the fixed leaves after heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying, wherein the heating temperature of the primary drying is 40°C, and the heating time is 3min, the rolling pressure of the secondary rolling is 100N, and the rolling time is 5min, the heating temperature of the secondary drying is 100°C, and the heating time is 8min, and the rolled leaves are obtained after the secondary drying;

[0202] S4, mixing the tea leaves obtained in step S3 with brown sugar to obtain a mixture, wherein the mass fraction of brown sugar in the mixture is 10wt%, and placing the mixture in a closed environment for anaerobic fermentation at a temperature of 35° C. for 55 days;

[0203] S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

[0204] The color, luster, appearance, aroma and taste of the sour tea prepared in Example 1 were tested according to the Tea Production License Review Rules, Q / LZS0003S-2024 "Sour Tea" (Loose Tea).

[0205] The test results are shown in Table 1.

[0206] Table 1

[0207]

[0208]

[0209] It can be seen from the test data provided in Table 1 that the sour tea prepared by the present invention meets the product implementation standard Q / LZS0003S.

[0210] The hypoglycemic western medicine components in the sour tea prepared in Example 1 of the present invention were tested, and the test results are shown in Table 2.

[0211] Table 2

[0212]

[0213]

[0214] It can be seen from the test data provided in Table 2 that the sour tea prepared by the present invention does not contain any hypoglycemic western medicine ingredients and is not added.

[0215] The hypoglycemic effect of the acid tea prepared in Example 1 was tested, and the specific testing steps were as follows:

[0216] (1) Test substance

[0217] 30 g of the acid tea prepared in Example 1 was weighed and added to 250 mL of distilled water, and heated in a water bath at 80-90° C. for 10 minutes. The extract after filtering the tea leaves was used as the test substance.

[0218] (2) Experimental animals and groups

[0219] Twenty-five healthy male SD rats (180±20g) were selected. After adaptive feeding for 3 to 5 days, 5 rats were randomly selected as the blank group, and the remaining 20 rats were used to establish a hyperglycemia animal model. The 20 model rats with successful modeling were randomly divided into a model group, a low-dose group, a medium-dose group, and a high-dose group, with 5 rats in each group. The blank group and the model group were gavaged with normal saline, and the low-dose group, the medium-dose group, and the high-dose group were gavaged at 0.5g / kg, 1.0g / kg, and 2.0g / kg, respectively, once a day for 30 consecutive days.

[0220] (3) Modeling method

[0221] After the rats were adaptively fed for 3 to 5 days, 5 rats were randomly selected to measure the blood glucose of empty acid as the basal blood glucose value of the batch of animals. Then the animals were fed for 24 hours (free drinking water), and injected with alloxan (freshly prepared before use) to establish the model. The rats were intraperitoneally injected with 150 mg / kg BW. After 5 to 7 days, the animals were fasted for 3 to 5 hours and the blood glucose was measured. When the blood glucose value was within the range of 10 to 25 mmol / L, the hyperglycemia model was successfully established.

[0222] (4) Observation indicators

[0223] The fasting blood glucose level of the rats was measured with a blood glucose meter 30 days after intragastric administration. The test results are shown in Table 3.

[0224] Table 3

[0225]

[0226]

[0227] It can be seen from the test data provided in Table 3 that, compared with the model group, the fasting blood glucose values ​​of rats in the different dose sample groups decreased after 30 days of intragastric administration, which indicates that the acid tea prepared by the present invention has a certain blood sugar-lowering effect.

[0228] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a sour tea having a hypoglycemic effect, characterized in that: The preparation method comprises: S1, preparing organic fertilizer, and using the organic fertilizer to plant tea seedlings; S2, after the tea trees grow and mature, pick fresh leaves of uniform size, one bud and two leaves or one bud and three leaves; S3, withering, killing and rolling the picked fresh leaves in sequence to obtain tea leaves; S4, mixing the tea leaves obtained in step S3 with brown sugar and placing them in a closed environment for anaerobic fermentation; S5, spreading the tea leaves after anaerobic fermentation to dry in the sun to obtain the sour tea.

2. The preparation method according to claim 1, characterized in that: In step S1, the organic fertilizer is prepared by the following method: The method comprises the following steps: mixing sheep manure, pig manure, cow manure, bagasse, composite modified biochar, humic acid, bean dregs, brown sugar and water uniformly to obtain a fermentation stock solution; sending the fermentation stock solution into a fermentation tank for anaerobic fermentation to obtain a fermentation product; adding nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer to the fermentation product, and mixing them uniformly to obtain the organic fertilizer.

3. The preparation method according to claim 2, characterized in that: Based on 100 parts by weight of the fermentation stock solution, it includes the following components in parts by weight: The fermentation temperature of the anaerobic fermentation is 45-55°C; The fermentation time of the anaerobic fermentation is 6 to 8 days; The ratio of the mass of the nitrogen fertilizer to the total mass of the sheep manure, pig manure and cow manure in the fermentation stock solution is 1:(9-10); The ratio of the mass of the phosphate fertilizer to the total mass of the sheep manure, pig manure and cow manure in the fermentation stock solution is 1:(9-10); The ratio of the mass of the potash fertilizer to the total mass of the sheep manure, pig manure and cow manure in the fermentation stock solution is 1:(8-9); The nitrogen fertilizer comprises ammonium bicarbonate and / or diammonium phosphate; The phosphate fertilizer includes superphosphate and / or diammonium phosphate; The potash fertilizer includes potassium chloride and / or potassium sulfate.

4. The preparation method according to claim 2, characterized in that: The composite modified biochar is prepared by the following method: (a) mixing crop straw and bagasse, drying, crushing and sieving in sequence to obtain a raw material powder, mixing the raw material powder with a phosphoric acid solution, and wet ball milling to obtain a raw material mixture; placing the raw material mixture in a tubular vacuum furnace, and pyrolyzing and carbonizing it under a nitrogen atmosphere to obtain modified biochar; (b) mixing the modified biochar with the sodium silicate solution and placing the mixture in a shaker for shaking, performing solid-liquid separation after the shaking, drying the solid obtained after the separation and placing the mixture in a tubular vacuum furnace for high-temperature calcination under a nitrogen atmosphere to obtain the composite modified biochar.

5. The preparation method according to claim 4, characterized in that: In step (a), the mesh size of the sieve is 100 to 200 meshes; The mass fraction of the phosphoric acid solution is 10-15wt%; The mixing ratio of the crop straw, bagasse and phosphoric acid solution is 1 g: (0.7-0.8) g: (8-10) mL; The ball milling speed of the wet ball milling is 400-500 rpm; The wet ball milling time is 15 to 25 minutes; The heating rate of the pyrolysis carbonization is 10 to 20°C / min; The heating temperature of the pyrolysis carbonization is 700-800°C; The heat preservation time of the pyrolysis carbonization is 2 to 3 hours; In step (b), the mass ratio of the modified biochar to the sodium silicate solution is 1:(8-12); The mass fraction of the sodium silicate solution is 5 to 10 wt %; The shaking speed of the shaking table is 150-200 r / min; The shaking time of the shaking table is 2 to 3 hours; The heating temperature of the high temperature calcination is 550-650°C; The heating time of the high temperature calcination is 2 to 3 hours.

6. The preparation method according to claim 1, characterized in that: In step S3, the withering process includes: (1) Blowing air: Put the picked fresh leaves into the withering trough, shake them loose and flatten them, so that the flattened leaf layer is fluffy, and blow air into the withering trough through an axial flow fan; (2) Shaking: After blowing air for a period of time, the axial flow fan is turned off, and the fresh leaves in the withering trough are thrown up and then naturally fall to shake. The shaken fresh leaves are flattened again and left to stand for a period of time. After the standing period, the axial flow fan is turned on to blow air into the withering trough again; (3) repeating steps (1) and (2) at least five times until the leaf stems bend, the leaves shrink and the surface loses its luster, thus completing the withering treatment and obtaining withered leaves; In step (1), the thickness of the leaf layer after the fresh leaves are flattened is 5 to 8 cm; The axial flow fan has a blast volume of 1800 to 2000 m 3 / h; The air temperature blown by the axial flow fan is 25-35°C; The relative humidity of the air blown by the axial flow fan is 50-60%; In step (2), after blowing air for 0.5 to 1.5 hours, the axial flow fan is turned off to shake the fresh leaves; The height of the fresh leaves when being flipped and shaken is 10 to 20 cm; The standing time after the fresh leaves are shaken is 10 to 20 minutes; In step (3), the total time of the withering treatment is 10 to 15 hours; The moisture content of the withered leaves is 60-70%.

7. The preparation method according to claim 1, characterized in that: In step S3, the fixing process includes: The withered leaves obtained after the withering treatment are steam-sterilized; then, the steam-sterilized withered leaves are sent into a microwave chamber for a microwave heating, and the withered leaves are continuously turned over during the microwave heating process to make the withered leaves evenly heated; then, the heating is stopped, and the withered leaves are thrown up in the microwave chamber and then fall naturally to cool the withered leaves; finally, the withered leaves are evenly flattened and subjected to a second microwave heating to obtain sterilized leaves; The steam temperature of the steam-killing is 90-100°C; The steam flow rate of the steam killing is 150-200 kg / h; The steam pressure of the steam sterilization is 0.03-0.05 MPa; The steam killing time is 1 to 2 minutes; Before sending the steam-sterilized withered leaves into the microwave chamber, preheating the microwave chamber to 100-150° C.; The microwave power of the primary microwave heating is 1200-1300W; The time of the microwave heating is 3 to 5 minutes; The terminal temperature of the cooling of the withering leaves is 45-55°C; The microwave power of the secondary microwave heating is 1500-1800W; The secondary microwave heating time is 30 to 40 seconds.

8. The preparation method according to claim 1, characterized in that: In step S3, the kneading process includes: The withered leaves are fed into a rolling machine, and the withered leaves are sequentially subjected to light rolling, medium rolling and heavy rolling, wherein the rolling pressure of the light rolling is less than the rolling pressure of the medium rolling and less than the rolling pressure of the heavy rolling; subsequently, the withered leaves after heavy rolling are sequentially subjected to primary drying, secondary rolling and secondary drying to obtain rolled leaves; The kneading pressure of the light kneading is 50-60N; The light kneading time is 10 to 20 minutes; The medium kneading pressure is 70-80N; The medium kneading time is 30 to 40 minutes; The heavy kneading pressure is 100-120N; The heavy kneading time is 15 to 25 minutes; The heating temperature of the primary drying is 30-40°C; The heating time of the primary drying is 3 to 5 minutes; The kneading pressure of the secondary kneading is 90-100N; The kneading time of the secondary kneading is 5 to 8 minutes; The heating temperature of the secondary drying is 90-100°C; The heating time of the secondary drying is 8 to 10 minutes.

9. The preparation method according to claim 1, characterized in that: In step S4, the mass fraction of brown sugar in the mixture of tea leaves and brown sugar is 5-10wt%; The temperature of the anaerobic fermentation is 25-35°C; The anaerobic fermentation time is 55 to 65 days.

10. A sour tea with hypoglycemic effect, characterized in that: The sour tea is prepared by the preparation method according to any one of claims 1 to 9.

Images