Olive green tea and method for making the same

Abstract

This invention discloses an olive green tea and its production method, belonging to the field of tea processing technology. The method includes the following steps: fresh olives are washed, sliced, and pitted; then soaked in a color-protecting solution, drained, steamed, and microwave-sterilized; the sterilized olive slices are vacuum-dried until the moisture content is below 5%; then pulverized and sieved to obtain olive powder; the olive powder is mixed evenly with raw green tea leaves and vacuum-dried until the moisture content is below 5%; a segmented aroma enhancement process is used; and after natural cooling, the tea is nitrogen-filled and packaged. This invention effectively removes the bitterness of olives through a color-protecting soaking combined with a two-stage sterilization process. Low-temperature vacuum drying and segmented aroma enhancement preserve functional components and enhance aroma complexity. The olive green tea produced by this method has low bitterness, harmonious aroma, and high retention rate of functional components, showing good market application prospects.

Description

Technical Field

[0001] This invention belongs to the field of green tea technology, specifically relating to an olive green tea and its production method. Background Technology

[0002] Olives, belonging to the genus *Olive* of the family Burseraceae, are rich in polyphenols, flavonoids, organic acids, vitamin C, and other active ingredients, possessing properties such as clearing heat and detoxifying, relieving sore throat, and promoting saliva production. Green tea, as a traditional beverage, has health benefits including antioxidant and lipid-lowering effects. Developing compound tea drinks by combining olives and green tea has promising market prospects. However, existing olive green tea products suffer from a strong bitter taste and unbalanced flavor profile. Summary of the Invention

[0003] The purpose of this invention is to provide an olive green tea and its preparation method to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for producing olive green tea, comprising the following steps: S1. Preparation of olive powder: Wash fresh olives, slice them and remove the pits. The thickness of the slices should be 2-3 mm. Soak the slices in a color-protecting solution. After soaking, drain them and steam them first, then microwave them to kill the green. After killing the green, immediately blow them to cool them. Vacuum dry the green olive slices until the moisture content is less than 5%. Then crush and sieve them to obtain olive powder. S2. Green tea fresh leaf processing and rolling: Select one bud and one leaf or one bud and two leaves fresh leaves picked in spring. After spreading and rolling, they enter the rolling process. During the rolling process, add the olive powder prepared in S1. The mass ratio of olive powder to fresh leaves is 1:3 to 1:5. Roll until evenly mixed and the leaves are rolled into strips. S3. Drying: Vacuum dry the kneaded mixture, controlling the temperature at 50-60℃ and the vacuum degree at -0.08 to -0.09 MPa, until the moisture content is below 5%; S4. Fragrance Enhancement: Processed using a segmented fragrance enhancement process; S5. Cooling Packaging: After aroma enhancement, the product is naturally cooled and then packaged with nitrogen.

[0005] Preferably, the color-protecting solution in S1 is a mixed aqueous solution of 0.2% to 0.5% citric acid and 0.1% to 0.2% ascorbic acid, and the soaking time is 20 to 40 minutes.

[0006] Preferably, the specific process for de-astringency and blanching in S1 is as follows: steam temperature 80-85℃, processing time 0.5-1.5min; microwave blanching power 2-4 kW, temperature 70-80℃, processing time 1-2min.

[0007] Preferably, the vacuum drying temperature in S1 is 50-60℃, the vacuum degree is -0.08 to -0.09 MPa, and the sieve mesh size for pulverizing and sieving is 80 mesh.

[0008] Preferably, the temperature of the drum blanching in S2 is 200-240℃, and the spreading time is 3-5 h.

[0009] Preferably, the vacuum drying time in step S3 is 2 to 3 hours.

[0010] Preferably, the segmented aroma extraction process in S4 includes: a first stage at a temperature of 60-70°C for 15-25 minutes; a second stage at a temperature of 75-85°C for 25-35 minutes; a third stage at a temperature of 85-90°C for 8-12 minutes; and turning the material once after each stage.

[0011] The fresh olives mentioned in S1 are 70% to 80% ripe.

[0012] The present invention also provides an olive green tea, which is prepared by the above method.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the bitterness of olives is effectively removed by soaking in a color-protecting solution combined with a two-stage blanching process using steam and microwave, while retaining their characteristic aroma. The resulting olive green tea has a mellow taste and a noticeable sweet aftertaste, with a significant reduction in bitterness. The low-temperature vacuum drying and segmented aroma extraction process significantly improves the retention rate of total polyphenols and flavonoids in olives, which is beneficial to enhancing the health benefits of the product.

[0014] 2. In this invention, olive slices and green tea are organically combined through a compounding and shaping process. The resulting product has a regular shape and gradually unfolds after brewing. The segmented aroma enhancement process allows the fresh aroma of olives and the aroma of green tea to be deeply integrated, resulting in a rich and lasting aroma with a more harmonious flavor compared to existing products. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of the preparation of olive powder and green tea preparation in this invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0017] See Figure 1 This invention provides a method for preparing olive green tea: Example 1

[0018] This embodiment provides a method for preparing olive green tea, including the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives at 70% ripeness, remove insect-infested and damaged fruits, wash, slice and remove pits, with the pulp slices being 2 mm thick. Soak the pulp slices in a mixed aqueous solution of 0.3% citric acid and 0.1% ascorbic acid for 30 min. Remove and drain, then place in a steam blanching machine at 80℃ for 1 min; subsequently transfer to a microwave blanching device at 3 kW microwave power and 75℃ for 1.5 min, and immediately cool with air after blanching. Place the blanched olive slices in a vacuum drying oven at 55℃ and a vacuum of -0.08 MPa until the moisture content is below 5%, then pulverize and pass through an 80-mesh sieve to obtain olive powder.

[0019] S2. Green Tea Fresh Leaf Processing and Rolling: Select fresh leaves with one bud and one leaf in spring. After spreading for 4 hours, perform 220℃ drum fixation. After fixation, put the leaves into the rolling machine while still hot. Add the above-mentioned olive powder 1 minute after the start of rolling. The mass ratio of olive powder to fresh leaves is 1:4. Continue rolling for a total of 15 minutes until the powder and tea leaves are evenly mixed and the leaves are tightly rolled into strips.

[0020] S3. Drying: Spread the kneaded mixture evenly on the tray of the vacuum drying oven at 55℃ and a vacuum of -0.08 MPa for 2.5 h. The moisture content is 4.5%.

[0021] S4. Aroma Enhancement: A segmented aroma enhancement process is adopted. The first stage is 65℃ for 20 minutes; the second stage is 80℃ for 30 minutes; and the third stage is 85℃ for 10 minutes. The feed is turned over once after each stage.

[0022] S5. Cooling Packaging: After aroma enhancement, the product is naturally cooled to room temperature and then packaged in nitrogen-filled aluminum foil composite bags.

[0023] The olive green tea prepared in this embodiment has a loose appearance with tightly rolled tea leaves and olive powder evenly adhering to the surface. Testing revealed a total polyphenol content of 12.3 g / 100g and a flavonoid content of 4.8 g / 100g. Sensory evaluation of bitterness yielded a score of 2.1 out of 10, while the control sample prepared using a traditional direct drying process scored 6.5 out of 10. Brewing tests showed that the product rapidly unfurled in 85℃ hot water, retaining a distinct flavor even after the third infusion, with a long-lasting aroma. Example 2

[0024] This embodiment provides a method for preparing olive green tea, including the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives that are 80% ripe, wash them, slice them, remove the pits, and make slices 3 mm thick. Soak the slices in a mixed aqueous solution of 0.5% citric acid and 0.2% ascorbic acid for 20 min. Remove and drain. Process with steam at 85℃ for 0.5 min; or with microwave at 4 kW at 70℃ for 2 min. After blanching, cool with air. Vacuum dry the blanched olive slices (temperature 60℃, vacuum degree -0.09 MPa, until moisture content <5%), pulverize them through an 80-mesh sieve to obtain olive powder.

[0025] S2. Green tea fresh leaf processing and rolling: Select fresh leaves with one bud and two leaves in spring. After spreading and rolling to kill the green, add olive powder during the rolling process. The mass ratio of olive powder to fresh leaves is 1:5. Roll until evenly mixed.

[0026] S3. Drying: Temperature 60℃, vacuum degree -0.09 MPa, drying time 2 h, moisture content 4.8%.

[0027] S4. Enhance aroma: First stage 70℃, 15 min; second stage 85℃, 25 min; third stage 90℃, 8 min, turn once in each stage.

[0028] S5. Cooling and packaging: Same as in Example 1.

[0029] The olive green tea prepared in this embodiment has a total polyphenol content of 11.8 g / 100g, a flavonoid content of 4.5 g / 100g, a bitterness score of 1.9, and a rich and lasting aroma. Example 3

[0030] This embodiment provides a method for preparing olive green tea, including the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives at 70% ripeness, slice them to a thickness of 2.5 mm, and soak them in a solution of 0.2% citric acid and 0.15% ascorbic acid for 40 min. Remove and drain. Process with steam at 82℃ for 1.2 min; or with microwave at 2 kW at 80℃ for 1 min. After blanching, cool with air. Vacuum dry the blanched olive slices (50℃, vacuum -0.085 MPa, until moisture content <5%), then pulverize through an 80-mesh sieve to obtain olive powder.

[0031] S2. Green tea fresh leaf processing and rolling: Select fresh leaves with one bud and one leaf in spring. After spreading and fixing, add olive powder during the rolling process. The mass ratio of olive powder to fresh leaves is 1:3. Roll until evenly mixed.

[0032] S3. Drying: Temperature 50℃, vacuum degree -0.085 MPa, drying time 3 h, moisture content 4.2%.

[0033] S4. Flavoring: First stage 60℃, 25 min; second stage 75℃, 35 min; third stage 88℃, 12 min, turning once in each stage.

[0034] S5. Cooling and packaging: Same as in Example 1.

[0035] The olive green tea prepared in this embodiment has a total polyphenol content of 12.5 g / 100g, a flavonoid content of 5.0 g / 100g, a bitterness score of 2.3, and a mellow taste with a noticeable sweet aftertaste after brewing. Example 4

[0036] This embodiment provides a method for preparing olive green tea, which differs from Embodiment 1 in the ratio of dried olive powder to fresh leaves, and includes the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives at 70% ripeness, wash, slice, and remove pits, with each slice 2.5 mm thick. Soak the slices in a mixed aqueous solution of 0.25% citric acid and 0.12% ascorbic acid for 35 min. Drain and process with steam at 83℃ for 1.2 min; or with microwave at 78℃ for 1.8 min, followed by blanching and cooling with air. Vacuum dry the blanched olive slices (52℃, -0.085 MPa, until moisture content <5%), then pulverize through an 80-mesh sieve to obtain olive powder.

[0037] S2. Green tea fresh leaf processing and rolling: Select fresh leaves with one bud and one leaf in spring. After spreading and fixing, add olive powder during the rolling process. The mass ratio of olive powder to fresh leaves is 1:3.5. Roll until evenly mixed.

[0038] S3. Drying: Temperature 52℃, vacuum degree -0.085 MPa, drying time 2.8 h, moisture content detected 4.3%.

[0039] S4. Aroma Enhancement: First stage 62℃, 22 min; Second stage 78℃, 28 min; Third stage 86℃, 11 min. Turn the feed once after each stage.

[0040] S5. Cooling and packaging: Same as in Example 1.

[0041] The olive green tea prepared in this embodiment has a loose appearance and the dried olive powder is evenly adhered. Testing showed that the product has a total polyphenol content of 12.0 g / 100g and a flavonoid content of 4.6 g / 100g. The bitterness score was 2.0. Brewing tests showed that the material rapidly absorbs water and expands in 85℃ hot water, and still has a noticeable flavor even in the third infusion. Example 5

[0042] This embodiment provides a method for preparing olive green tea, which differs from Embodiment 1 in the composition of the color-protecting solution and the soaking time, while also adjusting the microwave fixation parameters. The process includes the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives that are 80% ripe, wash them, slice them, remove the pits, and make slices 2 mm thick. Soak the slices in a mixed aqueous solution of 0.4% citric acid and 0.18% ascorbic acid for 25 min. Remove and drain. Process with steam at 80℃ for 0.8 min; or with microwave at 3.5 kW at 72℃ for 1.2 min. After blanching, cool with air. Vacuum dry the blanched olive slices (temperature 58℃, vacuum degree -0.09 MPa, until moisture content <5%), pulverize them through an 80-mesh sieve to obtain olive powder.

[0043] S2. Green tea fresh leaf processing and rolling: Select fresh leaves with one bud and two leaves in spring. After spreading and fixing, add olive powder during the rolling process. The mass ratio of olive powder to fresh leaves is 1:4.5. Roll until evenly mixed.

[0044] S3. Drying: Temperature 58℃, vacuum degree -0.09 MPa, drying time 2.2 h, moisture content detected 4.0%.

[0045] S4. Aroma Enhancement: First stage 68℃, time 18 min; Second stage 82℃, time 32 min; Third stage 88℃, time 9 min. Turn the feed once after each stage.

[0046] S5. Cooling and packaging: Same as in Example 1.

[0047] The olive green tea prepared in this embodiment has a total polyphenol content of 11.5 g / 100g and a flavonoid content of 4.3 g / 100g. Its bitterness and astringency score is 1.8. Brewing tests show that the tea soup has a sweet taste with a noticeable aftertaste. Example 6

[0048] This embodiment provides a method for producing olive green tea, which differs from Embodiment 1 in that the green tea raw material is selected from summer fresh leaves, and the temperature and time for staged aroma enhancement are adjusted. The process includes the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives at 70% ripeness, wash, slice, and remove pits, with each slice 3 mm thick. Soak the slices in a mixed aqueous solution of 0.35% citric acid and 0.15% ascorbic acid for 30 min. Drain and process with steam at 84℃ for 1 min; or with microwave at 3 kW at 76℃ for 1.5 min, followed by cooling with air. Vacuum dry the olive slices (56℃, -0.082 MPa, until moisture content <5%), then pulverize through an 80-mesh sieve to obtain olive powder.

[0049] S2. Green Tea Leaf Processing and Rolling: Select fresh leaves of one bud and two leaves from summer. After spreading and traditional pan-frying to kill the green, add dried olive powder during the rolling process. The mass ratio of dried olive powder to fresh leaves is 1:4. Roll until evenly mixed. Summer green tea raw materials have a stronger flavor, and pairing them with olives can enhance the thickness of the tea soup.

[0050] S3. Drying: Temperature 56℃, vacuum degree -0.082 MPa, drying time 2.4 h, moisture content detected 4.6%.

[0051] S4. Aroma Enhancement: First stage: 65℃, 20 min; Second stage: 80℃, 30 min; Third stage: 90℃, 10 min. Turn the feed once after each stage.

[0052] S5. Cooling and packaging: Same as in Example 1.

[0053] The olive green tea prepared in this embodiment has a deep green color, a mellow taste, good integration of olives and green tea, a long-lasting sweet aftertaste, and can be brewed up to four times while still having a distinct flavor. Example 7

[0054] This embodiment provides a method for producing olive green tea, which differs from Embodiment 1 in that the drying process is divided into two steps: pre-drying and vacuum drying, in order to improve the initial drying uniformity of the material. The process includes the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives at 70% ripeness, wash, slice, and remove pits, with each slice 2.5 mm thick. Soak the slices in a mixed aqueous solution of 0.3% citric acid and 0.1% ascorbic acid for 30 min. Drain and process with steam at 82℃ for 1 min; or with microwave at 3 kW at 75℃ for 1.5 min, followed by cooling with air. Vacuum dry the blanched olive slices (55℃, vacuum -0.08 MPa, until moisture content <5%), then pulverize through an 80-mesh sieve to obtain olive powder.

[0055] S2. Green tea fresh leaf processing and rolling: Select fresh leaves with one bud and one leaf in spring. After spreading and fixing, add olive powder during the rolling process. The mass ratio of olive powder to fresh leaves is 1:4. Roll until evenly mixed.

[0056] S3. Drying: This step consists of two parts: S3.1 and S3.2. S3.1 Pre-drying: Spread the kneaded mixture evenly in a hot air circulating drying oven at 40℃ for 30 minutes to allow the surface moisture of the material to evaporate quickly.

[0057] S3.2 Vacuum drying: Transfer the pre-dried material into a vacuum drying oven at 55℃ and a vacuum of -0.08MPa for 2 hours. The moisture content is then measured to be 4.2%.

[0058] S4. Fragrance Enhancement: Same as the segmented fragrance enhancement process in Example 1.

[0059] S5. Cooling and packaging: Same as in Example 1.

[0060] The olive green tea prepared in this embodiment, due to pre-drying treatment, dries quickly on the surface, has uniform internal moisture, and is less prone to clumping. Testing revealed a total polyphenol content of 12.2 g / 100g and a flavonoid content of 4.7 g / 100g. The bitterness score was 2.0. Brewing tests showed that the material slowly unfurled in 85℃ hot water, releasing a stable flavor in the tea soup, with a uniform flavor in the first three infusions. Example 8

[0061] This embodiment provides a method for producing olive green tea, which is a preferred embodiment of Embodiment 1. The difference from Embodiment 1 is that the olive slices undergo a low-temperature freezing treatment before fixation to improve the textural properties of the subsequent dried powder. The method includes the following steps: S1. Preparation of Olive Powder: Harvest 10 kg of fresh olives at 70% ripeness, wash, slice, and remove pits, with each slice being 2 mm thick. Soak the slices in a mixed aqueous solution of 0.3% citric acid and 0.1% ascorbic acid for 30 min. Then drain the soaked olive slices, spread them evenly on a stainless steel tray, and freeze them at -18℃ for 2 h. After freezing, allow them to thaw naturally to room temperature. Process the thawed olive slices according to the de-astringency and blanching process in Example 1 (steam 80℃ / 1 min, microwave 3 kW / 75℃ / 1.5 min), then vacuum dry (55℃, -0.08 MPa, until moisture content <5%), and pulverize through an 80-mesh sieve to obtain olive powder.

[0062] S2. Green tea fresh leaf processing and rolling: Select fresh leaves with one bud and one leaf in spring. After spreading and fixing, add the above-mentioned dried olive powder during the rolling process. The mass ratio of dried olive powder to fresh leaves is 1:4. Roll until evenly mixed.

[0063] S3. Drying: Same as the vacuum drying process in Example 1.

[0064] S4. Flavoring: Same as Example 1.

[0065] S5. Cooling and packaging: Same as in Example 1.

[0066] The olive green tea prepared in this embodiment has a finer powder due to the freeze-drying process of the raw materials, which resulted in moderate cell wall damage. Testing showed that the total polyphenol content was 12.8 g / 100g and the flavonoid content was 5.0 g / 100g, both higher than in other embodiments. The bitterness score was 1.7. Brewing tests showed a significantly improved extraction rate of functional components, a pronounced aftertaste, and a more complete integration of olive flavor with green tea.

[0067] The olive green tea prepared in this embodiment exhibits a microporous structure formed by the melting of fine ice crystals on the surface of the olive slices. Testing revealed a total polyphenol content of 12.8 g / 100g and a flavonoid content of 5.0 g / 100g, both higher than in other embodiments. The bitterness score was 1.7. Brewing tests showed that due to the moderate cell wall damage caused by freezing, the tea flavor was released more fully, with a pronounced aftertaste, and the extraction rate of functional components was significantly improved. Freezing also made the olive slices softer, allowing them to bind more tightly with the tea leaves during rolling, making the product less prone to breakage during transportation and storage.

[0068] Examples 1 to 8 above demonstrate various implementation methods of the present invention from aspects such as raw material ratio, molding method, color protection process, drying parameters, aroma enhancement conditions, pre-drying treatment, and freeze treatment.

Claims

1. A method for producing olive green tea, characterized in that, Includes the following steps: S1. Preparation of olive powder: Wash fresh olives, slice them and remove the pits. The thickness of the slices should be 2-3 mm. Soak the slices in a color-protecting solution. After soaking, drain them and steam them first, then microwave them to kill the green. After killing the green, immediately blow them to cool them. Vacuum dry the green olive slices until the moisture content is less than 5%. Then crush and sieve them to obtain olive powder. S2. Green tea fresh leaf processing and rolling: Select one bud and one leaf or one bud and two leaves fresh leaves picked in spring. After spreading and rolling, they enter the rolling process. During the rolling process, add the olive powder prepared in S1. The mass ratio of olive powder to fresh leaves is 1:3 to 1:

5. Roll until evenly mixed and the leaves are rolled into strips. S3. Drying: Vacuum dry the kneaded mixture, controlling the temperature at 50-60℃ and the vacuum degree at -0.08 to -0.09 MPa, until the moisture content is below 5%; S4. Fragrance Enhancement: Processed using a segmented fragrance enhancement process; S5. Cooling Packaging: After aroma enhancement, the product is naturally cooled and then packaged with nitrogen.

2. The method for producing olive green tea according to claim 1, characterized in that, The color-protecting solution in S1 is a mixed aqueous solution of 0.2% to 0.5% citric acid and 0.1% to 0.2% ascorbic acid, and the soaking time is 20 to 40 minutes.

3. The method for producing olive green tea according to claim 1, characterized in that, The specific process for de-astringency and blanching in S1 is as follows: steam temperature 80-85℃, processing time 0.5-1.5 min; microwave blanching power 2-4 kW, temperature 70-80℃, processing time 1-2 min.

4. The method for producing olive green tea according to claim 1, characterized in that, The vacuum drying temperature in S1 is 50-60℃, the vacuum degree is -0.08 to -0.09 MPa, and the sieve mesh size for pulverizing and sieving is 80 mesh.

5. The method for producing olive green tea according to claim 1, characterized in that, The temperature of the drum blanching in S2 is 200-240℃, and the spreading time is 3-5 hours.

6. The method for producing olive green tea according to claim 1, characterized in that, The vacuum drying time in S3 is 2 to 3 hours.

7. The method for producing olive green tea according to claim 1, characterized in that, The segmented aroma extraction process in S4 includes: the first stage temperature is 60-70℃ and the time is 15-25 min; the second stage temperature is 75-85℃ and the time is 25-35 min; the third stage temperature is 85-90℃ and the time is 8-12 min; the material is turned over once after each stage.

8. The method for producing olive green tea according to claim 1, characterized in that, The fresh olives mentioned in S1 are 70% to 80% ripe.

9. An olive green tea, characterized in that, The olive green tea is prepared by the method described in any one of claims 1 to 8.

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