Coffee-flavor plant extract and preparation method thereof

Abstract

The invention discloses a coffee-flavor plant extract and a preparation method thereof, and the coffee-flavor plant extract is refined by using lophatherum gracile, Chinese olive, folium cortex eucommiae, dendrobium officinale, astragalus membranaceus, codonopsis pilosula, dandelion and liquorice as composite plant raw materials through multi-strain synergistic fermentation and oak barrel aging and curing technologies. The dissolution rate and bioavailability of various bioactive components such as chlorogenic acid, ginsenoside, curcumin and dendrobium polysaccharides are effectively improved through multi-strain synergistic fermentation. The oak barrel ageing endows the product with unique baking, nut and vanilla flavors, the taste is mellow, and the flavor characteristic of coffee is effectively simulated. The plant extract prepared by the invention is rich in various functional components, and can assist in improving the memory ability. Meanwhile, a healthy, caffeine-free and rich-flavor herbaceous plant beverage is provided for consumers, a new solution is provided for product development of plant extracts, and huge market potential and economic value are achieved.

Description

TECHNICAL FIELD

[0001] The application discloses a coffee-flavored plant extract and a preparation method thereof, and belongs to the field of nutrition and health. BACKGROUND

[0002] At present, with the improvement of consumers' health awareness, the market of natural and healthy beverages is developing rapidly. Among them, herbal beverages are attracting attention due to their natural and healthy properties. The prior art discloses various herbal beverages, such as eucommia tea and ginseng drinks prepared by simple decoction or extraction process. These products meet the consumers' specific health needs to some extent. At the same time, in order to meet the needs of people who are not suitable for caffeine intake but have a strong demand for coffee flavor, various coffee substitutes have appeared on the market, which usually use by-products and raw materials of chrysanthemum plants (such as wheat germ, chicory, etc.) to simulate the flavor of coffee (CN104663996B). In addition, fermentation technology is also applied to the development of plant-based beverages to improve flavor and nutritional value, such as fermented soy milk and fermented fruit and vegetable juice (MDPI: Plant-Based Fermented Beverages).

[0003] However, the prior art still has the following significant defects: 1. Limitation of flavor and taste: Although the existing coffee substitutes can simulate some of the bitterness or roasting of coffee, they generally lack the richness and complex layers of flavor of premium coffee. Its aroma is single and difficult to form changes in front, middle and back. 2. Single plant source product, low acceptance: The current traditional herbal beverage category is single, and the plant source paste often has a strong medicinal or bitter taste that consumers do not easily accept, and the market acceptance is low. There is no public report on the creative combination of complex herbal formula, multi-strain composite fermentation technology and "oak barrel aging" process used in high-end wine aging. This leads to a huge room for improvement in the seniority of the existing product flavor and the stability of the quality.

[0004] Therefore, it is a technical problem to be solved in the field to develop a caffeine-free herbal plant beverage that can provide a complex sensory experience comparable to or even surpassing premium coffee, and achieve synergistic effects of multiple health functions with high bioavailability through scientific compounding and innovative fermentation process. SUMMARY

[0005] In view of the low market acceptance of existing herbal plant products, the single herbal beverage, and the low reduction of coffee substitutes, the present application aims to provide a coffee-flavored plant extract for improving memory ability and a preparation method thereof. The method uses innovative raw material compounding, multi-strain synergistic fermentation, and oak barrel aging and maturation technology to prepare a product that has a multi-layered sensory flavor similar to coffee and synergistic health effects of multiple plant components.

[0006] The first object of the present application is to provide a preparation method of a plant extract with coffee flavor but without coffee beans, comprising the following steps:

[0007] S1, pulverizing and uniformly mixing Ginkgo biloba L., Terminalia chebula Retz., Eucommia ulmoides Oliv., Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and Glycyrrhiza uralensis in proportions to obtain a herbal plant composite powder;

[0008] S2, baking and ultrasonic water extraction of the plant composite powder of step S1 to obtain a fermentation base liquid;

[0009] S3, microbial fermentation of the fermentation base liquid of step S2;

[0010] S4, sterilization and cooling of the fermentation liquid of step S3, and then transferring into an oak barrel for aging treatment;

[0011] S5, centrifugation, homogenization, sterilization, and drying of the aged liquid of step S4 to obtain a plant extract.

[0012] Optionally, in an embodiment of the present application, the plant composite powder in step S1 is mixed in proportions by weight as follows: Ginkgo biloba L. 20-28 parts, Terminalia chebula Retz. 14-25 parts, Eucommia ulmoides Oliv. 11-19 parts, Dendrobium officinale 8-16 parts, Astragalus membranaceus 5-10 parts, Codonopsis pilosula 5-10 parts, Taraxacum mongolicum 5-10 parts, and Glycyrrhiza uralensis 2-8 parts.

[0013] Optionally, in an embodiment of the present application, the baking temperature in step S2 is 160-180℃, and the baking time is 20 min-40 min; the ultrasonic water extraction frequency is 120-180 kHz, the extraction temperature is 80-90℃, the extraction time is 1-2 h, and the solid-liquid ratio is 1:10 (w / w).

[0014] Optionally, in an embodiment of the present application, the microorganism fermentation in step S3 uses Lactobacillus and Saccharomyces cerevisiae as the strains, the fermentation pH is 6.5-7.5, the inoculation amount is 1×10 6 -1×10 7 CFU / mL (viable bacteria count / fermentation base liquid volume), the fermentation temperature is 37-40℃, the fermentation time is 24-48 h, and the inoculation amount of Lactobacillus and Saccharomyces cerevisiae is 2:1.

[0015] Optionally, in an embodiment of the present application, the oak barrel in step S4 is an oak barrel subjected to baking treatment, including a light baking oak barrel, a medium baking oak barrel, or a heavy baking oak barrel; the aging treatment temperature is 10-20℃, and the aging treatment time is 15-30 days.

[0016] Optionally, in an embodiment of the present application, the centrifugation in step S5 is horizontal screw centrifugation, the speed is 3000 rpm; the homogenization pressure is 25-35 MPa; the sterilization is 135-142℃ for 5-15 s; and the drying method is one of spray drying, freeze drying and reduced pressure drying.

[0017] Optionally, in an embodiment of the present application, the present application provides a preparation method of coffee-flavored plant extract, comprising the following steps:

[0018] S1, pulverize and uniformly mix Lophatherum gracile Brongn., Terminalia chebula Retz., Eucommia ulmoides Oliv. leaves, Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and licorice according to proportions to obtain a herbal plant composite powder, the proportions are as follows: 20-28 parts of Lophatherum gracile Brongn., 14-25 parts of Terminalia chebula Retz., 11-19 parts of Eucommia ulmoides Oliv. leaves, 8-16 parts of Dendrobium officinale, 5-10 parts of Astragalus membranaceus, 5-10 parts of Codonopsis pilosula, 5-10 parts of Taraxacum mongolicum, and 2-8 parts of licorice;

[0019] S2, roast and ultrasonic water extract the herbal plant composite powder in step S1 to obtain a fermentation base liquid. The roasting temperature is 160-180℃, and the roasting time is 20-40 min; the ultrasonic water extraction frequency is 120-180 kHz, the extraction temperature is 80-90℃, the extraction time is 1-2 h, and the solid-liquid ratio is 1:10 (w / w);

[0020] S3, microorganism ferment the fermentation base liquid in step S2, the microorganism fermentation uses Lactobacillus and Saccharomyces cerevisiae, the fermentation pH is 6.5-7.5, the inoculation amount is 1×10 6 -1×10 7 CFU / mL (viable bacteria count / fermentation base liquid volume), the fermentation temperature is 37-40℃, the fermentation time is 24-48 h, and the inoculation amount of Lactobacillus and Saccharomyces cerevisiae is 2:1;

[0021] S4, after sterilization and cooling of the fermentation liquid in step S3, transfer the fermentation liquid into an oak barrel for aging treatment, the oak barrel is an oak barrel that has been roasted, including a lightly roasted oak barrel, a moderately roasted oak barrel or a heavily roasted oak barrel; the aging treatment temperature is 10-20℃, and the aging treatment time is 15-30 days;

[0022] S5, centrifuge, homogenize, sterilize and dry the aging liquid in step S4 to obtain the plant extract. The centrifugation is horizontal screw centrifugation, the speed is 3000 rpm; the homogenization pressure is 25-35 MPa; the sterilization is 135-142℃ for 5-15 s.

[0023] A second object of the present application is to provide a plant extract having a coffee flavor but not containing coffee beans, prepared according to any of the above-mentioned methods.

[0024] A third object of the present application is to provide the use of the above-mentioned plant extract in foodstuffs, including beverages, dairy products, solid beverages, meal replacement powders or instant teas.

[0025] Advantages of the present application:

[0026] 1. High reduction degree of coffee flavor: By combining raw material roasting, multi-strain fermentation and core oak barrel aging process, the product of the present application not only has the mellow and smoky bottom of coffee, but also combines ester aroma, herbal origin aroma produced by fermentation, and vanilla, spice and other aging aroma imparted by oak barrel, forming a complex, smooth and high-grade sensory experience far superior to existing coffee substitutes.

[0027] 2. Innovative application of herbal plants: The present application improves the dissolution rate and bioavailability of active ingredients by scientifically compounding and innovatively extracting herbal plants. The product of the present application is 100% derived from plant raw materials and does not contain caffeine. No chemical solvents, artificial flavors, pigments and preservatives are added during production, meeting the demand for clean label and natural products in the healthy consumption market.

[0028] 3. New effect of herbal plant extract: The present application innovatively discovers that the plant extract prepared by the present application has the effect of significantly improving memory. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Sensory evaluation radar chart (10-point system) for examples, comparative examples, and commercially available coffee powder.

[0030] Figure 2 Schematic diagram of the results of the conditioned fear experiment of the examples of the present application.

[0031] Figure 3 Schematic diagram of the results of the maze experiment of the examples of the present application. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. The present application can be better understood from the following examples. However, those skilled in the art will readily understand that the specific material ratios, process conditions and results described in the examples are only for illustrating the present application and should not and will not limit the present application described in detail in the claims.

[0033] Example 1

[0034] A coffee-flavored plant extract for improving memory, the specific steps are as follows:

[0035] (1) A certain amount of lophatherum gracile, Terminalia chebula, Eucommia ulmoides Oliv, Dendrobium officinale, Astragalus membranaceus, radix, dandelion, licorice is crushed, and then 28 parts of lophatherum gracile, 25 parts of Terminalia chebula, 19 parts of Eucommia ulmoides Oliv, 16 parts of Dendrobium officinale, 10 parts of Astragalus membranaceus, 10 parts of radix, 10 parts of dandelion, and 8 parts of licorice are mixed to obtain a composite herbal plant powder;

[0036] (2) The composite herbal plant powder obtained in step (1) is placed in an oven for baking, the baking temperature is 180°C, and after baking for 40 min, the composite herbal plant powder is dissolved in 1260 parts of pure water, ultrasonic water extraction is performed, the ultrasonic frequency is set to 180 kHz, the extraction temperature is 90°C, and after extraction for 2 h, a fermentation base liquid is obtained.

[0037] (3) The fermentation base liquid obtained in step (2) is transferred into a fermentation tank, the pH is adjusted to 7.5, the temperature is set to 40°C, 6.6x10 6 CFU / mL of lactobacillus plantarum bacteria and 3.3x10 6 CFU / mL of saccharomyces cerevisiae are inoculated, and fermentation is carried out for 24 h;

[0038] (4) The fermentation liquid obtained in step (3) is heated and sterilized, and after cooling, it is transferred into a lightly toasted oak barrel for aging treatment, the aging treatment temperature is set to 20°C, and the aging time is 15 days;

[0039] (5) The aged liquid obtained in step (4) is subjected to horizontal screw centrifugation at a speed of 3000 rpm, then homogenized under a pressure of 35 MPa, finally sterilized by an ultra-high temperature instantaneous sterilization machine, the sterilization temperature is set to 142°C, the holding time is 5 s, after sterilization, freeze-drying is carried out, and a herbal plant base instant powder is obtained.

[0040] Example 2

[0041] A coffee-flavored plant extract preparation method for improving memory ability, the specific steps are as follows:

[0042] (1) A certain amount of lophatherum gracile, Terminalia chebula, Eucommia ulmoides Oliv, Dendrobium officinale, Astragalus membranaceus, radix, dandelion, and licorice are crushed, and then 24 parts of lophatherum gracile, 20 parts of Terminalia chebula, 15 parts of Eucommia ulmoides Oliv, 12 parts of Dendrobium officinale, 7 parts of Astragalus membranaceus, 8 parts of radix, 7 parts of dandelion, and 5 parts of licorice are mixed to obtain a composite herbal plant powder;

[0043] (2) The composite herbal plant powder obtained in step (1) is placed in an oven for baking, the baking temperature is 170°C, and the baking time is 30 min; the composite herbal plant powder is dissolved in 980 parts of water, ultrasonic water extraction is performed, the ultrasonic frequency is 150 kHz, the extraction temperature is 85°C, and after extraction for 1.5 h, a fermentation base liquid is obtained.

[0044] (3) The fermentation base liquid obtained in step (2) is transferred into a fermentation tank, the pH is adjusted to 7, the temperature is set to 38°C, 3x10 6 CFU / mL of Lactobacillus plantarum bacteria and 1.5x10 6 CFU / mL of Saccharomyces cerevisiae are inoculated, and fermentation is performed for 36 h;

[0045] (4) The fermentation liquid obtained in step (3) is warmed and sterilized, and after cooling, it is transferred into a lightly toasted oak barrel for aging treatment, the temperature for aging treatment is set to 15°C, and aging is performed for 22 days;

[0046] (5) The aged liquid obtained in step (4) is subjected to horizontal screw centrifugation at a speed of 3000 rpm, then homogenized under a pressure of 30 MPa, and finally sterilized by an ultra-high temperature instantaneous sterilization machine, the sterilization temperature is set to 139°C, the holding time is 10 s, after sterilization, spray drying is performed, and a herbal plant-based instant powder is obtained.

[0047] Example 3

[0048] A coffee-flavored plant extract preparation method for improving memory ability, the specific steps are as follows:

[0049] (1) A certain amount of lamiophlomis rotata, Terminalia chebula, Eucommia ulmoides, Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and licorice are crushed, and then 20 parts of lamiophlomis rotata, 14 parts of Terminalia chebula, 11 parts of Eucommia ulmoides, 8 parts of Dendrobium officinale, 5 parts of Astragalus membranaceus, 5 parts of Codonopsis pilosula, 5 parts of Taraxacum mongolicum, and 2 parts of licorice are mixed uniformly to obtain a composite herbal plant powder;

[0050] (2) The composite herbal plant powder obtained in step (1) is baked in an oven, the baking temperature is 160°C, and the baking time is 20 min; the composite herbal plant powder is dissolved in 700 parts of water, and ultrasonic water extraction is performed, the ultrasonic frequency is set to 120 kHz, the extraction temperature is 80°C, and the extraction time is 1 h, and then a fermentation base liquid is obtained.

[0051] (3) The fermentation base liquid obtained in step (2) is transferred into a fermentation tank, the pH is adjusted to 6.5, the temperature is set to 37°C, 7x10 5 CFU / mL of Lactobacillus plantarum bacteria and 3.5x10 5 CFU / mL of Saccharomyces cerevisiae are inoculated, and fermentation is performed for 48 h;

[0052] (4) The fermentation liquid obtained in step (3) is warmed and sterilized, and after cooling, it is transferred into a lightly toasted oak barrel for aging treatment, the temperature for aging treatment is set to 10°C, and aging is performed for 30 days;

[0053] (5) The maturation liquid obtained in step (4) is subjected to horizontal screw centrifugation at a speed of 3000 rpm; then homogenization is performed under a pressure of 25 MPa, and finally sterilization is performed by an ultra-high temperature instantaneous sterilization machine, with the sterilization temperature set to 135 ℃ and the holding time set to 15 s; after sterilization, the product is subjected to reduced-pressure drying to obtain the herbal plant-based instant powder.

[0054] Comparative Example 1

[0055] The preparation method is the same as that in Example 1, except that the herbal plant extract is prepared without microbial synergistic fermentation. The specific steps are as follows:

[0056] (1) A certain amount of lophatherum gracile, Terminalia chebula, Eucommia ulmoides leaf, Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and licorice are crushed, and then 28 parts of lophatherum gracile, 25 parts of Terminalia chebula, 19 parts of Eucommia ulmoides leaf, 16 parts of Dendrobium officinale, 10 parts of Astragalus membranaceus, 10 parts of Codonopsis pilosula, 10 parts of Taraxacum mongolicum, and 8 parts of licorice are mixed uniformly to obtain a composite herbal plant powder;

[0057] (2) The composite herbal plant powder obtained in step (1) is placed in an oven for baking, with the baking temperature set to 180 ℃ and the baking time set to 40 min; then the composite herbal plant powder is dissolved in 1260 parts of pure water, and ultrasonic water extraction is performed, with the ultrasonic frequency set to 180 kHz and the extraction temperature set to 90 ℃; after 2 h of extraction, a fermentation base liquid is obtained.

[0058] (3) The fermentation base liquid obtained in step (2) is subjected to liquid sterilization, and after cooling, it is transferred into a lightly toasted oak barrel for maturation treatment, with the maturation temperature set to 20 ℃ and the maturation time set to 15 days;

[0059] (4) The maturation liquid obtained in step (3) is subjected to horizontal screw centrifugation at a speed of 3000 rpm; then homogenization is performed under a pressure of 35 MPa, and finally sterilization is performed by an ultra-high temperature instantaneous sterilization machine, with the sterilization temperature set to 142 ℃ and the holding time set to 5 s; after sterilization, the product is subjected to freeze-drying to obtain the herbal plant-based instant powder.

[0060] Comparative Example 2

[0061] The preparation method is the same as that in Example 1, except that the herbal plant extract is prepared without oak barrel maturation. The specific steps are as follows:

[0062] (1) A certain amount of lophatherum gracile, Terminalia chebula, Eucommia ulmoides leaf, Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and licorice are crushed, and then 28 parts of lophatherum gracile, 25 parts of Terminalia chebula, 19 parts of Eucommia ulmoides leaf, 16 parts of Dendrobium officinale, 10 parts of Astragalus membranaceus, 10 parts of Codonopsis pilosula, 10 parts of Taraxacum mongolicum, and 8 parts of licorice are mixed uniformly to obtain a composite herbal plant powder;

[0063] (2) The composite herbal plant powder obtained in step (1) is placed in an oven for baking, the baking temperature is 180°C, and after baking for 40 min, the composite herbal plant powder is dissolved in 1260 parts of pure water, ultrasonic water extraction is performed, the ultrasonic frequency is set to 180 kHz, the extraction temperature is 90°C, and after extraction for 2 h, a fermentation base liquid is obtained.

[0064] (3) The fermentation base liquid obtained in step (2) is transferred into a fermentation tank, the pH is adjusted to 7.5, the temperature is set to 40°C, 6.6x10 6 CFU / mL of Lactobacillus plantarum bacteria and 3.3x10 6 CFU / mL of Saccharomyces cerevisiae are inoculated, and fermentation is performed for 24 h.

[0065] (4) The fermentation liquid obtained in step (3) is subjected to horizontal screw centrifugation at a speed of 3000 rpm, then homogenization is performed under a pressure of 35 MPa, and finally sterilization is performed by an ultra-high temperature instantaneous sterilization machine, the sterilization temperature is set to 142°C, the holding time is 5 s, after sterilization, freeze-drying is performed, and a herbal plant-based instant powder is obtained.

[0066] Comparative Example 3

[0067] The preparation method is the same as that of Example 1, except that no microbial synergistic fermentation is performed and no oak barrel aging is performed, and a herbal plant extract is prepared. The specific steps are as follows:

[0068] (1) A certain amount of lamiophlomis rotata, Terminalia chebula, Eucommia ulmoides leaf, Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and licorice are crushed, 28 parts of lamiophlomis rotata, 25 parts of Terminalia chebula, 19 parts of Eucommia ulmoides leaf, 16 parts of Dendrobium officinale, 10 parts of Astragalus membranaceus, 10 parts of Codonopsis pilosula, 10 parts of Taraxacum mongolicum, and 8 parts of licorice are taken, and mixed uniformly to obtain a composite herbal plant powder;

[0069] (2) The composite herbal plant powder obtained in step (1) is placed in an oven for baking, the baking temperature is 180°C, and after baking for 40 min, the composite herbal plant powder is dissolved in 1260 parts of pure water, ultrasonic water extraction is performed, the ultrasonic frequency is set to 180 kHz, the extraction temperature is 90°C, and after extraction for 2 h, a fermentation base liquid is obtained.

[0070] (3) The fermentation base liquid obtained in step (2) is subjected to horizontal screw centrifugation at a speed of 3000 rpm, then homogenization is performed under a pressure of 35 MPa, and finally sterilization is performed by an ultra-high temperature instantaneous sterilization machine, the sterilization temperature is set to 142°C, the holding time is 5 s, after sterilization, freeze-drying is performed, and a herbal plant-based instant powder is obtained.

[0071] Results of Examples and Comparative Examples, and comparison:

[0072] 1. Comparative analysis of physical and chemical indicators

[0073] Herbal plants contain a variety of active components. The method of this invention can enhance the dissolution of active components from herbal plants, thus efficiently utilizing herbal raw materials. The polysaccharide content, chlorogenic acid content, 2-methylfuran, total flavonoid content, and DPPH free radical scavenging rate (instant powder concentration 1 mg / mL) of the samples from Examples 1-3 and Comparative Examples 1-3 were determined respectively. The test results are shown in Table 1.

[0074] Table 1 Comparison of Physicochemical Indicators of Different Products

[0075]

[0076] The results in Table 1 show that the plant extracts prepared in Examples 1-3 have significantly higher contents of chlorogenic acid and total flavonoids compared to Comparative Examples 1-3. Specifically, the chlorogenic acid content of the instant powder in Example 1 is more than twice that of the instant powder in Comparative Example 3. Multi-strain synergistic fermentation degrades accompanying components such as carbohydrates and proteins, resulting in increased dissolution rates of active ingredients. Chlorogenic acid and 2-methylfuran are important non-volatile and volatile components in coffee flavor components, respectively, and the contents of these flavor components in the plant extracts prepared in Examples 1-3 are significantly higher than those in the comparative examples. The herbal plant extracts prepared by this invention exhibit significantly improved active content, which is beneficial for improving the utilization rate of herbal plant raw materials and has important significance for the development and promotion of herbal plant products.

[0077] 2. Sensory evaluation comparative analysis

[0078] Ten professionally trained sensory evaluators conducted a blind taste test (out of 10) using quantitative descriptive analysis (QDA) on seven samples of Examples 1-3, Comparative Examples 1-3, and commercially available coffee powder, evaluating them based on dimensions such as aroma (fragrance, flavor), taste (body, acidity, aftertaste, balance), and overall preference. Sensory evaluation radar charts (out of 10) for different products are shown below. Figure 1 As shown.

[0079] pass Figure 1 The results showed that the instant powders prepared in Examples 1-3 scored higher than commercially available coffee powders in terms of overall preference, aftertaste, balance, and body. Their aroma, flavor, and acidity were also extremely similar to those of commercially available coffee powders. The instant powder in Comparative Example 3, which did not undergo extensive co-fermentation with various microorganisms or oak barrel aging, had an overall preference score approximately 50% lower than that of the instant powder in Example 1. This indicates that the herbal-based instant powder prepared according to this invention can deeply reproduce the flavor of coffee, resulting in a harmonious blend of flavors and a balanced taste.

[0080] 3. Animal experiments to enhance memory

[0081] Thirty-six healthy 5-week-old male C57BL / 6J mice were selected and, after 1 week of acclimatization, were randomly divided into three groups (n=12) according to their body weight: blank control group, comparative group 1, and example group 1.

[0082] Comparative Example 1: The plant extract suspension of Comparative Example 1 was administered by gavage at a dose of 0.1 g / kg / day;

[0083] Example 1 group: Gavage administration of the plant extract suspension from Example 1 at a dose of 0.1 g / kg / day;

[0084] Blank control group: Gavage with an equal volume of placebo (maltodextrin solution).

[0085] Intervention period: 6 consecutive weeks. All mice were housed under identical environmental conditions with free access to food and water. Behavioral tests were conducted after the intervention.

[0086] (1) Situational fear conditioning experiment: used to assess hippocampal dependent situational memory.

[0087] On training days, mice were placed in a specific situation and given a foot shock. After 24 hours, they were returned to the original situation, and the duration of rigidity was recorded within 5 minutes. The percentage of rigidity time was calculated. A higher percentage of rigidity indicates a stronger memory of the dangerous situation. This behavior mainly relies on the combined functions of the hippocampus (for forming episodic memories) and the amygdala (for processing fear).

[0088] (2) Y-maze experiment: used to assess spatial working memory and exploration desire.

[0089] Mice were placed in the center of a Y-maze and allowed to explore freely for 8 minutes. The number of times and the time taken for each arm to enter were recorded. The exploration time of novel arms is a key indicator for assessing spatial memory. Assuming the overall exploration desire is the same, a longer exploration time of novel arms directly reflects stronger spatial working memory ability.

[0090] Through such Figure 2 The results of the conditioned fear experiment in mice showed that, after intervention, the proportion of conditioned rigidity fear in the mice in Example 1 group was significantly increased compared with that in the control group, reaching 15.8%, indicating that the plant extract obtained in Example 1 group can enhance non-hippocampal dependent memory in mice.

[0091] Through such Figure 3 The results of the mouse maze experiment shown indicate that, after intervention, the time for mice in Example 1 to explore new foreign walls was significantly increased compared to that in Comparative Example 1, indicating that the plant extract obtained in Example 1 can improve the spatial memory ability of mice.

[0092] The behavioral test results show that the plant extract of Example 1 can simultaneously and significantly enhance hippocampus-dependent spatial memory (Y-maze) and hippocampus-amygdala involved contextual fear memory, while the extract of Comparative Example 1 has limited effect. This may be related to the increase in the contents of chlorogenic acid, polysaccharide and flavonoids in the plant extract, which synergistically improve energy, regulate mood and concentration, thereby improving memory capacity.

[0093] 4. Human experiment for assisting in improving memory capacity

[0094] In this experiment, a random double-blind and placebo-controlled design was adopted. 90 subjects aged 50-59 years old who complained of memory decline were recruited and randomly divided into an experimental group, a control group 1 and a blank group, with 30 people in each group. After a 2-week introduction period, the experimental group, the control group and the blank group took 10 g of the plant extract prepared by Example 1 of the application, 10 g of the plant extract prepared by Comparative Example 1 of the application and 10 g of placebo maltodextrin respectively every day, for 12 weeks of continuous intervention. The main test adopted standardized tools such as Wechsler Memory Scale and auditory word learning test, and cognitive function was evaluated before and after intervention. The results are shown in Table 2.

[0095] Table 2: Results of cognitive function evaluation of plant extract

[0096]

[0097] From the data in Table 2, it can be found that after the intervention of the plant extract prepared by Example 1 of the application, the subjects in the experimental group had significantly improved Wechsler memory quotient and auditory word learning ability, which were better than those in the control group and the blank group, indicating that the plant extract prepared by the application was helpful to improve memory capacity, which may be related to the increase in the contents of chlorogenic acid, polysaccharide and flavonoids in the plant extract, which synergistically improve energy, regulate mood and concentration, thereby improving memory capacity.

[0098] The above only describes the preferred embodiments of the application, and it should be noted that for those skilled in the art, without departing from the principles of the application, some improvements and refinements can be made, which should also be considered within the protection scope of the application.

Claims

1. A method for preparing a plant extract with a coffee flavor but without coffee beans, characterized in that, Includes the following steps: S1. Powder the following herbs: Lophatherum gracile, Terminalia chebula, Eucommia ulmoides, Dendrobium officinale, Astragalus membranaceus, Codonopsis pilosula, Taraxacum mongolicum, and Glycyrrhiza uralensis. Mix them evenly in a certain proportion to obtain a compound powder of herbal plants. S2. The plant compound powder described in step S1 is baked and ultrasonically extracted to obtain a fermentation base liquid; S3. Microbial fermentation is carried out on the fermentation base liquid described in step S2; S4. After sterilizing and cooling the fermentation liquid described in step S3, transfer it to an oak barrel for maturation. S5. Centrifuge, homogenize, sterilize and dry the maturation liquid obtained in step S4 to obtain plant extract.

2. The method according to claim 1, characterized in that, The plant compound powder in step S1 is formulated in the following proportions by weight: 20-28 parts of Lophatherum gracile, 14-25 parts of Terminalia chebula, 11-19 parts of Eucommia ulmoides, 8-16 parts of Dendrobium officinale, 5-10 parts of Astragalus membranaceus, 5-10 parts of Codonopsis pilosula, 5-10 parts of Taraxacum mongolicum, and 2-8 parts of Glycyrrhiza uralensis.

3. The preparation method according to claim 1, characterized in that, In step S2, the baking temperature is 160-180℃ and the time is 20 min-40 min; the ultrasonic water extraction has an ultrasonic frequency of 120-180 kHz, an extraction temperature of 80-90℃, an extraction time of 1-2 h, and a material-to-liquid ratio of 1:10 (w / w).

4. The method according to claim 1, characterized in that, The microbial fermentation in step S3 uses Lactobacillus plantarum and Saccharomyces cerevisiae strains, with a fermentation pH of 6.5-7.5 and an inoculum size of 1×10⁻⁶. 6 -1×10 7 The optimal fermentation conditions were: CFU / mL (viable bacteria count / fermentation base volume), fermentation temperature 37-40℃, fermentation time 24-48 h, and inoculation ratio of Lactobacillus plantarum and Saccharomyces cerevisiae 2:

1.

5. The method according to claim 1, characterized in that, The oak barrels mentioned in step S4 are oak barrels that have undergone baking treatment, including lightly baked oak barrels, medium-baked oak barrels, or heavily baked oak barrels; the baking treatment temperature is 10-20℃, and the time is 15-30 days.

6. The method according to claim 1, characterized in that, In step S5, centrifugation is performed by horizontal screw centrifugation at a speed of 3000 rpm; homogenization pressure is 25-35 MPa; sterilization is performed at 135-142℃ for 5-15 seconds; and drying is performed by one of spray drying, freeze drying, or vacuum drying.

7. A plant extract having a coffee flavor but containing no coffee beans, prepared by the method according to any one of claims 1-6.

8. The application of the plant extract according to claim 7 in foods including beverages, dairy products, solid beverages, meal replacement powders or freshly made tea drinks.

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