Preparation formula of freeze-dried flash-extracted white tea coffee

Abstract

The invention discloses a freeze-dried white tea coffee composition and a preparation method thereof, and belongs to the technical field of food processing. The method comprises the following steps: carrying out targeted enzymolysis treatment on a white tea raw material to gain the characteristic flower and fruit fragrance; then extracting the white tea subjected to enzymolysis, and carrying out coupling co-extraction on coffee powder by innovatively using the obtained high-aroma white tea extract as a solvent, so as to realize source fusion of tea and coffee flavors; performing ultrahigh-pressure perturbation treatment on the obtained tea and caffeine co-extraction liquid so as to stabilize and lock the fused fragrance; finally, a functional carrier is added, freeze drying is conducted, and the final composition is obtained. According to the method, the problems of tea and caffeine flavor separation and serious fragrance loss caused by traditional physical mixing are fundamentally solved. The obtained composition has the beneficial effects of integrated flavor, rich white tea characteristic flower and fruit fragrance, high fragrance stability, good instant solubility, mellow taste and the like.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a freeze-dried flash-extracted white tea coffee preparation formula. Background Technology

[0002] In recent years, with the increasing demand from consumers for diversified and personalized beverages, cross-border fusion products of tea and coffee, namely "tea-coffee," have become a highly anticipated emerging category in the beverage market. To meet the needs of modern fast-paced lifestyles, producing tea-coffee products in an instant form that is easy to store and brew, especially freeze-dried powder that can retain the original flavor substances to the greatest extent, has become an important direction for industry research and development.

[0003] Currently, the preparation method for freeze-dried tea and coffee products on the market typically involves a simple physical mixing of separately prepared tea and coffee concentrates, followed by freeze-drying of the mixture. However, this traditional method has insurmountable technical drawbacks. Because tea and coffee each possess complex and unique flavor systems, simple physical mixing often fails to achieve an organic fusion of their flavors. This results in a final product with a often abrupt flavor contrast, or even flavor stratification, where the tea and coffee flavors are separated and uncoordinated. Sometimes, the simple superposition of polyphenols can also produce an unpleasant astringency, negatively impacting the overall drinking experience.

[0004] Furthermore, for some tea raw materials with delicate flavors and elegant aromas, such as white tea, the subject of this invention, their core value lies in their unique aroma of downy hairs, flowers, and fruits. During conventional hot water extraction and subsequent processing, these heat-sensitive and precious top aroma compounds are easily volatilized and lost or destroyed. Existing preparation processes focus more on extraction efficiency but neglect the protection and presentation of these delicate flavor compounds, resulting in the final product failing to reflect the flavor characteristics that high-quality raw materials should possess. Simultaneously, during freeze-drying, despite the mild conditions, a large amount of volatile aroma components are still lost with the sublimation of moisture, further weakening the aroma fullness and persistence of the final product, making it difficult for the product to meet the demands of discerning consumers for a high-quality flavor experience. Summary of the Invention

[0005] The technical problem this invention aims to solve is that existing tea-coffee products prepared through simple physical mixing suffer from flavor stratification, loss of the delicate aroma of white tea and other tea leaves, and potential unpleasant astringency. To achieve a deep and organic fusion of tea and coffee flavors while preserving their key flavor compounds to the greatest extent possible, this invention provides a novel freeze-dried white tea-coffee composition and its preparation method.

[0006] In a first aspect, the present invention provides a method for preparing freeze-dried white tea coffee, which systematically solves the above-mentioned technical problems through a unique sequence of process steps, from raw material processing to flavor fusion, flavor locking and final shaping.

[0007] Specifically, the preparation method includes the following steps:

[0008] Step 1 involves enzymatic pretreatment of white tea raw materials to obtain enzymatically hydrolyzed white tea.

[0009] This step is fundamental to building the product's unique flavor. In some preferred embodiments, the enzymatic pretreatment involves using a solution containing β-

[0010] A complex enzyme preparation of glucosidase and pectinase is used to process white tea raw materials. Its technical mechanism lies in: β-

[0011] Glucosidase can specifically hydrolyze naturally occurring aroma precursors (such as glycosides) in white tea that do not inherently possess aroma, thereby releasing active small molecule compounds with pleasant floral and fruity aromas. Simultaneously, pectinase can gently act on the cell wall structure of tea leaves, increasing their permeability. This step is not intended to increase the extraction rate, but rather to proactively and directionally increase the concentration and variety of usable characteristic flavor compounds in the system before extraction, providing a richer material basis for flavor fusion in subsequent steps.

[0012] Step 2 involves extracting the enzymatically hydrolyzed white tea to obtain a white tea extract, and then using the white tea extract as a solvent to extract coffee raw materials to obtain a tea-coffee co-extract.

[0013] This step is central to achieving a deep flavor fusion. It abandons the simple mixing of two extracts, instead creatively using the product of one extraction process as the reaction medium for the next. In some preferred embodiments, this step specifically includes: first, extracting enzymatically hydrolyzed white tea at a low temperature of 75-85°C to obtain a white tea extract. This low temperature is designed to precisely extract the freshness of theanine and the heat-labile top aroma molecules released in step one. Subsequently, this white tea extract is heated to 90-94°C and immediately used as an extraction solvent for high-temperature extraction of coffee raw materials. The technical mechanism lies in the fact that the white tea extract, rich in active ingredients such as tea polyphenols and theanine, can immediately interact at the molecular level with substances such as chlorogenic acid and alkaloids dissolved in the coffee during the high-temperature extraction process. The umami flavor of theanine can effectively balance the bitterness of coffee, while the interaction between tea polyphenols and coffee polyphenols may form new and more complex flavor compounds. Thus, the organic fusion of flavors and the balance of taste are achieved at the source of extraction, and the resulting tea-coffee co-extract has a unified and harmonious flavor profile.

[0014] Step 3 involves subjecting the tea-coffee co-extract to ultra-high pressure treatment;

[0015] This step is crucial for locking in and stabilizing the integrated flavor. The technical mechanism does not utilize the conventional sterilization function of ultra-high pressure technology, but rather its physical perturbation effect. In some preferred embodiments, the applied pressure is 200-450 MPa, and the holding time is 1-5 minutes. Under these conditions, the strong hydrostatic pressure promotes the formation of non-covalent complexes between small-molecule aroma substances in the solution system and macromolecules such as tea polyphenols and polysaccharides. This interaction is equivalent to constructing a physical "protective shell" for volatile aroma molecules, stably embedding them within the macromolecular network, greatly reducing their escape and loss during subsequent vacuum freeze-drying.

[0016] Step four involves vacuum freeze-drying the tea-coffee co-extract that has undergone ultra-high pressure treatment to obtain the freeze-dried white tea coffee.

[0017] This step is the final stage in solidifying the liquid-based blended flavors into a stable product. In some preferred embodiments, a functional carrier is added to the tea-coffee co-extract processed under ultra-high pressure before this step. The functional carrier is preferably inulin and / or gum arabic. This carrier serves multiple purposes: as a cryoprotectant, it protects the structural integrity of the flavor complex during freezing; as a structural framework, it forms a highly porous microstructure after freeze-drying, ensuring excellent solubility; and as a mouthfeel improver, it increases the body and smoothness of the final beverage. The vacuum freeze-drying process includes pre-freezing, primary drying, and secondary drying steps. By directly sublimating water under low temperature and high vacuum, moisture is removed in the gentlest way, thereby maximizing the retention of flavor substances formed and locked in the previous steps.

[0018] In some preferred embodiments, the white tea raw material is White Peony tea and / or Moonlight White tea; the coffee raw material is Arabica coffee beans.

[0019] In a second aspect, the present invention provides a freeze-dried white tea-coffee composition prepared by the above method.

[0020] This composition is a direct product of the aforementioned unique preparation method, and its flavor compounds exist in a deeply integrated form, unlike compositions obtained through simple physical mixing. On a dry basis by weight percentage, this freeze-dried white tea coffee composition comprises the following components:

[0021] Coffee-derived solids: 60.0%-85.0%;

[0022] Solids content from white tea: 14.0%-39.0%;

[0023] Functional carrier: 1.0%-5.0%.

[0024] In summary, the present invention has at least one of the following beneficial technical effects:

[0025] 1. This invention employs an innovative tea-coffee co-extraction method, using white tea extract as a solvent to extract coffee. This achieves molecular-level interaction and fusion at the source of flavor substance generation, resulting in a tea-coffee composition with integrated flavors. This deep fusion fundamentally solves the problems of flavor stratification and taste conflict between tea and coffee caused by traditional physical mixing, resulting in a final product with a harmonious, balanced taste and unique overall flavor characteristics.

[0026] 2. This invention utilizes targeted enzymatic pretreatment of white tea raw materials before extraction to actively transform substances existing in the form of non-volatile precursors in the tea leaves into free-state characteristic aroma molecules with pleasant floral and fruity aromas. This step greatly enriches the aroma material base available for extraction, enabling the final freeze-dried white tea coffee product to exhibit a white tea characteristic aroma that is far richer, clearer, and more layered than that produced using traditional methods.

[0027] 3. This invention introduces an ultra-high pressure processing step, utilizing physical perturbation to induce volatile aroma molecules to form stable complexes with macromolecules such as tea polyphenols and polysaccharides, thus achieving effective physical aroma locking. This significantly improves the stability and persistence of the product's aroma, effectively solving the technical problem of aroma loss during the drying and long-term storage of freeze-dried products, ensuring the uniformity and durability of product quality.

[0028] 4. The freeze-dried composition obtained by this invention has excellent instant solubility and a rich, smooth taste. This is attributed to the addition of a functional carrier before freeze-drying, which forms a highly porous microstructure framework after freeze-drying, greatly facilitating rapid water penetration, achieving rapid disintegration and dissolution of the product, while increasing the richness of the brewed beverage, thus optimizing the consumer's user experience and taste.

[0029] 5. This invention provides a systematic solution that organically combines innovative steps such as enzymatic hydrolysis for aroma enhancement, coupled co-extraction, and ultra-high pressure aroma locking. Each technical feature is interconnected and mutually reinforcing. From the active construction and deep fusion of flavor to the subsequent effective locking and final perfect presentation, a complete technical closed loop is formed, thereby comprehensively improving the overall quality of tea-coffee blended products and ultimately obtaining freeze-dried white tea and coffee products that far surpass the level of existing technologies. Detailed Implementation

[0030] Example 1

[0031] This embodiment provides a method for preparing a freeze-dried white tea and coffee composition, wherein the components and parameters are selected as intermediate values ​​within the range defined in the claims.

[0032] 1. Targeted enzymatic hydrolysis of white tea raw materials

[0033] Weigh out 100g of Fujian White Peony Tea and set aside.

[0034] β-

[0035] Glucosidase and pectinase were dissolved in deionized water at a mass ratio of 3:1 to prepare a compound enzyme solution.

[0036] Add white peony tea to 1000mL (material-to-liquid ratio 1:10).

[0037] In the above compound enzyme solution (g / mL), adjust the pH to 5.0 and carry out the enzymatic hydrolysis reaction in a constant temperature water bath at 48℃ for 50 minutes.

[0038] After the reaction was completed, the system was rapidly heated to 90°C and maintained for 3 minutes to terminate enzyme activity. Then, it was dried with hot air at 55°C to obtain the enzymatically hydrolyzed aroma-enhanced white tea raw material.

[0039] 2. Segmented temperature-coupled extraction

[0040] Add the above enzymatically hydrolyzed white tea raw materials to 2000 mL (material-to-liquid ratio 1:20).

[0041] Extract the tea in deionized water (g / mL) at 80℃ for 90 seconds, then immediately filter to obtain a highly aromatic white tea extract.

[0042] Weigh out 300g of lightly roasted Yunnan Arabica coffee beans and grind them to 50 mesh.

[0043] The above-mentioned highly aromatic white tea extract was rapidly heated to 92°C and then used as a solvent to be added to the coffee powder (the ratio of extract to liquid was approximately 1:10).

[0044] The extract was prepared by flash extraction (g / mL) for 65 seconds, followed by filtration to obtain a tea-coffee co-extract.

[0045] 3. Ultra-high voltage perturbation processing

[0046] The obtained tea-coffee co-extract was rapidly cooled to 20°C.

[0047] The cooled liquid was placed in an ultra-high pressure device and subjected to a pressure of 325 MPa for 3 minutes.

[0048] 4. Carrier addition and freeze-drying

[0049] Inulin, accounting for 3.0% of the total liquid mass, was added to the tea-coffee co-extract that had undergone ultra-high pressure treatment as a functional carrier, and homogenized at 6000 rpm for 8 minutes using a high-shear homogenizer.

[0050] The homogenized liquid was pre-frozen at -45°C for 3 hours, followed by vacuum freeze-drying. The first drying was carried out for 12 hours under a vacuum of 10 Pa and a plate temperature increased from -20°C to +20°C; the second drying was carried out under a vacuum of 5 Pa.

[0051] The process was carried out for 6 hours under conditions where the plate temperature was raised to 35°C.

[0052] After drying, the product is crushed, sieved, and packaged with nitrogen.

[0053] A freeze-dried white tea and coffee composition was obtained. Calculations showed that, on a dry basis, the composition contained approximately 72.0% coffee-derived solids, approximately 25.0% white tea-derived solids, and 3.0% functional carrier.

[0054] Example 2

[0055] This embodiment provides a method for preparing a freeze-dried white tea and coffee composition, wherein the components and parameters are selected at the upper limit or near the upper limit of the range defined in the claims.

[0056] 1. Targeted enzymatic hydrolysis of white tea raw materials

[0057] Weigh out 100g of Yunnan Moonlight White Tea and set aside.

[0058] β-

[0059] Glucosidase and pectinase were dissolved in deionized water at a mass ratio of 4:1 to prepare a compound enzyme solution.

[0060] Add Moonlight White Tea to 800mL (material-to-liquid ratio 1:8)

[0061] In the above compound enzyme solution (g / mL), adjust the pH to 5.5 and carry out the enzymatic hydrolysis reaction in a constant temperature water bath at 55℃ for 75 minutes.

[0062] After the reaction was completed, the system was rapidly heated to 95°C and maintained for 2 minutes to terminate enzyme activity. Then, it was vacuum dried at 60°C to obtain the enzymatically hydrolyzed aroma-enhanced white tea raw material.

[0063] 2. Segmented temperature-coupled extraction

[0064] Add the above-mentioned enzymatically hydrolyzed white tea raw materials to 1500mL (material-to-liquid ratio 1:15).

[0065] Extract the tea in deionized water (g / mL) at 85℃ for 120 seconds, then immediately filter to obtain a highly aromatic white tea extract.

[0066] Weigh out 600g of lightly roasted Yunnan Arabica coffee beans and grind them to 40 mesh.

[0067] The above-mentioned highly aromatic white tea extract was rapidly heated to 94°C and then used as a solvent to be added to the coffee powder (the ratio of extract to liquid was approximately 1:8).

[0068] The extract was flash-extracted (g / mL) for 90 seconds, and then filtered to obtain a tea-coffee co-extract.

[0069] 3. Ultra-high voltage perturbation processing

[0070] The obtained tea-coffee co-extract was rapidly cooled to 15°C.

[0071] The cooled liquid is placed in an ultra-high pressure device and a pressure of 450 MPa is applied and maintained for 5 minutes.

[0072] 4. Carrier addition and freeze-drying

[0073] Gum arabic (1.0% by weight of the total liquid mass) was added as a functional carrier to the tea-coffee co-extract treated under ultra-high pressure, and then homogenized using a high-shear homogenizer at 8000 °C.

[0074] Homogenize at rpm for 5 minutes.

[0075] The homogenized liquid was pre-frozen at -50°C for 2 hours, followed by vacuum freeze-drying. The first drying was carried out for 15 hours under a vacuum of 12 Pa and a plate temperature increased from -20°C to +20°C; the second drying was carried out under a vacuum of 8 Pa.

[0076] The process was carried out for 5 hours under conditions where the plate temperature was raised to 45°C.

[0077] After drying, the product is crushed, sieved, and packaged with nitrogen.

[0078] A freeze-dried white tea and coffee composition was obtained. Calculations showed that, on a dry basis, the composition contained approximately 85.0% coffee-derived solids, approximately 14.0% white tea-derived solids, and 1.0% functional carrier.

[0079] Example 3

[0080] This embodiment provides a method for preparing a freeze-dried white tea and coffee composition, wherein the components and parameters are selected as the lower limit or near the lower limit of the range defined in the claims.

[0081] 1. Targeted enzymatic hydrolysis of white tea raw materials

[0082] Weigh out 100g of Fujian White Peony Tea and set aside.

[0083] β-

[0084] Glucosidase and pectinase were dissolved in deionized water at a mass ratio of 2:1 to prepare a compound enzyme solution.

[0085] Add white peony tea to 1200mL (material-to-liquid ratio 1:12).

[0086] In the above compound enzyme solution (g / mL), adjust the pH to 4.5 and carry out the enzymatic hydrolysis reaction in a constant temperature water bath at 40℃ for 30 minutes.

[0087] After the reaction was completed, the system was rapidly heated to 85°C and maintained for 5 minutes to terminate enzyme activity. Then, it was dried with hot air at 50°C to obtain the enzymatically hydrolyzed aroma-enhanced white tea raw material.

[0088] 2. Segmented temperature-coupled extraction

[0089] Add the above-mentioned enzymatically hydrolyzed white tea raw materials to 2500mL (material-to-liquid ratio 1:25).

[0090] Extract the tea in deionized water at 75°C (g / mL) for 60 seconds, then immediately filter to obtain a highly aromatic white tea extract.

[0091] Weigh out 180g of lightly roasted Yunnan Arabica coffee beans and grind them to 60 mesh.

[0092] The above-mentioned highly aromatic white tea extract was rapidly heated to 90°C and then used as a solvent to be added to the coffee powder (the ratio of extract to liquid was approximately 1:12).

[0093] The extract was flash-extracted (g / mL) for 45 seconds and then filtered to obtain a tea-coffee co-extract.

[0094] 3. Ultra-high voltage perturbation processing

[0095] The obtained tea-coffee co-extract was rapidly cooled to 25°C.

[0096] The cooled liquid is placed in an ultra-high pressure device and a pressure of 200 MPa is applied and maintained for 1 minute.

[0097] 4. Carrier addition and freeze-drying

[0098] Add a mixture of inulin and gum arabic (mass ratio 1:1) at 5.0% of the total liquid mass to the tea-coffee co-extract that has been treated under ultra-high pressure as a functional carrier, and homogenize it at 5000 rpm for 10 minutes using a high-shear homogenizer.

[0099] The homogenized liquid was pre-frozen at -40℃ for 4 hours, followed by vacuum freeze drying. The first drying was carried out for 10 hours under a vacuum of 15 Pa and a plate temperature increased from -20℃ to +20℃; the second drying was carried out for 8 hours under a vacuum of 10 Pa and a plate temperature increased to 30℃.

[0100] After drying, the product is crushed, sieved, and packaged with nitrogen.

[0101] A freeze-dried white tea and coffee composition was obtained. Calculations showed that, on a dry basis, the composition contained approximately 60.0% coffee-derived solids, approximately 35.0% white tea-derived solids, and 5.0% functional carrier.

[0102] Comparative Example 1

[0103] Compared to Example 1, the difference lies in that the coupled extraction method in step 2 is changed to the traditional method of separate extraction followed by physical mixing: that is, 100g of enzymatically hydrolyzed white tea is extracted separately using 1000mL of deionized water at 80℃, and 300g of coffee powder is extracted separately using 2000mL of deionized water at 92℃. The two extracts are then mixed to obtain a mixture. All other steps, parameters, and the types and amounts of raw materials are the same as in Example 1.

[0104] Comparative Example 2

[0105] Compared to Example 1, the difference lies in that the targeted enzymatic hydrolysis step of the white tea raw material in step 1 is omitted. That is, 100g of untreated white peony tea raw material is directly used for the subsequent coupled extraction in step 2. The remaining steps, parameters, and raw material amounts are the same as in Example 1.

[0106] Comparative Example 3

[0107] Compared to Example 1, the difference lies in that the ultra-high pressure perturbation treatment step in step 3 is omitted. That is, the tea-coffee co-extract obtained in step 2 is cooled and then directly subjected to carrier addition and freeze-drying in step 4 without undergoing ultra-high pressure treatment. The remaining steps, parameters, and raw material amounts are the same as in Example 1.

[0108] Comparative Example 4

[0109] Compared to Example 1, the difference lies in the omission of step 4, which involves adding a functional carrier (inulin). That is, the tea-coffee co-extract processed under ultra-high pressure is directly subjected to subsequent pre-freezing and vacuum freeze-drying without any carrier. All other steps, parameters, and raw material amounts are the same as in Example 1.

[0110] Test Example 1: Sensory Evaluation Comparison Experiment

[0111] Experimental steps

[0112] Sample Preparation: Take one sample each of the lyophilized powder samples prepared in Example 1 and Comparative Examples 1, 2, 3, and 4. Accurately weigh 1.0 g of each sample and place them in clean, odorless evaluation cups, assigning each sample a random three-digit code. Quickly pour 100 mL of purified water at 85°C into each cup and gently stir with a stirring rod for 5 seconds to completely dissolve the sample, thus preparing the beverage to be evaluated.

[0113] Evaluation Panel: A sensory evaluation panel consisting of 15 professionals who have long been engaged in food flavor research, are familiar with the flavor characteristics of tea and coffee, and have passed olfactory and gustatory threshold tests.

[0114] Assessment Environment: The assessment was conducted in a sensory analysis laboratory that meets national standards. Each assessor operated in a separate assessment cubicle, which was kept well-ventilated, odor-free, and the temperature was controlled at 22±2℃.

[0115] Evaluation Criteria and Methods: Evaluators are required to score the samples on five indicators. A 10-point scale is used, with 1 point indicating extremely weak or absent sensory characteristics, and 10 points indicating extremely strong characteristics. Evaluation indicators include: flavor integration, intensity of floral and fruity aromas, aroma fullness, body of mouth, and intensity of bitterness.

[0116] Evaluation Process: Evaluators will taste five coded samples in a random order. Between each pair of samples, evaluators will clean their mouths with purified water and unflavored soda crackers to remove any taste residue. Evaluators will record their scores on a dedicated sensory evaluation form.

[0117] Data processing: Collect all evaluation forms, statistically analyze the scores of each indicator for each sample, remove extreme values, and calculate the average score as the final evaluation result for that indicator.

[0118] Experimental data

[0119] Table 1 Comparison of Average Sensory Evaluation Scores

[0120]

[0121] Experimental Results and Analysis

[0122] The sensory evaluation results in Table 1 clearly demonstrate the systematic advantages of the technical solution adopted in this invention. The sample of Example 1 performed exceptionally well in all positive indicators, while scoring the lowest in negative indicators, directly attributable to its unique preparation method. The core difference between Comparative Example 1 and Example 1 lies in the combination of flavor substances; its "flavor fusion" score was only 3.2, far lower than Example 1's 9.1, while its "bitterness intensity" significantly increased. This strongly confirms the innovation of the "coupled co-extraction" method used in this invention. By using white tea extract rich in tea polyphenols and theanine as a solvent to extract coffee, molecular-level interaction and reconstruction of the two flavors at their source are achieved, effectively neutralizing some of the sharp bitterness in the coffee and forming a harmonious and unified flavor whole. In contrast, traditional physical mixing cannot achieve this deep fusion, resulting in flavor stratification and a prominent bitterness.

[0123] Comparing the results of Example 1 and Comparative Example 2 clearly demonstrates the crucial role of the enzymatic hydrolysis pretreatment step in constructing the characteristic aroma of the product. Comparative Example 2, lacking the enzymatic hydrolysis step, scored only 3.5 in "floral and fruity aroma intensity," while Example 1 achieved a high score of 8.8. This is entirely consistent with the mechanism described in this invention: through β-

[0124] The action of complex enzymes such as glucosidase effectively hydrolyzes flavor precursors in white tea, which exist in the form of aromaless glycosides, releasing a large amount of molecules with pleasant floral and fruity aromas, such as linalool and geraniol. This step actively enhances the flavor base at the raw material level, which is the fundamental guarantee for obtaining a rich and characteristic aroma in the subsequent process. In addition, compared with Comparative Example 3, the "aroma fullness" score dropped sharply from 9.3 to 5.5, which reveals the decisive contribution of ultra-high pressure treatment to flavor preservation. The physical perturbation effect of ultra-high pressure promotes the formation of stable complexes between these released, volatile aroma molecules and macromolecules in the solution, which is equivalent to building a "protective shell" for the aroma, significantly reducing its escape during the subsequent drying process, thereby making the aroma of the final product fuller and more lasting.

[0125] Finally, the results of Comparative Example 4 highlight the crucial role of functional carriers in the final product's form and taste. In the absence of a functional carrier, the sample's "body" score was only 2.5, exhibiting a noticeably watery texture, far below the 8.5 score of Example 1. This indicates that the added inulin or gum arabic, acting as a structural framework and taste modifier, significantly enhances the beverage's body and smoothness, optimizing the consumer's final experience. In conclusion, the sensory evaluation results demonstrate that this invention is not merely an improvement on a single technology, but rather a systematic solution to the shortcomings of existing technologies through the organic combination and synergistic effect of four innovative points: enzymatic flavor enhancement, coupled co-extraction, ultra-high pressure aroma locking, and carrier optimization. This results in a novel product with integrated flavor, rich aroma, and a mellow taste.

[0126] Test Example 2: Volatile Aroma Component Analysis Experiment

[0127] Experimental steps

[0128] Sample preparation: Accurately weigh 1.0 g of each of the lyophilized powder samples prepared in Example 1 and Comparative Example 2, and place them in separate 20 mL headspace vials. Add 5 mL of saturated sodium chloride solution to each vial to facilitate the escape of volatile substances. Immediately seal the vials with caps fitted with PTFE / silicone septa.

[0129] Extraction conditions: Headspace solid-phase microextraction (HS-SPME) was used for extraction. The sample vials were placed in a constant temperature water bath at 60°C for equilibration for 15 minutes. Subsequently, a 50 / 30 μm DVB / CAR / PDMS extraction head was inserted into the headspace portion of the sample vials, and adsorption extraction was performed at the same temperature for 30 minutes.

[0130] Chromatography-mass spectrometry (GC-MS) analysis conditions:

[0131] Chromatographic column: DB-5ms quartz capillary column (30m×0.25mm×0.25μm).

[0132] Programmed temperature rise: Initial temperature 40℃, hold for 3 minutes; rise to 150℃ at a rate of 5℃ / minute; then rise to 280℃ at a rate of 10℃ / minute, hold for 5 minutes.

[0133] Inlet temperature: 250℃.

[0134] Carrier gas: high-purity helium, flow rate 1.0 mL / min.

[0135] Mass spectrometry conditions: The ion source is an electron impact (EI) source with an electron energy of 70 kilometres per minute.

[0136] eV, ion source temperature 230℃, scan range m / z 35-500.

[0137] Qualitative and quantitative analysis: Compounds were identified by comparing the mass spectra of the samples with the NIST standard mass spectrum library. Semi-quantitative analysis of the relative content of each volatile component was performed using peak area normalization.

[0138] Experimental data

[0139] Table 2 Comparison of relative contents of volatile aroma components (peak area × 10^5)

[0140]

[0141]

[0142] Experimental Results and Analysis

[0143] The instrumental analysis data in Table 2 provide objective and strong evidence for the effectiveness of the bio-enzymatic hydrolysis pretreatment step used in this invention. The data shows that, compared to Comparative Example 2 which did not undergo enzymatic hydrolysis, the content of several key compounds representing typical floral and fruity aromas of white tea in the Sample of Example 1 showed a significant increase in quantity. For example, the relative content of substances such as linalool (with a lily of the valley aroma), geraniol (with a rose aroma), and phenylethyl alcohol (with a rose and honey aroma) in Example 1 was ten to twenty times higher than that in Comparative Example 2. This result directly confirms the core mechanism of the enzymatic hydrolysis step in the method of this invention: it is not a simple physical treatment, but rather an active, targeted hydrolysis of flavor precursors (glycosides) present in large quantities in the raw materials that do not contribute to aroma themselves, through a specific biocatalytic reaction, thereby "unlocking" and releasing these high-value, free aroma molecules.

[0144] The innovation of this invention lies in its recognition that the aroma potential of high-quality white tea has not been fully explored by traditional extraction methods. The results of Comparative Example 2 reflect the baseline of aroma substances obtainable by traditional hot water extraction, namely, only a small amount of naturally occurring free aroma molecules in the tea leaves can be extracted. However, this invention, by introducing enzymatic hydrolysis as a "pre-enhancing aroma" step, greatly enriches the material basis of the extraction system, proactively constructing the product's unique flavor characteristics from the source. This step transforms the "aroma potential" of white tea into "actual aroma," providing a far richer source of "high-quality raw materials" for subsequent flavor fusion and locking compared to traditional methods. Its role is fundamental and a prerequisite for achieving the superior results of all subsequent steps.

[0145] Combining this objective data with the sensory evaluation results, we can conclude that the reason why Example 1 exhibits a rich, full-bodied, and distinctive floral and fruity aroma is fundamentally due to the massive enrichment of key aroma substances brought about by the enzymatic hydrolysis step. These actively released aroma molecules form the cornerstone of flavor fusion in the subsequent coupled co-extraction process and become the key targets for protection by the ultra-high pressure aroma-locking technology. Therefore, this enzymatic hydrolysis pretreatment step is an indispensable part of the systematic solution of this invention and one of the core technical supports for achieving the unique flavor characteristics of the final product.

[0146] Test Example 3: Accelerated Aging Test for Aroma Stability

[0147] Experimental steps

[0148] Initial sample analysis (day 0): The freeze-dried powder samples prepared in Example 1 and Comparative Example 3 were taken and analyzed using the same HS-SPME-GC-MS method as in Test Example 2. The key volatile aroma components (linalool, geraniol, phenylethanol) in the samples were detected and their initial peak areas were recorded as the baseline values.

[0149] Accelerated aging treatment: The samples from Example 1 and Comparative Example 3 were sealed in nitrogen-filled aluminum foil bags using the same high-barrier materials. Subsequently, all packaged samples were placed in a constant temperature and humidity incubator and subjected to accelerated aging storage for 4 weeks at a temperature of 37°C and a relative humidity of 50%.

[0150] Analysis of aged samples (4 weeks): After the storage period, the samples were removed from the incubator and equilibrated at room temperature for 2 hours. Subsequently, the aroma components of the aged samples were detected again using the same HS-SPME-GC-MS method as the initial analysis, and the final peak area was recorded.

[0151] Data Calculation: Based on the peak area data before and after aging, the retention rate of each key aroma compound is calculated. The calculation formula is: Retention rate (%) = (Peak area after aging / Initial peak area) × 100%.

[0152] Experimental data

[0153] Table 3 Comparison of retention rates of key aroma compounds after accelerated aging (%)

[0154] Volatile components Example 1 Comparative Example 3 Linalool 91.5 35.8 Geraniol 88.2 28.5 Phenylethanol 93.6 41.2

[0155] Experimental Results and Analysis

[0156] Table 3 data visually reveals the decisive impact of the ultra-high pressure treatment step on the flavor stability of the product. After four weeks of accelerated aging, the retention rate of key aroma substances in the samples of Example 1 generally remained at an extremely high level of around 90%, while the aroma retention rate of Comparative Example 3, which omitted the ultra-high pressure step, dropped sharply to the range of 30-40%. This significant difference fully demonstrates that ultra-high pressure treatment is the core step in this invention to achieve long-lasting aroma preservation and solve the problem of easy aroma loss in freeze-dried products in the prior art.

[0157] The excellent aroma stability exhibited in Example 1 is due to the fact that the physical perturbation effect of ultra-high pressure is not a simple physical mixing, but rather alters the state of aroma substances at the molecular level. The strong hydrostatic pressure overcomes the steric hindrance between molecules, causing the free aroma molecules (such as linalool and geraniol) formed in the coupling co-extraction step to form more compact non-covalent complexes with the macromolecules such as tea polyphenols and polysaccharides in the solution system. This interaction is equivalent to constructing a dense "protective shell" for the volatile and easily oxidized aroma molecules, stably embedding them within the macromolecular network, greatly reducing their migration rate and reactivity during subsequent drying and long-term storage.

[0158] In contrast, in the sample of Comparative Example 3, these key aroma molecules remained in a highly active, free state. Without the protection of macromolecular complexes, they are highly susceptible to loss during storage through oxidation, degradation, or volatilization from the matrix, leading to rapid deterioration of the product's flavor over time. Therefore, the innovation of this invention lies not only in creating a unique blended flavor but also in providing a technical solution that can effectively solidify and maintain this flavor over a long period. The ultra-high pressure aroma-locking step, acting as a bridge between the enzymatic hydrolysis and co-extraction processes, efficiently locks in the valuable flavor results, ensuring that the final product maintains its initially designed high-quality flavor characteristics throughout its entire shelf life.

[0159] Test Example 4: Comparison Experiment of Solubility

[0160] Experimental steps

[0161] Experimental setup preparation: Add 200 mL of deionized water, precisely controlled at 85 °C, to a 250 mL beaker. Place the beaker on a magnetic stirrer, insert a stir bar, and set the stirring speed to a constant 300 rpm.

[0162] Sample weighing: Accurately weigh 2.0 g of each of the lyophilized powder samples prepared in Example 1 and Comparative Example 4.

[0163] Dissolution process: Start the magnetic stirrer. After the water forms a stable vortex, quickly pour the weighed 2.0g sample into the center of the beaker all at once, and start the stopwatch at the same time.

[0164] Endpoint determination: The experimenter closely observes the state of the solution. When there are no undissolved particles or clumps visible to the naked eye and the solution is homogeneous, the timing is stopped immediately and the time taken is recorded.

[0165] Repeat and observe: Repeat the above steps 3 times for each sample, and calculate the average of the three dissolution times. At the same time, record the clarity of the liquid after the sample is completely dissolved and whether there are any insoluble substances or precipitates.

[0166] Experimental data

[0167] Table 4 Comparison of solubility

[0168]

[0169] Experimental Results and Analysis

[0170] The experimental data in Table 4 clearly demonstrate that the addition of a functional carrier plays a crucial role in improving the physical properties of the final product. The sample in Example 1 dissolved completely in less than 13 seconds, while Comparative Example 4, lacking the functional carrier, took nearly a minute to dissolve, and the dissolution process was accompanied by undesirable agglomeration. This significant performance difference directly reflects the necessity and innovation of the technical considerations in the final product molding stage of this invention.

[0171] The superior instant solubility observed in this invention is due to the unique role of the added functional carriers (such as inulin and gum arabic) during the freeze-drying process. During the pre-freezing stage, these macromolecules, together with the tea and coffee solids, form a homogeneous solid matrix. In the subsequent sublimation drying process, after the water is removed, these carriers act as a microscopic "structural framework," supporting a highly porous, hydrophilic, and loose network structure. When hot water is poured in, it can instantly penetrate every corner of the particles through strong capillary action, greatly increasing the contact area between water and the solids, thereby achieving rapid disintegration and dissolution.

[0172] In contrast, Comparative Example 4, lacking this structural framework, exhibits a denser particle structure and potentially stronger surface hydrophobicity after freeze-drying. Moisture struggles to penetrate the particles quickly, causing the outer layer to dissolve first, forming a viscous barrier that hinders further wetting of the internal powder, resulting in clumping and significantly slowing the dissolution rate. Therefore, the introduction of a functional carrier is not simply a matter of adding components, but rather about constructing an optimized microscopic physical structure to endow the product with superior application performance. It ensures that the unique flavor meticulously crafted through enzymatic hydrolysis, co-extraction, and ultra-high pressure processes can be experienced by users in the most convenient and perfect way, serving as a crucial bridge connecting complex preparation processes with the end-user experience.

[0173] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing freeze-dried white tea coffee, characterized in that, Includes the following steps: Step 1: Pre-treat the white tea raw materials with enzymatic hydrolysis to obtain enzymatically hydrolyzed white tea; Step 2: Extract the enzymatically hydrolyzed white tea to obtain white tea extract, and use the white tea extract as a solvent to extract coffee raw material to obtain tea-coffee co-extract; Step 3: Perform ultra-high pressure treatment on the tea-coffee co-extract; Step 4: The tea-coffee co-extract that has undergone ultra-high pressure treatment is subjected to vacuum freeze-drying to obtain the freeze-dried white tea coffee.

2. The method according to claim 1, characterized in that, The enzymatic pretreatment in step one includes treating the white tea raw material with a complex enzyme preparation containing β-glucosidase and pectinase.

3. The method according to claim 1, characterized in that, Step two specifically includes: b1. The enzymatically hydrolyzed white tea is subjected to low-temperature extraction to obtain the white tea extract; b2. After heating the white tea extract, use it as a solvent to extract coffee raw materials at high temperature to obtain the tea-coffee co-extract.

4. The method according to claim 3, characterized in that, The low-temperature extraction temperature in step b1 is 75-85℃, and the high-temperature extraction temperature in step b2 is 90-94℃.

5. The method according to claim 1, characterized in that, The ultra-high pressure treatment in step three is performed at a pressure of 200-450 MPa, with a holding time of 1-5 minutes.

6. The method according to claim 1, characterized in that, Before step four, step c is also included: adding a functional carrier to the tea-coffee co-extract that has undergone ultra-high pressure treatment.

7. The method according to claim 6, characterized in that, The functional carrier is inulin and / or gum arabic.

8. The method according to claim 1, characterized in that, The white tea raw material is White Peony tea and / or Moonlight White tea; the coffee raw material is Arabica coffee beans.

9. The method according to claim 6, characterized in that, The vacuum freeze drying in step four includes pre-freezing, primary drying, and secondary drying steps.

10. A freeze-dried white tea and coffee composition, characterized in that, It contains the following components by dry weight percentage: Coffee-derived solids: 60.0%-85.0%; Solids content from white tea: 14.0%-39.0%; Functional carrier: 1.0%-5.0%.

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