A method for preparing mixed tea that is conducive to preservation

Abstract

The invention discloses a method for preparing a mixed tea that is conducive to preservation, comprising the following steps: S1, pre-picking treatment; S2, premixing; S3, sun-drying; S4, stir-frying; S5, rolling; S6, drying. The mixed tea prepared by the method of the invention has a strong aroma, a sweet taste, and is not dry. In the stir-frying process, passion fruit leaves and oolong tea tender leaves are mixed in a ratio of 7:3, and the shelf life of the tea prepared by this process is greatly extended. The shelf life can reach half a year at room temperature, and the tea aroma and sweet taste can still be stored at room temperature for 5 to 6 months. Adding passion fruit seed oil in the stir-frying process can protect the color and freshness, improve the fragrance, and prevent scorching.

Description

Technical Field

[0001] The invention belongs to the technical field of tea production, and in particular relates to a method for preparing mixed tea which is conducive to preservation. Background Art

[0002] Passion fruit, scientifically known as Passiflora, belongs to the Passifloraceae family and Passiflora genus. It is a tropical and subtropical perennial evergreen vine berry fruit tree with fleshy shallow roots, hollow stems, smooth and hairless, with tendrils and climbing nature; leaves are alternate, three-lobed, green; petals are 5, the same length as the sepals; berries are ovoid, 3-4 cm in diameter, and hairless. Passion fruit contains more than 165 kinds of aromatic substances, which can emit the rich aroma of many fruits such as lychee, banana, guava, etc., hence the name "passion fruit". Its juice is rich in nutrition and has the reputation of "king of juice". The juice of passion fruit has excellent color, fragrance and taste, and is rich in nutrition. It contains 17 kinds of amino acids essential to the human body and various vitamins, trace elements and other beneficial ingredients. It has the effects of beauty, digestion, anti-aging, detoxification, and heat clearing, and is loved by consumers. The branches and leaves are rich in secondary metabolites such as volatile oils, alkaloids, triterpenes and flavonoid components mainly composed of quercetin, vitexin, luteolin, apigenin, etc. These components have the effects of preventing cancer, anti-oxidation and aging, sterilization and anti-inflammatory, etc. In particular, flavonoid components can remove excessive free radicals in the human body, reduce oxidative damage to the body, play a role in prolonging life and maintaining the health of the body. Compared with synthetic antioxidants, natural flavonoid antioxidants from plants have fewer side effects, so their application as exogenous antioxidants has attracted widespread attention.

[0003] With the continuous expansion of passion fruit planting and processing industry in my country, a large number of fruit leaves will be produced every year. After the orchard collects the fruit leaves, it is generally discarded or buried directly, which seriously wastes the secondary metabolite resources to a certain extent. It has been reported in the literature that passion fruit roots and leaves have traditional effects such as anti-inflammatory and analgesic, blood pressure reduction, blood sugar reduction, treatment of insomnia and treatment of anxiety. If they are used in functional food development, food additive development, cosmetics industry, etc., it will greatly promote the development and utilization of natural small molecule compounds in the by-products of the passion fruit industry. There are also a small number of reports on preparing passion fruit leaves into tea, but the passion fruit leaf tea in the current technology usually only simply picks the fruit leaves for drying and frying to make fruit leaf tea, which has a poor taste and the tea tastes dry after being brewed in water.

[0004] Since oolong tea is a semi-fermented tea, it can only be stored at room temperature for about 2 months, and no more than 3 months. After being stored at room temperature for 60 days, it will regain moisture and leak, affecting the taste. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for preparing mixed tea which is conducive to preservation.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for preparing mixed tea that is conducive to preservation, characterized in that it comprises the following steps:

[0008] S1. Treatment before picking: 10 to 15 days before picking passion fruit leaves, spray animal protein amino acids containing 1 to 3% of the trace elements iron, manganese, copper and zinc by mass fraction on the passion fruit leaves at a rate of 50 to 80 g / mu;

[0009] S2, premixing: take passion fruit fresh leaves with one bud and three leaves or one bud and two leaves and oolong tea tender leaves as raw materials according to a mass percentage of 7:3, and mix them evenly;

[0010] S3, sun drying: evenly spread the premixed tea leaves in step S2 on a bamboo basket and place them in the sun to dry until the moisture content reaches 50-60%;

[0011] S4, stir-frying: stir-fry the tea leaves after sun drying in step S3, rapidly heating the temperature from 120°C to 160°C within 10 to 20 minutes, 50 to 60 times / min, and stir-fry until the moisture content reaches 30 to 35%, then enter the next process;

[0012] S5, rolling: rolling the tea leaves after the stir-frying in step S4 with a rolling machine for 30 to 50 minutes, until the tea leaves are tightly rolled, the tea juice fully overflows and adheres to the surface of the leaves, and the tea juice overflows without dripping when the leaves are tightly held by hand;

[0013] S6, drying: the tea leaves treated in step S5 are spread on a drying machine for drying at a temperature of 60-80° C. until the moisture content of the tea leaves is 5-7%.

[0014] Furthermore, the passion fruit leaves in step S1 are purple passion fruit, and the oolong tea is Tieguanyin.

[0015] Furthermore, in step S4, 0.5-1% passion fruit seed oil is added before stir-frying.

[0016] The present invention also provides a mixed tea prepared by the above steps.

[0017] The implementation of the present invention has the following beneficial effects:

[0018] The present invention combines the characteristics of passion fruit leaves, adds an appropriate amount of animal protein amino acids containing trace elements of iron, manganese, copper and zinc 10 to 15 days before picking, wherein the amino acids can chelate metal elements, improve the physiological activity of trace elements, and provide chelated trace elements such as iron, manganese, copper and zinc for crops. Some amino acids also have physiological regulation effects, play the role of plant endogenous hormones to a certain extent, and can promote cell division and expansion growth. According to the inventor's research, spraying foliar fertilizer on the passion fruit leaf surface can greatly increase the amino acid content of the leaves, effectively promote the effect of tea polyphenols and protein, and enhance the sweet taste. At the same time, spraying on the leaf surface can penetrate into the wax layer of the leaf, promote the absorption of nutrients, and the fertilizer liquid stays on the leaf surface for a long time, has good moisture retention, and improves the absorption efficiency of nutrients. Therefore, the prepared passion fruit leaf tea has a strong aroma, a sweet taste, and is not dry.

[0019] Lightly fermented tea is usually not easy to preserve at room temperature, and its flavor and taste will deteriorate significantly in about 60 to 80 days. The inventors found that by mixing passion fruit leaves and young oolong tea leaves in a ratio of 7:3 in the stir-frying process, the shelf life of the tea prepared by this process is greatly extended. The shelf life at room temperature can reach half a year, and the tea aroma and sweet taste can still be stored at room temperature for 5 to 6 months.

[0020] Passion fruit seed oil contains polyphenols, which have strong antioxidant effects, can effectively remove lipid free radicals, and can prevent lipid peroxidation, while also inhibiting the occurrence of aging diseases. In the process of stir-frying, adding passion fruit seed oil can not only protect the color and freshness and improve the fragrance, but also prevent scorching. DETAILED DESCRIPTION

[0021] In order to better understand the present invention, the present invention is further described in detail below in conjunction with the embodiments. However, those skilled in the art understand that the following embodiments are not limitations on the scope of protection of the present invention, and any changes and modifications made on the basis of the present invention are within the scope of protection of the present invention.

[0022] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0023] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0024] Example 1

[0025] A method for preparing mixed tea that is conducive to preservation, characterized in that it comprises the following steps:

[0026] S1. Treatment before picking: 10 to 15 days before picking passion fruit leaves, spray animal protein amino acids containing 1 to 3% of the trace elements iron, manganese, copper and zinc by mass fraction on the passion fruit leaves at a rate of 50 to 80 g / mu;

[0027] In combination with the characteristics of passion fruit leaves, the inventor sprays animal protein amino acids containing 1-3% of trace elements of iron, manganese, copper and zinc on the passion fruit leaves at a rate of 50-80g / mu 10-15 days before picking. Among them, amino acids can chelate metal elements, improve the physiological activity of trace elements, and provide chelated trace elements such as iron, manganese, copper and zinc for crops. Some amino acids also have physiological regulation effects, and to a certain extent play the role of plant endogenous hormones, which can promote cell division and expansion growth. According to the inventor's research, spraying foliar fertilizer on the passion fruit leaves can greatly increase the amino acid content of mature leaves, effectively promote the effect of tea polyphenols and protein, and enhance the sweet taste. At the same time, spraying on the leaves can penetrate into the wax layer of the leaves, promote the absorption of nutrients, and the fertilizer solution stays on the leaves for a long time, has good moisture retention, and improves the absorption efficiency of nutrients. The prepared passion fruit leaf tea has a strong aroma, a sweet taste, and is not dry.

[0028] S2, premixing: take passion fruit fresh leaves with one bud and three leaves or one bud and two leaves and oolong tea tender leaves as raw materials according to a mass percentage of 7:3, and mix them evenly;

[0029] Lightly fermented tea is usually not easy to preserve at room temperature, and its flavor and taste will deteriorate significantly in about 60 to 80 days. The inventor picked passion fruit leaves and oolong tea leaves in a ratio of 7:3, then dried, fried, rolled and dried. In the subsequent process, passion fruit leaves and oolong tea leaves interact with each other, and the shelf life of the tea prepared by this process is greatly extended. The shelf life can reach half a year at room temperature, and it still has tea aroma and sweet taste when stored at room temperature for 5 to 6 months.

[0030] S3, sun drying: evenly spread the premixed tea leaves in step S2 on a bamboo basket and place them in the sun to dry until the moisture content reaches 50-60%;

[0031] S4, stir-frying: stir-fry the tea leaves after sun drying in step S3, rapidly heating the temperature from 120°C to 160°C within 10 to 20 minutes, 50 to 60 times / min, and stir-fry until the moisture content reaches 30 to 35%, then enter the next process;

[0032] S5, rolling: rolling the tea leaves after the stir-frying in step S4 with a rolling machine for 30 to 50 minutes, until the tea leaves are tightly rolled, the tea juice fully overflows and adheres to the surface of the leaves, and the tea juice overflows without dripping when the leaves are tightly held by hand;

[0033] S6, drying: the tea leaves treated in step S5 are spread on a drying machine for drying at a temperature of 60-80° C. until the moisture content of the tea leaves is 5-7%.

[0034] Example 2

[0035] A method for preparing mixed tea that is conducive to preservation, characterized in that it comprises the following steps:

[0036] S1. Treatment before picking: 10 to 15 days before picking passion fruit leaves, spray animal protein amino acids containing 1 to 3% of the trace elements iron, manganese, copper and zinc by mass fraction on the passion fruit leaves at a rate of 50 to 80 g / mu;

[0037] S2, premixing: take passion fruit fresh leaves with one bud and three leaves or one bud and two leaves and oolong tea tender leaves as raw materials according to a mass percentage of 7:3, and mix them evenly;

[0038] S3, sun drying: evenly spread the premixed tea leaves in step S2 on a bamboo basket and place them in the sun to dry until the moisture content reaches 50-60%;

[0039] S4, stir-frying: stir-fry the tea leaves after sun-drying in step S3, add 0.5-1% passion fruit seed oil before stir-frying, quickly raise the temperature from 120°C to 160°C within 10-20min, 50-60 times / min, stir-fry until the moisture content is 30-35%, and then enter the next process;

[0040] Passion fruit seed oil contains polyphenols, which have strong antioxidant effects, can effectively remove lipid free radicals, and can prevent lipid peroxidation, while also inhibiting the occurrence of aging diseases. In the process of stir-frying, adding passion fruit seed oil can not only protect the color and freshness and improve the fragrance, but also prevent scorching.

[0041] S5, rolling: rolling the tea leaves after the stir-frying in step S4 with a rolling machine for 30 to 50 minutes, until the tea leaves are tightly rolled, the tea juice fully overflows and adheres to the surface of the leaves, and the tea juice overflows without dripping when the leaves are tightly held by hand;

[0042] S6, drying: the tea leaves treated in step S5 are spread on a drying machine for drying at a temperature of 60-80° C. until the moisture content of the tea leaves is 5-7%.

[0043] Comparative Example 1

[0044] In this comparative example, in step S4, passion fruit leaves and young oolong tea leaves are stir-fried in a mass ratio of 6:4, and other steps and conditions are the same as those in Example 1.

[0045] Comparative Example 2

[0046] In this comparative example, in step S4, passion fruit leaves and young oolong tea leaves are stir-fried in a mass percentage of 8:2, and other steps and conditions are the same as those in Example 1.

[0047] Comparative Example 3

[0048] In this comparative example, pure oolong tea was used for frying without adding passion fruit leaves, and other steps and conditions were the same as those in Example 1.

[0049] Comparative Example 4

[0050] In this comparative example, pure passion fruit leaves were used for frying without adding oolong tea leaves, and other steps and conditions were the same as those in Example 1.

[0051] According to the tea sensory evaluation method of GB / T 23776-2018 and the tea sensory evaluation terminology of GB / T 14487-2017, tea tasters with relevant qualifications were asked to evaluate the blended teas prepared in Examples 1 to 2 and Comparative Examples 1 to 4, and the sensory qualities of the above 6 blended teas were compared. The results are shown in Table 2 below; after being placed at room temperature for 60 days, the sensory qualities of the above 5 blended teas were compared again. The results are shown in Table 3 below.

[0052] Table 2 Sensory evaluation results of the mixed teas prepared in the examples and comparative examples

[0053]

[0054]

[0055] As can be seen from Table 2, in Comparative Examples 1 and 2, passion fruit leaves and oolong tea leaves were stir-fried in a mass percentage of 6:4 and 8:2, respectively, and the quality of the tea in terms of sweetness and dryness was lower than that of Example 1 or Example 2. Comparative Example 3 used pure oolong tea for stir-frying, and the sweetness was poor, while Comparative Example 4 used pure passion fruit leaves for stir-frying, and the taste was dry. In Example 2, 0.5-1% passion fruit seed oil was added in step S4, and the quality in terms of color and aroma was higher than that of Example 1.

[0056] Table 3 Sensory evaluation results of the mixed tea prepared in the examples and comparative examples after 60 days of storage

[0057]

[0058]

[0059] It can be seen from Table 3 that after being placed at room temperature for 60 days, the quality of Comparative Examples 1 to 4 in terms of aroma and taste is lower than that of Example 1 or Example 2.

[0060] In summary, the blended tea prepared by the method of the present invention has a strong aroma, a sweet taste and a long shelf life. Adding passion fruit seed oil during the stir-frying process can protect the color, improve the aroma and prevent the tea from burning.

[0061] The above description is only a partial embodiment of the present invention and is not intended to limit the present invention: for those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a mixed tea that is conducive to preservation, characterized in that: The following steps are included: S1. Pre-harvest treatment: 10-15 days before picking passion fruit leaves, spray animal protein amino acids containing 1-3% of the trace elements iron, manganese, copper and zinc at a rate of 50-80 g / mu on the passion fruit leaves; S2, premixing: take passion fruit fresh leaves with one bud and three leaves or one bud and two leaves and oolong tea tender leaves as raw materials according to a mass percentage of 7:3, and mix them evenly; S3, sun drying: evenly spread the premixed tea leaves in step S2 on a bamboo basket and place them in the sun to dry until the moisture content reaches 50-60%; S4, stir-frying: adding 0.5-1% passion fruit seed oil to the tea leaves after sun-drying in step S3, stir-frying, rapidly heating from 120° C. to 160° C. within 10-20 min, 50-60 times / min, stir-frying until the moisture content reaches 30-35%, and then entering the next step; S5, rolling: rolling the tea leaves after the stir-frying in step S4 with a rolling machine for 30 to 50 minutes, until the tea leaves are tightly rolled, the tea juice fully overflows and adheres to the surface of the leaves, and the tea juice overflows without dripping when the leaves are tightly held by hand; S6, drying: spreading the tea leaves treated in step S5 on a drying machine for drying at a temperature of 60-80° C. until the moisture content of the tea leaves is 5-7%.

2. The method for preparing mixed tea according to claim 1, wherein the passion fruit is purple passion fruit, and the oolong tea is Tieguanyin.

3. The blended tea prepared by the method for preparing blended tea according to any one of claims 1 to 2.

Images