Tea extract, its preparation method and application

Abstract

The present application provides a kind of coffee or tea extract and its preparation method, specifically, the present application is related to the present application provides a kind of coffee or tea extraction method, it includes with emulsified fat composition to the coffee or tea extraction step;Wherein, the emulsified fat composition contains fat base product, water and optional emulsifier;The fat content in the composition is 1-50%, and the protein content is 0-2%.The method described in the present application can significantly improve the oil-soluble flavor substance extraction yield in coffee or tea extract compared with traditional water extraction method, while maintaining the water-soluble active ingredient yield is equivalent.In addition, compared with the extraction method of skim milk or whole milk with higher protein content, the bitterness of the product can be reduced.The extract can be used to prepare milk-containing coffee, milk tea and other products with unique flavor.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 202011360617.6, filed with the Chinese Patent Office on November 27, 2020, entitled "An Extract of Coffee or Tea and a Method for Preparing the Same Thereof". This application also claims priority to Chinese Patent Application No. 201911200601.6, filed with the Chinese Patent Office on November 29, 2019, entitled "An Extract of Coffee or Tea and a Method for Preparing the Same Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a method for extracting coffee or tea using a diluted cream or other emulsified fat system as the extraction medium. Compared to traditional water extraction methods, this method significantly increases the extraction yield of oil-soluble flavor compounds in coffee or tea while maintaining a comparable yield of water-soluble active ingredients. Furthermore, compared to extraction methods using skim milk or whole milk, which have higher protein content, this method significantly reduces the bitterness of the product. Background Technology

[0003] Coffee and tea beverages are loved by consumers worldwide. The traditional method of drinking coffee and tea is to brew them with hot water. However, using water as an extraction medium has a drawback—water-soluble substances are easily extracted, but oil-soluble substances have a relatively low extraction rate. Summary of the Invention

[0004] The inventors have developed a method for extracting coffee or tea using an emulsified, fat-containing extraction medium. This extraction medium better extracts oil-soluble flavor compounds from (ground) coffee beans or tea leaves, thereby better preserving these flavor compounds. This is likely due to the fat emulsification system forming a stable structure that encapsulates the flavor compounds. The coffee or tea extract obtained by this method can be used to prepare ready-to-drink beverages, solid beverages, or solid foods containing milk, such as milk coffee or milk tea, with improved flavor.

[0005] In one aspect, this application provides a method for extracting coffee or tea.

[0006] It includes the step of extracting the coffee or tea using an emulsified fat composition; wherein,

[0007] The emulsified fat composition contains a fat-based product, water, and optionally an emulsifier; the fat content of the composition is 1-50%, and the protein content is 0-2%. In some preferred embodiments, the fat content of the composition is 1-30%, and the protein content is 0-1%.

[0008] In embodiments of this application, the fat and / or protein content in the composition can be adjusted to a target value based on the fat and / or protein content indicated in the commercially available raw materials. If necessary, the fat and protein content can also be detected using methods known in the art, such as the method for detecting the fat content in the composition according to GB 5413.3-2010, or the method for detecting the protein content in the composition according to GB 5009.5-2010.

[0009] In some embodiments, the composition contains 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 35%, 40%, 45%, or 50% fat.

[0010] Commercially available fat-based products, such as cream, butter, or vegetable oils, inevitably contain a certain amount of protein. However, it should be noted that, based on experimental studies, protein does not significantly promote extraction yield, and it can flocculate and precipitate under the influence of organic acids and polyphenols found in medicinal and edible plants, affecting the extraction process. To achieve the objectives of this invention, the protein content in the emulsified fat composition is 0-2%, for example, 0-1%. In some embodiments, the protein content in the composition is 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2.0%.

[0011] As used herein, fat-based products refer to products that provide fat, an important component of the composition. In some embodiments, the fat-based product is selected from one or more of the following: animal fats and fats and their products, vegetable oils and fats and their products, and milk fats and their products.

[0012] In some embodiments, the animal fats and their products are selected from lard, tallow, mutton tallow, fish oil, and any combination thereof.

[0013] In some embodiments, the vegetable oils and their products are selected from vegetable oils, hydrogenated vegetable oils, non-dairy creamer, cocoa butter substitutes, and any combination thereof. In some preferred embodiments, the vegetable oil may be, for example, peanut oil, soybean oil, sunflower seed oil, coconut oil, palm oil, cocoa butter, linseed oil, sesame oil, castor oil, rapeseed oil, or any combination thereof. In some preferred embodiments, the hydrogenated vegetable oil may be, for example, hydrogenated peanut oil, hydrogenated soybean oil, hydrogenated sunflower seed oil, hydrogenated coconut oil, hydrogenated palm oil, hydrogenated cocoa butter, hydrogenated linseed oil, hydrogenated sesame oil, hydrogenated castor oil, hydrogenated rapeseed oil, or any combination thereof. The non-dairy creamer is commercially available, for example, K28 non-dairy creamer. In some embodiments, the main components of the non-dairy creamer include glucose syrup, hydrogenated vegetable oil, milk powder, sodium caseinate, mono- and diglycerides of fatty acids, diacetyl tartrate mono- and diglycerides, sodium stearoyl lactylate, dipotassium hydrogen phosphate, sodium hexametaphosphate, sodium citrate, and silicon dioxide, etc.

[0014] In some embodiments, the milk fat and its products are selected from milk fat, cream, and butter.

[0015] The milk fat referred to in this article is the fatty portion extracted from the milk of animals (such as cows or sheep) and contains almost no water.

[0016] The light cream described herein refers to the fat-containing portion separated from milk, which is an O / W type emulsion with a fat content of 10.0%-80.0%. The light cream used in the embodiments of this application has a fat content of 38%.

[0017] The butter described herein refers to a product made from milk and / or cream or light cream (fermented or unfermented) with a fat content of not less than 80.0%. The butter used in the embodiments of this application has a fat content of 80%.

[0018] In some embodiments, the emulsified fat composition of this application consists of light cream and water. The ratio of the two depends on the fat content in the composition, such that the fat content in the composition is 1-50% and the protein content is 0-2%, for example, the fat content in the composition is 1-30% and the protein content is 0-1%.

[0019] In some embodiments, the emulsified fat composition of this application is an emulsion formed by dispersing a fat-based product and optionally an emulsifier in water. The emulsion is an aggregate of a large number of particles of different sizes. To characterize the emulsion, this application measures the particle size. As is known in the art, the size of a particle is called particle size, and the diameter of a particle is called particle diameter. The size of a particle (i.e., particle size) is usually measured based on its diameter (i.e., particle diameter). However, the shape of actual particles is often very complex and difficult to describe using a single scale (such as particle diameter). Therefore, the concept of "equivalent particle diameter" is introduced in particle size testing. The equivalent particle diameter is the diameter of a spherical particle when a certain physical property of the particle is the same as or similar to that of a homogeneous spherical particle. Common equivalent particle diameters include equivalent volume diameter, Stokes diameter, and equivalent sieve diameter. This application measures the equivalent volume diameter of the emulsified fat composition using a laser particle size analyzer. The term "D90 particle size" refers to the equivalent particle size of the largest particle when the cumulative distribution in the measured particle size distribution curve of the sample reaches 90%. Physically, it means that 90% of the particles in the sample have a diameter smaller than this value. Similarly, the term "D50 particle size" refers to the equivalent particle size of the largest particle when the cumulative distribution in the measured particle size distribution curve of the sample reaches 50%. Physically, it means that 50% of the particles in the sample have a diameter smaller than this value, and it is often used to characterize the average particle size of an emulsion. In some embodiments, the emulsified fat composition described in this application is an emulsion with a D90 particle size less than 100 μm, for example, less than 50 μm, or even less than 15 μm. The emulsified fat composition can be prepared according to suitable methods in the art. For example, the emulsified fat composition can be obtained through high-shear or homogenization treatment. In some embodiments, an emulsifier may be added to promote emulsification. Suitable emulsifiers are those with an HLB value of 8-18 (e.g., 10-16), such as glyceryl monosuccinate, glyceryl disuccinate, sodium caseinate, sodium octenyl succinate starch, sucrose fatty acid esters, sorbitan fatty acid esters, etc., and further examples include diacetyl tartaric acid monoglyceride, sodium stearoyl lactylate, sucrose fatty acid esters, and combinations thereof with lipophilic emulsifiers such as saturated fatty acid monoglycerides; preferably, sucrose fatty acid esters with an HLB value of 15. In some embodiments, the emulsifier accounts for 0.1-2% of the total weight of the composition. In some embodiments, the emulsifier accounts for 0.3-1% of the total weight of the composition.

[0020] In some embodiments, the emulsified fat composition comprises butter or vegetable oil, water, and an emulsifier (e.g., sucrose ester). The butter or vegetable oil provides the fat, the emulsifier is added in an amount of 0.3-1% of the total amount of the emulsified fat composition, and the water is used such that the fat content in the composition is 1-50%, for example, 1-30%.

[0021] In some implementations, the method includes the following steps:

[0022] Add 5-50 times the weight of the emulsified fat composition to coffee or tea, stir at 1-95°C for 5-120 min, centrifuge, and collect the centrifuged liquid; optionally, the process also includes a post-treatment step of the centrifuged liquid (e.g., concentration, freeze drying, or spray drying).

[0023] In some implementation schemes, the extraction temperature is 2-4°C;

[0024] In some implementation schemes, the extraction temperature is 40-90°C;

[0025] In some implementation schemes, the extraction temperature is 60-70°C;

[0026] In some implementations, centrifugation at 10-4000g for 1-10 minutes is performed.

[0027] In some preferred embodiments, 10-25 times the amount of the emulsified fat composition is added to the coffee or tea. In some preferred embodiments, 10-20 times the amount of the emulsified fat composition is added to the ground coffee or tea.

[0028] In some preferred embodiments, heating and stirring are performed for 5-60 minutes. In some preferred embodiments, heating and stirring are performed for 15-30 minutes.

[0029] In some embodiments, the post-processing step refers to the step of concentrating and / or drying the centrifuged liquid, such as by vacuum (or freeze-drying) concentration, or spray drying.

[0030] In some preferred embodiments, the coffee is coffee powder; preferably, it is coffee powder made from lightly roasted, medium roasted, or dark roasted coffee beans.

[0031] In some preferred embodiments, the tea is tea powder; preferably, it is lightly fermented tea, semi-fermented tea, fully fermented tea, or post-fermented tea, or tea powder obtained by pulverizing it; more preferably, it is tea powder obtained by pulverizing and passing it through a 40-mesh sieve; even more preferably, it is black tea powder.

[0032] In another aspect, this application provides a coffee powder extract prepared by the aforementioned method. In some preferred embodiments, the total tannin content in the extract does not exceed 110% of the total tannin content in an aqueous extract under equivalent conditions.

[0033] In another aspect, this application provides a tea extract prepared by the aforementioned method. In some preferred embodiments, the total tannin content in the extract does not exceed 110% of the total tannin content in an aqueous extract under equivalent conditions.

[0034] In another aspect, this application provides a composition containing the aforementioned coffee extract or tea extract. In some preferred embodiments, the composition is a ready-to-drink beverage, solid beverage, or solid food containing milk coffee or tea.

[0035] Unless otherwise stated, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, the laboratory procedures described herein are all standard procedures widely used in the relevant fields. Additionally, to better understand this invention, definitions and explanations of relevant terms are provided below.

[0036] As used herein, the term "Brix value" refers to the total soluble solids content (in %) in a solution as measured by a refractometer.

[0037] The methods and emulsified fat compositions described herein are also applicable to the extraction of fruits or edible or medicinal plants (e.g., vegetables). The fruits may include, for example, Rosaceae fruits: such as apples, crabapples, crabapples, cherries, loquats, hawthorns, pears (fragrant pears, snow pears, etc.), quince, rose hips, rowan, apricots, cherries, peaches (nectarines, nectarines, flat peaches, etc.), plums, prunes, white plums, blackberries, raspberries, cloudberries, raspberries, white berries, strawberries, pineapple berries, etc.; Rutaceae fruits: such as tangerines, mandarins, oranges, lemons, limes, pomelos, kumquats, grapefruits, citrons, Buddha's hand citrons, finger limes, wampee, etc.; Cucurbitaceae fruits: such as watermelons, cantaloupes, honeydew melons, white melons, horned melons, golden bells (golden bells), etc.; Musaceae fruits: such as bananas, plantains, South Sea red bananas, etc.; Rhamnaceae fruits: such as jujubes. Fruits of the Vitaceae family: such as grapes, raisins, etc.; Fruits of the Currantaceae family: such as currants, blackcurrants, redcurrants, etc.; Fruits of the Ericaceae family: such as blueberries, cranberries, blueberries, and black berries, etc.; Fruits of the Anacardiaceae family: such as mangoes, etc.; Fruits of the Actinidiaceae family: such as kiwifruit, yellow-fleshed kiwifruit, hardy kiwifruit, and red-fleshed kiwifruit, etc.; Fruits of the Bromeliaceae family: such as pineapples, etc.; Fruits of the Myricaceae family: such as waxberries, etc.; Fruits of the Ebenaceae family: such as persimmons, black dates, and black persimmons, etc.; Fruits of the Caricaceae family: such as papayas, etc.; Fruits of the Moraceae family: such as mulberries, figs, jackfruit, paper mulberry fruits, and milk fruit, etc.; Fruits of the Cactaceae family: such as dragon fruit, yellow dragon fruit, red dragon fruit, and prickly pear fruit. Fruits from the following families are included: Sapindaceae (e.g., lychee, longan, rambutan); Bombacaceae (e.g., durian, baobab fruit); Oxalidaceae (e.g., star fruit, amaranth); Lythraceae (e.g., pomegranate); Arecaceae (e.g., coconut, areca nut, date palm, salsa, acai berry); Clusiaceae (e.g., mangosteen); Myrtaceae (e.g., wax apple, jaboticaba, guava, feijoa, Surinamese bitter cherry); Passifloraceae (e.g., passion fruit); Lauraceae (e.g., avocado); Annonaceae (e.g., custard apple, oxheart custard apple); Solanaceae (e.g., goji berry, cantaloupe). Fruits of the following families include: * **Ginseng Fruit (Ginseng Fruit),** * **Lysimachia Fruit (Lysimachia Fruit),** * **Cherry Tomato (Cherry Tomato)**, etc.; * **Elaeagnaceae Fruits:** Examples include sea buckthorn and milkberry; * **Euphorbiaceae Fruits:** Examples include amla and wood apple; * **Caesalpiniaceae Fruits:** Examples include tamarind; * **Schisandraceae Fruits:** Examples include black tiger fruit; * **Panunculusceae Fruits:** Examples include pandanus fruit (also known as wild pineapple / hala fruit); * **Sapotaceae Fruits:** Examples include miracle fruit, yellow jujube, sapodilla, egg fruit; * **Meliaceae Fruits:** Examples include dragon fruit (Dragon Palace Fruit / Dragon Tribute / Lengsha / Lansa Fruit); * **Caprifoliaceae Fruits:** Examples include bitter melon (Platycodon grandiflorus / Forked Loquat Fruit); * **Loniceraceae Fruits:** Examples include cat's poop melon (Akobi Fruit); * **Malvaceae Fruits:** Examples include guabuasuo; * **Melastomataceae Fruits:** Examples include acerola cherry.The vegetables mentioned can be, for example, cruciferous vegetables: such as radishes, turnips, Chinese cabbage (including Chinese cabbage and its subspecies), cabbage (including varieties of head cabbage, kohlrabi, cauliflower, and broccoli), mustard greens (including root vegetables and varieties of pickled mustard greens); umbelliferous vegetables: such as celery, carrots, fennel, and coriander; solanaceous vegetables: such as tomatoes, eggplants, and peppers (including varieties of sweet peppers); cucurbitaceous vegetables: such as cucumbers, zucchini, pumpkins, winter melons, loofahs, bottle gourds, bitter melons, and chayote. Legumes: such as green beans (including dwarf beans and vinca varieties), cowpeas, peas, broad beans, edamame (i.e., soybeans), lentils, sword beans, etc.; Liliaceae vegetables: such as leeks, scallions, onions, garlic, daylilies, asparagus, lilies, etc.; Asteraceae vegetables: such as lettuce (including head lettuce and wrinkled lettuce varieties), lettuce, garland chrysanthemum, burdock, Jerusalem artichokes, artichokes, etc.; Chenopodiaceae vegetables: such as spinach, beets (including root beets and leaf beets varieties), etc.

[0038] Beneficial effects of the invention

[0039] This application provides a method for extracting coffee or tea, which uses an emulsified fat composition as the extraction medium, particularly diluted light cream, emulsified butter, or emulsified vegetable oil (coconut oil, palm oil, non-dairy creamer, etc.). The method of this invention can achieve at least one of the following technical effects:

[0040] 1. Compared with traditional water extraction, extraction using diluted cream or other emulsified fat systems can significantly improve the extraction yield of some oil-soluble flavor substances without sacrificing the yield of water-soluble components;

[0041] 2. Diluted cream and whole milk with the same fat content have similar extraction yields of oil-soluble flavor compounds, but the yield is higher than that of non-fat skim milk. Furthermore, cream extracts have a lower bitterness compared to extracts from whole milk and skim milk.

[0042] 3. In terms of improving the extraction yield of fat-soluble flavor substances, emulsified systems (butter or coconut oil) are superior to non-emulsified systems; homogenized cream is superior to non-homogenized cream; and emulsified butter, homogenized cream, and emulsified coconut oil systems are all superior to water extraction. Attached Figure Description

[0043] Figure 1 The changes in total dissolved solids in coffee aqueous extract with temperature and time are shown (in %).

[0044] Figure 2 Cluster analysis of flavor components in blends of roasted coffee extracted using different media is presented.

[0045] Figure 3The total tannin content (in ppm) in blends of dark roast coffee extracted using different media is shown.

[0046] Figure 4 The sensory profile diagram generated from the sensory evaluation of coffee blends made with cream and water is shown.

[0047] Figure 5 The changes in total dissolved solids in the aqueous extract of black tea with temperature and time are shown (unit: %).

[0048] Figure 6 The total tannin content (unit: ppm) in the compound extracts of black tea obtained by different extraction methods is shown. Detailed Implementation

[0049] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0050] The coffee powder used in the examples is illy medium roast and dark roast coffee powder; the black tea is black tea powder collected by crushing granular Sri Lankan highland black tea with a small grinder for 10 seconds and then passing it through a 40-mesh sieve; the cream is Bluemiji cream (38% fat, 2% protein); the butter is Yili butter (82% fat, <2% protein); the vegetable oil is Yihai Kerry refined coconut oil and palm oil; the non-dairy creamer is Jiahe coconut oil powder CS35B (containing 38% coconut oil) or non-dairy creamer K28 (containing 28% palm oil).

[0051] First, solid-phase microextraction was used to enrich the flavor compounds in coffee and black tea. Then, the adsorbed aroma components were thermally desorbed at the gas chromatograph injection port. Mass spectrometry was used to qualitatively analyze the flavor composition of coffee and black tea. More than 10 major flavor compounds were selected, and corresponding standards were purchased for quantitative detection of the content of these flavor compounds in the extract samples of the examples. The characteristic flavor compounds of coffee and black tea standards and their relative solubility are shown in Table 1. In the examples of the present invention below, the oil-soluble and water-soluble components are the components in Table 1.

[0052] Table 1. Standards and solubility of characteristic flavor compounds in coffee and black tea

[0053]

[0054]

[0055] The detection methods for various components in the following examples are as follows:

[0056] Characteristic volatile flavor compounds can be detected using GC-MS:

[0057] Take 10 mL of sample and place it in a 20 mL headspace vial, then seal it. Simultaneously, dissolve the selected pure flavor compound standards in the same matrix as the sample (e.g., water, light cream, blended milk, etc.) to prepare concentrations of 1, 10, 100, 1000, and 10000 ppb, and take 10 mL of each standard solution and place it in a headspace vial, then seal it. Equilibrate the headspace vials containing the samples at 85°C for 40 minutes in the headspace chamber of an Agilent 7697. The upper gas layer is then introduced into an Agilent 7000C gas chromatograph-mass spectrometer (GC-MS) with a DB-WAX column (30 m * 250 μm * 0.25 μm). Establish a linear standard curve of concentration versus peak area based on the peak areas of the standard compounds at different concentrations, thereby calculating the content of each flavor compound in the sample.

[0058] Characteristic water-soluble active ingredients can be detected using HPLC:

[0059] Methods for detecting active ingredients in coffee:

[0060] Vortex the sample for 30 seconds, take 1 ml, add 9 ml of 1% trichloroacetic acid, vortex for 30 seconds, let stand for 10 minutes, and filter the supernatant for analysis. Prepare a 1000 ppm stock solution of pure standards (such as caffeine, trigonelline, chlorogenic acid, etc.) with methanol. Inject 10 μL of sample into an Agilent 1200 liquid chromatograph using an Agilent Poroshell 120EC-C18 4.6*150 mm, 2.7 μm column and a VWD detector (detection wavelength 254 nm).

[0061] Methods for detecting active ingredients in black tea:

[0062] Theanine: Vortex the sample for 30 seconds, take 1 ml of the sample, dilute with water to 10 ml in a volumetric flask, transfer to a centrifuge tube, centrifuge at 5000 rpm, and filter the supernatant for testing.

[0063] Caffeine and theaflavins: Vortex the sample for 30 seconds, take 1 ml of sample, add 1 ml of methanol, vortex for 1 min, centrifuge at 5000 rpm, and filter the supernatant for testing.

[0064] Preparation of standards: Prepare a 1000 ppm stock solution of theanine standard with water. Prepare a 1000 ppm stock solution of caffeine and theaflavins standards with methanol.

[0065] Theanine HPLC detection method (OPA method):

[0066] Instrument: Agilent 1200 liquid chromatograph, FLD detector (detection wavelength 338nm)

[0067] Column: Agilent Poroshell 120EC-C18 4.6*150mm, 2.7um

[0068] HPLC detection method for caffeine and theaflavins:

[0069] Instrument: Agilent 1200 liquid chromatograph, DAD detector (detection wavelength 278nm)

[0070] Column: Agilent Poroshell 120EC-C18 4.6*150mm, 2.7um

[0071] The total tannin content in the extract can be detected using UV-Vis (Folin-C method):

[0072] Add 5 ml of 95% ethanol, 3 ml of 1% trichloroacetic acid, and 1 ml of 1% sodium chloride sequentially to 10 g of extract. Dilute to 25 ml with 95% ethanol, mix well, and let stand for 10 min before filtering. Take 1.0 mL each of the filtrate, gallic acid working solution (concentrations of 10, 20, 40, 60, 80, and 100 μg / mL), and water (for blank control) into graduated test tubes. Add 5.0 mL of 10% Folin-Ciocalteu reagent to each test tube, shake well, and add 4.0 mL of 7.5% Na₂CO₃ solution within 3-8 min of the reaction time, shaking well. Let stand at room temperature for 1 h. Measure the absorbance using a UV-Vis spectrophotometer at 765 nm using a 10 mm cuvette. Calculate the total tannin content in the extract based on the gallic acid standard curve.

[0073] Brix value determination of extract:

[0074] Using a handheld ATAGO PAL-1 refractometer, add 3-5 drops of extract to the sample well using a pipette, spread evenly, and then measure the Brix value for sugar content. Repeat the measurement at least 5 times and take the average value. Suitable for measuring aqueous extracts.

[0075] Flavor, texture, and other sensory characteristics were quantitatively described and analyzed in accordance with standards such as ISO 13299-2016, and sensory profile diagrams were generated.

[0076] Example 1: Coffee Extraction Method (Taking Diluted Cream Extraction at 90℃ as an Example)

[0077] Weigh 30g of light cream into a 1L beaker, add pure water to a final volume of 300g, and stir well to obtain a 3.8% fat content light cream solution. Seal the beaker appropriately with aluminum foil, preheat in a 90℃ water bath, then quickly add 20g of dark roast coffee powder (1:15 material-to-liquid ratio), and stir magnetically at a low speed of ~100rpm. Incubate in a water bath for 15 minutes. Remove the beaker and rapidly cool it in an ice-water bath, adding any evaporated water if necessary. Then transfer the mixture to a centrifuge cup and centrifuge at 1000rpm (centrifugal force ~150g) for 1 minute. Collect the supernatant to obtain the coffee extract.

[0078] Example 2: Using diluted cream as the extraction medium, the factors affecting the coffee extraction process were investigated.

[0079] (1) Fat content in the extraction medium

[0080] Weigh appropriate amounts of light cream and dilute it with pure water to different ratios, stirring well to obtain light cream solutions with fat contents of 1.9%, 3.8%, 5.7%, 7.6%, 19.0%, and 38% respectively (unless otherwise stated, all percentages are by weight). Following the extraction method in Example 1, using light cream and water with different fat contents as the extraction medium, at a material-to-liquid ratio of 1:15, extract the dark roast coffee powder at 90°C for 15 minutes. The content of characteristic flavor compounds in the obtained extracts was determined. Based on the solubility classification in Table 1, the contents of oil-soluble and water-soluble components were normalized according to the relative percentages of the corresponding components in the water extract. The results are shown in Table 2. The data in Table 2 refer to the percentage values ​​obtained by dividing the actual content value of each component in the measured extract by the actual content value of the corresponding component in the water extract.

[0081] Table 2. Effect of fat content in extraction medium on the composition of coffee extract.

[0082]

[0083] The results in the table above show that the extraction media with fat content ranging from 1.9% to 38% yielded higher yields of flavor compounds than water extraction, especially the overall yield of oil-soluble components, which was several times higher. Even with a cream extract containing 38% fat content, which experienced some loss during transfer and separation due to its viscosity, the overall yield of oil-soluble components was still more than 50% higher than that of water extraction.

[0084] (2) Extraction material-liquid ratio

[0085] Following the extraction method in Example 1, using light cream with a fat content of 3.8% as the extraction medium, and with a solid-liquid ratio ranging from 1:10 to 1:25, dark roast coffee powder was extracted at 90°C for 15 minutes. The contents of water-soluble and oil-soluble components in the extract were measured separately. After correcting the solid-liquid ratio, the extract was normalized to the relative percentage of the corresponding components in the extract at a solid-liquid ratio of 1:25. The results are shown in Table 3.

[0086] Table 3. Effect of the ratio of extract to liquid on the composition of coffee extract.

[0087]

[0088] The results showed that, under laboratory extraction conditions, a material-to-liquid ratio of 1:10–1:25 yielded higher yields of both oil-soluble and water-soluble flavor components. Considering the high energy consumption of concentration at lower product concentrations, a suitable material-to-liquid ratio, such as 1:10, can be selected for industrial production.

[0089] (3) Extraction temperature

[0090] First, using water as the extraction medium, the changes in the total amount of dissolved solids in coffee extract under different extraction temperatures and times were investigated by measuring the Brix value of the extract.

[0091] The results are as follows Figure 1 As shown, when coffee is extracted with water at 50℃, the total amount of dissolved solids reaches saturation in 60 minutes; at temperatures above 70℃, the total amount of dissolved solids reaches saturation in 30 minutes.

[0092] Furthermore, using light cream with a fat content of 3.8% as the extraction medium, the effects of different temperature conditions on the water-soluble and oil-soluble components in the coffee extract were investigated.

[0093] Following the extraction method in Example 1, using light cream with a fat content of 3.8% as the extraction medium, and a material-to-liquid ratio of 1:10, dark roast coffee powder was extracted at 40-90℃ for 15 minutes each. The contents of water-soluble and oil-soluble components in the extracts were measured separately, and normalized according to the relative percentage of the corresponding components in the extract at 90℃. The results are shown in Table 4.

[0094] Table 4. Effect of extraction temperature on the composition of coffee extract

[0095]

[0096] The analysis results show that high-temperature extraction may cause some flavor compounds to volatilize. From the perspective of extracting and retaining the selected flavor compounds, 60℃ is the best, followed by 70℃. 70℃ is a suitable temperature for pasteurization and is better than 60℃ in terms of total dissolved solids. Therefore, 70℃ can be considered as a suitable coffee extraction temperature.

[0097] (4) Extraction time

[0098] Following the extraction method in Example 1, using light cream with a fat content of 3.8% as the extraction medium, and a material-to-liquid ratio of 1:10, dark roast coffee was extracted at 70°C for 5-60 minutes. The contents of water-soluble and oil-soluble components in the extract were measured separately, and the results were normalized according to the relative percentage of the corresponding components in the extract after 60 minutes. The results are shown in Table 5.

[0099] Table 5. Effect of extraction time on the composition of coffee extract.

[0100]

[0101] The results showed that extraction times of 5-60 minutes were effective in extracting both water-soluble and oil-soluble flavor components from the product. From the perspective of extracting and retaining the selected flavor substances, 5 minutes was optimal; however, based on the aforementioned experiments, the total amount of dissolved solids was relatively low under these conditions; therefore, considering the total amount of dissolved solids, extraction at 70℃ for 30 minutes was selected.

[0102] Example 3: Effect of extraction medium on flavor compounds in coffee extract

[0103] Following the extraction method in Example 1, water, light cream with 3.8% fat content, skim milk (fat <0.5%, protein 3.5%), and whole milk (fat 3.8%, protein 3.4%) were used as extraction media, with a material-to-liquid ratio of 1:10. Dark roast coffee (or medium roast coffee) was extracted at 70°C for 30 minutes. The extracts were obtained by centrifugation. For parallel comparison of sensory evaluation and flavor detection, appropriate amounts of light cream, skim milk, or water were added to the extracts from the four different media, diluting the four extracts by an equal volume ratio of 2.5 times, ensuring that each of the four dilutions contained 2% fat and 1.5% protein. It should be noted that this blending was performed after the extraction process was completed; the added protein and fat did not affect the extraction effect. The purpose of the blending was solely to allow for parallel comparison of differences in taste and flavor components by using four extracts from different media under the same matrix conditions of fat and protein. The results of flavor compound content detection are shown in Table 6.

[0104] Table 6. Effects of extraction medium on flavor compounds in dark roast coffee extracts (unit: ppb)

[0105]

[0106]

[0107] As shown in the table above, diluted cream has a significantly higher extraction yield for most oil-soluble flavor compounds (2-methylfuran, 1-methylpyrrole, furfuryl methyl sulfide, furfuryl acetate, and 1-furfurylpyrrole) than water extraction or skim milk extraction. For example, the extraction yields for 2-methylfuran, furfuryl methyl sulfide, and 1-furfurylpyrrole are 4-5 times higher. However, the extraction yields for other characteristic flavor compounds are similar between diluted cream and water extraction.

[0108] In the extraction of oil-soluble flavor components from medium-roasted coffee, diluted cream showed a similar significant advantage over water extraction (results are shown in Table 7).

[0109] Table 7. Effects of extraction medium on flavor compounds in medium-roasted coffee extract (unit: ppb)

[0110]

[0111]

[0112] After normalizing the content of flavor components in four medium-roast coffee media extracts, the relative percentage content of each component was obtained. Then, cluster analysis of the relative contents of 16 flavor components in the four extracts was performed using SPSS software (IBM SPSS Statistics 24). The results are as follows: Figure 2 As shown, the flavor composition of the cream extract is very similar to that of the whole milk extract, and significantly different from that of the skim milk extract, while the first three differ greatly from the water extract.

[0113] Example 4: Effect of extraction medium emulsification on flavor compounds in dark roast coffee extract

[0114] Using a similar experimental method to Example 3, the effect of emulsification of the extraction medium on flavor compounds in the coffee extract was investigated. In this example, except for water and skim milk, the fat content of all other extraction media was 3.8%. Types of fat included, but not limited to, cream, butter, and coconut oil. Unhomogenized cream refers to the diluted cream used in Examples 1-3, which is a cream liquid obtained by simply mixing pure cream with water. The average particle size D50 of the unhomogenized cream emulsion was 2.291 μm (Malvin Mastersizer 2000, D90 = 4.674 μm). Homogenized cream, on the other hand, refers to a cream liquid obtained by homogenizing cream and water using an APX-1000 homogenizer at 250 bar pressure. The average particle size D50 of the homogenized cream emulsion was 0.806 μm (Malvin Mastersizer 2000, D90 = 1.593 μm). Emulsified butter and emulsified coconut oil are liquid emulsified butter or emulsified coconut oil produced by rapidly stirring 3.8% butter or coconut oil into an aqueous solution containing 0.5% sucrose ester (Mitsubishi S-1570, HLB value 15), and then homogenizing it under a homogenizer at a pressure of 250 bar.

[0115] After being diluted 2.5 times and compounded, the flavor substance content of the compound extract was tested, and the results are shown in Table 8.

[0116] Table 8. Effect of extraction medium emulsification on flavor compounds in coffee extract (unit: ppb)

[0117]

[0118]

[0119] The results above show that, firstly, emulsified fat systems (emulsified butter or emulsified coconut oil) outperform their corresponding unemulsified systems in terms of extraction yield of oil-soluble flavor components. Besides sucrose esters, emulsifiers can also include hydrophilic emulsifiers such as diacetyl tartaric acid mono- and diglycerides, sodium stearoyl lactylate, and combinations of these hydrophilic emulsifiers with lipophilic emulsifiers similar to saturated monoglycerides. It should be noted that the unemulsified oils mentioned here are stirred during coffee extraction, thus achieving a partial emulsification effect. When unemulsified oils are not stirred during coffee extraction, their extraction efficiency is even worse.

[0120] Secondly, the yields of oil-soluble components extracted from coffee by emulsified butter and emulsified whipping cream were basically similar. Homogenized whipping cream was superior to unhomogenized whipping cream in extracting oil-soluble flavor components from coffee, possibly because the emulsion of homogenized whipping cream is smaller (average particle size of homogenized whipping cream is 0.8 μm, while that of unhomogenized whipping cream is 2.3 μm), allowing it to penetrate the coffee particles better and thus improve the extraction effect.

[0121] Example 5: Extraction of coffee flavor components from light cream and emulsified butter with 10-20% fat content.

[0122] Referring to Example 1, medium-roast coffee was extracted using light cream and emulsified butter with 10% and 20% fat content, respectively, at a material-to-liquid ratio of 1:10, at 70°C for 30 minutes. Flavor component analysis results also showed that the extraction yield of oil-soluble flavor components was higher than that of the traditional water extraction method (see Table 9). Specifically, the emulsion with 10% fat content emulsified butter had an average particle size D50 of 1.232 μm (Malvin Mastersizer 2000, D90 = 12.610 μm). When the fat content reached 20%, the extract system had a certain viscosity, resulting in slight loss during residue separation, but the overall component content was still higher than that obtained by water extraction.

[0123] Table 9. Effects of higher fat extraction medium on flavor compounds in coffee extract (unit: ppb)

[0124]

[0125] Example 6: Extraction of medium-roast coffee from non-dairy creamer or a combination of non-dairy creamer and milk fat emulsion system.

[0126] In this embodiment, the non-dairy creamer is Jiahe coconut oil powder CS35B (containing 38% coconut oil) and non-dairy creamer K28 (containing 28% palm oil).

[0127] Weigh an appropriate amount of palm oil non-dairy creamer K28, add water and stir to obtain a non-dairy creamer extract containing 3.8% palm oil. Following the method in Example 1, extract medium-roast coffee at a material-to-liquid ratio of 1:10, at 70℃ for 30 minutes. The flavor components of the extract were then analyzed. As shown in Table 10, the results indicate that the flavor components obtained from the non-dairy creamer extract containing 3.8% palm oil were significantly higher than those obtained by water extraction. Similar results were observed when extracting medium-roast coffee with non-dairy creamer containing 10% coconut oil.

[0128] Not only a single oil system, but also a mixed oil system of 5% coconut oil (from CS35B non-dairy creamer), 5% palm oil (from K28 non-dairy creamer), and 5% fat in light cream is used to extract medium-roast coffee powder. The extraction rate of oil-soluble flavor components is significantly better than that of water extraction.

[0129] Table 10. Effects of vegetable oils and mixed oil systems with different fat contents on flavor compounds in coffee extract (unit: ppb)

[0130]

[0131] Example 7: Homogenized whipped cream and water for room temperature and low temperature cold brewing of medium roast coffee

[0132] Weigh an appropriate amount of Lambji whipping cream, dilute it with water to a whipping cream solution with a fat content of 3.8%, stir well, and then homogenize it using a homogenizer (APX-1000) at a pressure of 250 bar to obtain homogenized whipping cream with a fat content of 3.8%. Take 500g of homogenized whipping cream or water into a covered glass bottle, keep it at a constant temperature of 20℃ in a water bath, add 50g of medium-roasted coffee powder, and stir magnetically at low speed for 1 hour. Centrifuge to obtain the extract, and analyze the content of coffee flavor components. The results are shown in Table 11.

[0133] Table 11 Flavor compound content of coffee extracted at 20℃ using water and homogenized cream (unit: ppb)

[0134]

[0135] Table 11 shows that, under 1-hour cold extraction conditions, homogenized cream can extract most oil-soluble flavor compounds (such as 2-methylfuran, 1-methylpyrrole, furfuryl methyl sulfide, and 1-furfurylpyrrole) faster than water. When the extraction temperature is lowered to 2-4℃ (low-temperature cold extraction), homogenized cream can extract more oil-soluble flavor compounds than water in the same amount of time (see Table 12 for specific results).

[0136] Table 12 Flavor compound content of coffee extracted with water and homogenized cream at 3°C ​​(unit: ppb)

[0137]

[0138] Example 8: Analysis of active ingredients and total tannin content in coffee extract

[0139] Referring to Example 3, water, non-homogenized light cream with 3.8% fat content, skim milk, and whole milk were used as extraction media at a material-to-liquid ratio of 1:10. Dark roast coffee was extracted at 70°C for 30 minutes. After centrifugation, the extracts were diluted equally with appropriate amounts of light cream, skim milk, or water to create samples containing the same matrix of 2.0% fat and 1.5% protein. The active ingredients and total tannin content were then analyzed.

[0140] (1) Water-soluble active ingredients

[0141] HPLC analysis of the active components in the extract of heavily roasted coffee was performed, and the results are shown in Table 13. The main active components included caffeine, trigonelline, chlorogenic acid, neochlorogenic acid, and cryptochlorogenic acid. Because these active components are primarily water-soluble, they were mostly precipitated after extraction at 50℃ for more than 5 minutes, with no significant difference in yield between extraction at 60 minutes and extraction at 50℃. Table 13 shows that the extraction yields of water-soluble active components were similar between dilute cream extraction and water extraction.

[0142] Table 13 Comparison of water-soluble active ingredients extracted from coffee using different methods (unit: ppm)

[0143]

[0144] (2) Detection of bitter substances - total tannins

[0145] When the four media extracts were blended to equal amounts of fat and protein, internal tasting assessments revealed differences in bitterness among the different media extracts: the bitterness was more pronounced in whole milk and skim milk extracts than in cream extracts.

[0146] The total tannin content of the compound solution was determined by UV-Vis absorption spectroscopy (Folin-C method), and the results are shown below. Figure 3 The total tannin content in diluted cream extract is similar to that in water extract, while the total tannin content in skim milk and whole milk extract is at least 20% higher than that in water extract.

[0147] Whole milk and skim milk extract more bitter compounds from coffee than cream extract, consistent with internal tasting assessments. This is likely because the proteins in whole milk and skim milk chelate more bitter tannins.

[0148] Furthermore, through quantitative description and sensory evaluation by the judging panel, it was found that compared to water-extracted coffee, the cream extract was significantly stronger in overall flavor intensity, roasted coffee flavor, caramel aroma, and smoky flavor, and also had floral notes. The results are as follows... Figure 4 As shown, Figure 4 Sensory profiles generated from sensory evaluations of coffee blends extracted with cream and coffee blends extracted with water are shown.

[0149] Example 9: Black Tea Extraction Method

[0150] Granular Sri Lankan highland black tea was pulverized for 10 seconds using a small grinder and then passed through a 40-mesh sieve to collect the black tea powder for later use. Referring to Example 1, a light cream solution containing 3.8% fat was prepared. A beaker was appropriately sealed with aluminum foil, preheated in a water bath at a set temperature, and then an appropriate amount of black tea powder was quickly added. The mixture was stirred at low speed with a magnetic stirrer and kept in the water bath for the set extraction time. The beaker was then removed and rapidly cooled in an ice-water bath. If necessary, any evaporated water could be added back. The mixture was then transferred to a centrifuge cup and centrifuged at 1000 rpm for 1 minute. The supernatant was collected to obtain the black tea extract.

[0151] Example 10: Using diluted light cream as the extraction medium, the factors affecting the extraction process of black tea were investigated.

[0152] (1) Fat content in the extraction medium

[0153] Appropriate amounts of light cream were weighed and diluted with pure water to obtain light cream solutions with fat contents of 1.9%, 3.8%, 5.7%, 7.6%, 19.0%, and 38%, respectively. Following the extraction method in Example 8, using light cream with different fat contents as the extraction medium, at a material-to-liquid ratio of 1:15, black tea powder was extracted at 90°C for 15 minutes. The content of characteristic flavor compounds in the obtained extracts was determined, and the content of all flavor components (all oil-soluble) was normalized according to the relative percentage of the corresponding components in the light cream extract with a fat content of 1.9%. The results are shown in Table 14.

[0154] Table 14 Effect of fat content in extraction medium on flavor components in black tea extract.

[0155]

[0156] The results showed that cream with a fat content of 1.9-19% could effectively extract oil-soluble flavor components from black tea. The extract obtained from cream with a fat content of 3.8% showed a higher overall yield of oil-soluble flavor components.

[0157] (2) Extraction material-liquid ratio

[0158] Following the extraction method of Example 9, light cream with a fat content of 3.8% was used as the extraction medium, and the material-to-liquid ratio ranged from 1:10 to 1:25. Black tea powder was extracted at 90°C for 15 minutes. The content of flavor components in the extract was measured separately. After correcting for the material-to-liquid ratio, the extract was normalized according to the relative percentage of the corresponding components in the extract at a material-to-liquid ratio of 1:10. The results are shown in Table 15.

[0159] Table 15 Effect of the ratio of extract material to liquid on flavor components in black tea extract.

[0160]

[0161] The results showed that, under laboratory conditions, a material-to-liquid ratio of 1:10–1:25 yielded relatively high amounts of oil-soluble flavor components. Considering the high energy consumption for concentration at low product concentrations, a suitable material-to-liquid ratio, such as 1:20, can be selected for industrial production.

[0162] (3) Extraction temperature

[0163] First, using water as the extraction medium, the changes in the total amount of dissolved solids in the black tea extract under different extraction temperatures and times were investigated by measuring the Brix value of the extract.

[0164] The results are as follows Figure 5 As shown, when black tea is extracted with water at 50-90℃ for 30 minutes, the total amount of dissolved solids basically reaches saturation.

[0165] Furthermore, using light cream with a fat content of 3.8% as the extraction medium, the effects of different temperature conditions on the flavor components in the black tea extract were investigated.

[0166] Following the extraction method of Example 9, using light cream with a fat content of 3.8% as the extraction medium, and a material-to-liquid ratio of 1:20, black tea powder was extracted at 40-90℃ for 15 minutes. The content of characteristic flavor substances (all oil-soluble) in the extracts was measured, and normalized according to the relative percentage of the corresponding components in the 90℃ extract. The results are shown in Table 16.

[0167] Table 16 Effect of extraction temperature on flavor components in black tea extract

[0168]

[0169] The analysis results show that temperature has a smaller impact on the volatilization of oil-soluble flavor compounds in black tea than in coffee, with 80℃ being the relatively optimal temperature.

[0170] (4) Extraction time

[0171] Following the extraction method of Example 9, using light cream with a fat content of 3.8% as the extraction medium, and a material-to-liquid ratio of 1:20, black tea powder was extracted at 80°C for 5-60 minutes. The content of flavor components in the extract was measured and normalized according to the relative percentage of the corresponding components in the extract after 60 minutes. The results are shown in Table 17.

[0172] Table 17 Effect of extraction time on flavor components in black tea extract.

[0173]

[0174]

[0175] The results showed that extraction times of 5-60 minutes were effective in extracting oil-soluble flavor components from the product. From the perspective of the content of characteristic flavor components extracted, 5 minutes was the optimal extraction time. However, as the aforementioned experiments indicated, the total amount of soluble solids was relatively low under these conditions. Considering industrial experience and the total amount of soluble solids, 30 minutes was selected as the appropriate extraction time.

[0176] Example 11 Effect of extraction medium on flavor compounds in black tea extract

[0177] Following the extraction method of Example 9, black tea powder was extracted for 30 minutes at 80°C using water, light cream with 3.8% fat content, skim milk, and whole milk (as extraction media, with a material-to-liquid ratio of 1:20). For fair comparison in sensory evaluation and flavor testing, appropriate amounts of light cream, skim milk, or water were added to the extracts from the four different media to create blends. The four extracts were diluted 2.5 times in equal volumes, ensuring that each dilution contained 2% fat and 1.5% protein. Under the same matrix conditions of fat and protein, the content of flavor compounds in the blends extracted from the four media was detected and compared. The results are shown in Table 18.

[0178] Table 18 Effect of extraction medium on flavor components in black tea extract (unit: ppb)

[0179]

[0180]

[0181] The data in the table above show that diluted cream has a significantly higher extraction yield for most oil-soluble flavor components than water extraction or skim milk extraction, while the extraction yields of other characteristic flavor substances are similar between diluted cream and water extraction.

[0182] Example 12 Effect of Emulsification of Extraction Medium on Flavor Compounds in Black Tea Extract

[0183] Using a similar experimental method to Example 10, the effect of emulsification of the extraction medium on flavor compounds in black tea extract was investigated. In this example, the fat content of all extraction media except water and skim milk was 3.8%. Unhomogenized cream refers to the diluted cream used in Examples 9-11, which is a liquid cream obtained by simply mixing pure cream with water. Homogenized cream refers to a liquid cream obtained by homogenizing cream and water under a 250 bar pressure using a homogenizer (APX-1000). Emulsified butter and coconut oil were obtained by rapidly adding 3.8% butter or coconut oil to an aqueous solution containing 0.5% sucrose ester (Mitsubishi S-1570, HLB value 15), followed by homogenization under a 250 bar pressure. After appropriate equal-volume dilution and compounding, the flavor compound content in the compound extracts under the same matrix was measured, and the results are shown in Table 19.

[0184] Table 19. Effects of emulsification of the extraction medium on flavor compounds in black tea extract.

[0185]

[0186]

[0187] The results in the table above show that: First, the emulsified fat systems (emulsified butter or emulsified coconut oil) outperformed their corresponding unemulsified systems in terms of extraction yield of oil-soluble flavor components. Emulsifiers can also be hydrophilic emulsifiers such as diacetyl tartaric acid mono- and diglycerides, sodium stearoyl lactylate, and combinations of these hydrophilic emulsifiers with lipophilic emulsifiers similar to saturated monoglycerides. Second, the yields of oil-soluble components extracted from black tea by emulsified butter and emulsified cream were similar. Finally, homogenized cream extracted slightly more oil-soluble flavor components from black tea than non-homogenized cream, possibly because the emulsion particles of homogenized cream were smaller and more easily penetrated the black tea powder.

[0188] Example 13: Analysis of active ingredients and total tannin content in black tea extract

[0189] Referring to Example 11, black tea powder was extracted at 80°C for 30 minutes using water, unhomogenized light cream with 3.8% fat content, skim milk, and whole milk as extraction media, respectively, at a material-to-liquid ratio of 1:20. After centrifugation, the extract was diluted with an appropriate amount of light cream, skim milk, or water to form a sample containing 2.0% fat and 1.5% protein in the same matrix.

[0190] (1) Water-soluble active ingredients

[0191] HPLC analysis of water-soluble active ingredients in black tea was performed, and the results are shown in Table 20. The main active ingredients in black tea include caffeine, theanine, theaflavins, and their derivatives. The results showed that the extraction yields of the main active ingredients were similar between cream extraction and water extraction. Furthermore, skim milk and whole milk yielded higher extraction rates of theaflavins and other polyphenols than cream and water extraction, possibly because the proteins in skim milk and whole milk readily chelate polyphenols.

[0192] Table 20. Content of active ingredients in black tea extracts from different media (unit: ppm)

[0193]

[0194]

[0195] (2) Detection of bitter substances - total tannins

[0196] Similarly, after blending the four media extracts with equal amounts of fat and protein, the total tannin content of the blended solutions was determined using UV-Vis absorption spectroscopy (Folin-C method). The results are shown below. Figure 5 The total tannin content in diluted cream extract is similar to that in water extract, while the total tannin content in skim milk and whole milk extract is more than 30% higher than that in water extract.

[0197] Whole milk and skim milk extracted more bitter substances from black tea than cream, consistent with internal tasting assessments. This may be because the proteins in whole milk and skim milk may chelate more bitter tannins.

[0198] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed, and all such changes are within the scope of protection of the invention. The full scope of the invention is given by the appended claims and any equivalents thereof.

Claims

1. A method for extracting tea that enriches flavor compounds and reduces bitterness, comprising the following steps: The tea is extracted using an emulsified fat composition; the tea is black tea; wherein... The emulsified fat composition contains a fat-based product, water, and an emulsifier; the fat content of the composition is 1-10%, and the protein content is 0-1%; the emulsifier accounts for 0.1-2% of the total weight of the composition. The fat-based product is selected from milk fat and its products; the milk fat and its products are selected from cream and butter; the emulsifier is selected from diacetyl tartrate monoglyceride, sodium stearoyl lactylate, and sucrose fatty acid ester. The extraction material-to-liquid ratio is 1:10 to 1:25; The extraction temperature is 80-90°C. o C, the extraction time is 5~60min.

2. The method of claim 1, wherein the emulsified fat composition is an emulsion having a D90 particle size of less than 100 μm.

3. The method of claim 2, wherein the emulsified fat composition is an emulsion with a D90 particle size of less than 50 μm.

4. The method of claim 3, wherein the emulsified fat composition is an emulsion. D90 particles have a diameter of less than 15 μm.

5. The method of claim 1, wherein the emulsifier is selected from emulsifiers with an HLB value of 8-18.

6. The method of claim 1, comprising the following steps: Add 10-25 times the weight of the emulsified fat composition to the tea, stir at a constant temperature of 80-90℃ for 5-60 min, centrifuge, and collect the centrifuged liquid; the process also includes a post-treatment step of the centrifuged liquid; the post-treatment includes concentration, freeze drying or spray drying.

7. A tea extract prepared by any one of claims 1-6; wherein the total tannin content in the extract does not exceed 110% of the total tannin content in an aqueous extract under the same conditions.

8. A composition comprising the tea extract of claim 7; which is a ready-to-drink beverage or solid food of tea.

9. Use of the method according to any one of claims 1 to 6 in enriching tea flavor substances, comprising the step of extracting tea using an emulsified fat composition; The flavor compounds of the tea include one or more of 2-methylbutanal, isovaleral, hexanal, trans-2-hexenal, 2-pentylfuran, benzaldehyde, linalool, β-cyclocitral, methyl salicylate, nerol, or geraniol.

10. Use of the method according to any one of claims 1 to 6 in reducing the content of bitter substances, comprising the step of extracting the raw material containing bitter substances using an emulsified fat composition; wherein, The bitter substances include tannins.

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