Preparation method of sweet and fragrant schisandra chinensis leaf substitutional tea with high lignan retention

Abstract

The invention discloses a preparation method of sweet and fragrant schisandra chinensis leaf substitutional tea with high lignan retention, and relates to the technical field of functional food development. The method adopts medium-temperature rapid and uniform fixation, critical state functional flavor carrier loading, low-temperature aroma fog coupling and low-temperature vacuum drying, and comprises the following steps: firstly, carrying out short-time medium-temperature fixation and enzyme deactivation on mature functional Chinese magnoliavine leaves and keeping green; spraying a functional flavor carrier solution at the critical temperature of the leaves to construct a flavor adsorption substrate; then, low-temperature aroma atomization adsorption is performed to realize fusion of the flower fragrance and the original flavor; and finally, performing low-temperature vacuum drying to complete shape fixing, taste locking and deep dehydration. The lignan retention rate of the finished tea prepared by the method is remarkably higher than that of a traditional high-temperature process product, the finished tea has fragrant rose sweet fragrance and mellow taste, and the bitterness is greatly reduced. The whole process is free of high-temperature superposition treatment, the bottleneck that the effect preservation and taste improvement of a traditional process cannot be achieved at the same time is successfully broken, and the prepared product has high health-care potential and excellent sensory experience and has good industrial application prospects.

Description

Technical Field

[0001] This invention relates to the field of functional food development technology, and in particular to a method for preparing a sweet-smelling Schisandra chinensis leaf substitute tea with high lignan retention. Background Technology

[0002] Schisandra chinensis, a traditional Chinese medicine with astringent and consolidating effects, is rich in unique lignan active ingredients such as schisandrol A, schisandrol B, and schisandrin A in its leaves. These ingredients have excellent health benefits such as anti-oxidation and liver protection, which has led to the widespread development of Schisandra chinensis leaves as a substitute tea beverage, showing broad development prospects in the health consumer market.

[0003] However, the currently widely used processing techniques for Schisandra chinensis substitute tea mostly borrow from or follow traditional tea heat processing techniques, resulting in two prominent technical defects that severely restrict the improvement of product quality and the exploitation of its value: Firstly, functional components are easily damaged during heat processing: core steps in existing processes, such as fixation and drying, rely on high-temperature treatment above 150℃. The lignans in Schisandra chinensis leaves are heat-labile and easily degrade, transform, or be lost under such high temperatures and prolonged heat, leading to the actual health benefits of the final product being far lower than theoretically expected, and the core value of this health beverage being difficult to guarantee. Secondly, the product's flavor and quality are poor, and its palatability is low: traditional high-temperature processing not only makes precise control difficult but also easily triggers excessive heat reactions, resulting in a strong grassy smell and a noticeable bitter taste in the finished tea, lacking a pleasant aroma and rich flavor profile. This results in insufficient appeal to ordinary consumers, limiting the product to a niche market for a long time.

[0004] Therefore, there is an urgent need in this field for an innovative and systematic processing method that aims to fundamentally break through the above-mentioned technical bottlenecks, namely, to simultaneously achieve a revolutionary improvement in the flavor and quality of Schisandra chinensis leaves while effectively preserving their core functional components, thereby promoting the development of Schisandra chinensis leaf substitute tea towards high-quality, high-value-added health products. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a sweet-smelling Schisandra chinensis leaf substitute tea with high lignan retention, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a method for preparing Schisandra chinensis leaf substitute tea, characterized by comprising the following steps: (1) Blanching: Blanch the mature fresh Schisandra chinensis leaves at a temperature of 105-115℃ for 60-90 seconds; (2) Functional flavor integration: After blanching, the Schisandra chinensis leaves are naturally cooled to 50-60℃, and then a functional flavor carrier solution at 40-50℃ is sprayed on the leaf surface. (3) Kneading: Knead the Schisandra chinensis leaves obtained in step (2) and roll them into shape; (4) Aroma mist coupling treatment: The Schisandra chinensis leaves obtained in step (3) are placed in an aroma mist at 0-10℃ to achieve the adsorption of aroma mist by the Schisandra chinensis leaves; (5) Low-temperature vacuum drying: The Schisandra chinensis leaves obtained in step (4) are subjected to low-temperature vacuum drying to obtain the Schisandra chinensis leaf substitute tea; In step (2), the functional components in the functional flavor carrier solution include natural sweeteners and soluble dietary fiber; In step (4), the aroma mist is the atomized gas of edible natural floral fragrance atomizing raw material; more preferably, it is the atomized gas of rose hydrosol or rose essential oil. In step (5), the temperature of the low-temperature vacuum drying process is 40-60℃.

[0007] Furthermore, the natural sweetener includes steviol glycosides, and the soluble dietary fiber includes inulin.

[0008] Furthermore, the mass ratio of steviol glycosides to inulin is 1:3.

[0009] Furthermore, the total concentration of steviol glycosides and inulin in the functional flavor carrier solution is 7%-8% (w / v).

[0010] Furthermore, the amount of the functional flavor carrier solution sprayed is: based on the mass of Schisandra chinensis leaves after blanching and before rolling, 10-30 ml of functional flavor carrier solution is added per 100 g of Schisandra chinensis leaves.

[0011] Furthermore, the kneading time in step (3) is 20-30 minutes.

[0012] Furthermore, the adsorption time in step (4) is 40-50 min.

[0013] Further, the low-temperature vacuum drying process is as follows: the Schisandra chinensis leaves after adsorbing the aroma mist in step (4) are evenly spread on a tray and placed in a vacuum drying chamber. Through program control, the material is dehydrated and dried at a mild temperature of 40-60℃ and a vacuum of 0.5-10 kPa until the moisture content of the leaves drops below 8%.

[0014] Furthermore, the low-temperature vacuum drying process adopts segmented program control; in the initial stage of drying, it is first dried at a temperature of 40-45℃ and a vacuum of 5-10 kPa for 2-4 hours, and then enters the enhanced drying stage, where the conditions are adjusted to 50-60℃ and a vacuum of 0.5-5 kPa, and drying continues until the moisture content meets the standard.

[0015] The present invention also provides a Schisandra chinensis leaf substitute tea prepared by the above preparation method.

[0016] This invention employs a medium-temperature rapid and uniform blanching process at 105-115℃ for 60-90 seconds. This rapidly inactivates polyphenol oxidase and peroxidase within the leaves, inhibiting enzymatic browning and lignan degradation. Furthermore, the short processing time and controllable heat exposure prevent the degradation of heat-sensitive lignan components caused by prolonged high-temperature treatment. Following blanching, a low-temperature process is used throughout. The leaves are spread out to 50-60℃ for flavor loading, and subsequent rolling, aroma coupling, and vacuum drying are all completed under low-temperature conditions. This completely avoids the damage to lignans caused by traditional high-temperature drying, forming a complete protective chain of instantaneous enzyme inactivation and low-temperature protection, maximizing the preservation of the core health-promoting activities of Schisandra chinensis leaves.

[0017] This invention preferably involves spraying a functional flavor carrier solution prepared from steviol glycosides and inulin in a 1:3 ratio when the leaves are cooled to a critical state of 50-60°C. At this temperature, the leaf cells have good permeability and a soft texture, allowing the atomized solution to adhere evenly to the leaf surface and promoting the penetration of steviol glycosides and inulin into the leaf tissue. Inulin, as a soluble dietary fiber, not only acts as a slow-release carrier for sweet components, allowing the sweetness to develop naturally and avoiding a superficial sweetness, but also forms a porous adsorption structure on and inside the leaf surface, providing ample adsorption sites for subsequent low-temperature aroma coupling. Simultaneously, the uniform coating of the solution reduces localized oxidation during leaf processing, ensuring the stability of the appearance and color.

[0018] In a low-temperature environment of 0-10℃, plant-derived aroma molecules atomized by ultrasonication can rapidly diffuse and be captured by adsorption sites on the leaf surface and soluble dietary fiber carrier. The low temperature environment reduces the volatilization rate of aroma molecules and avoids chemical changes in aroma components due to high temperatures. The subsequent low-temperature vacuum drying process is carried out in a mild dehydration environment. Under medium-low vacuum (0.5-10 kPa), the boiling point of water is significantly reduced, allowing moisture to be effectively removed at a relatively low temperature of 40-60℃. This process avoids damage to leaf tissue and aroma molecules caused by high temperatures. At the same time, the mild dehydration kinetics create uniform microporous channels inside the leaves, better preserving the curled shape obtained after rolling, ultimately achieving a deep and lasting fusion of floral fragrance, sweetness, and the original flavor of Schisandra chinensis.

[0019] This invention utilizes a comprehensive process to ensure the overall quality of Schisandra chinensis leaf substitute tea: After fixation, the leaves remain soft and moist, creating ideal conditions for flavor carrier loading; the rolling process serves a dual purpose, both shaping the leaves into strips and effectively expanding their surface area, laying a solid foundation for subsequent aroma adsorption; low-temperature aroma coupling technology specifically enhances the product, imparting a harmonious sweet aroma; and the low-temperature vacuum drying process simultaneously achieves the three core objectives of solidification, flavor locking, and moisture reduction. The entire process avoids high-temperature superimposed treatments, preventing the loss of active ingredients such as lignans in the Schisandra chinensis leaves and preventing deterioration issues such as browning and brittleness; furthermore, the synergistic effect of flavor carriers and aroma molecules significantly improves the product's palatability. Ultimately, this invention successfully achieves the goals of high health benefits and excellent sensory experience, overcoming the technical bottleneck of traditional processing methods where efficacy and flavor enhancement are mutually exclusive.

[0020] The present invention discloses the following technical effects: This invention provides a method for preparing Schisandra chinensis leaf substitute tea, which significantly improves the overall quality of the product and achieves efficient retention of heat-sensitive lignan functional components and synergistic optimization of sweet aroma. By employing a medium-temperature instantaneous fixation combined with a low-temperature post-treatment process throughout, enzymes are rapidly inactivated and the green color is preserved, effectively inhibiting the degradation of lignans during processing. Simultaneously, it avoids the loss of active ingredients caused by traditional high-temperature superimposed processing, greatly improving the retention rate of core lignan functional components and solving common problems in traditionally processed products such as yellow-brown discoloration, brittleness, and morphological deterioration.

[0021] This invention utilizes innovative flavor integration technology to construct a rich and harmonious sensory system. A composite solution loaded with steviol glycosides and inulin is placed in a "critical state" (i.e., a specific moisture content after fixation and before drying), allowing the sweetness to develop naturally without being overpowering. The porous network structure formed by inulin during drying provides efficient adsorption sites for aroma molecules. Combined with a low-temperature aroma coupling process, rose aroma molecules are stably attached and deeply integrated with the base flavor of Schisandra chinensis leaves. The final product, dry tea, exhibits a clear and pleasant rose sweet aroma, with a mellow brewed taste and significantly reduced bitterness. Compared to the burnt astringency of traditional processes or the bland flavor of some optimized processes, the sensory experience is significantly improved.

[0022] In summary, this invention, through precise coordination of the entire process, successfully overcomes the technical bottleneck of the traditional tea substitute processing where it is difficult to balance efficacy preservation and flavor enhancement. While efficiently preserving highly active health-promoting ingredients, it endows the product with excellent sensory quality and good storage stability, providing reliable technical support for the high-value, standardization, and industrial upgrading of Schisandra chinensis leaf substitute tea. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 The images show the appearance of the finished tea products obtained in Example 1 (labeled as finished product A), Comparative Example 1 (labeled as finished product B), and Comparative Example 2 (labeled as finished product C) of the present invention. Figure 2 Sensory evaluation of the finished tea products obtained in Example 1, Comparative Example 1, and Comparative Example 2 of this invention. Detailed Implementation

[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0029] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0030] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0031] The first aspect of this invention provides a method for preparing Schisandra chinensis leaf substitute tea, comprising the following steps: (1) Medium-temperature rapid and uniform blanching: Mature fresh Schisandra chinensis leaves are blanched at a temperature of 105-115℃ for 60-90 seconds. (2) Loading of critical state flavor carrier: After the Schisandra chinensis leaves are blanched, they are naturally cooled to 50-60℃, and then a functional flavor carrier solution at 40-50℃ is sprayed on the surface of the leaves. (3) Wrapping and light kneading: Knead the Schisandra chinensis leaves obtained in step (2) and curl them into shape; the kneading process adopts the cycle mode of "light pressure - complete loosening and turning leaves - light pressure" until the leaves are initially curled into strips and the leaf surface has a slightly sticky feel, then stop kneading.

[0032] (4) Low-temperature aroma mist coupling treatment: The Schisandra chinensis leaves obtained in step (3) are placed in an aroma mist at 0-10℃ to achieve the adsorption of aroma mist by the Schisandra chinensis leaves; (5) Low-temperature vacuum drying: The Schisandra chinensis leaves obtained in step (4) are subjected to low-temperature vacuum drying to obtain the Schisandra chinensis leaf substitute tea; In step (2), the functional components in the functional flavor carrier solution include natural sweeteners and soluble dietary fiber; In step (4), the aroma mist is the atomized gas of edible natural floral fragrance atomizing raw material; more preferably, it is the atomized gas of rose hydrosol or rose essential oil. In step (5), the temperature of the low-temperature vacuum drying process is 40-60℃.

[0033] Preferably, before step (1) is cut into green, the raw material pretreatment step is also included: select a sunny morning around 10 o'clock to pick mature functional leaves of Schisandra chinensis (the 3rd-4th leaves in the middle of the branch), remove diseased leaves, damaged leaves and other unqualified leaves after picking, rinse qualified leaves with pure water to remove surface dust and impurities, and then place the rinsed leaves on a clean screen and drain until there are no water droplets left on the surface of the leaves.

[0034] Preferably, the natural sweetener includes steviol glycosides, and the soluble dietary fiber includes inulin.

[0035] Preferably, the mass ratio of steviol glycosides to inulin is 1:3.

[0036] Preferably, the total concentration of steviol glycosides and inulin in the functional flavor carrier solution is 7%-8% (w / v).

[0037] Preferably, the amount of the functional flavor carrier solution sprayed is: based on the mass of Schisandra chinensis leaves after blanching and before rolling, 10-30 ml of functional flavor carrier solution is added per 100 g of Schisandra chinensis leaves.

[0038] Preferably, the kneading time in step (3) is 20-30 minutes.

[0039] Preferably, the adsorption time in step (4) is 40-50 min.

[0040] Preferably, the low-temperature vacuum drying process is as follows: the Schisandra chinensis leaves after adsorbing the aroma mist in step (4) are evenly spread on a tray and placed in a vacuum drying chamber. Through program control, the material is dehydrated and dried at a mild temperature of 40-60℃ and a vacuum of 0.5-10kPa until the moisture content of the leaves drops below 8%.

[0041] Preferably, the low-temperature vacuum drying process is controlled by a segmented program. In the initial stage of drying, the drying is carried out at a temperature of 40-45℃ and a vacuum of 5-10 kPa for 2-4 hours. Then, in the enhanced drying stage, the conditions are adjusted to 50-60℃ and a vacuum of 0.5-5 kPa, and drying continues until the moisture content meets the standard.

[0042] A second aspect of the present invention is to provide a Schisandra chinensis leaf substitute tea prepared by the above-described preparation method.

[0043] Example 1 This embodiment provides a sweet-smelling Schisandra chinensis leaf substitute tea with high lignan retention. The preparation steps are as follows: (1) Raw material pretreatment: Select a sunny morning around 10 am to pick mature functional leaves of Schisandra chinensis (the 3rd-4th leaves in the middle of the branch). After picking, remove diseased leaves, damaged leaves and other unqualified leaves. Rinse qualified leaves with pure water to remove surface dust and impurities. Then place the rinsed leaves on a clean screen and drain until there are no water droplets left on the surface of the leaves.

[0044] (2) Medium-temperature rapid and uniform fixation: After draining, put the Schisandra chinensis leaves into a uniform heat field fixation machine that has been preheated to 110°C and fix them for 75 seconds. The leaves will turn dark green and become soft to the touch. The grassy smell of the fresh leaves will completely disappear and a fresh fragrance will begin to appear. At this time, the leaves will be taken out immediately and spread out thinly to dissipate heat.

[0045] (3) Critical state flavor carrier loading: The temperature of the spread-out leaves was monitored in real time using an infrared thermometer. When the leaf temperature dropped to 55℃, the spraying operation of the flavor carrier solution was started. The flavor carrier solution was prepared as follows: food-grade steviol glycosides and inulin were taken at a mass ratio of 1:3 and dissolved in warm water at 45℃. The mixture was stirred continuously until completely dissolved to prepare a solution with a total concentration of 8% steviol glycosides and inulin. The solution was sprayed evenly on the leaf surface using an ultra-fine atomizing nozzle. The spraying amount was controlled based on the weight of the leaves after blanching and before rolling. The ratio was 20ml of functional flavor carrier solution per 100g of leaves. During the spraying process, the leaves were gently turned over to ensure that each leaf could be evenly contacted with the solution.

[0046] (4) Wrapping and light kneading: The leaves that have been sprayed with flavor carrier solution are manually kneaded. The kneading process adopts a cycle of "light pressure - complete loosening and turning leaves - light pressure". The total kneading time is 25 minutes. Kneading is stopped when the leaves are initially curled into strips and the leaf surface has a slightly sticky feel.

[0047] (5) Low-temperature aroma mist coupling treatment: The kneaded leaves are loosely laid in a porous tray, and then the tray is placed in a sealed cavity that is refrigerated and equipped with an ultrasonic atomizer. The cavity temperature is set to 5°C. Edible rose hydrosol is injected into the atomizer, and the refrigeration function of the cavity and the atomizer are activated, so that the leaves can be left to stand and absorb the rose aroma mist in a low-temperature rose aroma mist environment at 5°C for 50 minutes.

[0048] (6) Shaping and Low-Temperature Vacuum Drying: First, shaping is performed. After adsorption, the leaves are quickly arranged into a uniform thin layer in a tray. Then, low-temperature vacuum drying is carried out: the tray containing the leaves is transferred to the drying chamber of the low-temperature vacuum dryer and dried according to the set program. In the first stage, drying is carried out for 3 hours under the conditions of vacuum degree of 5 kPa and material temperature of 45℃. In the second stage, the drying conditions are adjusted to vacuum degree of 1 kPa and material temperature of 55℃, and drying continues for 2.5 hours. During the drying process, the temperature of the material is continuously monitored by sensors to ensure that it does not exceed 60℃, and drying is carried out until the moisture content drops to 7%.

[0049] (7) Packaging: After low-temperature vacuum drying, in a dry and clean environment with a relative humidity of <20%, the finished leaves are quickly packed into an aluminum foil composite bag, nitrogen is filled into the bag and then sealed to obtain a sweet-smelling Schisandra leaf substitute tea with high lignan retention (referred to as finished tea A).

[0050] Comparative Example 1 This comparative example uses a traditional heat processing technique to prepare Schisandra chinensis leaf substitute tea. The specific steps are as follows: (1) Raw material pretreatment: Same as in Example 1, pick mature functional leaves of Schisandra chinensis (3rd-4th leaves in the middle of the branch) around 10 am on a sunny day, remove diseased and damaged leaves, rinse with pure water and drain on a clean sieve until there are no water droplets on the surface.

[0051] (2) Medium-temperature rapid and uniform blanching: Put the drained leaves into a blanching machine that has been preheated to 110°C and blanched for 75 seconds. After the leaves turn dark green, feel soft, and the grassy smell disappears, immediately remove them from the pot and spread them out thinly.

[0052] (3) Conventional rolling: After blanching, the leaves are directly subjected to conventional rolling treatment for 25 minutes until the leaves are curled and formed.

[0053] (4) Hot air drying: Place the kneaded leaves into a hot air dryer at 120°C and dry them once until the moisture content of the leaves drops to below 5%.

[0054] (5) Packaging: After drying, the product is cooled to room temperature in a clean environment and then sealed in a conventional packaging container to obtain finished tea B.

[0055] Comparative Example 2 Unlike Example 1, this comparative example uses a process that optimizes temperature control but does not integrate flavors to prepare Schisandra chinensis leaf substitute tea. The specific steps are as follows: (1) Raw material pretreatment: exactly the same as in Example 1, pick mature functional leaves of Schisandra chinensis (the 3rd-4th leaf in the middle of the branch) around 10 am on a sunny day, remove diseased and damaged leaves, rinse with pure water and drain on a clean sieve until there are no water droplets on the surface.

[0056] (2) Medium-temperature rapid and uniform fixation: Put the drained leaves into a uniform hot field fixation machine that has been preheated to 110℃ and fix for 75 seconds. The leaves will turn dark green, feel soft, and the grassy smell will disappear. Then immediately remove them from the pot and spread them out to cool down.

[0057] (3) Wrapping and light kneading: The leaves after blanching and drying are lightly kneaded. The kneading process adopts a cycle of "light pressure - complete loosening and turning of leaves - light pressure". The total kneading time is 25 minutes. Kneading is stopped when the leaves are initially curled into strips and the leaf surface has a slightly sticky feel.

[0058] (4) Shaping and Low-Temperature Vacuum Drying: The Schisandra chinensis leaves, which were kneaded and shaped in step (3), were arranged into a uniform thin layer in a tray, and then the tray was transferred to the drying chamber of the low-temperature vacuum dryer. The drying program was set as follows: First stage: Drying for 3 hours at a material temperature of 45℃ and a vacuum of 5 kPa. Second stage: Adjusting the drying conditions to 55℃ and a vacuum of 1 kPa, and continuing to dry for 2.5 hours. During the drying process, the material temperature was monitored by a sensor to ensure that it never exceeded 60℃. After drying, the moisture content of the leaves was measured to be 7%.

[0059] (5) Packaging: After low-temperature vacuum drying, the finished tea leaves are quickly packed into aluminum foil composite bags in a dry and clean environment with a relative humidity of <20%, filled with nitrogen, and then sealed to obtain finished tea C.

[0060] The technical effects of the products of Example 1 (process of the present invention, finished tea A), Comparative Example 1 (traditional hot processing process, finished tea B), and Comparative Example 2 (partially optimized process, finished tea C) were comprehensively compared and analyzed from three aspects: appearance, flavor and sensory experience, and retention of functional components. The results are as follows: 1. Comparison of appearance and form Figure 1 These are images of the finished tea products obtained in Example 1 (labeled as Finished Product A), Comparative Example 1 (labeled as Finished Product B), and Comparative Example 2 (labeled as Finished Product C) of the present invention. It can be seen that: Finished Product A: The leaves are strip-shaped and have a uniform natural dark green color; Finished Product B: The leaves are strip-shaped, but the unevenly colored parts appear yellowish-brown; Finished Product C: The leaves are strip-shaped, and also have the problem of uneven color.

[0061] 2. Flavor Sensory Comparison Finished Tea A: Even in its dry stage, the tea exudes a distinct and complex sweet rose aroma. After brewing, the rose fragrance, natural sweetness, and the flavor of Schisandra chinensis in the tea soup are harmoniously integrated, resulting in a mellow and smooth taste with no obvious bitterness. This superior flavor originates from the synergistic effect of critical state flavor carrier loading and low-temperature aroma mist coupling: the carrier system formed by steviol glycosides and inulin enables endogenous sweetness, while the rose aroma molecules atomized by ultrasonication under low-temperature conditions are uniformly adsorbed, ultimately achieving deep integration and stable retention of the flavor.

[0062] Finished Tea B: The flavor is mainly characterized by the aroma of high-temperature roasting, with a slight burnt smell. The taste is thin and the astringency is significant. This is because traditional high-temperature processing not only causes excessive heat reaction that produces a burnt flavor, but also destroys the natural components in the leaves that improve the taste. At the same time, the lack of flavor optimization steps results in an inability to mask the bitterness and astringency, leading to poor palatability.

[0063] Finished Tea C: Only a faint grassy aroma and mild sweetness can be perceived; the flavor is bland and lacks complexity. Due to the omission of flavor integration steps in the processing, neither exogenous sweet aroma components are introduced nor aroma coupling treatment is carried out. Only the basic flavor of Schisandra chinensis leaves is retained, resulting in a sensory experience inferior to Finished Tea A.

[0064] 3. Retention of functional components The content data of the core functional components determined by high performance liquid chromatography (HPLC) are shown in the table below (the results are expressed as “mean ± standard deviation”, unit: mg / g).

[0065] Table 1 Analysis Conclusion: The data in the table above shows that the finished tea A produced using the complete process of this invention has significantly higher contents of the three core lignans than the finished tea B produced using the traditional process in Comparative Example 1, and also higher than the finished tea C produced using some optimized processes in Comparative Example 2. This result fully demonstrates that the low-temperature vacuum drying process used in this invention, compared to traditional hot air drying, can more effectively reduce the degradation and loss of heat-sensitive functional components during the drying stage. Simultaneously, the complete process chain (including critical state carrier loading) has a synergistic promoting effect on the efficient retention of functional components. Therefore, this invention has significant advantages in retaining the natural active ingredients of Schisandra chinensis leaves.

[0066] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a Schisandra chinensis leaf substitute tea, characterized in that, Includes the following steps: (1) Blanching: Blanch the mature fresh Schisandra chinensis leaves at a temperature of 105-115℃ for 60-90 seconds; (2) Functional flavor integration: After blanching, the Schisandra chinensis leaves are naturally cooled to 50-60℃, and then a functional flavor carrier solution at 40-50℃ is sprayed on the leaf surface. (3) Kneading: Knead the Schisandra chinensis leaves obtained in step (2) and roll them into shape; (4) Aroma mist coupling treatment: The Schisandra chinensis leaves obtained in step (3) are placed in an aroma mist at 0-10℃ to achieve the adsorption of aroma mist by the Schisandra chinensis leaves; (5) Low-temperature vacuum drying: The Schisandra chinensis leaves obtained in step (4) are subjected to low-temperature vacuum drying to obtain the Schisandra chinensis leaf substitute tea; In step (2), the functional components in the functional flavor carrier solution include natural sweeteners and soluble dietary fiber; In step (4), the aroma mist is the atomized gas of edible natural floral fragrance atomized raw material; In step (5), the temperature of the low-temperature vacuum drying process is 40-60℃.

2. The method for preparing Schisandra chinensis leaf substitute tea according to claim 1, characterized in that, The natural sweetener includes steviol glycosides, and the soluble dietary fiber includes inulin.

3. The method for preparing Schisandra chinensis leaf substitute tea according to claim 2, characterized in that, The mass ratio of steviol glycosides to inulin is 1:

3.

4. The method for preparing Schisandra chinensis leaf substitute tea according to claim 1, characterized in that, The total concentration of steviol glycosides and inulin in the functional flavor carrier solution is 7%-8% by mass-volume ratio.

5. The method for preparing Schisandra chinensis leaf substitute tea according to claim 4, characterized in that, The amount of the functional flavor carrier solution to be sprayed is: based on the weight of Schisandra chinensis leaves after blanching and before rolling, 10-30 ml of functional flavor carrier solution is sprayed per 100 g of leaves.

6. The method for preparing Schisandra chinensis leaf substitute tea according to claim 1, characterized in that, The adsorption time in step (4) is 40-50 min.

7. The method for preparing Schisandra chinensis leaf substitute tea according to claim 1, characterized in that, The steps of the low-temperature vacuum drying process are as follows: the Schisandra chinensis leaves obtained in step (4) are dehydrated and dried at a temperature of 40-60℃ and a vacuum of 0.5-10 kPa until the moisture content of the leaves drops below 8%.

8. The method for preparing Schisandra chinensis leaf substitute tea according to claim 7, characterized in that, The low-temperature vacuum drying process employs a segmented temperature program: first, drying at 40-45℃ and 5-10 kPa for 2-4 hours, and then drying at 50-60℃ and 0.5-5 kPa until the moisture content meets the standard.

9. Schisandra leaf substitute tea prepared by the preparation method according to any one of claims 1-8.

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