Acidic beverage containing nanoberry anthocyanins and method for preparing same

Abstract

The present application relates to the technical field of fermentation engineering, and specifically discloses an acidic beverage containing nano blueberry anthocyanins and a preparation method thereof, which comprises, in terms of weight parts, 400-450 parts of blueberry juice, 0.4-0.5 parts of nano blueberry anthocyanin powder, 50-60 parts of white granulated sugar, 8-10 parts of fructooligosaccharide, 40-50 parts of full-fat milk powder, 2-3 parts of pectin and 400-500 parts of purified water; wherein the particle size of the nano blueberry anthocyanin powder is not more than 100 nanometers, and the nano blueberry anthocyanin powder is coated nano blueberry anthocyanin powder; the present application provides an extremely efficient industrial processing scheme, which nano-treats blueberry anthocyanin raw materials, and at the same time, the nano blueberry anthocyanins are further coated with pectin-chitosan double layers, so that a dense physical barrier is formed by the double-layer coating; in addition, the small-particle-size raw materials can form a stable colloidal dispersion system in the beverage, thereby avoiding the agglomeration and sedimentation of ordinary micrometer-size particles due to gravity and molecular attraction.

Description

Technical Field

[0001] This invention relates to the field of fermentation engineering technology, specifically to an acidic beverage containing nano-blueberry anthocyanins and its preparation method. Background Technology

[0002] Blueberries, as a typical example of small berries, are tender and juicy, but after harvesting they are extremely susceptible to rotting due to mechanical damage, physiological metabolism, and microbial infection. The fruit is not resistant to handling and turning, has poor storage and transportation capabilities, and easily loses its commercial characteristics and edible value. Blueberries contain a large amount of anthocyanins, as well as abundant vitamins A and E, carotenoids, etc. Numerous reports have proven that anthocyanins have the effects of scavenging free radicals in the body, anti-tumor, anti-cancer, anti-inflammatory, inhibiting lipid peroxidation and platelet aggregation, preventing diabetes, weight loss, and protecting eyesight. Therefore, existing technologies have developed blueberry anthocyanin extraction techniques. The extracted blueberry anthocyanins can be used as food components, and one common application is in acidic beverages.

[0003] However, existing acidic beverages containing blueberry anthocyanins are essentially prepared by "direct addition of raw materials." Blueberry anthocyanins are easily degraded and difficult to disperse, and have a somewhat sour and astringent taste. When preparing acidic beverages, especially when fermentation processes are involved, the content of blueberry anthocyanins will become very low under acidic or high-temperature conditions. Therefore, how to improve the stability of blueberry anthocyanins to adapt to the complex and ever-changing food preparation environment is the technical problem that this invention aims to solve. Summary of the Invention

[0004] The purpose of this invention is to provide an acidic beverage containing nano-blueberry anthocyanins and its preparation method, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An acidic beverage containing nano-blueberry anthocyanins, comprising the following components by weight:

[0007] The ingredients are: 400-450 parts blueberry juice, 0.4-0.5 parts nano-blueberry anthocyanin powder, 50-60 parts white sugar, 8-10 parts fructooligosaccharides, 40-50 parts whole milk powder, 2-3 parts pectin, and 400-500 parts purified water; wherein the particle size of the nano-blueberry anthocyanin powder does not exceed 100 nanometers, and the nano-blueberry anthocyanin powder is coated nano-blueberry anthocyanin powder.

[0008] Furthermore, the coated nano-blueberry anthocyanin powder comprises two layers: an inner layer of pectin and an outer layer of chitosan.

[0009] Furthermore, the preparation method of the coated nano-blueberry anthocyanin powder includes:

[0010] Blueberry anthocyanin raw materials were placed in a liquid nitrogen freezing device and the freezing temperature was set not to exceed -186 degrees Celsius for ultra-low temperature freezing crystallization pretreatment.

[0011] Start the suction pump to suck the pretreated blueberry anthocyanin raw material into the feeding chamber;

[0012] Open the discharge valve of the feeding chamber and put the blueberry anthocyanin raw material into the pressure stabilizing chamber;

[0013] Blueberry anthocyanin raw material is drawn into the high-pressure chamber of the primary air jet mill from the pressure stabilizing chamber and subjected to primary air milling to obtain primary abrasive.

[0014] The first classifier classifies the primary abrasive, and the primary abrasive with a thickness greater than 10 micrometers is transported to the high-pressure chamber of the primary air-flow mill, while the primary abrasive with a thickness of no more than 10 micrometers is transported to the high-pressure chamber of the secondary air-flow mill.

[0015] The primary abrasive is processed by the high-pressure chamber of a two-stage airflow mill to obtain the secondary abrasive;

[0016] The secondary abrasive is classified by the second classifier. The secondary abrasive with a thickness greater than 500 nanometers is transported to the high-pressure chamber of the secondary air jet mill, and the secondary abrasive with a thickness of no more than 500 nanometers is transported to the fluid energy deagglomeration chamber.

[0017] The secondary abrasive is processed by the flow energy deagglomeration chamber and screened to obtain blueberry anthocyanin powder; the particle size of the blueberry anthocyanin powder is no greater than 100 nanometers.

[0018] Blueberry anthocyanin powder was coated; the coating materials included pectin and chitosan.

[0019] Furthermore, the preparation method of the coated nano-blueberry anthocyanin powder also includes:

[0020] The particle size of the secondary abrasive at the high-pressure chamber outlet of the secondary air classifier is obtained in real time by an online particle size analyzer built into the second classifier, and D50 is determined.

[0021] The D50 generates adjustment commands directed to the high-pressure chamber of the secondary airflow mill; the adjustment target is air pressure.

[0022] The particle size of the abrasive at the outlet of the fluid energy depolymerization chamber is obtained in real time by an online particle size analyzer installed in the fluid energy depolymerization chamber, and the D50 is determined.

[0023] The D50 generates adjustment commands directed to the flow energy depolymerization chamber; the adjustment target is air pressure.

[0024] Furthermore, the step of coating the blueberry anthocyanin powder includes:

[0025] Preparation of pectin solution;

[0026] Blueberry anthocyanin powder was added to the pectin solution and stirred to obtain the first mixture;

[0027] To prepare a chitosan solution, the first mixture is added dropwise to the chitosan solution and stirred to obtain a second mixture.

[0028] The second mixture was dispersed to obtain an emulsion; the dispersion process employed an ultrasonic treatment method.

[0029] The emulsion was freeze-dried to obtain a coated powder.

[0030] Furthermore, the step of coating the blueberry anthocyanin powder also includes:

[0031] The spectrum was acquired using a near-infrared spectrometer, and A520 and A450 were determined. The ratio of A520 to A450 was then calculated as the peak ratio.

[0032] Viscosity of emulsions is measured using an online viscosity probe;

[0033] The adjustment instructions are determined based on the peak ratio and viscosity. These instructions are used to control the stirring speed and the operating parameters of the ultrasonic treatment scheme.

[0034] The present invention also provides a method for preparing an acidic beverage containing nano-blueberry anthocyanins, the preparation method comprising:

[0035] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60-62℃, and cool to 40℃ to obtain the base liquid; stir at 300-400 rpm for 10 minutes.

[0036] Dissolve whole milk powder and pectin in purified water at 60-62℃ and stir to obtain the milk matrix; the stirring speed is 400-500 rpm and the stirring time is 10 minutes.

[0037] Mix the emulsion matrix into the base solution; stir at 300-350 rpm for 5-8 minutes;

[0038] The nano-blueberry anthocyanin powder was dispersed in the base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 9000-10000 rpm and the homogenization time was 3-4 min.

[0039] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and perform static fermentation for 6-8 hours, controlling the pH to drop to 4.2-4.4.

[0040] Heat to 65℃ and hold for 10 minutes;

[0041] Fill after cooling to room temperature.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] This invention provides a highly efficient industrial processing solution that nano-scales blueberry anthocyanin raw materials and then further coats the nano-blueberry anthocyanins with a pectin-chitosan double-layer coating. Due to the extremely high dispersibility of nanomaterials, the coating quality is exceptionally high during the coating process. The double-layer coating forms a dense physical barrier that prevents oxygen in the beverage from contacting the anthocyanins, thus avoiding oxidative degradation. Chitosan (weakly alkaline) buffers the acidity of the beverage (pH 3.0-4.5), reducing the damage to the anthocyanin structure caused by the acidic environment. Furthermore, the small particle size of the raw materials forms a stable colloidal dispersion system in the beverage, preventing ordinary micron-sized particles from agglomerating and settling due to gravity and molecular attraction. Moreover, the nanoparticles have a large specific surface area, so for the same color and efficacy requirements, the amount of coated nano-anthocyanins added is only 60%-70% of that of ordinary anthocyanins, reducing the source of sourness and astringency from the source and significantly improving product quality without adding too many additional components. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0045] Figure 1 The process layout diagram for the graded processing is shown.

[0046] In the diagram: 1-Feeding chamber, 2-Feeding negative pressure chamber, 3-Mixing dryer, 4-Pressure stabilizing chamber, 5-First-stage air jet mill high-pressure chamber, 6-First-stage air jet mill negative pressure chamber, 7-First-stage classifier, 8-Second-stage air jet mill high-pressure chamber, 9-Second-stage air jet mill negative pressure chamber, 10-Second-stage classifier, 11-Fluid energy depolymerization pretreatment chamber, 12-Fluid energy depolymerization chamber, 13-Finished product negative pressure chamber, 14-Finished product automatic packaging machine. Detailed Implementation

[0047] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0048] Material:

[0049] Unless otherwise specified, the methods used in this invention are conventional methods known to those skilled in the art, and the reagents and materials used are commercially available products. Some materials are described below:

[0050] Blueberry anthocyanin raw materials are existing products. For example, Shandong Pingju Biotechnology Co., Ltd. and Jiangsu Caiwei Biotechnology Co., Ltd. produce blueberry anthocyanins, which are in powder form and are food-grade. Fructooligosaccharides, pectin, and chitosan are similar. Shanghai Yuanye Biotechnology Co., Ltd. produces finished products: fructooligosaccharides (purity: BR, 95%; item number: S11133-100g), pectin (purity: high purity, 65%, apple-derived; item number: S11082-25g), and chitosan (chitosanamine) (purity: BR, degree of deacetylation 90%, viscosity ≤500cps, item number: S11064-100g). In fact, many other manufacturers also provide these raw materials; you can directly search and purchase them on the Gaide Chemicals website.

[0051] In addition, the technical solution of the present invention also involves some solutions. For the solutions, the mass fraction is defined. In actual preparation, the required amount of water can be determined based on the content and mass fraction of the raw materials. This process is well known to those skilled in the art and will not be described in detail in the following process.

[0052] equipment:

[0053] Unless otherwise specified, all equipment used in this invention is conventional equipment known to those skilled in the art. Embodiments 1 and 3-8 provided in this invention all employ such... Figure 1 The equipment layout shown is as follows: Figure 1 This is only used to illustrate the layout architecture of the entire production process for reference. The equipment in each instance may be arranged in other ways, which is not a limitation.

[0054] Example 1:

[0055] In this embodiment of the invention, an acidic beverage containing nano-blueberry anthocyanins is provided, comprising the following components by weight:

[0056] The ingredients are: 450 parts blueberry juice, 0.5 parts nano-blueberry anthocyanin powder, 60 parts white sugar, 10 parts fructooligosaccharides, 50 parts whole milk powder, 2 parts pectin, and 500 parts purified water; among which, the particle size of the nano-blueberry anthocyanin powder is 100 nanometers.

[0057] The preparation method of the nano-blueberry anthocyanin powder includes:

[0058] Blueberry anthocyanin raw materials were placed in a liquid nitrogen freezing device and the freezing temperature was set to -186 degrees Celsius for ultra-low temperature freezing crystallization pretreatment.

[0059] Start the suction pump to suck the pretreated blueberry anthocyanin raw material into the feeding chamber; the negative pressure of the suction pump is -0.06Mpa;

[0060] Open the discharge valve of the feeding chamber and feed the blueberry anthocyanin raw material into the pressure stabilizing chamber; the pressure stabilizing chamber is maintained at 0.05 MPa.

[0061] Blueberry anthocyanin raw material is drawn into the high-pressure chamber of a primary air mill from a pressure stabilizing chamber for primary air milling to obtain primary abrasive; the air pressure of the primary air mill high-pressure chamber is 0.45MPa, the nozzle diameter is 2.2mm, the gas flow rate is 2.3m³ / min, and the processing time is 6min.

[0062] The first classifier classifies the primary abrasive, and the primary abrasive with a thickness greater than 10 micrometers is transported to the high-pressure chamber of the primary air-flow mill, while the primary abrasive with a thickness of no more than 10 micrometers is transported to the high-pressure chamber of the secondary air-flow mill. The first classifier has a classification disc diameter of 300 mm, a rotation speed of 900 rpm, an air intake volume of 2.0 m³ / min, and an inlet-outlet pressure difference of 180 Pa.

[0063] The primary abrasive is processed by a secondary air mill high-pressure chamber to obtain a secondary abrasive; the air pressure of the secondary air mill high-pressure chamber is 0.7 MPa, the nozzle diameter is 1.0 mm, the gas flow rate is 1.8 m³ / min, and the processing time is 12 min.

[0064] The secondary abrasive is classified by the second classifier. The secondary abrasive with a thickness greater than 500 nanometers is transported to the high-pressure chamber of the secondary airflow mill, and the secondary abrasive with a thickness of no more than 500 nanometers is transported to the flow energy deagglomeration chamber. The classification disc of the second classifier has a diameter of 150 mm, a rotation speed of 3600 rpm, an air intake volume of 1.4 m³ / min, and an inlet and outlet pressure difference of 500 Pa.

[0065] The secondary abrasive is processed by the flow energy depolymerization chamber and screened to obtain blueberry anthocyanin powder; the particle size of the blueberry anthocyanin powder is no greater than 100 nanometers; the air pressure of the flow energy depolymerization chamber is 1.0 MPa, the nozzle flow rate is 5 times the speed of sound, the single cycle time is 6s, and the number of cycles is 600.

[0066] The preparation method for acidic beverages is as follows:

[0067] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60°C, and cool to 40°C to obtain the base liquid; stir at 300 rpm for 10 minutes.

[0068] Whole milk powder and pectin were dissolved in purified water at 60°C and stirred to obtain a milk matrix; the stirring speed was 500 rpm and the stirring time was 10 min.

[0069] Mix the emulsion matrix into the base solution; stir at 350 rpm for 6 minutes;

[0070] The nano-blueberry anthocyanin powder was dispersed in the base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 10,000 rpm and the homogenization time was 4 min.

[0071] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and allow it to ferment statically for 8 hours, controlling the pH to drop to 4.4; the concentration of the lactic acid bacteria culture is 1×10⁻⁶. 9 CFU / mL;

[0072] Heat to 65℃ and hold for 10 minutes;

[0073] Fill after cooling to room temperature;

[0074] The amount of purified water used to prepare the emulsion matrix was 240 parts, and the amount of purified water used to prepare the base solution was 260 parts.

[0075] Example 2:

[0076] In this embodiment of the invention, an acidic beverage containing conventional blueberry anthocyanins is provided, comprising the following components by weight:

[0077] 450 parts blueberry juice, 0.5 parts coated blueberry anthocyanin powder, 60 parts white sugar, 10 parts fructooligosaccharides, 50 parts whole milk powder, 2 parts pectin, and 500 parts purified water.

[0078] Unlike Example 1, the coated blueberry anthocyanin powder comprises two layers: an inner layer of pectin and an outer layer of chitosan.

[0079] The preparation method of the coated blueberry anthocyanin powder includes:

[0080] Prepare a pectin solution; the pectin mass fraction in the pectin solution is 0.5%, and the pH value is 4;

[0081] Blueberry anthocyanin powder was added to the pectin solution and stirred to obtain the first mixture; the stirring speed was 1000 rpm and the temperature was 40℃.

[0082] To prepare a chitosan solution, the first mixture was added dropwise to the chitosan solution and stirred to obtain a second mixture; the stirring speed was 600 rpm and the stirring time was 15 min; the mass fraction of chitosan in the chitosan solution was 0.6%, and the pH was 5.5; the dropping rate was 8 mL / min.

[0083] The second mixture was dispersed to obtain an emulsion. The dispersion treatment was carried out using an ultrasonic treatment scheme with an ultrasonic power of 80W, a treatment time of 3min, and an ultrasonic frequency of 20Hz.

[0084] The emulsion was freeze-dried to obtain a coated powder. The freeze-drying temperature was -40℃ and the processing time was 48h.

[0085] The preparation method for acidic beverages is as follows:

[0086] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60°C, and cool to 40°C to obtain the base liquid; stir at 300 rpm for 10 minutes.

[0087] Whole milk powder and pectin were dissolved in purified water at 60°C and stirred to obtain a milk matrix; the stirring speed was 500 rpm and the stirring time was 10 min.

[0088] Mix the emulsion matrix into the base solution; stir at 350 rpm for 6 minutes;

[0089] The nano-blueberry anthocyanin powder was dispersed in the base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 10,000 rpm and the homogenization time was 4 min.

[0090] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and allow it to ferment statically for 8 hours, controlling the pH to drop to 4.4; the concentration of the lactic acid bacteria culture is 1×10⁻⁶. 9 CFU / mL;

[0091] Heat to 65℃ and hold for 10 minutes;

[0092] Fill after cooling to room temperature;

[0093] The amount of purified water used to prepare the emulsion matrix was 240 parts, and the amount of purified water used to prepare the base solution was 260 parts.

[0094] Example 3:

[0095] The difference from Example 2 is that the coated blueberry anthocyanin powder was replaced with coated nano-blueberry anthocyanin powder;

[0096] The preparation method of coated nano-blueberry anthocyanin powder is as follows:

[0097] Blueberry anthocyanin raw materials were placed in a liquid nitrogen freezing device and the freezing temperature was set to -186 degrees Celsius for ultra-low temperature freezing crystallization pretreatment.

[0098] Start the suction pump to suck the pretreated blueberry anthocyanin raw material into the feeding chamber; the negative pressure of the suction pump is -0.06Mpa;

[0099] Open the discharge valve of the feeding chamber and feed the blueberry anthocyanin raw material into the pressure stabilizing chamber; the pressure stabilizing chamber is maintained at 0.05 MPa.

[0100] Blueberry anthocyanin raw material is drawn into the high-pressure chamber of a primary air mill from a pressure stabilizing chamber for primary air milling to obtain primary abrasive; the air pressure of the primary air mill high-pressure chamber is 0.45MPa, the nozzle diameter is 2.2mm, the gas flow rate is 2.3m³ / min, and the processing time is 6min.

[0101] The first classifier classifies the primary abrasive, and the primary abrasive with a thickness greater than 10 micrometers is transported to the high-pressure chamber of the primary air-flow mill, while the primary abrasive with a thickness of no more than 10 micrometers is transported to the high-pressure chamber of the secondary air-flow mill. The first classifier has a classification disc diameter of 300 mm, a rotation speed of 900 rpm, an air intake volume of 2.0 m³ / min, and an inlet-outlet pressure difference of 180 Pa.

[0102] The primary abrasive is processed by a secondary air mill high-pressure chamber to obtain a secondary abrasive; the air pressure of the secondary air mill high-pressure chamber is 0.7 MPa, the nozzle diameter is 1.0 mm, the gas flow rate is 1.8 m³ / min, and the processing time is 12 min.

[0103] The secondary abrasive is classified by the second classifier. The secondary abrasive with a thickness greater than 500 nanometers is transported to the high-pressure chamber of the secondary airflow mill, and the secondary abrasive with a thickness of no more than 500 nanometers is transported to the flow energy deagglomeration chamber. The classification disc of the second classifier has a diameter of 150 mm, a rotation speed of 3600 rpm, an air intake volume of 1.4 m³ / min, and an inlet and outlet pressure difference of 500 Pa.

[0104] The secondary abrasive is processed by the flow energy depolymerization chamber and screened to obtain blueberry anthocyanin powder; the particle size of the blueberry anthocyanin powder is no greater than 100 nanometers; the air pressure of the flow energy depolymerization chamber is 1.0 MPa, the nozzle flow rate is 5 times the speed of sound, the single cycle time is 6s, and the number of cycles is 600.

[0105] Blueberry anthocyanin powder was coated; the coating materials included pectin and chitosan.

[0106] The coating process is as follows:

[0107] Prepare a pectin solution; the pectin mass fraction in the pectin solution is 0.5%, and the pH value is 4;

[0108] Blueberry anthocyanin powder was added to the pectin solution and stirred to obtain the first mixture; the stirring speed was 1000 rpm and the temperature was 40℃.

[0109] To prepare a chitosan solution, the first mixture was added dropwise to the chitosan solution and stirred to obtain a second mixture; the stirring speed was 600 rpm and the stirring time was 15 min; the mass fraction of chitosan in the chitosan solution was 0.6%, and the pH was 5.5; the dropping rate was 8 mL / min.

[0110] The second mixture was dispersed to obtain an emulsion. The dispersion treatment was carried out using an ultrasonic treatment scheme with an ultrasonic power of 80W, a treatment time of 3min, and an ultrasonic frequency of 20Hz.

[0111] The emulsion was freeze-dried to obtain a coated powder. The freeze-drying temperature was -40℃ and the processing time was 48h.

[0112] The preparation method for acidic beverages is as follows:

[0113] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60°C, and cool to 40°C to obtain the base liquid; stir at 300 rpm for 10 minutes.

[0114] Whole milk powder and pectin were dissolved in purified water at 60°C and stirred to obtain a milk matrix; the stirring speed was 500 rpm and the stirring time was 10 min.

[0115] Mix the emulsion matrix into the base solution; stir at 350 rpm for 6 minutes;

[0116] The nano-blueberry anthocyanin powder was dispersed in the base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 10,000 rpm and the homogenization time was 4 min.

[0117] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and allow it to ferment statically for 8 hours, controlling the pH to drop to 4.4; the concentration of the lactic acid bacteria culture is 1×10⁻⁶. 9 CFU / mL;

[0118] Heat to 65℃ and hold for 10 minutes;

[0119] Fill after cooling to room temperature;

[0120] The amount of purified water used to prepare the emulsion matrix was 240 parts, and the amount of purified water used to prepare the base solution was 260 parts.

[0121] Example 4:

[0122] Unlike Example 1, a negative feedback regulation process was introduced during the preparation of nano-blueberry anthocyanin powder, specifically:

[0123] The particle size of the secondary abrasive at the high-pressure chamber outlet of the secondary air classifier is obtained in real time by an online particle size analyzer built into the second classifier, and D50 is determined.

[0124] The D50 generates adjustment commands directed to the high-pressure chamber of the secondary airflow mill; the adjustment target is air pressure.

[0125] The particle size of the abrasive at the outlet of the fluid energy depolymerization chamber is obtained in real time by an online particle size analyzer installed in the fluid energy depolymerization chamber, and the D50 is determined.

[0126] The D50 generates adjustment commands directed to the flow energy depolymerization chamber; the adjustment target is air pressure.

[0127] Specifically, regarding the adjustment:

[0128] Based on the particle size distribution curve of the primary abrasive detected by an online particle size analyzer, D50 is determined from the particle size distribution curve; D50 is the median diameter, indicating that 50% of the particles are smaller than this value; when D50 is greater than a preset threshold, an adjustment command pointing to the air pressure is generated, the threshold is 8 micrometers, and a single adjustment increases the air pressure by 0.02 MPa; the high-pressure chamber of the primary air mill contains a preset peak value, not exceeding 1 MPa and not lower than 0.35 MPa;

[0129] The adjustment process of the high-pressure chamber of the secondary airflow mill is as follows:

[0130] Based on the particle size distribution curve of the secondary abrasive detected by the online particle size analyzer, D50 is determined in the particle size distribution curve, and the threshold of D50 is 450 nanometers; when D50 is greater than the preset threshold, an adjustment command pointing to the air pressure is generated, and the single adjustment is an increase of air pressure by 0.02 MPa; the high pressure chamber of the primary air mill contains a preset peak value, which does not exceed 1.2 MPa and is not lower than 0.5 MPa.

[0131] The adjustment process of the kinetic energy depolymerization chamber is as follows:

[0132] Based on the particle size distribution curve of the secondary abrasive detected by an online particle size analyzer, D50 is determined from the particle size distribution curve, and the threshold of D50 is 80 nanometers. When D50 is greater than the preset threshold, an adjustment command pointing to the air pressure is generated, and the single adjustment is an increase of air pressure by 0.02 MPa. When D50 is less than the preset threshold, an adjustment command pointing to the air pressure is generated, and the single adjustment is a decrease of air pressure by 0.02 MPa. The high pressure chamber of the primary air mill contains a preset peak value, which does not exceed 1.5 MPa and is not lower than 0.8 MPa.

[0133] Example 5:

[0134] Unlike Example 2, a negative feedback regulation process was introduced during the preparation of the coated blueberry anthocyanin powder, specifically:

[0135] The spectrum was acquired using a near-infrared spectrometer, and A520 and A450 were determined. The ratio of A520 to A450 was then calculated as the peak ratio.

[0136] Viscosity of emulsions is measured using an online viscosity probe;

[0137] The adjustment instructions are determined based on the peak ratio and viscosity. These instructions are used to control the stirring speed and the operating parameters of the ultrasonic treatment scheme.

[0138] Parameters based on the spectrum obtained by a near-infrared spectrometer , Indicates at wavelength The absorbance, in this embodiment, is used and The former is the blueberry anthocyanin peak, and the latter is the yellow variegated peak. Using the latter as the baseline, the ratio of the former to the latter is calculated to obtain the peak ratio. Simultaneously, the viscosity of the emulsion is measured using an online viscosity probe. At this point, the peak ratio and viscosity are two parameters reflecting the coating quality. Weights are assigned to these two parameters: the former is 0.75, and the latter is 0.25. The quality score is then calculated. Note that the peak ratio itself is dimensionless, and the viscosity also needs to be normalized. The specific normalization method is as follows:

[0139] ;in, These are the normalized values. The preset standard viscosity, For the measured viscosity, As a preset allowable difference, the following is adopted: 20% as the final value;

[0140] By using weighted summation of two ratios, the resulting data reflects the coating quality, and the control scheme can be determined based on this data.

[0141] Example 6:

[0142] Unlike Example 3, the negative feedback regulation scheme for preparing nano-blueberry anthocyanin powder provided in Example 4 is introduced, as is the negative feedback regulation scheme for preparing coated blueberry anthocyanin powder provided in Example 5.

[0143] Example 7:

[0144] The difference from Example 6 is that: the amount of nano-blueberry anthocyanin powder is 0.4 parts, the mass fraction of pectin in the pectin solution during coating is 0.4%, and the mass fraction of chitosan in the chitosan solution is 0.5%.

[0145] Example 8:

[0146] The difference from Example 6 is that: the amount of nano-blueberry anthocyanin powder is 0.6 parts, the mass fraction of pectin in the pectin solution during coating is 0.6%, and the mass fraction of chitosan in the chitosan solution is 0.8%.

[0147] Comparative Example 1:

[0148] In this comparative example, an acidic beverage containing nano-blueberry anthocyanins is provided, comprising the following components by weight:

[0149] 450 parts blueberry juice, 0.5 parts blueberry anthocyanin powder, 60 parts white sugar, 10 parts fructooligosaccharides, 50 parts whole milk powder, 2 parts pectin, and 500 parts purified water.

[0150] The preparation method for acidic beverages is as follows:

[0151] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60°C, and cool to 40°C to obtain the base liquid; stir at 300 rpm for 10 minutes.

[0152] Whole milk powder and pectin were dissolved in purified water at 60°C and stirred to obtain a milk matrix; the stirring speed was 500 rpm and the stirring time was 10 min.

[0153] Mix the emulsion matrix into the base solution; stir at 350 rpm for 6 minutes;

[0154] Blueberry anthocyanin powder was dispersed in a base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 10,000 rpm and the homogenization time was 4 minutes.

[0155] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and allow it to ferment statically for 8 hours, controlling the pH to drop to 4.4; the concentration of the lactic acid bacteria culture is 1×10⁻⁶. 9 CFU / mL;

[0156] Heat to 65℃ and hold for 10 minutes;

[0157] Fill after cooling to room temperature;

[0158] The amount of purified water used to prepare the emulsion matrix was 240 parts, and the amount of purified water used to prepare the base solution was 260 parts.

[0159] Comparative Example 2:

[0160] In this comparative example, an acidic beverage containing nano-blueberry anthocyanins is provided, comprising the following components by weight: 450 parts blueberry juice, 50 parts nano-anthocyanin suspension, 60 parts white sugar, 10 parts fructooligosaccharides, 50 parts whole milk powder, 2 parts pectin, and 500 parts purified water.

[0161] The preparation method of nano-blueberry anthocyanins is as follows:

[0162] Blueberry anthocyanins were extracted from blueberry raw materials using an ethanol solution, and the crude extract was obtained by filtration; the ethanol solution had a mass fraction of 60%.

[0163] The crude extract was diluted to a solids content of 10%, pumped into a high-pressure homogenizer, and circulated 5 times at a pressure of 120 MPa.

[0164] Centrifugation was used to remove large, uncrushed particles to obtain a nano-anthocyanin suspension. The centrifugation parameters were: centrifugation speed 10,000 rpm, centrifugation time 20 min, and centrifugation temperature 4℃.

[0165] The preparation method for acidic beverages is as follows:

[0166] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60°C, and cool to 40°C to obtain the base liquid; stir at 300 rpm for 10 minutes.

[0167] Whole milk powder and pectin were dissolved in purified water at 60°C and stirred to obtain a milk matrix; the stirring speed was 500 rpm and the stirring time was 10 min.

[0168] Mix the emulsion matrix into the base solution; stir at 350 rpm for 6 minutes;

[0169] The anthocyanin nanoparticle suspension was dispersed in the base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 10,000 rpm and the homogenization time was 4 min.

[0170] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and allow it to ferment statically for 8 hours, controlling the pH to drop to 4.4; the concentration of the lactic acid bacteria culture is 1×10⁻⁶. 9 CFU / mL;

[0171] Heat to 65℃ and hold for 10 minutes;

[0172] Fill after cooling to room temperature;

[0173] The amount of purified water used to prepare the emulsion matrix was 240 parts, and the amount of purified water used to prepare the base solution was 260 parts.

[0174] Comparative Example 3:

[0175] Unlike Comparative Example 2, a coating process was added. The coating process is as follows:

[0176] Prepare a pectin solution; the pectin mass fraction in the pectin solution is 0.5%, and the pH value is 4;

[0177] The anthocyanin nanoparticle suspension was added to the pectin solution and stirred to obtain the first mixture; the stirring speed was 1000 rpm and the temperature was 40℃.

[0178] To prepare a chitosan solution, the first mixture was added dropwise to the chitosan solution and stirred to obtain a second mixture; the stirring speed was 600 rpm and the stirring time was 15 min; the mass fraction of chitosan in the chitosan solution was 0.6%, and the pH was 5.5; the dropping rate was 8 mL / min.

[0179] The second mixture was dispersed to obtain an emulsion. The dispersion treatment was carried out using an ultrasonic treatment scheme with an ultrasonic power of 80W, a treatment time of 3min, and an ultrasonic frequency of 20Hz.

[0180] The emulsion was freeze-dried to obtain a coated powder. The freeze-drying temperature was -40℃ and the processing time was 48h.

[0181] The preparation method for acidic beverages is as follows:

[0182] Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60°C, and cool to 40°C to obtain the base liquid; stir at 300 rpm for 10 minutes.

[0183] Whole milk powder and pectin were dissolved in purified water at 60°C and stirred to obtain a milk matrix; the stirring speed was 500 rpm and the stirring time was 10 min.

[0184] Mix the emulsion matrix into the base solution; stir at 350 rpm for 6 minutes;

[0185] The coated powder was dispersed in the base liquid and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 10,000 rpm and the homogenization time was 4 min.

[0186] Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and allow it to ferment statically for 8 hours, controlling the pH to drop to 4.4; the concentration of the lactic acid bacteria culture is 1×10⁻⁶. 9 CFU / mL;

[0187] Heat to 65℃ and hold for 10 minutes;

[0188] Fill after cooling to room temperature;

[0189] The amount of purified water used to prepare the emulsion matrix was 240 parts, and the amount of purified water used to prepare the base solution was 260 parts.

[0190] The embodiments 1-8 and comparative examples 1-3 described above are summarized as follows:

[0191] Comparative Example 1 used conventional blueberry anthocyanin powder. Comparative Example 2, based on Comparative Example 1, introduced a nano-blueberry anthocyanin preparation method based on high-pressure homogenization, which is difficult to industrialize. Comparative Example 3, based on Comparative Example 2, introduced a double-layer coating process. Example 1 provided a method for preparing nano-blueberry anthocyanin powder with a particle size strictly less than 100 nanometers, used to make acidic beverages. Example 2 did not use nano-powder but rather coated powder; that is, it was based on existing conventional blueberry anthocyanin powder. In fact, Example 2 is also a comparative example, and Example 3 is a dual scheme of nano-coating. Based on Examples 1-3, Example 4 corresponds to Example 1, and a negative feedback regulation scheme is introduced during the preparation of nanomaterials. Example 5 corresponds to Example 2, and a negative feedback regulation scheme is introduced in the coating stage. Example 6 corresponds to Example 3, and two negative feedback regulation schemes are introduced at the same time. Examples 7 and 8 are based on Example 6, and the content of nano-coated blueberry anthocyanin powder is adjusted, including the amount of nano-blueberry anthocyanin powder and the amount of coating material.

[0192] experiment:

[0193] Specific experiments were conducted on Examples 1-8 and Comparative Examples 1-3. The experimental process consisted of three parts, as follows:

[0194] 1. Referring to GB / T31121-2014 "Fruit and Vegetable Juices and Their Beverages", take 25 mL of sample and place it in a centrifuge tube. Centrifuge at 3000 r / min for 20 minutes and calculate the sediment volume percentage. At the same time, store the sample at 25℃ in the dark for 30 days and observe its appearance regularly.

[0195] 2. Refer to the pH differential method in T / NXFSA022-2022. Determine the initial content C1 after fermentation with added nano-anthocyanins and sterilization, and the content C2 after 60 days of storage at room temperature in the dark. Calculate the retention rate using the formula (C2 / C1)×100%.

[0196] 3. Refer to GB / T29604-2013 "Guidelines for Sensory Quality Control of Food" for sensory analysis. Form an evaluation team of 10 or more trained members to assess the sourness and astringency using a scale of 0-10, with 0 points indicating no sourness or astringency and 10 points indicating extremely strong sourness and astringency.

[0197] For the above experiments, 10 experiments were conducted for each example of Examples 1-8 and Comparative Examples 1-3, and the average of the 10 experiments was taken as the final test result for the corresponding example.

[0198] Test results:

[0199] Table 1

[0200]

[0201] Results explanation:

[0202] Using sedimentation rate as the benchmark, the examples were analyzed. Examples 3-8 (11%-18%) showed an overall stepwise decrease, while the sedimentation rates of Comparative Examples 1-3 and Examples 1-2 were in the higher range of 25%-38%, mainly due to the control of nanoparticle size and coating thickness. Considering the differences between the examples, Comparative Example 1 used conventional blueberry anthocyanin powder, Comparative Example 2 introduced a nano-blueberry anthocyanin preparation method based on high-pressure homogenization, and Comparative Example 3 introduced a double-layer coating process based on Comparative Example 2. By introducing new processes, it can be seen that the use of nanomaterials and coating processes can indeed improve product quality. This means that the coating and nano-processing processes are not contradictory.

[0203] Based on the above, Example 1 provides a method for preparing nano-blueberry anthocyanin powder with a particle size strictly less than 100 nanometers. Compared with Comparative Example 2, both methods employ nano-processing, but Example 1 has a finer particle size. Furthermore, its greater advantage is that it can be industrially produced with extremely high production efficiency. Example 2 does not use nano-powder but rather coated powder, that is, coating existing conventional blueberry anthocyanin powder. Compared with Comparative Example 1, coating represents a significant improvement. However, compared with Example 1, both methods have their strengths and weaknesses in various indicators. Therefore, when facing the optimization requirements of the aforementioned indicators, the final results obtained by these two methods are similar. However, Example 3 is a dual method of nano-powdering and coating, which brings extremely significant effects, with substantial improvements in all aspects.

[0204] Furthermore, Example 4 corresponds to Example 1, introducing a negative feedback adjustment scheme during nanomaterial preparation; Example 5 corresponds to Example 2, introducing a negative feedback adjustment scheme during the coating stage; Example 6 corresponds to Example 3, introducing two negative feedback adjustment schemes simultaneously. Building upon the already high yield achieved in Example 3, the introduction of a negative feedback adjustment scheme based on intelligent devices can optimize specific operating parameters, which is like icing on the cake. However, further optimization on an already high-quality foundation represents a significant advancement in itself.

[0205] Furthermore, regarding Examples 6-8, Example 6 represents an intermediate dosage, Example 7 a lower dosage, and Example 8 a higher dosage. From the above data, it can be seen that when Example 7 uses a lower dosage, its performance is slightly lower than that of Example 6. However, although Example 8 uses a higher dosage, its flavor is weaker, which is equivalent to some negative impact. Therefore, Examples 6 and 7 are both within a suitable range. If the above indicators are taken as the standard, Example 6 is the optimal solution.

[0206] Analysis of Example 6 showed that, in terms of retention rate, Example 6 was 1.7 times higher than that of Comparative Example 1, indicating that oxidation and photodegradation were significantly controlled; in terms of flavor, the sourness and astringency decreased by an average of about 3 points, which is in line with consumer preference trends.

[0207] Specifically, the reasons for the above optimization process are explained as follows:

[0208] Conventional anthocyanins readily bind to milk proteins in acidic beverages, leading to flocculent matter or sediment at the bottom of the finished product. Nanoparticles (1-100nm) can be uniformly dispersed in the milk matrix, resulting in a consistent color and a smooth, grain-free texture in acidic beverages. Furthermore, the acidic environment during fermentation (pH 4.0-4.6), the high temperatures during sterilization, and oxidation during refrigerated storage all contribute to the degradation and inactivation of conventional anthocyanins. The coating structure of nanoparticles (such as polysaccharide or liposome coating) can isolate these factors, increasing anthocyanin retention by over 40% and extending the shelf life of acidic beverages. Excessive concentrations of conventional anthocyanins can cause a noticeable sour taste, clashing with the sweet and sour flavor of acidic beverages. Due to their high absorption efficiency, nanoparticles can be added at 30%-50% less, preserving antioxidant nutrients without masking the original flavor of acidic beverages, resulting in a more harmonious taste.

[0209] It is worth mentioning that the acidic beverage provided in Example 6 theoretically has higher bioavailability and is easier to absorb nutrients. The acidic beverage has a limited residence time in the intestines. Conventional anthocyanins have large molecular weights and are not easily absorbed by the intestinal mucosa. The nanoscale structure can penetrate the intestinal barrier, and the absorption rate is 2-3 times higher than that of conventional products. The amount added can be reduced under the same nutritional effect. However, the testing process for this process is extremely difficult (in many aspects), and the specific data is not added to the table above.

[0210] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An acidic beverage containing nano-blueberry anthocyanins, characterized in that, By weight, it comprises the following components: The beverage contains 400-450 parts blueberry juice, 0.4-0.5 parts nano-blueberry anthocyanin powder, 50-60 parts white sugar, 8-10 parts fructooligosaccharides, 40-50 parts whole milk powder, 2-3 parts pectin, and 400-500 parts purified water. The acidic beverage containing nano-blueberry anthocyanins is prepared by mixing the above components and then fermenting them with lactic acid bacteria. The nano-blueberry anthocyanin powder is a coated nano-blueberry anthocyanin powder. The preparation method of the coated nano-blueberry anthocyanin powder includes: Blueberry anthocyanin raw materials were placed in a liquid nitrogen freezing device and the freezing temperature was set not to exceed -186 degrees Celsius for ultra-low temperature freezing crystallization pretreatment. Start the suction pump to suck the pretreated blueberry anthocyanin raw material into the feeding chamber; Open the discharge valve of the feeding chamber and put the blueberry anthocyanin raw material into the pressure stabilizing chamber; Blueberry anthocyanin raw material is drawn into the high-pressure chamber of the primary air jet mill from the pressure stabilizing chamber and subjected to primary air milling to obtain primary abrasive. The first classifier classifies the primary abrasive, and the primary abrasive with a thickness greater than 10 micrometers is transported to the high-pressure chamber of the primary air-flow mill, while the primary abrasive with a thickness of no more than 10 micrometers is transported to the high-pressure chamber of the secondary air-flow mill. The primary abrasive is processed by the high-pressure chamber of a two-stage airflow mill to obtain the secondary abrasive; The secondary abrasive is classified by the second classifier. The secondary abrasive with a thickness greater than 500 nanometers is transported to the high-pressure chamber of the secondary air jet mill, and the secondary abrasive with a thickness of no more than 500 nanometers is transported to the fluid energy deagglomeration chamber. The secondary abrasive is processed by the flow energy deagglomeration chamber and screened to obtain blueberry anthocyanin powder; the particle size of the blueberry anthocyanin powder is no greater than 100 nanometers. Coating blueberry anthocyanin powder; the step of coating blueberry anthocyanin powder includes: Preparation of pectin solution; Blueberry anthocyanin powder was added to the pectin solution and stirred to obtain the first mixture; To prepare a chitosan solution, the first mixture is added dropwise to the chitosan solution and stirred to obtain a second mixture. The second mixture was dispersed to obtain an emulsion; the dispersion process employed an ultrasonic treatment method. The emulsion was freeze-dried to obtain coated nano-blueberry anthocyanin powder.

2. The acidic beverage containing nano-blueberry anthocyanins according to claim 1, characterized in that, The preparation method of the coated nano-blueberry anthocyanin powder further includes: The particle size of the secondary abrasive at the high-pressure chamber outlet of the secondary air classifier is obtained in real time by an online particle size analyzer built into the second classifier, and D50 is determined. The D50 generates adjustment commands directed to the high-pressure chamber of the secondary airflow mill; the adjustment target is air pressure. The particle size of the abrasive at the outlet of the fluid energy depolymerization chamber is obtained in real time by an online particle size analyzer installed in the fluid energy depolymerization chamber, and the D50 is determined. The D50 generates adjustment commands directed to the flow energy depolymerization chamber; the adjustment target is air pressure.

3. The acidic beverage containing nano-blueberry anthocyanins according to claim 1, characterized in that, The step of coating the blueberry anthocyanin powder further includes: The spectrum was acquired using a near-infrared spectrometer, and A520 and A450 were determined. The ratio of A520 to A450 was then calculated as the peak ratio. Viscosity of emulsions is measured using an online viscosity probe; The adjustment instructions are determined based on the peak ratio and viscosity. These instructions are used to control the stirring speed and the operating parameters of the ultrasonic treatment scheme.

4. A method for preparing an acidic beverage containing nano-blueberry anthocyanins as described in any one of claims 1-3, characterized in that, The preparation method includes: Mix blueberry juice, purified water, granulated sugar, and fructooligosaccharides, heat to 60-62℃, and cool to 40℃ to obtain the base liquid; stir at 300-400 rpm for 10 minutes. Dissolve whole milk powder and pectin in purified water at 60-62℃ and stir to obtain the milk matrix; the stirring speed is 400-500 rpm and the stirring time is 10 minutes. Mix the emulsion matrix into the base solution; stir at 300-350 rpm for 5-8 minutes; The nano-blueberry anthocyanin powder was dispersed in the base solution and emulsified and homogenized using a high-speed homogenizer; the pressure of the high-speed homogenizer was 9000-10000 rpm and the homogenization time was 3-4 min. Cool the homogenized liquid to 37°C, add 10 mL of lactic acid bacteria culture, and perform static fermentation for 6-8 hours, controlling the pH to drop to 4.2-4.

4. Heat to 65℃ and hold for 10 minutes; Fill after cooling to room temperature.

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