Rice-based milk tea functional beverage and preparation method thereof

Abstract

The invention discloses a rice-based milk tea functional beverage and a preparation method thereof, and the rice-based milk tea functional beverage is prepared by using coarse rice powder, defatted rice bran powder, rice bran residue powder and tea powder as raw materials, using a proper amount of water, rice oil and fat-soluble bioactive substances as auxiliary materials, and performing processes of mechanical pretreatment, moderate enzymolysis, emulsification and the like. The preparation method comprises the following steps: uniformly mixing coarse rice powder, defatted rice bran powder, rice bran residue powder and a tea powder solution through mechanical pretreatment, carrying out moderate enzymolysis on the mixed solution by using amylosidase, cellulase and protease, and adding rice oil and fat-soluble bioactive substances for emulsification and homogenization. The prepared rice-based milk tea functional beverage is good in taste, balanced in nutrition, good in stability and rich in physiological activators such as tea polyphenol, oryzanol, alpha-tocopherol and gamma-aminobutyric acid, rice processing by-products such as defatted rice bran and rice bran residues are fully utilized, and a new treatment mode is provided for high-value full utilization of grain and oil processing by-products.

Description

Technical Field

[0001] This invention relates to a rice-based milk tea functional beverage and its preparation method, belonging to the field of beverage processing. Background Technology

[0002] Tea is one of the world's most popular beverages, boasting numerous health benefits such as antioxidant, anti-cancer, and antibacterial properties. For a long time, people have enjoyed adding tea to milk to make milk tea because milk enhances the sensory characteristics of tea. However, over 90% of Asians are lactose intolerant, and milk tea made from milk can easily cause adverse reactions such as bloating, abdominal pain, and diarrhea in those with lactose intolerance. In recent years, many plant-based foods have entered the market as alternatives to animal products, becoming increasingly diverse, including plant-based meat, plant-based seafood, plant-based cakes, plant-based milk powder, and plant-based cheese. Using plant-based milk instead of cow's milk to make milk tea could meet the needs of lactose-intolerant individuals.

[0003] China is a major rice producer, with an annual output exceeding 200 million tons, essentially achieving the goal of absolute food security. Sufficient rice reserves are a crucial safeguard for the country in responding to risks such as natural disasters and fluctuations in international grain prices. However, the rice reserves used for rotation suffer from problems such as poor taste, low processing utilization, and low added value. In recent years, the concept of a "broad food perspective"—developing food resources through multiple channels and in all aspects—has gained widespread acceptance, and the high-value, tiered, and cyclical utilization of rice processing byproducts is receiving increasing attention. Rice bran, as the most important byproduct of rice processing, is rich in dietary fiber, protein, lipids, and phenolic substances. Furthermore, the residue left after extracting soluble protein from defatted rice bran also contains abundant insoluble protein, polysaccharides, and polyphenols, showing great development potential. Compared to milk protein, rice bran protein is inferior in terms of solubility and functional properties. When tea polyphenols and other substances in tea come into contact with soluble rice bran protein, they interact, forming aggregates and precipitation. Existing patent document CN109463489A discloses a rice bran protein tea beverage and its preparation method. Specifically, it provides a liquid tea beverage with good stability using only rice bran protein as the protein raw material and its processing technology, but does not reuse the processing residue such as rice bran residue. Furthermore, the current existing technology cannot meet the production requirements of rice-based milk tea functional beverages made from brown rice flour, defatted rice bran powder, and rice bran residue powder. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art, utilize rice bran residue, the residue of rice bran protein processing, and provide a rice-based milk tea functional beverage with brown rice flour, defatted rice bran powder, rice bran residue powder and tea powder as the main raw materials, which is nutritionally balanced and has good stability, thereby further extending the rice processing industry chain and increasing the added value of the product.

[0005] To achieve the above objectives, the present invention provides a method for preparing a rice-based milk tea functional beverage, comprising the following steps:

[0006] (1) Mechanical pretreatment: Disperse brown rice flour, defatted rice bran powder, and rice bran residue powder in water, stir to fully hydrate, and then heat for a period of time to obtain rice-based mixed liquid; dissolve tea powder in water, boil, cool to room temperature, and filter to remove impurities to obtain tea powder extract; add tea powder extract to rice-based mixed liquid, and perform shearing, homogenization, and ultrasonic pretreatment in sequence to obtain rice-based tea mixed liquid;

[0007] (2) Three-step enzymatic hydrolysis: In the rice-based tea mixture described in step (1), α-amylase, β-amylase, maltase and glucose isomerase are added to carry out the first step of enzymatic hydrolysis; then, cellulase is added to carry out the first step of enzymatic hydrolysis; finally, trypsin is added to carry out the third step of enzymatic hydrolysis to obtain the enzymatic hydrolysate.

[0008] (3) Emulsification: Rice oil containing fat-soluble bioactive substances is added to the enzymatic hydrolysate obtained in step (2), and ultrasonic treatment is performed to obtain crude emulsion, which is then homogenized to obtain rice-based milk tea functional beverage.

[0009] In one embodiment of the present invention, the raw materials, by weight percentage, consist of the following components: 1.0% to 1.5% brown rice flour, 2.0% to 2.5% defatted rice bran powder, 1.0% to 1.5% rice bran residue powder, 0.5% to 1.0% tea powder, 2.0% to 3.0% rice bran oil, and the balance being water; wherein the content of fat-soluble bioactive substances in the rice bran oil is 0.8 to 1.2 mg / g.

[0010] In one embodiment of the present invention, the raw materials, by weight percentage, consist of the following components: 1.0%–1.2% brown rice flour, 2.0%–2.4% defatted rice bran powder, 1.0%–1.2% rice bran residue powder, 0.5%–0.6% tea powder, 2.0%–3.0% rice bran oil, and the balance being water; wherein the content of fat-soluble bioactive substances in the rice bran oil is 0.8–1.2 mg / g.

[0011] In one embodiment of the present invention, in step (1), the mixture is stirred at room temperature to fully hydrate, and then heated to 100-130°C for a period of time to obtain a rice-based mixed liquid.

[0012] In one embodiment of the present invention, in step (1), the concentration of tea powder dissolved in water is controlled at 1.0wt%-2wt%.

[0013] In one embodiment of the present invention, in step (1), the shearing condition is 10000-12000 r / min for 2-3 min.

[0014] In one embodiment of the present invention, in step (1), the homogenization conditions are homogenization 2 to 4 times at 100 to 120 MPa.

[0015] In one embodiment of the present invention, in step (1), the ultrasonic treatment is performed at 300-400W for 10-20 minutes.

[0016] In one embodiment of the present invention, in step (1), brown rice flour, defatted rice bran powder, rice bran residue powder, and tea powder are all food-grade raw materials.

[0017] Brown rice flour is a product obtained by grinding rice after hulling. It contains 8.22% to 10.50% protein, 5.52% to 7.27% crude fat, 73.41% to 75.65% starch, and 3.32% to 4.54% dietary fiber.

[0018] Defatted rice bran powder is a byproduct obtained by pulverizing rice bran oil extracted from brown rice bran. It contains 15.01%–16.90% protein, 1.22%–1.43% crude fat, and 28.21%–32.33% dietary fiber.

[0019] Rice bran residue powder is a byproduct obtained by pulverizing defatted rice bran after extracting rice bran protein. It contains 10.70%–12.65% protein, 0.71%–0.93% crude fat, and 30.72%–33.95% dietary fiber.

[0020] The tea powder is instant green tea powder with a tea polyphenol content of 243mg / g to 262mg / g.

[0021] In one embodiment of the present invention, in step (2), the α-amylase activity is 40,000 to 50,000 U / g. The amount of α-amylase added relative to the mass of brown rice flour is 0.2 wt% to 0.5 wt%. More preferably, it is 0.2 wt% to 0.3 wt%.

[0022] In one embodiment of the present invention, in step (2), the β-amylase activity is 80,000–85,000 U / g. The amount of β-amylase added relative to the mass of brown rice flour is 0.2 wt%–0.5 wt%. More preferably, it is 0.2 wt%–0.3 wt%.

[0023] In one embodiment of the present invention, in step (2), the enzyme activity of maltase (also known as α-glucosidase) is 9000-10000 U / g. The amount of maltase added relative to the mass of brown rice flour is 0.1wt%-0.3wt%.

[0024] In one embodiment of the present invention, in step (2), the activity of the glucose isomerase is 100,000 to 200,000 U / g. The amount of glucose isomerase added relative to the mass of brown rice flour is 0.1 wt% to 0.3 wt%.

[0025] In one embodiment of the present invention, in step (2), the first enzymatic hydrolysis is carried out at 40-45°C for 4-6 hours.

[0026] In one embodiment of the present invention, in step (2), the cellulase activity is 10,000–12,000 U / g. The amount of cellulase added relative to the total mass of brown rice flour, defatted rice bran flour, and rice bran residue is 0.5 wt%–0.8 wt%. Further optional is 0.5 wt%–0.6 wt%.

[0027] In one embodiment of the present invention, in step (2), the conditions for the second enzymatic hydrolysis are a reaction at 35-40°C for 1-2 hours.

[0028] In one embodiment of the present invention, in step (2), the trypsin enzyme activity is 2800-3000 U / g. The amount of trypsin added relative to the total mass of brown rice flour, defatted rice bran flour, and rice bran residue is 0.2wt% to 0.5wt%. Further optional is 0.2wt% to 0.3wt%.

[0029] In one embodiment of the present invention, in step (2), the conditions for the third enzymatic hydrolysis are a reaction at 35-40°C for 20-40 min.

[0030] In one embodiment of the present invention, the rice bran oil used in step (3) is all food-grade raw material. The rice bran oil contains 5.35-8.61 mg / g of oryzanol and 0.82-1.07 mg / g of α-tocopherol.

[0031] In one embodiment of the present invention, in step (3), the fat-soluble bioactive substance is β-carotene.

[0032] In one embodiment of the present invention, in step (3), the ultrasonic treatment is performed at 200-300W for 5-10 minutes.

[0033] In one embodiment of the present invention, in step (3), the homogenization conditions are to homogenize 2 to 4 times at 100 to 120 MPa.

[0034] In one embodiment of the present invention, the preparation method of the rice-based milk tea functional beverage specifically includes the following steps:

[0035] (1) Mechanical pretreatment: 1.0%–1.2% brown rice flour, 2.0%–2.4% defatted rice bran powder, and 1.0%–1.2% rice bran residue powder are dispersed in 45.0%–47.0% purified water and stirred at 120–160 r / min for 4–6 hours to fully hydrate. The mixture is then maintained at a pressure of 0.12–0.14 MPa and a temperature of 121–125℃ for 30–35 minutes to obtain a rice-based mixed liquor. 0.5%–0.6% tea powder is dissolved in 4… The tea powder extract was obtained by boiling in 4.6%–48.5% purified water for 5–6 minutes, cooling to room temperature, and filtering to remove impurities. The tea powder extract was then added to a rice-based mixture and mechanically pretreated by high-speed shearing (10,000–12,000 r / min for 2–3 minutes), high-pressure homogenization (100–120 MPa for 2–4 times), and ultrasonication (300–400 W for 10–20 minutes) to obtain a rice-based tea mixture.

[0036] (2) Moderate enzymatic hydrolysis: To the rice-based tea mixture described in step (1), add 0.2%–0.3% α-amylase (enzyme activity 40,000–50,000 U / g), 0.2%–0.3% β-amylase (enzyme activity 80,000–85,000 U / g), 0.1%–0.3% maltase (enzyme activity 9,000–10,000 U / g), and 0.1%–0.3% glucose isomerase (enzyme activity 100,000–200,000 U / g) equivalent to the total mass of brown rice flour. The mixture is prepared by reacting the following steps: First, add 0.5%–0.6% of cellulase (enzyme activity 10000–12000 U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 35–40℃ for 1–2 hours. Then, add 0.2%–0.3% of trypsin (enzyme activity 2800–3000 U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 35–40℃ for 20–40 minutes to obtain the enzymatic hydrolysate.

[0037] (3) Emulsification: Add 0.8 to 1.2 mg / g of fat-soluble bioactive substances (based on oil) to 2.0% to 3.0% rice bran oil, and then add the rice bran oil to the enzymatic hydrolysate described in step (2). Sonicate at 200 to 300 W for 5 to 10 minutes to obtain a crude emulsion, and then homogenize at 100 to 120 MPa 2 to 4 times to obtain a rice-based milk tea functional beverage.

[0038] In the preparation method of this invention, the invention first promotes the structural development of macromolecules such as proteins, lipids, and polysaccharides in brown rice flour, defatted rice bran powder, and rice bran residue powder through mechanical pretreatment techniques such as high-speed shearing, high-pressure homogenization, and ultrasound, and regulates the interaction between them and tea powder to form composite particles with good physical and oxidative stability; then, moderate enzymatic hydrolysis is used to enhance the interfacial adsorption characteristics of the composite particles, while also giving the raw materials better taste, flavor, and nutritional value; finally, an appropriate amount of rice bran oil and fat-soluble bioactive components are added, and emulsification is performed to form a rice-based milk tea functional beverage.

[0039] This invention provides a rice-based milk tea functional beverage prepared using the above method.

[0040] The beneficial effects of this invention are as follows:

[0041] (1) The rice-based milk tea functional beverage of the present invention has a mellow and slightly sweet taste, with both tea and rice aromas. It is nutritionally balanced and rich in a variety of natural physiologically active substances, including dietary fiber (1.92-2.14g / 100g), protein (0.66-0.72g / 100g), tea polyphenols (150.15-156.29mg / 100g), oryzanol (12.22-16.35mg / 100g), α-tocopherol (2.40-3.06mg / 100g), and γ-aminobutyric acid (4.22-5.87mg / 100g). It has various physiological activities such as regulating intestinal flora and anti-oxidation.

[0042] (2) The rice-based milk tea functional beverage of this invention fully utilizes the synergistic effect of the antioxidant and antibacterial components contained in the raw materials to form a stable Pickering emulsion system with a high retention rate of encapsulated fat-soluble bioactive substances. After 30 days of storage at room temperature, the beverage exhibits no stratification, flocculation, precipitation, or lipid floating, and the retention rate of β-carotene reaches 93.3%–95.0%.

[0043] (3) The rice-based milk tea functional beverage of the present invention makes full use of rice processing by-products such as defatted rice bran and rice bran residue, providing a new disposal mode for the high-value full utilization of grain and oil processing by-products. Detailed Implementation

[0044] The present invention will be further described below with reference to the embodiments.

[0045] The raw materials or enzyme preparations such as brown rice flour, defatted rice bran phenol, rice bran residue powder, tea powder, rice bran oil, and fat-soluble bioactive substances used in the embodiments of this invention are all obtained through conventional commercial channels.

[0046] The sources of the enzymes involved in this invention are as follows:

[0047] enzyme preparations source enzyme preparations source α-Amylase Aspergillus niger Glucosyl isomerase (xylose isomerase) Bacillus coagulans β-amylase Bacillus subtilis Cellulase Aspergillus niger Maltase (α-glucosidase) Aspergillus niger trypsin Pancreas of pigs or cows

[0048] The various test indicators of the rice-based milk tea functional beverage prepared by this invention were determined according to the following methods:

[0049] The determination of dietary fiber content in rice-based milk tea functional beverages was carried out in accordance with GB 5009.88-2023.

[0050] The protein content of rice-based milk tea functional beverages was determined in accordance with GB 5009.5-2025.

[0051] Sensory testing and polyphenol content determination of rice-based milk tea functional beverages were conducted in accordance with GB / T 21733-2008.

[0052] The determination of oryzanol content in rice-based milk tea functional beverages was performed according to LS / T 6121.2-2017 high performance liquid chromatography.

[0053] The determination of α-tocopherol content in rice-based milk tea functional beverages was carried out according to the high performance liquid chromatography method in GB / T 26635-2011.

[0054] The determination of γ-aminobutyric acid (GABA) content in rice-based milk tea functional beverages was performed according to the high performance liquid chromatography method in NY / T 2890-2016.

[0055] The determination of γ-aminobutyric acid (GABA) content in rice-based milk tea functional beverages was performed according to the high performance liquid chromatography method in NY / T 2890-2016.

[0056] The β-carotene retention rate of rice-based milk tea functional beverages was determined using the following method: 1 mL of the beverage was mixed with 1 mL of ethanol and 1.5 mL of n-hexane, and shaken continuously for 10 seconds. This operation was repeated twice until the aqueous phase became clear and transparent. The organic phases were then combined, and the absorbance of the organic phase at 450 nm was measured using a spectrophotometer. The β-carotene concentration of the beverage was calculated based on the absorbance. The β-carotene retention rate was calculated using the following formula.

[0057] β-carotene retention rate (%) = C t / C0×100%

[0058] C0 is the concentration of beta-carotene in fresh beverages. t This is the concentration of β-carotene after 30 days of storage at room temperature.

[0059] Example 1

[0060] The rice-based milk tea functional beverage of this embodiment has the following raw material formula based on 100% total weight: 1.0% brown rice flour, 2.0% defatted rice bran powder, 1.0% rice bran residue powder, 0.5% tea powder, 2.0% rice oil (with 0.8mg / g of fat-soluble bioactive substances added, calculated as oil), and 93.5% purified water.

[0061] Brown rice flour is a product obtained by grinding rice after hulling. It contains 8.22% protein, 5.52% crude fat, 75.65% starch, and 3.32% dietary fiber.

[0062] Defatted rice bran powder is a byproduct obtained by pulverizing rice bran oil extracted from brown rice bran. It contains 15.01% protein, 1.22% crude fat, and 32.33% dietary fiber.

[0063] Rice bran residue powder is a byproduct obtained by pulverizing defatted rice bran after extracting rice bran protein. It contains 10.70% protein, 0.71% crude fat, and 33.95% dietary fiber.

[0064] The tea powder is instant green tea powder with a tea polyphenol content of 243 mg / g.

[0065] Rice oil contains 5.35 mg / g of oryzanol and 0.82 mg / g of α-tocopherol.

[0066] The fat-soluble bioactive substance is β-carotene.

[0067] The preparation method of the rice-based milk tea functional beverage in this embodiment specifically includes the following steps:

[0068] (1) Mechanical pretreatment: 1.0 wt% brown rice flour, 2.0 wt% defatted rice bran powder, and 1.0 wt% rice bran residue powder were dispersed in 45.0 wt% purified water and stirred at 120 r / min for 4 h at room temperature to fully hydrate. The mixture was then kept at 0.12 MPa and 121℃ for 30 min to obtain a rice-based mixed liquid. 0.5 wt% tea powder was dissolved in 48.5 wt% purified water, boiled for 5 min, cooled to room temperature, and filtered to remove impurities to obtain a tea powder extract. The tea powder extract was added to the rice-based mixed liquid and mechanically pretreated sequentially by high-speed shearing (10000 r / min, 2 min), high-pressure homogenization (100 MPa, homogenization twice), and ultrasound (300 W, 10 min) to obtain a rice-based tea mixed liquid.

[0069] (2) Moderate enzymatic hydrolysis: In the rice-based tea mixture described in step (1), add 0.2% α-amylase (40,000 U / g), 0.2% β-amylase (80,000 U / g), 0.1% maltase (9,000 U / g), and 0.1% glucosidase (100,000 U / g) equivalent to the total mass of brown rice flour, and react at 40°C for 4 hours; then add 0.5% cellulase (10,000 U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 35°C for 1 hour; then add 0.2% trypsin (2,800 U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 35°C for 20 minutes to obtain the enzymatic hydrolysate.

[0070] (3) Emulsification: Add 0.8 mg / g of fat-soluble bioactive substances (based on oil) to 2.0% rice bran oil, and then add the rice bran oil to the enzymatic hydrolysate described in step (2). Sonicate at 200 W for 5 min to obtain crude emulsion, and then homogenize twice at 100 MPa to obtain rice-based milk tea functional beverage.

[0071] Testing revealed that the rice-based milk tea functional beverage obtained in this embodiment contained: 1.92g / 100g dietary fiber, 0.66g / 100g protein, 150.15mg / 100g tea polyphenols, 12.22mg / 100g oryzanol, 2.40mg / 100g α-tocopherol, and 4.22mg / 100g γ-aminobutyric acid. The beverage has a rich, slightly sweet taste, combining the aromas of tea and rice. After 30 days of storage at room temperature, the beverage showed no signs of stratification, flocculation, sedimentation, or lipid floating; the retention rate of β-carotene in the beverage reached 93.3%.

[0072] Example 2

[0073] The rice-based milk tea functional beverage of this embodiment has the following raw material formula based on 100% total weight: 1.1% brown rice flour, 2.2% defatted rice bran powder, 1.1% rice bran residue powder, 0.55% tea powder, 2.45% rice oil (with 1.0 mg / g of fat-soluble bioactive substances added, calculated as oil), and 92.6% purified water.

[0074] Brown rice flour is a product obtained by grinding rice after hulling. It contains 9.24% protein, 6.15% crude fat, 74.24% starch, and 4.02% dietary fiber.

[0075] Defatted rice bran powder is a byproduct obtained by pulverizing rice bran oil extracted from brown rice bran. It contains 16.07% protein, 1.35% crude fat, and 30.55% dietary fiber.

[0076] Rice bran residue powder is a byproduct obtained by pulverizing defatted rice bran after extracting rice bran protein. It contains 11.44% protein, 0.85% crude fat, and 31.88% dietary fiber.

[0077] The tea powder is instant green tea powder with a tea polyphenol content of 259 mg / g.

[0078] Rice oil contains 7.66 mg / g of oryzanol and 0.95 mg / g of α-tocopherol.

[0079] The fat-soluble bioactive substance is β-carotene.

[0080] The preparation method of the rice-based milk tea functional beverage in this embodiment specifically includes the following steps:

[0081] (1) Mechanical pretreatment: 1.1% brown rice flour, 2.2% defatted rice bran powder, and 1.1% rice bran residue powder were dispersed in 46.0% purified water and stirred at 140 r / min for 5 h to fully hydrate. The mixture was then kept at 0.13 MPa and 123℃ for 32 min to obtain a rice-based mixed liquid. 0.55% tea powder was dissolved in 46.6% purified water, boiled for 5.5 min, cooled to room temperature, and filtered to remove impurities to obtain a tea powder extract. The tea powder extract was added to the rice-based mixed liquid and mechanically pretreated sequentially by high-speed shearing (11000 r / min, 2.5 min), high-pressure homogenization (110 MPa, homogenization 3 times), and ultrasound (350 W, 15 min) to obtain a rice-based tea mixed liquid.

[0082] (2) Moderate enzymatic hydrolysis: In the rice-based tea mixture described in step (1), add 0.24% α-amylase (45000U / g), 0.24% β-amylase (82000U / g), 0.2% maltase (9500U / g), and 0.2% glucosidase (150000U / g) equivalent to the total mass of brown rice flour, and react at 42℃ for 5h; then add 0.55% cellulase (11000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 37℃ for 1.5h; then add 0.24% trypsin (2900U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 37℃ for 30min to obtain the enzymatic hydrolysate.

[0083] (3) Emulsification: Add 1.0 mg / g of fat-soluble bioactive substance (based on oil) to 2.45% rice bran oil, and then add the rice bran oil to the enzymatic hydrolysate described in step (2). Sonicate at 250 W for 8 min to obtain crude emulsion, and then homogenize at 110 MPa 3 times to obtain rice-based milk tea functional beverage.

[0084] Testing revealed that the rice-based milk tea functional beverage obtained in this embodiment contained: 2.07g / 100g dietary fiber, 0.70g / 100g protein, 154.77mg / 100g tea polyphenols, 14.29mg / 100g oryzanol, 2.87mg / 100g α-tocopherol, and 5.55mg / 100g γ-aminobutyric acid. The beverage has a rich, slightly sweet taste, combining the aromas of tea and rice. After 30 days of storage at room temperature, the beverage showed no signs of stratification, flocculation, sedimentation, or lipid floating; the retention rate of β-carotene in the beverage reached 94.6%.

[0085] Example 3

[0086] The rice-based milk tea functional beverage of this embodiment has the following raw material formula based on 100% total weight: 1.2% brown rice flour, 2.4% defatted rice bran powder, 1.2% rice bran residue powder, 0.6% tea powder, 3.0% rice oil (with 1.2 mg / g of fat-soluble bioactive substances added, calculated as oil), and 91.6% purified water.

[0087] Brown rice flour is a product obtained by grinding rice after hulling. It contains 10.50% protein, 7.27% crude fat, 73.41% starch, and 4.54% dietary fiber.

[0088] Defatted rice bran powder is a byproduct obtained by pulverizing rice bran oil extracted from brown rice bran. It contains 16.90% protein, 1.43% crude fat, and 28.21% dietary fiber.

[0089] Rice bran residue powder is a byproduct obtained by pulverizing defatted rice bran after extracting rice bran protein. It contains 12.65% protein, 0.93% crude fat, and 30.72% dietary fiber.

[0090] The tea powder is instant green tea powder with a tea polyphenol content of 262 mg / g.

[0091] Rice oil contains 8.61 mg / g of oryzanol and 1.07 mg / g of α-tocopherol.

[0092] The fat-soluble bioactive substance is β-carotene.

[0093] The preparation method of the rice-based milk tea functional beverage in this embodiment specifically includes the following steps:

[0094] (1) Mechanical pretreatment: 1.2% brown rice flour, 2.4% defatted rice bran powder, and 1.2% rice bran residue powder were dispersed in 47.0% purified water and stirred at 160 r / min for 6 hours at room temperature to fully hydrate. The mixture was then kept at 0.14 MPa and 125℃ for 35 minutes to obtain a rice-based mixed liquid. 0.6% tea powder was dissolved in 44.6% purified water, boiled for 6 minutes, cooled to room temperature, and filtered to remove impurities to obtain a tea powder extract. The tea powder extract was added to the rice-based mixed liquid and mechanically pretreated sequentially by high-speed shearing (12000 r / min, 3 minutes), high-pressure homogenization (120 MPa, homogenization 4 times), and ultrasound (400 W, 20 minutes) to obtain a rice-based tea mixed liquid.

[0095] (2) Moderate enzymatic hydrolysis: In the rice-based tea mixture described in step (1), add 0.3% α-amylase (enzyme activity of 50000U / g), 0.3% β-amylase (enzyme activity of 85000U / g), 0.3% maltase (enzyme activity of 10000U / g), and 0.3% glucosidase (enzyme activity of 200000U / g) equivalent to the total mass of brown rice flour, and react at 45℃ for 6h; then add 0.6% cellulase (enzyme activity of 12000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 40℃ for 2h; then add 0.3% trypsin (enzyme activity of 3000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and react at 40℃ for 40min to obtain the enzymatic hydrolysate.

[0096] (3) Emulsification: Add 1.2 mg / g of fat-soluble bioactive substances (based on oil) to 3.0% rice bran oil, and then add the rice bran oil to the enzymatic hydrolysate described in step (2). Sonicate at 300 W for 10 min to obtain crude emulsion, and then homogenize at 120 MPa 4 times to obtain rice-based milk tea functional beverage.

[0097] Testing revealed that the rice-based milk tea functional beverage obtained in this embodiment contained: 2.14 g / 100g dietary fiber, 0.72 g / 100g protein, 156.29 mg / 100g tea polyphenols, 16.35 mg / 100g oryzanol, 3.06 mg / 100g α-tocopherol, and 5.87 mg / 100g γ-aminobutyric acid. The beverage has a rich, slightly sweet taste, combining the aromas of tea and rice. After 30 days of storage at room temperature, the beverage showed no signs of stratification, flocculation, sedimentation, or lipid floating; the retention rate of β-carotene in the beverage reached 95.0%.

[0098] Comparative Example 1

[0099] Referring to Example 3, only the formula was adjusted to Formula 1 as follows: Based on a total weight of 100%, the raw material formula is as follows: 2% brown rice flour, 2.4% defatted rice bran powder, 2% rice bran residue powder, 0.6% tea powder, 3.0% rice oil (with added fat-soluble bioactive substances of 1.2 mg / g, calculated as oil), and 90% purified water. The preparation steps are the same as in Example 1, yielding the corresponding rice-based milk tea functional beverage.

[0100] Referring to Example 3, only the formula was adjusted to Formula 2 as follows: Based on a total weight of 100%, the raw material formula is as follows: 0.5% brown rice flour, 2.4% defatted rice bran powder, 0.5% rice bran residue powder, 0.6% tea powder, 3.0% rice oil (with added fat-soluble bioactive substances of 1.2 mg / g, calculated as oil), and 93% purified water. The preparation steps are the same as in Example 1, yielding the corresponding rice-based milk tea functional beverage.

[0101] Referring to Example 3, the formula was adjusted as follows: Based on a total weight of 100%, the raw material formula is as follows: 1.2% brown rice flour, 3.0% defatted rice bran powder, 1.2% rice bran residue powder, 0.6% tea powder, 3.0% rice oil (with added fat-soluble bioactive substances of 1.2 mg / g, calculated as oil), and 91% purified water. The preparation steps are the same as in Example 1, yielding the corresponding rice-based milk tea functional beverage.

[0102] Referring to Example 3, the formula is adjusted to Formula 4 as follows: Based on a total weight of 100%, the raw material formula is as follows: 1.2% brown rice flour, 1% defatted rice bran powder, 1.2% rice bran residue powder, 0.6% tea powder, 3.0% rice oil (with added fat-soluble bioactive substances of 1.2 mg / g, calculated as oil), and 93% purified water. The preparation steps are the same as in Example 1, yielding the corresponding rice-based milk tea functional beverage.

[0103] Referring to Example 3, only the formula is adjusted to Formula 5 as follows: Based on a total weight of 100%, the raw material formula is as follows: 1.2% brown rice flour, 2.4% defatted rice bran powder, 1.2% rice bran residue powder, 0.6% tea powder, 1.0% rice oil (with added fat-soluble bioactive substances of 1.2 mg / g, calculated as oil), and 93.6% purified water. The preparation steps are the same as in Example 1, yielding the corresponding rice-based milk tea functional beverage.

[0104] Referring to Example 3, only the formula is adjusted to Formula 6 as follows: Based on a total weight of 100%, the raw material formula is as follows: 1.2% brown rice flour, 2.4% defatted rice bran powder, 1.2% rice bran residue powder, 0.6% tea powder, 5.0% rice oil (with added fat-soluble bioactive substances of 1.2 mg / g, calculated as oil), and 89.6% purified water. The preparation steps are the same as in Example 1, yielding the corresponding rice-based milk tea functional beverage.

[0105] Following the same testing procedure, the results of the rice-based milk tea functional beverage obtained in Comparative Example 1 were measured, as shown in Table 1.

[0106] Table 1

[0107]

[0108] As shown in Table 1, the proportions of each component in the formula of rice-based milk tea functional beverages have a significant impact on the stability and other nutritional qualities of the final beverage product. Combining formulations 1-4 in Example 3 and Comparative Example 1, it is evident that brown rice flour, defatted rice bran powder, and rice bran residue powder, when combined in a specific proportion, synergistically produce a beverage product of better quality. Furthermore, considering formulations 5-6 in Example 3 and Comparative Example 1, the addition of rice oil is also crucial; inappropriate amounts can lead to uneven texture, easy separation of the beverage, and an inability to achieve the desired high-quality performance in the overall formula.

[0109] Comparative Example 2

[0110] The formula for the rice-based milk tea functional beverage is as described in Example 3.

[0111] Specifically, the following steps are included:

[0112] (1) Mechanical pretreatment: Same as in Example 3, to obtain rice-based tea mixture.

[0113] (2) Moderate enzymatic hydrolysis: Compared with Example 3, the process was adjusted to a two-step enzymatic hydrolysis process. Specifically, it includes: adding 0.3% α-amylase (enzyme activity of 50000U / g) and 0.3% β-amylase (enzyme activity of 85000U / g) equivalent to the total mass of brown rice flour to the rice-based tea mixture described in step (1), and adding 0.3% trypsin (enzyme activity of 3000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder and rice bran residue, and reacting at 45°C for 6 hours; then adding 0.3% maltase (enzyme activity of 10000U / g), 0.3% glucose isomerase (enzyme activity of 200000U / g), and adding 0.6% cellulase (enzyme activity of 12000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder and rice bran residue powder, and reacting at 40°C for 2 hours to obtain the enzymatic hydrolysate.

[0114] (3) Emulsification: Same as in Example 3, rice-based milk tea functional beverage was prepared.

[0115] Comparative Example 3

[0116] The formula for the rice-based milk tea functional beverage is as described in Example 3.

[0117] Specifically, the following steps are included:

[0118] (1) Mechanical pretreatment: Same as in Example 3, to obtain rice-based tea mixture.

[0119] (2) Moderate enzymatic hydrolysis: Compared with Example 3, the process was adjusted to a two-step enzymatic hydrolysis process. Specifically, it includes: adding 0.3% α-amylase (enzyme activity of 50000U / g), 0.3% β-amylase (enzyme activity of 85000U / g), 0.3% maltase (enzyme activity of 10000U / g), and 0.3% glucosidase (enzyme activity of 200000U / g) to the rice-based tea mixture in step (1), and reacting at 45°C for 6 hours; then adding 0.6% cellulase (enzyme activity of 12000U / g) to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and adding 0.3% trypsin (enzyme activity of 3000U / g) to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and reacting at 40°C for 2 hours to obtain the enzymatic hydrolysate.

[0120] (3) Emulsification: Same as in Example 3, rice-based milk tea functional beverage was prepared.

[0121] Comparative Example 4

[0122] The formula for the rice-based milk tea functional beverage is as described in Example 3.

[0123] Specifically, the following steps are included:

[0124] (1) Mechanical pretreatment: Same as in Example 3, to obtain rice-based tea mixture.

[0125] (2) Moderate enzymatic hydrolysis: Compared with Example 3, the process was adjusted to a one-step enzymatic hydrolysis process. Specifically, it includes: adding 0.3% α-amylase (enzyme activity of 50000U / g), 0.3% β-amylase (enzyme activity of 85000U / g), 0.3% maltase (enzyme activity of 10000U / g), and 0.3% glucosidase (enzyme activity of 200000U / g) to the rice-based tea mixture described in step (1), adding 0.6% cellulase (enzyme activity of 12000U / g) to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and adding 0.3% trypsin (enzyme activity of 3000U / g) to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and reacting at 45°C for 6 hours to obtain the enzymatic hydrolysate.

[0126] (3) Emulsification: Same as in Example 3, rice-based milk tea functional beverage was prepared.

[0127] Comparative Example 5

[0128] The formula for the rice-based milk tea functional beverage is as described in Example 3.

[0129] Specifically, the following steps are included:

[0130] (1) Mechanical pretreatment: Same as in Example 3, to obtain rice-based tea mixture.

[0131] (2) Moderate enzymatic hydrolysis: Compared with Example 3, the enzymatic hydrolysis process was adjusted. Specifically, it includes: adding 0.3% α-amylase (enzyme activity of 50000U / g), 0.3% β-amylase (enzyme activity of 85000U / g), 0.3% maltase (enzyme activity of 10000U / g), and 0.3% glucosidase (enzyme activity of 200000U / g) to the rice-based tea mixture described in step (1), and reacting at 45°C for 6 hours; then adding 0.3% trypsin (enzyme activity of 3000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue, and reacting at 40°C for 40 minutes; then adding 0.6% cellulase (enzyme activity of 12000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue, and reacting at 40°C for 2 hours to obtain the enzymatic hydrolysate.

[0132] (3) Emulsification: Same as in Example 3, rice-based milk tea functional beverage was prepared.

[0133] Following the same testing procedure as in Example 3, the results of the rice-based milk tea functional beverages obtained in Comparative Examples 2-5 were measured, as shown in Table 2.

[0134] Table 2

[0135]

[0136]

[0137] As can be seen from Table 2, the enzymatic hydrolysis process is also very important! Only with the combination of a specific three-step enzymatic hydrolysis process can the formula be synergistically formulated to achieve a rice-based milk tea functional beverage with excellent stability and superior quality.

[0138] Comparative Example 6

[0139] The formula for the rice-based milk tea functional beverage is as described in Example 3.

[0140] Specifically, the following steps are included:

[0141] (1) Mechanical pretreatment: Same as in Example 3, to obtain rice-based tea mixture.

[0142] (2) Moderate enzymatic hydrolysis: Compared with Example 3, maltase was not added in the first step of enzymatic hydrolysis, while other steps remained unchanged. Specifically, in the rice-based tea mixture described in step (1), 0.3% α-amylase (enzyme activity of 50,000 U / g), 0.3% β-amylase (enzyme activity of 85,000 U / g), and 0.6% glucosidase (enzyme activity of 200,000 U / g) equivalent to the total mass of brown rice flour were added, and the mixture was reacted at 45°C for 6 hours; then 0.6% cellulase (enzyme activity of 12,000 U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder were added, and the mixture was reacted at 40°C for 2 hours; subsequently, 0.3% trypsin (enzyme activity of 3,000 U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder were added, and the mixture was reacted at 40°C for 40 minutes to obtain the enzymatic hydrolysate.

[0143] (3) Emulsification: Same as in Example 3, rice-based milk tea functional beverage was prepared.

[0144] Comparative Example 7

[0145] The formula for the rice-based milk tea functional beverage is as described in Example 3.

[0146] Specifically, the following steps are included:

[0147] (1) Mechanical pretreatment: Same as in Example 3, to obtain rice-based tea mixture.

[0148] (2) Moderate enzymatic hydrolysis: Compared with Example 3, no glucose isomerase was added in the first step of enzymatic hydrolysis, and everything else remained the same. Specifically, it includes: adding 0.3% α-amylase (enzyme activity of 50000U / g), 0.3% β-amylase (enzyme activity of 85000U / g), and 0.6% maltase (enzyme activity of 10000U / g) equivalent to the total mass of brown rice flour to the rice-based tea mixture described in step (1), and reacting at 45°C for 6 hours; then adding 0.6% cellulase (enzyme activity of 12000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and reacting at 40°C for 2 hours; then adding 0.3% trypsin (enzyme activity of 3000U / g) equivalent to the total mass of brown rice flour, defatted rice bran powder, and rice bran residue powder, and reacting at 40°C for 40 minutes to obtain the enzymatic hydrolysate.

[0149] (3) Emulsification: Same as in Example 3, rice-based milk tea functional beverage was prepared.

[0150] Following the same testing procedure as in Example 3, the results of the rice-based milk tea functional beverages obtained in Comparative Examples 6-7 were measured, as shown in Table 3.

[0151] Table 3

[0152]

[0153] As can be seen from Table 3, each step of the three-step enzymatic hydrolysis process requires a specific design to achieve the final rice-based milk tea functional beverage with excellent stability and better quality.

[0154] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing a rice-based milk tea functional beverage, characterized in that, Includes the following steps: (1) Mechanical pretreatment: Disperse brown rice flour, defatted rice bran powder, and rice bran residue powder in water, stir to fully hydrate, and then heat for a period of time to obtain rice-based mixed liquid; dissolve tea powder in water, boil, cool to room temperature, and filter to remove impurities to obtain tea powder extract; add tea powder extract to rice-based mixed liquid, and perform shearing, homogenization, and ultrasonic pretreatment in sequence to obtain rice-based tea mixed liquid; (2) Three-step enzymatic hydrolysis: In the rice-based tea mixture described in step (1), α-amylase, β-amylase, maltase and glucose isomerase are added to carry out the first step of enzymatic hydrolysis; then, cellulase is added to carry out the first step of enzymatic hydrolysis; finally, trypsin is added to carry out the third step of enzymatic hydrolysis to obtain the enzymatic hydrolysate. (3) Emulsification: Rice oil containing fat-soluble bioactive substances is added to the enzymatic hydrolysate obtained in step (2), and ultrasonic treatment is performed to obtain crude emulsion, which is then homogenized to obtain rice-based milk tea functional beverage.

2. The method according to claim 1, characterized in that, The raw materials, by weight percentage, consist of the following components: 1.0%–1.5% brown rice flour, 2.0%–2.5% defatted rice bran powder, 1.0%–1.5% rice bran residue powder, 0.5%–1.0% tea powder, 2.0%–3.0% rice bran oil, and the balance being water; wherein, the content of fat-soluble bioactive substances in rice bran oil is 0.8–1.2 mg / g.

3. The method according to claim 1, characterized in that, In step (1), the mixture is stirred at room temperature to fully hydrate, and then heated to 100-130℃ for a period of time to obtain a rice-based mixed liquid.

4. The method according to claim 1, characterized in that, In step (1), the shearing conditions are 10000-12000 r / min for 2-3 min; the homogenization conditions are 100-120 MPa for 2-4 homogenizations.

5. The method according to claim 1, characterized in that, In step (1), the ultrasound is performed at 300-400W for 10-20 minutes.

6. The method according to claim 1, characterized in that, In step (2), the enzyme activity of α-amylase is 40,000–50,000 U / g, and the amount of α-amylase added relative to the mass of brown rice flour is 0.2 wt%–0.5 wt%; the enzyme activity of β-amylase is 80,000–85,000 U / g, and the amount of β-amylase added relative to the mass of brown rice flour is 0.2 wt%–0.5 wt%; the enzyme activity of maltase is 9,000–10,000 U / g, and the amount of maltase added relative to the mass of brown rice flour is 0.1 wt%–0.3 wt%; the enzyme activity of glucose isomerase is 100,000–200,000 U / g, and the amount of glucose isomerase added relative to the mass of brown rice flour is 0.1 wt%–0.3 wt%.

7. The method according to claim 1, characterized in that, In step (2), the cellulase activity is 10,000 to 12,000 U / g, and the amount of cellulase added relative to the total mass of brown rice flour, defatted rice bran flour and rice bran residue is 0.5 wt% to 0.8 wt%.

8. The method according to claim 1, characterized in that, In step (2), the enzyme activity of trypsin is 2800-3000 U / g, and the amount of trypsin added relative to the total mass of brown rice flour, defatted rice bran flour and rice bran residue is 0.2wt% to 0.5wt%.

9. The method according to claim 1, characterized in that, In step (2), the first step of enzymatic hydrolysis is carried out at 40-45℃ for 4-6 hours, the second step of enzymatic hydrolysis is carried out at 35-40℃ for 1-2 hours, and the third step of enzymatic hydrolysis is carried out at 35-40℃ for 20-40 minutes.

10. A rice-based milk tea functional beverage prepared by the method according to any one of claims 1-9.

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