Production process of double-lemon tea

Abstract

The invention belongs to the technical field of plant processing, and discloses a production process of double-lemon tea. The production process comprises the following steps: taking lemons, slicing the lemons, soaking the lemons in an anti-oxidation and anti-browning agent solution, taking out the lemon slices, airing the lemon slices, and performing freeze-drying treatment to obtain freeze-dried lemon slices; soaking tea leaves in water to obtain first tea juice and tea residues; soaking tea residues in water to obtain second tea juice, and mixing the first tea juice and the second tea juice to obtain a tea juice extracting solution; mixing the freeze-dried lemon slices, white granulated sugar, the tea juice extracting solution, auxiliaries and water to obtain double-lemon tea; in the primary extraction treatment process of the tea leaves, the temperature of the water is 30-40 DEG C, and the soaking time is 2-3 hours; in the secondary extraction treatment process of the tea leaves, the temperature of the water is 60-70 DEG C, and the soaking time is 10-15 minutes. The production process can retain the natural faint scent and sour and sweet taste of fresh lemons, and solves the problems of bitter taste, insufficient lemon fragrance and the like of lemon tea in the market.

Description

Technical Field

[0001] The present invention belongs to the technical field of plant processing, and particularly relates to a production process of double lemon tea. Background Art

[0002] Lemon tea has the sour and refreshing taste of lemon and the mellow and sweet taste of black tea. The tea juice of lemon black tea is clear and slightly red, with a proper combination of sour and sweet, and has the effect of strengthening the stomach and promoting digestion, especially suitable for drinking after meals. In addition, often drinking lemon black tea also has benefits such as moisturizing the skin, helping to whiten, promoting blood circulation, etc., and can effectively activate cells. The tea juice has a slightly red color, is clear, sweet and slightly sour, and is very refreshing, with the sour taste of lemon and the mellow taste of black tea. It has the fresh fragrance of lemon, strengthens the stomach and intestines to help digestion, and is quite suitable for drinking after meals. In addition, it can also moisturize the skin and promote blood circulation. Lemon is rich in vitamins, which has a certain auxiliary effect on improving blood pressure, relieving nerves, helping digestion and decomposing toxins in the body. The citrate in lemon juice can prevent kidney stones. Often eating lemon juice can also whiten teeth and help digestion. When the weather is hot, it has the effects of promoting the production of body fluid, quenching thirst and relieving heat.

[0003] Lemon fruits contain organic acids such as citric acid and malic acid, and also contain various nutrients such as vitamin C, vitamin B1, vitamin B2, nicotinic acid, sugars, calcium, phosphorus, and iron. It can promote the secretion of protein-decomposing enzymes in the stomach, increase gastrointestinal motility, help digestion and absorption, relieve cough, reduce phlegm, promote the production of body fluid and strengthen the spleen, and has a considerable benefit for the blood circulation of the human body and the absorption of calcium. Its rich vitamin C can not only prevent cancer, reduce cholesterol, eliminate fatigue, increase immunity, delay aging, maintain skin elasticity, but also has certain effects in overcoming diabetes, hypertension, anemia, colds, osteoporosis, etc.

[0004] At present, most of the lemon slices sold on the market are dried or sun-dried products. After fresh lemons are baked at high temperature, they are severely "woodified", showing shrinkage and browning phenomena, and the loss of heat-sensitive nutrients such as vitamins and bioactive components is also significant. The shelf life is only 2-3 months.

[0005] In addition, the existing lemon tea has problems such as a bitter taste and insufficient lemon aroma.

[0006] Therefore, there is an urgent need to provide a new lemon tea process to retain the natural fragrance and sour-sweet taste of fresh lemons to the greatest extent and solve the problems such as the bitter taste and insufficient lemon aroma of lemon tea on the market at present. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. For this purpose, the present invention provides a production process of double lemon tea. The production process of the present invention can retain the natural fragrance and sour-sweet taste of fresh lemons to the greatest extent and solve the problems such as the bitter taste and insufficient lemon aroma of lemon tea on the market at present.

[0008] The production process described in the present invention uses freeze-drying technology to process fresh lemon slices, retaining the natural fragrance and sour-sweet taste of fresh lemons to the greatest extent possible. Then, combined with the tea extraction (secondary tea extraction treatment) production process, it solves the problems such as bitter taste and insufficient lemon aroma in lemon tea on the market.

[0009] The production process described in the present invention greatly increases the citral content in lemon slices, and the tea extraction production process greatly increases the tea polyphenol content, thus solving the problems such as bitter taste and insufficient lemon aroma in lemon tea on the market.

[0010] Freeze-dried lemon slices are obtained by freezing fresh lemons and then using the sublimation principle in a vacuum state to remove the water in the lemons directly from the solid ice state to water vapor without melting, thereby achieving the drying of the food, which is suitable for making tea and cooking seasoning.

[0011] Freeze-drying is a method that can maximize the retention of the nutritional components and original flavor of lemons, and can obtain lemon slices that are well-preserved, safe and hygienic. Freeze-dried lemon slices are high-quality lemon slices produced using advanced technologies such as vacuum freeze-drying. They have a light yellow color without browning, a porous and loose structure, good rehydration properties, and the diameter, thickness, and flatness of the fruit slices have no obvious change compared with before drying. They have the unique fresh fragrance of lemons, with less loss of nutrients, and the quality is significantly better than baked lemon slices.

[0012] The present invention provides a production process for double lemon tea.

[0013] Specifically, a production process for double lemon tea includes the following steps:

[0014] (1) Freeze-drying treatment of lemons: Take lemons, slice them, soak them in an antioxidant and anti-browning agent solution, then take out the lemon slices, dry them, and then carry out freeze-drying treatment to obtain freeze-dried lemon slices;

[0015] (2) Primary tea extraction treatment: Soak tea leaves in water to obtain the first tea juice and tea residues;

[0016] (3) Secondary tea extraction treatment: Soak the tea residues in water to obtain the second tea juice, and mix the first tea juice and the second tea juice to obtain a tea juice extract;

[0017] (4) Mix the freeze-dried lemon slices, granulated sugar, tea juice extract, additives, and water to obtain the double lemon tea;

[0018] During the primary tea extraction treatment, the tea leaves are soaked in water at a temperature of 30 - 40 °C for 2 - 3 hours;

[0019] During the secondary extraction process of the tea leaves, the tea dregs are soaked in water at a temperature of 70-80°C for 10-15 minutes.

[0020] Compared with the traditional tea extraction method, the present invention adopts a secondary extraction process. First, the aroma substances in the tea leaves are extracted by a low-temperature cold extraction process, and then the tea flavor is extracted by a high-temperature extraction process. This method can solve and reduce the problem of the pre-packaged lemon tea on the market being too bitter and astringent.

[0021] The selection of the process conditions for the primary extraction process of the tea leaves and the process conditions for the secondary extraction process of the tea leaves makes the obtained tea juice extract blend well with the lemon flavor, and the overall flavor is relatively stimulating, meeting the product flavor requirements.

[0022] Preferably, during the primary extraction process of the tea leaves, the tea leaves are soaked in water at a temperature of 35-40°C for 2.5-3 hours.

[0023] Preferably, during the secondary extraction process of the tea leaves, the tea dregs are soaked in water at a temperature of 70-75°C for 12-15 minutes.

[0024] Preferably, in step (1), the lemons include yellow lemons and green lemons. For example, the yellow lemon is the South African clasp lemon, and the green lemon is the Guangdong perfume lemon. The peel of the South African clasp lemon is very soft, not bitter, has a compound floral fragrance, is hollow and seedless, has a lot of juice, is yellowish in color, has a moderate acidity, and has a sweet aftertaste. It is relatively resistant to brewing. The Guangdong perfume lemon is hammer-shaped, has a slightly thicker peel, is seedless, and has different fruit shapes in different seasons. The fruit in winter is the most fragrant, the peel has a strong fragrance, and the juice acidity is weak.

[0025] Preferably, in step (1), the freeze-drying process is as follows: Freeze in a freezer or refrigerator below -30°C for 4-8 hours, then lower the cold well temperature of the vacuum drying chamber to below -42°C, put the frozen lemon slices into the vacuum drying chamber, and prevent the frozen lemon slices from thawing during this process. Then evacuate the drying chamber, freeze in the drying chamber at a pressure of 40-60 Pa for 1-1.5 hours to ensure that the bound water in the lemon slices is fully frozen, and then start sublimation drying for 17-20 hours. After the sublimation drying is completed, carry out desorption drying for 3-6 hours, and take out the product when the pressure in the drying chamber is 20-30 Pa to obtain freeze-dried lemon slices with a moisture mass fraction of 2-5%.

[0026] Preferably, in step (1), the mass concentration of the antioxidant and anti-browning agent solution is 0.05-0.1%.

[0027] Preferably, in step (1), the antioxidant and anti-browning agent in the antioxidant and anti-browning agent solution is vitamin C.

[0028] Preferably, in step (1), the soaking time is 1 - 5 min, more preferably 1 - 3 min.

[0029] Preferably, in step (1), the thickness of the sliced lemon is 4 - 6 mm, such as 4 mm, 5 mm, or 6 mm.

[0030] Preferably, in step (2), during the first extraction treatment of the tea leaves, the dosage ratio of tea leaves to water is 12 - 15 g : 1 L, more preferably 13 - 15 g : 1 L. The first tea juice obtained from the first extraction treatment of the tea leaves has a strong aroma, a sweet aftertaste, a fresh fragrance, and no obvious bitterness or astringency.

[0031] Preferably, the tea leaves include black tea or green tea, preferably black tea.

[0032] Preferably, in step (3), during the second extraction treatment of the tea leaves, the dosage ratio of tea dregs to water is 8 - 15 g : 1 L, more preferably 13 - 15 g : 1 L. The second tea juice obtained from the second extraction treatment of the tea leaves has a strong aroma, a sweet aftertaste, a fresh fragrance, and a proper tea flavor.

[0033] Preferably, in step (4), the auxiliary agent includes at least one of fructose syrup, citric acid monohydrate, sodium citrate, vitamin C, and edible essence.

[0034] Preferably, in step (4), the edible essence includes at least one of lemon oil, cinnamon oil, and menthol.

[0035] Preferably, in step (4), the weight ratio of granulated sugar, tea juice extract, auxiliary agent, and water is (10 - 25) : (5 - 10) : (40 - 90) : (900 - 1000).

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] The production process of the present invention uses freeze - drying technology to process fresh lemon slices, retaining the natural fragrance and sour - sweet taste of fresh lemons to the greatest extent. Then, combined with the tea extraction (second extraction treatment of tea leaves) production process, it solves the problems such as bitter taste and insufficient lemon aroma in lemon tea on the current market. Compared with the traditional tea extraction method, the present invention adopts a two - stage extraction process. First, a low - temperature cold extraction process is used to extract the aroma substances in the tea leaves, and then a high - temperature extraction process is used to extract the tea flavor. This method can solve and reduce the problem of bitterness in pre - packaged lemon tea on the current market. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a diagram of green lemons and yellow lemons obtained in Example 1 of the present invention;

[0039] Figure 2 Schematic diagram of the production process flow of the double lemon tea in Embodiment 1 of the present invention. Specific implementation manners

[0040] In order to make those skilled in the art more clearly understand the technical solutions described in the present invention, the following embodiments are listed for illustration. It should be noted that the following embodiments do not limit the protection scope required by the present invention.

[0041] The raw materials, reagents or devices used in the following embodiments can be obtained from conventional commercial channels or can be obtained by existing known methods without special instructions.

[0042] Embodiment 1

[0043] A production process of double lemon tea includes the following steps:

[0044] (1) Freeze-drying treatment of lemon: After washing the whole lemon (the lemon includes yellow lemon and green lemon, the yellow lemon is South African lock lemon, and the green lemon is Guangdong perfume lemon), cut off the head and tail, remove the seeds and slice it, then soak it in a solution prepared with an edible antioxidant and anti-browning agent for 3 minutes. The antioxidant and anti-browning agent is vitamin C with a mass concentration of 0.05%;

[0045] Placing on a tray and quick-freezing: The soaked lemon slices are spread out on a tray to dry, and then the dried lemon slices are put into a freezer below -30°C and frozen for 5 hours;

[0046] Vacuum freeze-drying: Lower the cold well temperature of the vacuum drying chamber to below -42°C, then put the frozen lemon slices into the vacuum drying chamber. During this process, prevent the frozen lemon slices from thawing, then evacuate the drying chamber, freeze in the drying chamber with a pressure of 50 Pa for 1 hour to ensure that the bound water in the lemon slices is fully frozen, and then start sublimation drying for 17 hours. After the sublimation drying is completed, carry out desorption drying for 4 hours (the temperature of desorption drying is 25°C, the pressure is 110 Pa, and the time is 5 hours). When the pressure in the drying chamber is 30 Pa, take out of the chamber to obtain freeze-dried lemon slices with a moisture content of 4 ± 1%, and then sterilize with ultraviolet rays, bag (each bag contains: one green lemon and one yellow lemon), and seal and store;

[0047] (2) Primary extraction treatment of tea: Soak the tea (black tea leaves) in water at a temperature of 40°C for 2.5 hours, and the dosage ratio of tea leaves to water is 15 g: 1 L to obtain the first tea juice and tea residues;

[0048] (3) Secondary extraction treatment of tea leaves: Soak the tea dregs in water at a temperature of 70 °C for 15 minutes. The dosage ratio of tea dregs to water is 15 g:1 L to obtain the second tea juice. Mix the first tea juice and the second tea juice to obtain the tea juice extract. After filtering through 40-mesh and 80-mesh sieves, quickly cool it to below 15.0 °C, and then treat it with a centrifuge (centrifugation parameters: flow rate 7.5 tons / hour, 5000 revolutions / min), and then store it in a temporary storage tank for temporary storage and preparation;

[0049] (4) Mix white granulated sugar, tea juice extract, high fructose syrup, citric acid monohydrate, sodium citrate, vitamin C, edible essence, and water. The weight ratio of white granulated sugar, tea juice extract, auxiliary agent, and water is 20:8:90:1.5:0.4:0.5:0.9:900 to obtain the preparation liquid. Filter it through a filter with a filtration accuracy of ≤1 micron. After filtration, the preparation liquid is sterilized by a UHT device (ultra-high temperature sterilizer). Sterilization parameters: 135.0 ± 2.0 °C × 30 s, and then filled by a filling machine; The packaging container uses a PET (polyethylene terephthalate) bottle. The PET bottle and the bottle cap are respectively cleaned and disinfected by ultraviolet light or disinfectant solution. The packaging container is 500 ml / bottle, and then each bottle is paired with freeze-dried lemon slices (one slice of yellow lemon and one slice of green lemon) to obtain the double lemon tea (when drinking, directly mix the freeze-dried lemon slices with the preparation liquid for 15 minutes and then it can be drunk).

[0050] Figure 1 This is the figure of green lemons and yellow lemons obtained in Example 1 of the present invention; among them, Figure (a) is a yellow lemon slice and Figure (b) is a green lemon slice.

[0051] Example 2

[0052] Compared with Example 1, the difference in Example 2 is only that during the secondary extraction treatment of tea leaves, the dosage ratio of tea dregs to water is 8 g:1 L, and the rest of the process is the same as that in Example 1.

[0053] Example 3

[0054] Compared with Example 1, the difference in Example 3 is only that during the secondary extraction treatment of tea leaves, the water temperature is 80 °C, and the rest of the process is the same as that in Example 1.

[0055] Comparative Example 1

[0056] Compared with Example 1, the difference in Comparative Example 1 is only that Comparative Example 1 uses lemon slices that have been naturally dried in the sun for 30 days, and the rest of the process is the same as that in Example 1.

[0057] Comparative Example 2

[0058] Compared with Example 1, the difference in Comparative Example 2 is only that during the secondary extraction treatment of tea leaves, the water temperature is 60 °C, and the rest of the process is the same as that in Example 1.

[0059] Product Effect Test

[0060] 1. According to the standard of GB / T24800.9, test the citral content in the lemon slices naturally dried for 30 days in Comparative Example 1, and also test the citral content in the freeze-dried lemon slices in Example 1 after being placed for 30 days. The results show that the citral content in Comparative Example 1 is 85 mg / kg, while the citral content in Example 1 is 147 mg / kg.

[0061] Thus, it can be seen that among the lemon slices with and without freeze-drying treatment, the citral content in the freeze-dried lemon slices is significantly higher.

[0062] Citral is an organic compound with the chemical formula C 10 H 16 O. It is one of the most important components in lemon fragrance. Citral has a fresh lemon flavor, can stimulate the olfactory nerve of the human body, enhance attention and mental state, and can add more aroma levels and flavors to the lemon fragrance.

[0063] 2. Take the tea juice extracts prepared in Example 1, Example 3 and Comparative Example 2, and test the tea polyphenol content with reference to the standard of GB / T21733. The results are shown in Table 1.

[0064] Table 1

[0065]

[0066] As can be seen from Table 1, the conditions for the secondary extraction of tea leaves in Example 1 of the present invention are the most suitable. The tea juice extract not only has a high tea polyphenol content, but also has a good aftertaste. After changing the temperature of the secondary extraction of tea leaves in Comparative Example 2, the tea polyphenol content decreases significantly.

Claims

1. A production process of double lemon tea, characterized in that: The following steps are involved: (1) freeze-drying of lemon: taking a lemon, slicing it, and soaking it in an antioxidant anti-browning agent solution, then taking out the lemon slices, drying them, and then freeze-drying them to obtain freeze-dried lemon slices; (2) Primary extraction of tea leaves: soaking tea leaves in water to obtain first tea juice and tea residues; (3) secondary extraction of tea leaves: soaking the tea residue in water to obtain a second tea juice, and mixing the first tea juice and the second tea juice to obtain a tea juice extract; (4) mixing freeze-dried lemon slices, white sugar, tea extract, additives and water to obtain the double lemon tea; During the tea leaves' primary extraction process, the tea leaves are immersed in water at a temperature of 30-40° C. for 2-3 hours; During the secondary extraction of tea leaves, tea residues are soaked in water with a temperature of 70-80° C. for 10-15 minutes.

2. The production process according to claim 1, characterized in that: In step (1), the lemons include yellow lemons and green lemons.

3. The production process according to claim 1, characterized in that: In step (1), the freeze-drying process is as follows: freezing in a freezer or refrigerator below -30°C for 4-8 hours, then lowering the cold well temperature of the vacuum drying chamber to below -42°C, placing the frozen lemon slices in the vacuum drying chamber, then evacuating the drying chamber, freezing in the drying chamber at a pressure of 40-60 Pa for 1-1.5 hours to ensure that the bound water in the lemon slices is fully frozen, and then starting sublimation drying for 17-20 hours. After the sublimation drying is completed, analytical drying is performed for 3-6 hours, and the lemon slices are taken out of the chamber when the pressure in the drying chamber is 20-30 Pa, thereby obtaining freeze-dried lemon slices with a moisture content of 2-5% by mass.

4. The production process according to claim 1, characterized in that: In step (1), the mass concentration of the antioxidant anti-browning agent solution is 0.05-0.1%.

5. The production process according to claim 1, characterized in that: In step (1), the antioxidant and anti-browning agent in the antioxidant and anti-browning agent solution is vitamin C.

6. The production process according to claim 1, characterized in that: In step (1), the soaking time is 1-5 min; and / or the thickness of the sliced ​​lemon is 4-6 mm.

7. The production process according to claim 1, characterized in that: In step (2), during the one-time extraction process of the tea leaves, the ratio of tea leaves to water is 12-15 g:1 L.

8. The production process according to claim 1, characterized in that: In step (3), during the secondary extraction of tea leaves, the ratio of tea residue to water is 8-15 g:1 L.

9. The production process according to claim 1, characterized in that: In step (4), the auxiliary agent includes at least one of fructose-glucose syrup, citric acid monohydrate, sodium citrate, vitamin C, and edible flavoring.

10. The production process according to any one of claims 1 to 9, characterized in that: In step (4), the weight ratio of the white sugar, tea extract, auxiliary agent and water is (10-25): (5-10): (40-90): (900-1000).

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