Rice milk beverage and preparation method of rice milk beverage and nano-composite dispersion system

Abstract

The invention relates to the technical field of nano-composites, in particular to a rice milk beverage and a preparation method of the rice milk beverage and a nano-composite dispersion system.The preparation method of the nano-composite dispersion system comprises the steps that rice enzymatic hydrolysate serves as a matrix, and an active peptide-oligosaccharide composite system is obtained through a composite enzymolysis technology; then self-assembling with curcumin to form a nano compound; and finally, multi-stage homogenization and chitosan-sodium carboxymethyl cellulose synergistically stabilize to prepare the product. The rice milk beverage prepared by the method is rich in active ingredients such as curcumin, can be more effectively absorbed by a human body, and has high bioavailability, antioxidant activity and good sensory characteristics; meanwhile, the product stability is good, the technical problems of poor dispersion of fat-soluble components and inactivation of heat-sensitive substances in a traditional rice milk beverage can be effectively solved, and the problems of obvious layering, precipitation and the like cannot occur in the storage process.

Description

Technical Field

[0001] The invention relates to the technical field of nanocomposites, in particular to a rice milk beverage and a preparation method of a rice milk beverage and nanocomposite dispersion system. Background Art

[0002] In recent years, driven by the combined demands of health, fashion, and environmental protection, "plant-based" has become a new development direction in the global food and beverage industry. Among plant-based products, plant protein beverages have gained significant market favor due to their diverse plant protein ingredients, rich nutritional value, unique taste, and natural, healthy qualities. Rice beverages are a unique and popular beverage. Made primarily from high-quality rice, they undergo a series of processing steps, including soaking, steaming, refining, and enzymatic hydrolysis, followed by blending, homogenization, and sterilization. These nutritious beverages are rich in carbohydrates, protein, vitamins, and minerals, providing essential energy and nutrients. Their rich, smooth, and refreshing taste caters to diverse consumer preferences. Furthermore, they are mild and easy to digest, requiring minimal gastrointestinal stress, making them an ideal choice for those with lactose intolerance and allergies to other beverages. Advances in food processing technology are continuously improving the taste and quality of rice beverages. Manufacturers are innovating and launching products with a variety of flavors and functionalities, such as those with added fruits, grains, and vitamins, to meet the personalized needs of diverse consumers and further expand market demand. In some countries and regions focused on healthy eating, rice beverages have become popular supermarket items, with sales continuing to grow, demonstrating their continued vitality and promising development prospects in the modern market. However, existing rice beverages often suffer from poor taste, nutrient release, and bioavailability. Traditional processing methods can prevent the full dissolution of rice nutrients, and the beverage's stability and uniformity need improvement.

[0003] The current development of rice beverages faces the following challenges: First, the bioactive ingredients involved are largely unclear and low in content, hindering the product's health benefits. Furthermore, the release and bioavailability of nutrients are poor, and traditional processing methods hinder the full dissolution of nutrients from rice, hindering their absorption and utilization by the human body. Furthermore, developing stable and healthy rice milk beverages presents challenges. The addition of multiple new ingredients can introduce instability, and a lack of comprehensive consideration of comprehensive health benefits makes it difficult to meet consumer demands for healthy rice milk beverages that are nutritionally balanced, highly bioactive, and stable.

[0004] The Chinese invention patent application with application publication number CN 117084996 A (application number: 202310823602.6) discloses a drug-loaded and stable curcumin composite nanoparticle and its preparation method. The composite nanoparticles prepared by the invention are used to make oral drugs, foods, health products or animal feed. The composite nanoparticles are cross-linked with chondroitin sulfate, which significantly improves the solubility and dispersibility of rice protein hydrolysate and curcumin. The nanoparticles have a high curcumin loading rate and high stability. However, since chondroitin sulfate is derived from animal tissue, the raw material is difficult to obtain, the cost is high, and the supply may be affected by factors such as the animal source, which poses a risk of disease transmission; its aqueous solution is easily deacetylated or degraded when exposed to high temperature or strong acid. Although the stability is improved after compounding with rice protein hydrolysate, the performance of the nanoparticles may still be affected by charge shielding or structural damage under extreme conditions; curcumin composite nanoparticles are mainly used to make oral drugs, foods, health products or animal feed. The application scenarios are relatively limited, and the competitiveness in the direct-to-consumer beverage field is relatively weak. Summary of the Invention

[0005] The purpose of the present invention is to provide a rice milk beverage and a preparation method of a rice milk beverage and nanocomposite dispersion system, which can effectively solve the technical problems of poor dispersion of fat-soluble components and inactivation of heat-sensitive substances in traditional rice milk beverages, and will not cause obvious stratification, precipitation and other problems during storage.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for preparing a nanocomposite dispersion system comprises the following steps: using rice enzymatic hydrolysate as a matrix, obtaining an active peptide-oligosaccharide composite system through a composite enzymatic hydrolysis process, and then self-assembling with curcumin to form a nanocomposite; and finally adopting multi-stage homogenization and chitosan-sodium carboxymethyl cellulose collaborative stabilization to prepare the system.

[0008] Specifically:

[0009] (1) sampling according to a rice to water mass volume ratio of 1:5-8, grinding and pulping to obtain rice pulp;

[0010] (2) gelatinizing the rice pulp at 80-90° C. for 20-30 min to obtain a gelatinized liquid;

[0011] (3) cooling the gelatinized liquid to 60-80° C., adding a complex enzyme for enzymolysis, adjusting the pH to 5.5-7.0, and performing enzymolysis for 3-5 h before inactivating the enzyme and filtering to obtain a rice enzymolyzed liquid;

[0012] (4) slowly adding a curcumin ethanol solution having a mass concentration of 1-5 mg / mL to the rice enzymatic hydrolysate at a curcumin to rice enzymatic hydrolysate solid mass ratio of 1:10-20 to obtain a mixed solution;

[0013] (5) placing the resulting mixed solution in a microfluidic device and circulating the solution for 1-3 times;

[0014] (6) After the ethanol in the obtained composite dispersion is evaporated, chitosan with a mass volume fraction of 0.05-0.1% and sodium carboxymethyl cellulose with a mass volume fraction of 0.1-0.3% are added, and ultrasonic treatment is performed to obtain a nanocomposite dispersion system.

[0015] A further solution is that the apparent solubility of curcumin in the obtained rice milk beverage is greater than 80 μg / mL, and the centrifugal separation rate is less than 0.5%.

[0016] A method for preparing a rice milk beverage is also provided, comprising the following steps:

[0017] (1) sampling according to a rice to water mass volume ratio of 1:5-8, grinding and pulping to obtain rice pulp;

[0018] (2) gelatinizing the rice pulp at 80-90° C. for 20-30 min to obtain a gelatinized liquid;

[0019] (3) cooling the gelatinized liquid to 60-80° C., adding a complex enzyme for enzymolysis, adjusting the pH to 5.5-7.0, and performing enzymolysis for 3-5 h before inactivating the enzyme and filtering to obtain a rice enzymolyzed liquid;

[0020] (4) slowly adding a curcumin ethanol solution having a mass concentration of 1-5 mg / mL to the rice enzymatic hydrolysate at a curcumin to rice enzymatic hydrolysate solid mass ratio of 1:10-20 to obtain a mixed solution;

[0021] (5) placing the resulting mixed solution in a microfluidic device and circulating the solution for 1-3 times;

[0022] (6) After the ethanol in the obtained composite dispersion is evaporated, 0.05-0.1% by mass volume fraction of chitosan and 0.1-0.3% by mass volume fraction of sodium carboxymethyl cellulose are added, and ultrasonic treatment is performed to obtain a nanocomposite dispersion system;

[0023] (7) diluting the nanocomposite dispersion system with water at a mass ratio of 1:1-1:2, and sequentially adding 0.04%-0.06% of sodium isoVc, 2%-4% of oligofructose, 1%-2% of inulin, and 0.7%-1% of coconut oil powder by volume, and stirring uniformly to obtain a prepared solution;

[0024] (8) homogenizing the prepared liquid in two stages under a pressure of 20-30 MPa, wherein the first stage is homogenized at a pressure of 20-25 MPa and the second stage is homogenized at a pressure of 28-30 MPa to obtain a homogenized liquid;

[0025] (9) The homogenized liquid is sterilized to obtain a rice milk beverage.

[0026] A further solution is that the total amount of the complex enzyme in step (3) is 0.5%-2% of the mass of the rice.

[0027] A further solution is that the complex enzyme consists of α-amylase and protease, and the mass ratio of amylase to protease is 2:1.

[0028] A further solution is that the α-amylase activity is 2000-3000 U / mL, and the protease activity is 8000-10000 U / g.

[0029] In a further embodiment, the average particle size of the nanocomposite dispersion system in step (6) is 150-220 nm.

[0030] A further solution is that the conditions for ultrasonic treatment in step (6) are: ultrasonic frequency of 20 kHz, ultrasonic power of 300-500 W, and treatment time of 5-10 min.

[0031] A further solution is that the sterilization conditions in step (9) are: sterilization at 135-140°C for 4-6 seconds.

[0032] A further solution is that the nanocomposite dispersion system has a 6-hour release rate greater than 75% in simulated intestinal fluid, and a curcumin retention rate greater than 90% in an accelerated stability test stored at 40° C. and 75% relative humidity for 3 months.

[0033] At the same time, the invention also relates to a rice milk beverage prepared by the method.

[0034] The preparation method of the rice milk beverage provided in the above technical solution is rich in active ingredients such as curcumin, can be more effectively absorbed by the human body, and has high bioavailability, antioxidant activity and good sensory properties. At the same time, it also has the following effects:

[0035] 1. The nanocomposite dispersion system constructed by the present invention exhibits good physicochemical stability. The curcumin embedding rate in the complex can reach 85%, and the average particle size change rate of the nanocomposite dispersion system is less than 8% after storage at room temperature for 30 days. In addition, within the pH range of 5.5-7.0, the complex system remains stable, and the zwitterionic chitosan achieves pH-responsive protection through charge reversal. Further verification by accelerated stability experiments at 40°C and 75% relative humidity shows that the nanostructure of the hydrophobic core-hydrophilic shell can effectively resist hydrothermal degradation, and the curcumin retention rate is greater than 90% after storage for 3 months. This stability feature provides a solid foundation for the application of rice milk beverages in room temperature circulation and complex dietary environments.

[0036] 2. In terms of antioxidant properties, DPPH free radical scavenging experiments demonstrated that the phenolic hydroxyl groups of curcumin in the nanocomplex synergistically donate hydrogen with the reducing ends of oligosaccharides, increasing DPPH scavenging by 40%-50%. In vitro cell experiments demonstrated a 35%-40% increase in the inhibition of the inflammatory factor TNF-α. Simulated intestinal flora culture experiments increased the proliferation of beneficial bacteria such as Bifidobacterium by 25%-30%. Gradient homogenization and chitosan-sodium carboxymethylcellulose synergistic stabilization technology create a steric hindrance-electrostatic repulsion synergistic effect to inhibit Ostwald ripening, resulting in a centrifugal fractionation rate of less than 0.5%, with no precipitation or fat floating.

[0037] 3. This invention uses microfluidization and ultrasonic treatment to form a nanocomposite, embedding curcumin into the active peptide-oligosaccharide system. High-pressure shearing and fragmentation create submicron droplets with uniform particle size distribution. The instantaneous high temperature and high pressure facilitate the embedding of curcumin into the active peptide's β-pleated region and the oligosaccharide helical cavity. This nanostructured synergy significantly improves the bioavailability of curcumin in the rice milk beverage. Compared to conventional methods that directly add curcumin powder, the product of this invention achieves a bioavailability of 80%-85%. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a flow chart of the preparation process of the rice milk beverage;

[0039] Figure 2 This is a photo of the curcumin-rich rice milk beverage prepared by the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following examples. It should be understood that the following text is only used to describe one or more specific embodiments of the present invention and does not strictly limit the scope of protection of the present invention.

[0041] Embodiment 1: selected high-quality rice, according to the mass volume ratio of rice and water, is 1:6 grinding pulping, obtains rice mash; Mash is carried out gelatinization treatment 20-30min at 80-90 ℃; After gelatinization liquid is cooled to 60 ℃, add the complex enzyme (α-amylase activity is 2500U / mL, and protease activity is 9000U / g) consisting of amylase and protease, amylase and protease mass ratio is 1:1-3:1, and addition is 1.2% of rice quality, regulate pH to 5.5-6.5, in enzymolysis temperature 60-80 ℃ of enzymolysis 3-5h, after this enzyme go-out is filtered, and obtains rice enzymolysis solution.

[0042] A 3 mg / mL curcumin ethanol solution was slowly added to the rice hydrolysate at a curcumin to rice hydrolysate solid mass ratio of 1:15; the resulting mixture was placed in a microfluidizer at a pressure of 100 MPa and circulated twice; after evaporating the ethanol, 0.08% chitosan and 0.2% sodium carboxymethyl cellulose were added, and ultrasonic treatment was performed: the ultrasonic frequency was set at 20 kHz, the ultrasonic power was set at 400 W, and the ultrasonic time was set at 8 minutes to obtain a nanocomposite dispersion system.

[0043] The formation of a curcumin complex with the enzymatic hydrolyzate under different gelatinization conditions, set at a mass ratio of amylase to protease of 2:1, a hydrolysis temperature of 70°C, a pH of 6.0, and a hydrolysis time of 4 h, is shown in Table 1. The smallest nanocomposite particle size was observed at a gelatinization temperature of 85°C and a gelatinization time of 25 min. Gelatinization conditions significantly affected the particle size of the complex, and an optimal gelatinization temperature and time combination was identified. The highest curcumin encapsulation efficiency reached 85%, reaching 70% and 68% at 80°C / 20 min and 90°C / 30 min, respectively, indicating that appropriate gelatinization conditions are beneficial for improving curcumin encapsulation efficiency. The complex achieved the best stability at 85°C / 25 min, with a particle size change of 6.9% after 30 days of storage, compared to 10% and 15% at 80°C / 20 min and 90°C / 30 min, respectively. Optimal gelatinization conditions enhance complex stability.

[0044] Table 1 Formation of complex between enzymatic hydrolysate and curcumin under different gelatinization conditions

[0045]

[0046] The gelatinization temperature was set at 85°C for 25 minutes, the enzymatic hydrolysis temperature was 70°C, the pH was 6.0, and the enzymatic hydrolysis time was 4 hours. The formation of a complex between the enzymatic hydrolysis product and curcumin at different enzyme ratios is shown in Table 2. When the amylase:protease ratio increased from 1:1 to 3:1, the average particle size of the nanocomposite initially decreased and then increased, indicating that the particle size gradually decreased with increasing amylase ratio. This may be because the changing enzyme ratio alters the properties of the enzymatic hydrolysis product, resulting in a smaller particle size of the complex formed with curcumin. Excessive amylase ratios may disrupt the synergistic "hydrophobic embedding, charge stabilization, and steric protection" structure formed between the active peptides and oligosaccharides in the enzymatic hydrolysis product. The curcumin encapsulation efficiency increased from 60% to 85%, indicating that an appropriate amylase ratio facilitates enhanced curcumin encapsulation. The stability of the complex was also improved, with the particle size change rate decreasing from 15% to 6.9% after 30 days of storage, indicating that the complex exhibited less particle size fluctuation during storage and was more stable.

[0047] Table 2 Formation of complex between enzymatic hydrolysis products and curcumin at different ratios of complex enzymes

[0048]

[0049] The gelatinization temperature was set at 85°C, the gelatinization time was 25 minutes, the mass ratio of amylase to protease was 2:1, the pH was 6.0, and the enzymatic hydrolysis time was 4 hours. The formation of the enzymatic hydrolysis product and curcumin complex at different enzymatic hydrolysis temperatures is shown in Table 3. Measurements show that when the enzymatic hydrolysis temperature increases from 60°C to 80°C, the average particle size of the nanocomposite first decreases and then increases, reaching the minimum particle size at 70°C. This indicates that the enzymatic hydrolysis temperature has a significant effect on the particle size of the complex and that there is an optimal temperature that minimizes the particle size. The curcumin encapsulation efficiency reaches a maximum of 85% at 70°C. The complex stability is optimal at 70°C; both high and low temperatures can reduce the stability of the complex.

[0050] Table 3 Formation of complexes between enzymatic hydrolysis products and curcumin at different enzymatic hydrolysis temperatures

[0051]

[0052] The gelatinization temperature was set at 85°C for 25 minutes, the mass ratio of amylase to protease was 2:1, the enzymatic temperature was 70°C, and the enzymatic time was 4 hours. The formation of a complex between the enzymatic hydrolysis product and curcumin at different enzymatic pH values ​​is shown in Table 4. As the enzymatic pH value increased from 5.5 to 6.5, the average particle size of the nanocomposite first decreased and then increased, reaching the minimum particle size at pH 6.0. The highest curcumin encapsulation efficiency reached 85%, indicating that a suitable pH value is conducive to improving curcumin encapsulation efficiency. The complex stability was optimal at pH 6.0; deviations from the optimal pH value resulted in decreased complex stability.

[0053] Table 4 Formation of complexes between enzymatic hydrolysis products and curcumin at different enzymatic hydrolysis pH values

[0054]

[0055] The gelatinization temperature was set at 85°C, the gelatinization time was 25 min, the mass ratio of amylase to protease was 2:1, the hydrolysis temperature was 70°C, and the pH was 6.0. The formation of the enzymatic hydrolysis product and curcumin complex at different hydrolysis times is shown in Table 5. Measurements show that with increasing hydrolysis time, the average particle size of the nanocomposite first decreases and then increases, reaching the smallest particle size at 4 h, indicating that hydrolysis time affects the complex particle size. The curcumin encapsulation efficiency is highest at 4 h, indicating that a 4-h hydrolysis time is beneficial for improving curcumin encapsulation. The complex stability is optimal at 4 h.

[0056] Table 5 Formation of complex between enzymatic hydrolysis products and curcumin at different enzymatic hydrolysis times

[0057]

[0058] Comprehensive test results show that process parameters such as the ratio of the complex enzyme, hydrolysis temperature, pH, time, and gelatinization conditions significantly affect the properties of the rice hydrolyzate-curcumin complex. A 2:1 ratio of protease to amylase complex achieved the best results. The optimal values ​​for these parameters were a hydrolysis temperature of 70°C, a pH of 6.0, a hydrolysis time of 4 hours, and a gelatinization temperature of 85°C / 25 minutes. Under these conditions, the average particle size of the nanocomposite, the curcumin encapsulation efficiency, and the stability of the complex were all excellent.

[0059] Example 2

[0060] 0.8 kg of selected high-quality rice was ground and pulped according to a mass volume ratio of rice to water of 1:5 to obtain rice pulp; gelatinization was performed at 80°C for 20 min; after the obtained gelatinized solution was cooled to 70°C, a complex enzyme consisting of amylase and protease (α-amylase activity was 1800 U / mL, and protease activity was 8000 U / g) was added for enzymolysis, the mass ratio of α-amylase to protease was 2:1, and the total amount of complex enzyme was 0.5% of the rice mass; the pH was adjusted to 6.0, and the enzymolysis time was 3 h. Thereafter, the enzyme was inactivated and filtered to obtain a rice hydrolyzate; a curcumin ethanol solution with a mass concentration of 2 mg / mL was slowly added to the stirred rice hydrolyzate according to a curcumin to rice hydrolyzate solid mass ratio of 1:10; the obtained mixed solution was placed in a microfluidizer with a pressure of 108 MPa for circulation The method comprises the following steps: treating the mixture twice to obtain a rice hydrolysate-curcumin nanocomposite dispersion system; after evaporating the ethanol, adding 0.05% chitosan by mass volume fraction and 0.1% sodium carboxymethyl cellulose by mass volume fraction, performing ultrasonic treatment, setting the ultrasonic frequency to 20 kHz, the ultrasonic power to 300 W, and the treatment time to 10 min, to obtain a stable rice hydrolysate-curcumin nanocomposite dispersion system; diluting the mixture with water in a mass ratio of 1:1, and then sequentially adding 0.04% sodium isoVc, 2.8% oligofructose, 1.5% inulin, and 0.7% coconut oil powder by mass volume fraction, and stirring the mixture thoroughly to obtain a mixed solution; adopting a two-stage homogenization process: 15 MPa / time for the first stage and 25 MPa / time for the second stage; sterilizing the mixture at 135°C for 5 seconds, and then aseptically filling the mixture to obtain a finished rice milk beverage.

[0061] Dynamic light scattering analysis revealed an average particle size of 185±6 nm, a polydispersity index (PDI) of 0.23, and a curcumin encapsulation efficiency of 84%. During accelerated stability testing at 40°C and 75% relative humidity for three months, curcumin retention was 93%. In vitro simulated digestion studies revealed less than 5% curcumin release in gastric fluid and a cumulative release of 85% in intestinal fluid. High-performance liquid chromatography (HPLC) determined the apparent solubility of curcumin in the rice milk beverage to be 80 μg / mL, significantly higher than that of free curcumin, demonstrating that the nanocomposite technology effectively enhances its water solubility through hydrophobic encapsulation and hydrophilic modification. The centrifugal stability demix yielded a 0.42% yield at 4000 rpm / 15 min, lower than that of conventional plant protein beverages, attributed to the Brownian motion of the nanoparticles and the synergistic effect of the chitosan-sodium carboxymethylcellulose stabilizer. The beverage also boasts a rich, smooth flavor with a subtle rice aroma and refreshing fruity notes, and a clean, clean mouthfeel without any off-flavor or roughness.

[0062] Example 3

[0063] 0.7 kg of high-quality rice was selected and ground into a pulp according to a rice to water mass volume ratio of 1:7 to obtain rice pulp; the rice pulp was gelatinized at 85°C for 30 min; the obtained gelatinized liquid was cooled to 70°C, and then a complex enzyme consisting of amylase and protease (α-amylase activity of 2500 U / mL and protease activity of 9000 U / g) was added for enzymolysis, the mass ratio of α-amylase to protease being 1:1, and the total amount of complex enzyme being 0.7% of the rice mass was adjusted to pH 6.0, and the enzymolysis time was 4 h. Thereafter, the enzyme was inactivated and filtered to obtain a rice hydrolyzate; a curcumin ethanol solution with a mass concentration of 4 mg / mL was slowly added to the stirred rice hydrolyzate according to a curcumin to rice hydrolyzate solid mass ratio of 1:15; the obtained mixed solution was placed in a microfluidizer at a pressure of 92 MPa. The method comprises the following steps: circulating the mixture in a device for three times to obtain a rice hydrolysate-curcumin nanocomposite dispersion system; adding chitosan with a mass volume fraction of 0.06% and sodium carboxymethyl cellulose with a mass volume fraction of 0.1% after evaporating the ethanol, performing ultrasonic treatment, setting the ultrasonic frequency to 20 kHz, the ultrasonic power to 500 W, and the treatment time to 5 minutes to obtain a stable rice hydrolysate-curcumin nanocomposite dispersion system; diluting the mixture with water according to a mass ratio of 1:1.5, sequentially adding 0.05% sodium isoVc, 3% oligofructose, 2% inulin, and 1% coconut oil powder, and fully stirring the mixture to obtain a mixed solution; adopting a two-stage homogenization process: a first stage of 20 MPa / one time and a second stage of 30 MPa / two times; sterilizing the mixture at 140°C for 5 seconds, and then aseptically filling the mixture to obtain a finished rice milk beverage.

[0064] After measurement, the average particle size of the nanocomposite detected by dynamic light scattering was 170 ± 5nm, the polydispersity index (PDI) was 0.21, the curcumin encapsulation efficiency was 85%, and in the accelerated stability test stored for 3 months at 40 ° C and 75% relative humidity, the curcumin retention rate was 92%, and the nanocomposite particle size was 184nm; in the in vitro simulated intestinal fluid release test, the 6h curcumin cumulative release rate was 82%. The apparent solubility of curcumin in the rice milk beverage was 82 μg / mL by high performance liquid chromatography, and the centrifugal stability stratification rate was 0.4% at 4000rpm / 15min. Moreover, compared with the traditional non-nano process, the curcumin bioavailability of the beverage prepared in this embodiment was increased to 82%, the DPPH free radical scavenging rate was increased to 82%, and there was no visible stratification after 3 months of storage. Overall, the beverage has a delicate and smooth taste and moderate sweetness.

[0065] Example 4

[0066] 1.2 kg of high-quality rice was selected and ground into a pulp according to a mass volume ratio of rice to water of 1:8 to obtain rice pulp; gelatinization was performed at 90°C for 15 min; the obtained gelatinized solution was cooled to 70°C, and then a complex enzyme consisting of amylase and protease (α-amylase activity of 2200 U / mL and protease activity of 8500 U / g) was added for enzymolysis, the mass ratio of α-amylase to protease being 3:2, and the total amount of complex enzyme being 0.8% of the rice mass was adjusted to pH 6.5, and the enzymolysis time was 4 h. Thereafter, the enzyme was inactivated and filtered to obtain a rice hydrolyzate; a curcumin ethanol solution having a mass concentration of 3 mg / mL was slowly added to the stirred rice hydrolyzate according to a curcumin to rice hydrolyzate solid mass ratio of 1:20; the obtained mixed solution was placed in a microfluidizer at a pressure of 97 MPa. The method comprises the following steps: performing the cyclic treatment twice to obtain a rice hydrolysate-curcumin nanocomposite dispersion system; adding chitosan with a mass volume fraction of 0.05% and sodium carboxymethyl cellulose with a mass volume fraction of 0.08% after evaporating the ethanol, performing ultrasonic treatment, setting the ultrasonic frequency to 20 kHz, the ultrasonic power to 400 W, and the treatment time to 10 min to obtain a stable rice hydrolysate-curcumin nanocomposite dispersion system; diluting the mixture with water in a mass ratio of 1:2, and then sequentially adding 0.06% sodium isoVc, 2.5% oligofructose, 1.8% inulin, and 0.8% coconut oil powder, stirring the mixture thoroughly to obtain a mixed solution; adopting a two-stage homogenization process: 18 MPa / 1 time in the first stage and 28 MPa / 2 times in the second stage; sterilizing the mixture at 140°C for 7 seconds, and then aseptically filling the mixture to obtain a finished rice milk beverage.

[0067] After measurement, dynamic light scattering detection shows that the average particle size of the nanocomposite is 200±8nm, the polydispersity index (PDI) is 0.25, and the curcumin encapsulation efficiency is 83%. The results of the accelerated test (40℃ / 75% relative humidity, 3 months) show that the curcumin retention rate is 91% and the nanocomposite particle size is 218nm; in the in vitro simulated intestinal fluid release test, the 6h curcumin cumulative release rate is 78%. The apparent solubility of curcumin in the rice milk beverage measured by high performance liquid chromatography is 81μg / mL, and the centrifugal stability stratification rate is 0.5% at 4000rpm / 15min. In addition, compared with the traditional high temperature sterilization process (121℃ / 15min), the sterilization process of this embodiment (140℃ / 7s) significantly reduces the loss of heat-sensitive components in the rice milk beverage (Table 6). Overall, the beverage has a rich and mellow rice aroma and a refreshing taste.

[0068] Table 6 Comparison of the sterilization process of this embodiment (140°C / 7s) and the traditional high temperature sterilization process (121°C / 15min)

[0069]

[0070]

[0071] Example 5

[0072] High-quality rice is selected and ground into a pulp according to a rice to water mass volume ratio of 1:6 to obtain rice pulp; the pulp is gelatinized at 85°C for 25 minutes; after the gelatinized liquid is cooled to 70°C, a complex enzyme consisting of amylase and protease (with an α-amylase activity of 2500U / mL and a protease activity of 9000U / g) is added, with the amylase and protease mass ratio of 2:1 and the addition amount being 1.2% of the rice mass; the pH is adjusted to 6.0, and enzymatic hydrolysis is carried out for 4 hours, followed by enzyme inactivation and filtration to obtain a rice hydrolyzate. A 3 mg / mL curcumin ethanol solution was slowly added to the rice enzymatic hydrolysate at a curcumin to rice enzymatic hydrolysate solid ratio of 1:15. The resulting mixture was placed in a microfluidizer at a pressure of 100 MPa and circulated twice. After evaporating the ethanol, 0.05% chitosan and 0.1% sodium carboxymethyl cellulose were added, and ultrasonic treatment was performed: the ultrasonic frequency was set at 20 kHz, the ultrasonic power was set at 400 W, and the ultrasonic time was set at 8 minutes to obtain a stable nanocomposite dispersion system. The obtained dispersion system is diluted with water in a mass ratio of 1:1.5, and then 0.05% sodium isoVc, 3% oligofructose, 2% inulin and 1% coconut oil powder are added in sequence and stirred evenly to obtain a prepared liquid; the prepared liquid is homogenized in two stages under a pressure of 20-30 MPa, with the first stage homogenizing once at a pressure of 20 MPa and the second stage homogenizing twice at a pressure of 28 MPa; the homogenized liquid is sterilized at 135°C for 5 seconds and aseptically filled to obtain a finished rice milk beverage.

[0073] Analysis revealed an average particle size of 165±5 nm, a polydispersity index (PDI) of 0.22, and a curcumin encapsulation efficiency of 83%. The release rate in simulated intestinal fluid was 78% over 6 hours, and in an accelerated stability test after three months of storage at 40°C and 75% relative humidity, the curcumin retention rate was 91%. High-performance liquid chromatography (HPLC) determined the apparent solubility of curcumin in the rice milk beverage to be 81 μg / mL, and the centrifugal stability fractionation rate at 4000 rpm / 15 min was 0.45%.

[0074] Example 6

[0075] The preparation of rice hydrolysate is the same as that in Example 5. The addition of curcumin ethanol solution and microfluidization treatment are the same as those in Example 5; after evaporating the ethanol, chitosan with a mass volume fraction of 0.05% and sodium carboxymethyl cellulose with a mass volume fraction of 0.2% are added, and the ultrasonic treatment conditions are the same as those in Example 5. Subsequent preparation, homogenization and sterilization are the same as those in Example 5. After detection and analysis, it was found that the average particle size of the nanocomposite was 158±4nm, the PDI was 0.20, and the curcumin encapsulation efficiency was 85%. The 6h release rate in simulated intestinal fluid was 82%, and in the accelerated stability test stored for 3 months at 40°C and 75% relative humidity, the curcumin retention rate was 93%. The apparent solubility of curcumin in the rice milk beverage was measured by high performance liquid chromatography to be 83μg / mL, and the centrifugal stability stratification rate at 4000rpm / 15min was 0.35%.

[0076] Example 7

[0077] The preparation of rice enzymatic hydrolysate was the same as in Example 5. The addition of curcumin ethanol solution and microfluidization treatment were the same as in Example 5; after evaporating the ethanol, chitosan with a mass volume fraction of 0.05% and sodium carboxymethyl cellulose with a mass volume fraction of 0.3% were added, and the ultrasonic treatment conditions were the same as in Example 5. Subsequent blending, homogenization and sterilization were the same as in Example 5. After testing and analysis, it was found that the average particle size of the nanocomposite was 170±6nm, the PDI was 0.23, and the curcumin encapsulation efficiency was 84%. The 6h release rate in simulated intestinal fluid was 80%, and in the accelerated stability test stored for 3 months at 40°C and 75% relative humidity, the curcumin retention rate was 92%. The apparent solubility of curcumin in the rice milk beverage was measured by high performance liquid chromatography to be 82μg / mL, and the centrifugal stability stratification rate at 4000rpm / 15min was 0.42%.

[0078] Example 5-7 Results Analysis and Cause Discussion

[0079] The nanocomposite of Example 6 had the smallest average particle size. When the sodium carboxymethylcellulose concentration was low, the amount of sodium carboxymethylcellulose molecules adsorbed on the nanocomposite surface was low, resulting in limited steric hindrance and a tendency for particles to agglomerate, leading to a larger particle size. As the sodium carboxymethylcellulose concentration increased to 0.2%, the molecules formed a denser adsorption layer on the particle surface, effectively increasing the steric hindrance between particles, inhibiting agglomeration and reducing the particle size. However, when the concentration continued to increase to 0.3%, the excessive sodium carboxymethylcellulose chains entangled with each other, which in turn promoted particle aggregation and increased the particle size.

[0080] The curcumin encapsulation efficiency and apparent solubility of Example 6 are the highest. An appropriate amount of sodium carboxymethyl cellulose and chitosan work synergistically to build a more stable encapsulation structure around curcumin, reducing the leakage of curcumin, thereby improving the encapsulation efficiency. At the same time, the stable encapsulation structure makes the dispersibility of curcumin in the system better and increases its apparent solubility. When the sodium carboxymethyl cellulose concentration is too high or too low, it is impossible to form an optimized encapsulation structure, affecting the encapsulation efficiency and apparent solubility.

[0081] Example 6 achieved the lowest centrifugal stratification rate and the highest curcumin retention. At an appropriate sodium carboxymethylcellulose concentration, it interacts with chitosan, effectively inhibiting Ostwald ripening through a synergistic effect of steric hindrance and electrostatic repulsion, reducing stratification during storage. Furthermore, the stable structure provides enhanced protection for curcumin, reducing its degradation in accelerated stability testing and improving curcumin retention.

[0082] In Examples 2-7, the curcumin nanocomposite dispersion system, which plays an important role in the rice milk beverage of the present invention, is mainly tested. During the preparation process of the rice milk beverage, multiple ingredients such as sodium isoVc, oligofructose, inulin, coconut oil powder, etc. need to be added to the nanocomposite dispersion system and mixed, homogenized, sterilized, etc. These subsequent processes may affect the particle size, encapsulation efficiency, stability and other properties of the nanocomposite. If the rice milk beverage is tested directly, it is difficult to accurately judge the direct impact of various process parameters such as the ratio of complex enzymes, enzymatic hydrolysis conditions, gelatinization conditions, and the amount of chitosan and sodium carboxymethyl cellulose added on the properties of the nanocomposite itself. Therefore, independent testing of the nanocomposite dispersion system is first performed, which can more accurately screen out the optimal combination of key process parameters, providing a reliable theoretical basis and data support for the subsequent formulation optimization and process design of the rice milk beverage.

[0083] As shown in Table 7, in terms of antioxidant properties, DPPH free radical scavenging experiments confirmed that the phenolic hydroxyl groups of curcumin in the nanocomplex synergistically donated hydrogen with the reducing ends of oligosaccharides, increasing DPPH scavenging by 40%-50%. In vitro cell experiments showed a 35%-40% increase in the inhibition of the inflammatory factor TNF-α. Simulated intestinal flora culture experiments also showed a 25%-30% increase in the proliferation of beneficial bacteria such as Bifidobacterium.

[0084] Table 7 Comparison of functional activities of nanocomposites and physical mixing systems

[0085] Detection indicators Nanocomposite group Traditional physics mixed group DPPH clearance rate 78％±2.1％ 54％±1.8％ Inflammatory factor TNF-α inhibition rate 63％±2.3％ 28％±1.5％ Bifidobacterium proliferation (24h) <![CDATA[3.4×10 6 CFU / mL]]> <![CDATA[2.8×10 6 CFU / mL]]>

[0086] The above describes the implementation mode of the present invention in detail with reference to the embodiments. However, the present invention is not limited to the above implementation mode. After knowing the contents described in the present invention, ordinary technicians in this technical field can make several equivalent transformations and substitutions without departing from the principles of the present invention. These equivalent transformations and substitutions should also be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for preparing a nanocomposite dispersion system, characterized in that: It uses rice enzymatic hydrolysate as the matrix, and obtains an active peptide-oligosaccharide complex system through a composite enzymatic hydrolysis process, which is then self-assembled with curcumin to form a nanocomposite; finally, it is made by multi-stage homogenization and chitosan-sodium carboxymethyl cellulose synergistic stabilization.

2. The method for preparing the nanocomposite dispersion system according to claim 1, characterized in that: The apparent solubility of curcumin in the obtained nanocomposite dispersion system is greater than 80 μg / mL, and the centrifugal separation rate is less than 0.5%.

3. The method for preparing the nanocomposite dispersion system according to claim 1, characterized in that: The specific steps include: A. sampling according to the mass volume ratio of rice to water of 1:5-8, grinding and pulping to obtain rice pulp; B. gelatinizing the rice pulp at 80-90° C. for 20-30 min to obtain a gelatinized liquid; C. cooling the gelatinized liquid to 60-80° C., adding a complex enzyme for enzymolysis, inactivating the enzyme after 3-5 hours, and filtering to obtain a rice enzymolyzate; D. be the curcumin ethanol solution of 1-5mg / mL by mass concentration, press curcumin and rice enzymolyte solid content mass ratio 1: 10-20, slowly add in the rice enzymolyte, obtain mixed solution; E. placing the resulting mixed solution in a microfluidic device and circulating the solution for 1-3 times; F. After the ethanol in the obtained composite dispersion is evaporated, 0.05-0.1% chitosan and 0.1-0.3% sodium carboxymethyl cellulose are added and ultrasonic treatment is performed to obtain a nanocomposite dispersion.

4. The method for preparing the nanocomposite dispersion system according to claim 3, characterized in that: The total amount of the complex enzyme in step C is 0.5%-2% of the mass of the rice; the complex enzyme is composed of α-amylase and protease, and the mass ratio of amylase to protease is 1-3:1; the α-amylase activity is 2000-3000 U / mL, and the protease activity is 8000-10000 U / g.

5. The method for preparing the nanocomposite dispersion system according to claim 3, characterized in that: The average particle size of the nanocomposite dispersion system in step F is 150-220 nm.

6. The method for preparing the nanocomposite dispersion system according to claim 3, characterized in that: The conditions for ultrasonic treatment in step F are: ultrasonic frequency of 20 kHz, ultrasonic power of 300-500 W, and treatment time of 5-10 min.

7. The method for preparing a nanocomposite dispersion system according to claim 3, characterized in that: The nanocomposite dispersion system has a 6-hour release rate of greater than 75% in simulated intestinal fluid, and a curcumin retention rate of greater than 90% in an accelerated stability test stored at 40° C. and 75% relative humidity for 3 months.

8. A method for preparing a rice milk beverage, characterized in that: The following steps are involved: a. According to the rice and water mass volume ratio of 1: 5-8 sampling, grinding and pulping to obtain rice puree; b. The rice puree was gelatinized at 80-90 ℃ for 20-30min to obtain a gelatinized liquid; c. After the gelatinization solution was cooled to 60-80 ℃, a complex enzyme was added for enzymatic hydrolysis. After 3-5h of enzymatic hydrolysis, the enzyme was killed and filtered to obtain a rice hydrolyzate; d. The mass concentration of 1-5mg / mL of curcumin ethanol solution, curcumin and rice hydrolysate solid mass ratio of 1: 10-20, was slowly added to the rice hydrolysate to obtain a mixture; e. The resulting mixture was placed in a microfluidic device and circulated 1-3 times; f. After evaporating the ethanol from the resulting composite dispersion, 0.05-0.1% chitosan and 0.1-0.3% sodium carboxymethyl cellulose were added by volume and ultrasonically treated to obtain a nanocomposite dispersion. g. The nanocomposite dispersion was diluted with water, and sodium isoVc, oligofructose, inulin and coconut oil powder were added in sequence, and the mixture was stirred to obtain a uniform solution; h. The prepared liquid was homogenized in two stages at a pressure of 20-30MPa, the first stage was carried out at a pressure of 20-25MPa, and the second stage was carried out at a pressure of 28-30MPa to obtain a homogenous liquid; i. Sterilize the homogenized liquid to obtain the rice milk beverage.

9. The method for preparing the rice milk beverage according to claim 8, wherein: The sterilization conditions in step i are: 135-140° C. sterilization for 4-6 seconds.

10. A rice milk beverage prepared by the preparation method according to claim 8 or 9.

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