Method for preparing milk tea based on dried orange peel white tea

Abstract

The invention discloses a method for preparing milk tea based on pericarpium citri reticulatae white tea, which comprises the following steps: weighing Xinhui shredded pericarpium citri reticulatae and Fuding white tea in proportion, pre-fusing, softening with steam, pressing, drying to obtain pericarpium citri reticulatae white tea, brewing with ionized water to obtain tea soup, adding fresh milk and sugar into the tea soup, and uniformly mixing to obtain the pericarpium citri reticulatae white tea milk tea. By optimizing the process conditions, the obtained milk tea is uniform in color, remarkable in tea fragrance and milk fragrance, harmonious in taste and mellow and fine in taste, and has a good antioxidant effect.

Description

Technical Field

[0001] This invention belongs to the field of tea preparation technology, specifically relating to a method for preparing milk tea based on aged white tea with tangerine peel. Background Technology

[0002] Fuding white tea is an important category of Chinese white tea. Depending on the type of buds and leaves picked, it can be divided into varieties such as Silver Needle, White Peony, and Shoumei. Fuding white tea is rich in amino acids, tea polyphenols, and trace elements such as zinc and selenium. It has effects such as quenching thirst, boosting immunity, and promoting metabolism, making it a safe, green, and nutritious beverage. However, white tea is a light-aroma type of tea with a natural and refreshing flavor. When used to make milk tea, the delicate flavor of white tea itself may be masked by milk and other additives, making it difficult to highlight the unique flavor of white tea. If too much white tea is used, the overall flavor of the milk tea may be too weak, failing to meet consumers' expectations for a rich and flavorful milk tea. Furthermore, if the ratio of white tea to milk, sugar, and other ingredients is not properly adjusted during the preparation of milk tea, an imbalance in taste can easily occur. In addition, components in white tea, such as tea polyphenols and caffeine, may undergo chemical reactions when mixed with milk, affecting the stability of the milk tea and causing problems such as layering and spoilage, affecting the product's shelf life and quality. Therefore, there are currently very few milk tea products on the market made using white tea. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing milk tea based on tangerine peel and white tea. The resulting milk tea has a harmonious flavor, a significant tea and milk aroma, and a mellow and delicate taste, making it a novel milk tea product.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing milk tea based on aged tangerine peel and white tea includes the following steps: 1) Pressing of Chenpi White Tea: Weigh Xinhui tangerine peel strips and Fuding white tea in proportion, pre-blend them, soften them with steam, press them, and dry them to obtain Chenpi White Tea; 2) Brewing the tea: Brew the tangerine peel white tea with ionized water, then filter to obtain the tea infusion; 3) Preparation of Tangerine Peel White Tea Milk Tea: Add fresh milk and sugar to the tea soup and mix well to obtain Tangerine Peel White Tea Milk Tea.

[0005] Furthermore, the Xinhui tangerine peel shreds mentioned in step 1) are obtained by picking Xinhui tea branch tangerines, opening the peel, separating the peel, drying the peel with hot air for 6 hours, freeze-drying for 6 hours, and finally sun-drying for 6 days before shredding.

[0006] Furthermore, the Fuding white tea used in step 1) is either Shoumei or Gongmei.

[0007] Furthermore, in step 1), the mass percentage ratio of Xinhui tangerine peel strips to Fuding white tea is 10~20:80~90, preferably 20:80.

[0008] Furthermore, the pre-fusion described in step 1) involves dividing 5 kg into 3-4 layers, alternating between layers of Xinhui tangerine peel and Fuding white tea, and letting them stand for 24 hours.

[0009] Furthermore, the steam softening time in step 1) is 20 seconds.

[0010] Furthermore, the pressing pressure described in step 1) is 15t, and the time is 20s.

[0011] Furthermore, the drying temperature in step 1) is 60-100℃, and the drying time is 4-12h.

[0012] Furthermore, the ionized water in step 2) contains Mg 2+ 1.8 mg / L, Ca 2+ 1.8 mg / L, Na + 12 mg / L.

[0013] Furthermore, in step 2), the mass ratio of ionized water to tangerine peel white tea is 50:1.

[0014] Furthermore, the brewing temperature in step 2) is 90°C and the brewing time is 10 minutes.

[0015] Furthermore, in step 3), the volume ratio of tea to fresh milk is 1:3.

[0016] Furthermore, in step 3), the amount of sugar used is calculated as 10g per 100mL of tea infusion.

[0017] The significant advantages of this invention are: This invention optimizes the blending ratio of dried tangerine peel and white tea, the pressing process, the brewing water, and the proportions of tea soup with fresh milk and sugar. Without adding any other substances, it simply uses Xinhui dried tangerine peel strips, Fuding white tea, and fresh milk to prepare a dried tangerine peel white tea milk tea with a significant white tea aroma and milk flavor. It has a uniform color, harmonious taste, and mellow and delicate mouthfeel. Moreover, its process is simple, so it has good market prospects. Attached Figure Description

[0018] Figure 1 The effects of different extraction conditions on the biochemical components of tea infusion were investigated, including (A) different tea-to-water ratios; (B) different extraction temperatures; and (C) different extraction times.

[0019] Figure 2 A comparison of the antioxidant components in milk tea prepared with different formulas. Detailed Implementation

[0020] A method for preparing milk tea based on aged tangerine peel and white tea includes the following steps: 1) Pressing of Chenpi White Tea: Weigh Xinhui tangerine peel strips and Fuding white tea in a mass percentage ratio of 10~20:80~90. Divide each 5kg into 3-4 layers. Alternately layer the Xinhui tangerine peel strips and Fuding white tea, let them stand for 24 hours, soften them with steam for 20 seconds, press them with 15t pressure for 20 seconds, and then dry them at 60-100℃ for 4-12 hours to obtain Chenpi White Tea. 2) Brewing the tea: Use 90℃ deionized water to brew the tangerine peel white tea for 10 minutes at a tea-to-water ratio of 1:50, then filter to obtain the tea infusion. 3) Preparation of Tangerine Peel White Tea Milk Tea: Add fresh milk to the obtained tea soup at a volume ratio of 1:3, and add sugar at a ratio of 10g per 100mL of tea soup. Mix well to obtain Tangerine Peel White Tea Milk Tea.

[0021] The Xinhui tangerine peel shreds are made by picking Xinhui tea branch tangerines, opening the peel, separating the peel, drying the peel with hot air for 6 hours, freeze-drying for 6 hours, and finally sun-drying for 6 days before shredding them.

[0022] The varieties of Fuding white tea mentioned are Shoumei or Gongmei.

[0023] The ionized water contains Mg 2+ 1.8 mg / L, Ca 2+ 1.8 mg / L, Na + 12 mg / L.

[0024] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0025] Example 1: The effect of pressing process on the quality of aged white tea with tangerine peel 1. Experimental Methods 1.1 Single-factor experiment Single-factor experiments were conducted to design different processing methods based on four factors: blending ratio, steaming time, pressing time, and drying temperature. The specific procedures are as follows: Blending ratio: Set the amount of dried tangerine peel added to 10%, 12.5%, 15%, 17.5%, and 20%.

[0026] Steam time: Set the steam time to 10 s, 20 s, 30 s, or 40 s.

[0027] Compression time: Set the compression time to 10 s, 20 s, 30 s, 40 s, or 50 s.

[0028] Drying temperature: Set the drying temperature to 60℃, 70℃, 80℃, 90℃, or 100℃.

[0029] 1.2 Orthogonal Experiment Three factors were selected: steaming time, pressing time, and drying temperature. Sensory evaluation was used as the indicator to conduct an orthogonal experimental design for the pressing process. Specific information is shown in Table 1.

[0030] Table 1 Orthogonal experimental design of pressing process

[0031] 1.3 Sensory quality assessment According to the sensory evaluation method of compressed tea in GB / T 23776-2018 "Sensory Evaluation of Tea", the sensory evaluation of Chenpi white tea was carried out from five factors: appearance, liquor color, aroma, taste and infused leaves. The scoring criteria are shown in Table 2.

[0032] Table 2 Sensory Evaluation Criteria

[0033] 1.4 Determination of Physicochemical Components Determination of tea polyphenol content: The determination was carried out in accordance with GB / T 8313-2018 "Determination Method of Tea Polyphenol and Catechin Content in Tea"; Total flavonoid content was determined by the aluminum trichloride colorimetric method. Determination of free amino acid content: The determination was performed according to GB / T 8314-2013 "Determination of Total Free Amino Acid Content in Tea"; Determination of total soluble sugars: determined by the anthrone colorimetric method; Catechin components: HPLC detection method (column: C18, 3 µm, 4.6 × 100 mm; mobile phase: 0.01% acetic acid solution, acetonitrile, gradient elution; detector settings: DAD wavelength scan range 280 nm; other settings: column temperature 30℃, flow rate 0.2 mL / min, injection volume 1.0 μL).

[0034] 1.5 Data Analysis Each sample was tested three times. Statistical analysis of the data was performed using Microsoft Office 2019, and calculations and analysis were performed using IBM SPSS Statistics 26.

[0035] 2. Results and Analysis 2.1 Effects of different blending ratios on aged tangerine peel white tea Table 3. Effects of different blending ratios on the physicochemical components of aged tangerine peel white tea.

[0036] Tea polyphenols, mainly composed of catechins, flavonoids, and flavonols, can regulate the bitterness and astringency of tea infusions, significantly affecting the tea's flavor. Table 3 shows that the tea polyphenol content of white tea with five different amounts of tangerine peel ranged from 16.11±0.38% to 17.20±0.07%. The polyphenol content decreased with increasing tangerine peel content. When the tangerine peel content was 20%, the polyphenol content was significantly lower than the other tea samples, at 16.11±0.38%. This may be related to the formation of complexes between tea polyphenols and other substances in white tea, leading to a decrease in polyphenol content. The reduction in polyphenol content can lower the bitterness and astringency of the tea infusion, making it more mellow and palatable. Flavonoids mainly affect the antioxidant capacity of white tea, significantly influencing the thickness and concentration of the tea infusion, and having some impact on the yellow-green color of the tea. The total flavonoid content ranged from 7.70±0.09% to 10.11±0.40%. When the amount of dried tangerine peel added was 12.5%, the total flavonoid content was significantly higher than other tea samples. Free amino acids are the main flavor compounds affecting the freshness of the tea infusion and have a significant effect on its taste. With increasing dried tangerine peel addition, the free amino acid content showed a trend of first decreasing and then increasing. When the amount of dried tangerine peel added was 20%, the amino acid content was relatively high, at 4.53±0.11%. Soluble total sugars are the main flavor compounds affecting the sweetness of the tea infusion and have a significant effect on its taste. With increasing dried tangerine peel addition, the soluble sugar content showed a gradual increasing trend. When the amount of dried tangerine peel added was 20%, the soluble sugar content was significantly higher than other tea samples. The phenol-to-amino acid ratio, which is the ratio of tea polyphenols to free amino acids, is related to the concentration and freshness of the tea infusion. The phenol-to-amino acid ratio showed a trend of first increasing and then decreasing with the increase of tangerine peel addition. When the tangerine peel addition was 12.5%, the phenol-to-amino acid ratio was significantly higher than that of other tea samples, while when the tangerine peel addition was 20%, the phenol-to-amino acid ratio was lower.

[0037] Catechins are the main polyphenolic compounds in tea, possessing a bitter and astringent taste. They are divided into ester-type and non-ester-type catechins, with ester-type catechin EGCG having the highest content. EGCG's bitterness intensity is higher than its astringency intensity. Table 3 shows the catechin content in white tea with different amounts of tangerine peel. Non-ester-type catechins showed a trend of first decreasing and then increasing, while ester-type catechins exhibited fluctuating changes. The total catechin content of white tea with 12.5% ​​tangerine peel was significantly higher than other tea samples. The contents of non-ester-type catechins C and GC decreased with increasing tangerine peel content. The catechin C content of white tea with 20% tangerine peel was significantly lower than other tea samples, while the GC content of white tea with 15%, 17.5%, and 20% tangerine peel was significantly lower than other tea samples. In summary, white tea with 20% tangerine peel has the best quality.

[0038] 2.2 Effects of different steaming times on aged tangerine peel white tea Table 4. Effects of different steam treatments on the biochemical components of aged tangerine peel white tea.

[0039] Biochemical components such as tea polyphenols, total flavonoids, and free amino acids can affect the taste of tea infusion. The physicochemical components of aged tangerine peel white tea after different steaming times are shown in Table 4. The contents of tea polyphenols and total flavonoids increased with increasing steaming time. When the steaming time was 40 seconds, the contents of tea polyphenols and total flavonoids were relatively high, at 18.33±0.85% and 8.89±0.04%, respectively. The contents of free amino acids showed a trend of first increasing and then decreasing with increasing steaming time, reaching the highest level when the steaming time was 20 seconds. The soluble sugar content of aged tangerine peel white tea after different steaming treatments ranged from 2.40±0.39% to 3.66±0.11%. The soluble sugar content of aged tangerine peel white tea after steaming for 10 seconds and 20 seconds was significantly higher, at 3.48±0.31% and 3.66±0.11%, respectively. The phenol-to-amino acid ratio increased with increasing steam treatment time, with significantly lower ratios observed after 10 and 20 seconds of steam treatment in the aged tangerine peel white tea. Shorter steam treatment resulted in lower levels of tea polyphenols and total flavonoids, but higher levels of free amino acids and soluble total sugars, producing a more mellow and refreshing tea liquor. The total catechin content in the aged tangerine peel white tea after different steam treatments showed a trend of first increasing and then decreasing, with non-ester catechins showing an increasing trend. With increasing steaming time, ester catechins EGCG and GCG showed a trend of first increasing and then decreasing, with significantly higher EGCG content in aged tangerine peel white tea after 20 and 30 seconds of steam treatment compared to other tea samples. The GC and EGC content in aged tangerine peel white tea after 40 seconds of steam treatment were significantly higher than other tea samples. Ester catechins in aged tangerine peel white tea showed a trend of first increasing and then decreasing with increasing steaming time, resulting in a corresponding increase and decrease in bitterness and freshness in the tea liquor. Overall, aged tangerine peel white tea with a 20-second steam treatment yielded the best quality.

[0040] 2.3 Effects of different pressing times on aged tangerine peel white tea Table 5. Effects of different pressing treatments on the biochemical components of aged tangerine peel white tea.

[0041] Table 5 shows the biochemical composition of aged tangerine peel white tea after different pressing times. The content of tea polyphenols increased with increasing pressing time, with significantly higher polyphenol contents observed after pressing for 30, 40, and 50 seconds. The total flavonoid content was higher after pressing for 50 seconds. The free amino acid content ranged from 2.91±0.18% to 3.44±0.08% after different pressing times, with significantly higher contents (3.44±0.08%) at pressing times of 20 and 50 seconds. The soluble sugar content ranged from 3.11±0.24% to 3.56±0.50%, with little difference among the different pressing treatments. The phenol-to-amino acid ratio was significantly lower after pressing for 20 seconds. The total catechin content of aged tangerine peel white tea after different pressing treatments showed a trend of first decreasing and then increasing. With increasing pressing time, the non-ester catechins in aged tangerine peel white tea exhibited fluctuating changes, while ester catechins showed a trend of first decreasing and then increasing. The bitterness and freshness of the tea soup may have decreased and then increased accordingly. With increasing pressing time, the EGCG content showed a trend of first decreasing and then increasing. Aged tangerine peel white tea pressed for 10 s, 20 s, and 50 s had significantly higher EGCG content than other tea samples. Aged tangerine peel white tea pressed for 50 s had significantly higher EGC content than other tea samples. Overall, aged tangerine peel white tea processed with 20 s pressing yielded better quality.

[0042] 2.4 Effects of different drying temperatures on aged white tea with tangerine peel Table 6. Effects of different drying treatments on the biochemical components of aged tangerine peel white tea.

[0043] Table 6 shows the biochemical composition of Chenpi white tea after different drying temperatures. The polyphenol content of Chenpi white tea after different drying treatments ranged from 11.99±0.25 to 16.42±0.77%, with the polyphenol content of the tea sample dried at 100℃ being significantly higher than other tea samples. The flavonoid content ranged from 6.06±0.46 to 7.70±0.29%. The free amino acid content of Chenpi white tea dried at 90℃ was significantly higher than other tea samples, while the phenol-to-amino acid ratio was significantly lower. The soluble sugar content did not change significantly. With increasing drying temperature, the non-ester catechins in Chenpi white tea showed an increasing trend, while the ester catechins and total catechin content fluctuated. The EGC content increased with increasing drying temperature, with the EGC content of Chenpi white tea dried at 60℃ being significantly lower than other tea samples. The EGCG content of Chenpi white tea dried at 70℃ was significantly higher than other samples. In summary, a drying temperature of 90℃ resulted in better quality Chenpi white tea.

[0044] 2.5 Results of Orthogonal Experiments Table 7. Orthogonal experimental design and sensory scores and physicochemical composition results

[0045] An orthogonal experiment with three factors and three levels was conducted, using steam treatment, pressing, and drying as factors. Sensory evaluation was the primary method, with physicochemical components as a reference, to determine the optimal pressing process for aged white tea with tangerine peel. As shown in Table 7, the highest overall sensory evaluation score in the orthogonal experiment for aged white tea with tangerine peel was achieved with A2B2C3, characterized by a steaming time of 20 s, a pressing time of 20 s, and a drying temperature of 90℃. At this temperature, the tea liquor was bright golden yellow, with a sweet and lingering aftertaste, a rich flavor, and a rich, fruity aroma that was long-lasting.

[0046] Table 8 Range Analysis of Orthogonal Experiments

[0047] Based on the ranges in Table 8, the order of influence of steaming time, pressing time, and drying temperature on the sensory quality of Chenpi White Tea is A>B>C, meaning that steaming time has the greatest impact on the sensory quality of Chenpi White Tea, while drying temperature has a smaller impact. Similarly, the order of influence of factors affecting polyphenol content is B>C>A, meaning that pressing time has the greatest impact on the polyphenol content of Chenpi White Tea, while steaming time has a smaller impact. The order of influence of factors affecting free amino acids is A>B>C, meaning that steaming time has the greatest impact on the free amino acid content of Chenpi White Tea, while drying temperature has a smaller impact. The order of influence of factors affecting flavonoid and soluble sugar content is A>C>B, meaning that steaming time has the greatest impact on the flavonoid and soluble sugar content of Chenpi White Tea, while pressing time has a smaller impact. Based on the k-value, the optimal pressing process combination for Chenpi White Tea is determined to be A2B2C2, which is a steaming time of 20s, a pressing time of 20s, and a drying temperature of 80℃.

[0048] Table 9. Analysis of Variance of Orthogonal Experiments

[0049] The analysis of variance in Table 9 showed that the order of influence of factors affecting sensory scores and free amino acid content was A>B>C; the order of influence of factors affecting polyphenol content was B>C>A; and the order of influence of factors affecting flavonoid and soluble sugar content was A>C>B, consistent with the results of the range analysis. Specifically, steaming time had a highly significant impact on the sensory scores, flavonoid content, and soluble sugar content of aged tangerine peel white tea; steaming time had a significant impact on free amino acid content; and pressing time and drying temperature had significant impacts on sensory scores, flavonoid content, and soluble sugar content.

[0050] Example 2: Effects of different water qualities on the flavor of aged tangerine peel white tea infusion 1. Experimental Methods 1.1 Experimental Materials Tea sample: Xinhui tangerine peel strips and Fuding white tea were mixed in a 1:4 ratio and processed into tangerine peel white tea through steaming-pressing-drying process according to the optimal process obtained in Example 1.

[0051] Water sample: Select Mg dissolved in pure water 2+ Ca 2+ Na + The content was determined by three factors, with the content of physicochemical components as the indicator, and an orthogonal experimental design was carried out. Specific information is shown in Table 10.

[0052] Table 10 Orthogonal Experimental Design

[0053] 1.2 Water Sample Treatment Different water samples were used to brew tangerine peel white tea according to the sensory evaluation method for compressed tea in GB / T 23776-2018 "Sensory Evaluation Method for Tea".

[0054] 1.3 Determination of Physicochemical Components of Tea Infusion Determination of tea polyphenol content: The determination was carried out in accordance with GB / T 8313-2018 "Determination Method of Tea Polyphenol and Catechin Content in Tea"; Total flavonoid content was determined by the aluminum trichloride colorimetric method. Determination of free amino acid content: The determination was performed according to GB / T 8314-2013 "Determination of Total Free Amino Acid Content in Tea"; Soluble sugar determination: The anthrone colorimetric method was used.

[0055] 2. Results and Analysis Table 11 Orthogonal Experiment Table

[0056] As shown in Table 11, A1B1C1 has the highest amino acid content and the lowest phenol-amino acid ratio. Considering all factors, Mg is the best choice. 2+ The content is 1.8 mg / L, Ca 2+ The content is 1.8 mg / L, Na + The concentration is 12 mg / L.

[0057] Example 3: Milk Tea Formula Research An orthogonal optimization experiment was conducted on milk tea based on aged tangerine peel and white tea, using three key factors: tea addition, milk addition, and sugar addition. Based on sensory evaluation and physicochemical analysis of the results, the impact of each factor on the quality of the milk tea was comprehensively analyzed. The extraction conditions of the aged tangerine peel and white tea infusion and the milk tea formula were determined, providing a scientific basis for the production of aged tangerine peel and white tea milk tea.

[0058] 1. Experimental Methods 1.1 Tea Infusion Extraction Experiment Single-factor experiments were conducted with tea-to-water ratios of 1:20, 1:30, 1:40, 1:50, and 1:60, an extraction temperature of 100℃, and an extraction time of 10 min.

[0059] Single-factor experiments were conducted with extraction times of 5 min, 10 min, 15 min, 20 min, and 25 min, a tea-to-water ratio of 1:50, and an extraction temperature of 100℃.

[0060] A single-factor experiment was conducted with extraction temperatures of 60℃, 70℃, 80℃, 90℃, and 100℃, a tea-to-water ratio of 1:50, and an extraction time of 100℃.

[0061] 1.2 Orthogonal Experimental Design An orthogonal experimental design was conducted with three factors as independent variables: tea volume (ml), milk volume (ml), and sugar added volume (ml), and sensory evaluation as the test standard, as shown in Table 12.

[0062] Table 12 Orthogonal Experimental Design

[0063] 1.3 Sensory Quality Evaluation of Milk Tea Ten trained students formed an evaluation team to conduct sensory evaluations. Referring to the sensory requirements in "T / CTSS 75-2023 Basic Requirements for Terminology Classification of Freshly Made Tea Beverages," sensory evaluation standards were developed, as shown in Table 13. Milk tea made with aged white tea as a base was scored in four aspects: color, aroma, taste, and mouthfeel.

[0064] Table 13 Sensory Evaluation Table for Milk Tea

[0065] 1.4 Determination of physicochemical properties Stability determination of milk tea: expressed as centrifugal sedimentation rate. Accurately pipette 20 ml of milk tea into a 50 ml centrifuge tube, centrifuge at 5000 r / min for 20 min, remove the supernatant, and weigh the sediment.

[0066] Centrifugal sedimentation rate (%) , In the formula, m1 is the weight of the centrifuge tube (g); m2 is the weight of the centrifuge tube after centrifugation and draining (g); and m0 is the weight of the sample (g).

[0067] Determination of antioxidant properties of milk tea: The determination of ABTS free radical scavenging rate, iron ion reducing power, and DPPH free radical scavenging rate shall be performed according to the method on the kit. Determination of tea polyphenol content: The determination was carried out in accordance with GB / T 8313-2018 "Determination Method of Tea Polyphenol and Catechin Content in Tea"; Total flavonoid content was determined by the aluminum trichloride colorimetric method. Determination of free amino acid content: The determination was performed according to GB / T 8314-2013 "Determination of Total Free Amino Acid Content in Tea"; Soluble sugar determination: The anthrone colorimetric method was used.

[0068] 1.5 Data Analysis Each sample was tested three times. Statistical analysis of the data was performed using Microsoft Office 2019, and calculations and analysis were performed using IBM SPSS Statistics 26.

[0069] 2. Results and Analysis 2.1 Determination of the extraction conditions for aged tangerine peel white tea infusion Table 14 Sensory Scores of Tangerine Peel White Tea with Different Tea-to-Water Ratios, Extraction Temperatures, and Extraction Times

[0070] Depend on Figure 1 As shown in Figure (A), the contents of tea polyphenols, total flavonoids, free amino acids, and soluble sugars in the Chenpi white tea infusion all decreased with decreasing tea-to-water ratio. A higher tea-to-water ratio resulted in higher tea infusion concentration and greater leaching of internal substances. At a tea-to-water ratio of 1:20, the contents of tea polyphenols (2.64±0.11 mg / ml), total flavonoids (0.67±0.03 mg / ml), soluble sugars (0.59±0.01 mg / ml), and free amino acids (0.66±0.01 mg / ml) were significantly higher. Table 14 shows that the tea-to-water ratio significantly affected the sensory quality of the tea infusion; as the tea-to-water ratio decreased, the sensory score first increased and then decreased. At a tea-to-water ratio of 1:50, the sensory score of the tea infusion was significantly higher, with a bright red color, lasting aroma, and sweet taste. At a tea-to-water ratio of 1:20, the proportion of tea leaves was highest, resulting in a dark red color, bitterness, and poor flavor. Taking into account both cost and sensory factors, the tea-to-water ratio was determined to be 1:50.

[0071] Depend on Figure 1 As shown in (B), the contents of tea polyphenols, total flavonoids, free amino acids, and soluble total sugars increase with increasing extraction temperature. High temperature accelerates molecular motion and promotes the dissolution of internal substances. At an extraction temperature of 100℃, the contents of tea polyphenols (1.98±0.05 mg / ml) and free amino acids (0.42±0.01 mg / ml) in the tea soup are significantly higher. At extraction temperatures of 90℃ and 100℃, the contents of flavonoids and soluble sugars in the aged tangerine peel white tea are significantly higher. As shown in Table 14, the sensory scores of aged tangerine peel white tea first increase and then decrease with increasing extraction temperature. When the extraction temperature is 90℃, the tea soup is bright orange-red, smooth in taste, and has a lasting aroma. At 60℃, the tea soup is lighter in color, but the aroma is still relatively lasting. Based on the combined sensory and biochemical components, an extraction temperature of 90℃ was determined.

[0072] Depend on Figure 1 As shown in Figure (C), the contents of tea polyphenols, total flavonoids, free amino acids, and soluble sugars increased with increasing extraction time. At an extraction time of 25 min, the contents of tea polyphenols (2.08±0.09 mg / ml), total flavonoids (0.54±0.02 mg / ml), free amino acids (0.64±0.02 mg / ml), and soluble sugars (0.50±0.01 mg / ml) were significantly higher. Table 14 shows that the effect of extraction time on the sensory score of aged tangerine peel white tea followed the same trend as extraction temperature, first increasing and then decreasing. At an extraction time of 10 min, the tea soup had the highest sensory score, a bright color, normal taste, and lasting aroma; at an extraction time of 25 min, the tea soup was dark red and had a bitter taste. Considering cost, sensory characteristics, and biochemical components, an extraction time of 10 min was determined.

[0073] 2.2 Effects of different formulations on tangerine peel white tea milk tea Table 15. Effects of orthogonal experiments on the physicochemical properties of tangerine peel white tea milk tea.

[0074] Table 15 shows that the physicochemical components of tangerine peel white tea milk tea differed significantly depending on the formula used. The formula A2B2C3 (200 ml tea, 200 ml milk, 15 g sugar) had the highest sensory score; this formula produced milk tea with a uniform, milky-brown color, a harmonious tea and milk aroma, and a delicate taste. The pH range of the tangerine peel white tea milk teas from different formulas was 6.85±0.01 to 6.88±0.01, indicating a slightly acidic pH. The stability of the milk tea could be represented by the centrifugal sedimentation rate. The stability was related to the particle settling velocity, which was positively correlated with particle diameter and negatively correlated with system viscosity. The combination with the highest centrifugal sedimentation rate was A3B3C2 (300 ml tea, 300 ml milk, 10 g sugar). The precipitate formed in the milk tea was related to the complex formed by the interaction of tea polyphenols and proteins. The polyphenol content of tangerine peel white tea milk tea prepared with different formulas varied significantly, ranging from 881.22±11.24 to 1056.11±3.47 mg / L, which meets the minimum requirement for polyphenol content in tea beverages (≥200 mg / L). The total flavonoid content of the tangerine peel white tea milk tea prepared with different formulas ranged from 43.06±1.13 to 89.20±3.81 mg / L. The combination A3B1C3 (300 ml tea, 100 ml milk, 15 g sugar) showed significantly higher polyphenol and flavonoid content, at 1056.11±3.47 mg / L and 89.20±3.81 mg / L, respectively. The soluble protein content of the tangerine peel white tea milk tea prepared with different formulas also varied significantly, ranging from 3.84±0.28 to 13.82±0.16 mg / ml. The A1B3C3 combination (100 ml tea, 300 ml milk, 15 g sugar) has a significantly higher soluble protein content, at 13.82 ± 0.16 mg / ml, and this combination has a relatively high proportion of milk.

[0075] Tangerine peel white tea milk tea contains tea polyphenols, among which the catechin EGCG has relatively strong antioxidant properties. The antioxidant properties of tangerine peel white tea milk tea made with different formulas are as follows: Figure 2 As shown. The stronger the DPPH free radical scavenging ability, the stronger the antioxidant capacity. The DPPH free radical scavenging rate of the tangerine peel white tea milk tea prepared with different formulas ranged from 55.09±0.25 to 74.91±0.66%. ABTS reacts with potassium persulfate, turning the solution green. Catechins in the tea soup have multiple ortho- and posterior phenolic carboxyl groups, which are easily oxidized to quinones and provide H+. + This scavenges ABTS free radicals. The ABTS scavenging rate of different formula milk teas, measured using the ABTS method, ranged from 19.49±0.25% to 60.89±0.75%. Antioxidants inhibited endogenous interference under acidic conditions in acetate buffer, reducing Fe... 3+ -TPTZ is reduced to Fe. 2+This causes the solution to turn blue. The FRAP method showed significant differences in the antioxidant capacity measured for different formula milk teas, with the measured Fe... 2+ The equivalent range is 0.18±0.02~0.69±0.12 mmol Fe 2+ The combination A3B1C3 (300 ml tea, 100 ml milk, 15g sugar) exhibits significantly stronger DPPH and ABTS free radical scavenging abilities and iron ion reducing abilities, and this combination contains a higher proportion of tea infusion.

[0076] 2.3 Optimization of the Tangerine Peel White Tea Milk Tea Recipe Table 16. Range Analysis of Orthogonal Experiment for Tangerine Peel White Tea Milk Tea Formula

[0077] As shown in Table 16, the order of influence of tea addition, milk addition, and sugar addition on the sensory score, pH value, antioxidant activity (FRAP, DPPH, ABTS), tea polyphenols, and total flavonoid content of Chenpi White Tea Milk Tea is: A>B>C. That is, tea addition has the greatest impact on sensory score, pH value, antioxidant activity (FRAP, DPPH, ABTS), tea polyphenols, and total flavonoid content. The factors affecting the centrifugal sedimentation rate and soluble protein content of Chenpi White Tea Milk Tea, from highest to lowest, are: B>A>C. That is, milk addition has the greatest impact on centrifugal sedimentation rate and soluble protein content. Using sensory score as an indicator, the optimal combination is clearly: A2B2C2, i.e., 200 ml of tea, 200 ml of milk, and 10 g of sugar.

[0078] Table 17. Orthogonal Experimental Analysis of Tangerine Peel White Tea Milk Tea Recipe

[0079] To further verify this, an analysis of variance was conducted. Table 17 shows that the order of influence of sensory score, pH value, antioxidant activity (FRAP, DPPH, ABTS), tea polyphenols, and total flavonoid content was A>B>C. The order of influence of centrifugal sedimentation rate and soluble protein content was B>A>C, consistent with the results of the range analysis. The amount of tea added was significantly related to the DPPH free radical scavenging rate and tea polyphenol content, and the amount of milk added was significantly related to the DPPH free radical scavenging rate. A confirmatory experiment was conducted between the optimized formula and the formula with the highest orthogonal experimental score. The results showed that the tangerine peel white tea milk tea made with the optimized formula had a uniform texture, moderate sweetness, delicate taste, and harmonious flavor, with a sensory score of 34.11±0.58, significantly higher than other combinations.

[0080] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A method for preparing milk tea based on aged tangerine peel and white tea, characterized in that, Includes the following steps: 1) Pressing of Chenpi White Tea: Weigh Xinhui tangerine peel strips and Fuding white tea in proportion, pre-blend them, soften them with steam, press them, and dry them to obtain Chenpi White Tea; 2) Brewing the tea: Brew the tangerine peel white tea with ionized water, then filter to obtain the tea infusion; 3) Preparation of Tangerine Peel White Tea Milk Tea: Add fresh milk and sugar to the tea soup and mix well to obtain Tangerine Peel White Tea Milk Tea.

2. The method for preparing milk tea based on tangerine peel and white tea according to claim 1, characterized in that, The mass percentage ratio of Xinhui tangerine peel strips to Fuding white tea used in step 1) is 10~20:80~90.

3. The method for preparing milk tea based on tangerine peel and white tea according to claim 1 or 2, characterized in that, The Xinhui tangerine peel shreds are made by picking Xinhui tea branch tangerines, opening the peel, separating the peel, drying the peel with hot air for 6 hours, freeze-drying for 6 hours, and finally sun-drying for 6 days before shredding them.

4. The method for preparing milk tea based on tangerine peel and white tea according to claim 1 or 2, characterized in that, The Fuding white tea used is either Shoumei or Gongmei.

5. The method for preparing milk tea based on tangerine peel and white tea according to claim 1, characterized in that, The pre-fusion process described in step 1) involves layering Xinhui tangerine peel and Fuding white tea alternately in 3-4 layers per 5kg batch and letting them stand for 24 hours.

6. The method for preparing milk tea based on tangerine peel and white tea according to claim 1, characterized in that, The steam softening time in step 1) is 20s; the pressing pressure is 15t and the time is 20s; the drying temperature is 60-100℃ and the time is 4-12h.

7. The method for preparing milk tea based on tangerine peel and white tea according to claim 1, characterized in that, The mass ratio of ionized water to aged tangerine peel and white tea used in step 2) is 50:

1.

8. The method for preparing milk tea based on tangerine peel and white tea according to claim 1 or 7, characterized in that, The ionized water contains Mg 2+ 1.8 mg / L, Ca 2+ 1.8 mg / L, Na + 12 mg / L.

9. The method for preparing milk tea based on tangerine peel and white tea according to claim 1, characterized in that, The brewing temperature in step 2) is 90℃ and the brewing time is 10 minutes.

10. The method for preparing milk tea based on tangerine peel and white tea according to claim 1, characterized in that, In step 3), the volume ratio of tea to fresh milk is 1:3, and the amount of sugar is calculated as 10g per 100mL of tea.

Images