A method for making blueberry euglena milk tablets

Abstract

This invention discloses a method for producing blueberry Euglena milk tablets, comprising: selecting slender Euglena algae, homogenizing and breaking down the cell walls under high pressure micro-jet, and spray drying to obtain Euglena powder; enzymatically hydrolyzing the Euglena powder with honey, a complex enzyme of cellulase and pectinase (total enzyme activity 500-2000 U / mL); homogenizing blueberry juice with a stabilizer under high pressure to obtain stabilized blueberry juice; dissolving gelatin powder in blueberry juice to obtain a binder; mixing the enzymatic hydrolysate, stabilized blueberry juice, binder, and remaining honey to obtain a composite nutrient solution; mixing with corn starch and milk powder to form a soft material, followed by static curing, gradient drying (35-40℃ hot air + 45-50℃ vacuum), granulation and tableting, and constant temperature and humidity curing to obtain the final product. The product of this invention has an anthocyanin retention rate ≥90%, Euglena polysaccharide retention rate ≥87%, disintegration time ≤5 minutes, no Euglena fishy smell, clean ingredients, good formability and rapid solubility, overcoming the technical challenge of simultaneously achieving high activity retention and good sensory qualities.

Description

Technical Field

[0001] This invention belongs to the field of functional food processing technology, specifically relating to a method for producing blueberry Euglena milk tablets, and more particularly to a blueberry Euglena milk tablet prepared by enzymatic hydrolysis, low-temperature gradient drying and preservation process and its application. Background Technology

[0002] Blueberries are rich in anthocyanins, flavonoids, and other active ingredients, offering significant health benefits such as antioxidant properties, vision protection, and immune system enhancement. Developing blueberries into convenient and portable milk tablets is a key area of ​​development in the functional food sector. Milk powder, a high-quality source of protein and calcium, can be further enhanced by combining it with blueberries to improve the product's nutritional value.

[0003] Currently, there have been attempts to develop technologies for preparing milk tablets by combining blueberries and milk powder. For example, Chinese patent application CN105076442A discloses a "blueberry milk tablet and its preparation method." This technical solution uses blueberry processing byproducts—blueberry pomace powder (70-75 parts by weight)—and milk powder (25-30 parts by weight) as base materials, and adds excipients such as non-dairy creamer (10-15% by weight of base materials), fructooligosaccharides (6-8% by weight of base materials), and citric acid (0.1-0.3% by weight of base materials). The product is manufactured through processes such as mixing, tableting, and drying at 60°C for 2 hours. This solution reflects the intention of comprehensively utilizing blueberry resources, and the preparation method is relatively simple.

[0004] However, after analysis, the above-mentioned existing technical solutions still have the following areas for improvement: Firstly, heat-sensitive components are easily damaged. This method uses blueberry pomace powder (i.e., the fruit pomace remaining after blueberry juicing, which is dried and crushed) as the blueberry source. Some heat-sensitive active components are lost during the drying process of the blueberry pomace. At the same time, the subsequent preparation process uses drying at 60℃ for 2 hours. This long high-temperature treatment may further damage the remaining heat-sensitive functional components such as anthocyanins, which is not conducive to the full preservation of active ingredients.

[0005] Secondly, the cleanliness of the ingredients needs improvement. The formula uses non-dairy creamer (which may contain trans fatty acids) and fructooligosaccharides, among other excipients. Given that contemporary consumers seek natural, clean-label foods, the use of these additives is inconsistent with modern healthy eating concepts, and the cleanliness of the product's ingredients needs further improvement.

[0006] Third, the nutritional structure needs optimization. The main nutritional sources of this solution are blueberry pomace powder and milk powder, resulting in a relatively simple nutritional composition and a lack of further enhancement in the product's functional dimensions.

[0007] Therefore, it is necessary to develop a functional milk tablet product that can better preserve the active ingredients of blueberries, has cleaner and more natural ingredients, and has a more scientific nutritional structure, in order to meet consumers' higher demands for healthy food. Summary of the Invention

[0008] In view of the technical defects in the preparation of blueberry milk tablets, such as the easy damage of heat-sensitive components, the need to improve the cleanliness of ingredients, and the single nutritional structure, the purpose of this invention is to provide a method for preparing blueberry Euglena milk tablets and their application.

[0009] The objective of this invention is achieved through the following technical solution.

[0010] In a first aspect, the present invention provides a method for preparing blueberry Euglena milk tablets, comprising the following steps: S1: Preparation of Euglena gracilis powder: Select slender Euglena gracilis, wash, homogenize and break down the cell walls under high pressure micro-jet, and spray dry to obtain Euglena gracilis powder; S2: Enzymatic hydrolysis: Mix the Euglena powder obtained in step S1 with honey and compound enzyme, and enzymatically hydrolyze at 40-50℃ for 20-40 min to obtain enzymatic hydrolysate; the compound enzyme includes cellulase and pectinase, and the total enzyme activity concentration of the compound enzyme in the enzymatic hydrolysate is 500-2000 U / mL. S3: Stabilization treatment of blueberry juice: Mix blueberry juice with stabilizer and homogenize under high pressure to obtain stabilized blueberry juice; S4: Preparation of fish glue adhesive liquid: Dissolve fish glue powder in some blueberry juice, heat to 40-50℃ to dissolve, and obtain fish glue adhesive liquid; S5: Preparation of compound nutrient solution: Mix the enzymatic hydrolysate obtained in step S2, the stabilized blueberry juice obtained in step S3, the fish glue binder obtained in step S4, and the remaining honey evenly to obtain the compound nutrient solution. S6: Wet granulation: Corn starch and milk powder are mixed to obtain the main powder. The compound nutrient solution is slowly added to the main powder and stirred to form a soft material. After granulation, wet granules are obtained. S7: Gradient drying: The wet granules are first dried with hot air at 35-40℃, and then dried with vacuum at 45-50℃, controlling the moisture content to ≤8%; S8: Tableting and Curing: After drying, the granules are sized and compressed into tablets. The resulting tablets are then cured in an environment with a temperature of 20-25℃ and a relative humidity of 52%-58% for 12-24 hours to obtain blueberry Euglena milk tablets.

[0011] Furthermore, in step S1, the high-pressure microjet homogenization pressure is 100-150MPa, and the number of treatments is 2-3; the inlet air temperature of the spray dryer is 160-180℃, and the outlet air temperature is 70-85℃.

[0012] Furthermore, in step S2, the mass ratio of Euglena powder to honey is 1:2 to 1:4.

[0013] Furthermore, in step S3, the stabilizer is selected from one or more of inulin, flaxseed gum, and gum arabic, and its addition amount is 1-3% of the weight of blueberry juice; the high-pressure homogenization pressure is 80-100 MPa.

[0014] Furthermore, in step S6, after preparing the soft material, the wet particles are allowed to stand at 4-10°C for 2-4 hours to mature.

[0015] Furthermore, in step S7, the relative humidity of the first stage hot air drying is 30-40%, and the drying time is 1-2 hours; the vacuum degree of the second stage vacuum drying is -0.08 to -0.1 MPa, and the drying time is 0.5-1 hours.

[0016] Furthermore, the raw materials consist of the following components in parts by weight: 45-55 parts blueberry juice, 30-35 parts honey, 4-6 parts Euglena powder, 75-85 parts corn starch, 18-22 parts milk powder, 6-8 parts gelatin powder, 1-3 parts stabilizer, and 0.1-0.3 parts compound enzyme.

[0017] Furthermore, after tableting in step S8, the process further includes spraying a coating solution onto the surface of the tablet. The coating solution is composed of beeswax, hydroxypropyl starch, and water in a mass ratio of 1:5:20.

[0018] Secondly, the present invention also provides a blueberry Euglena milk tablet, which is prepared by any of the preparation methods described above.

[0019] Furthermore, the blueberry Euglena milk tablets have an anthocyanin retention rate of ≥90%, a moisture content of 5-8%, and a hardness of 50-90N.

[0020] Furthermore, the blueberry Euglena milk tablets contain a total anthocyanin content of ≥120 mg / 100g and an Euglena polysaccharide content of ≥2.5 g / 100g, and all raw materials are of edible grade.

[0021] Furthermore, the blueberry Euglena milk tablets have a disintegration time of ≤5 min. In a simulated saliva environment at 37°C, the surface begins to disintegrate within 30 seconds and is completely dispersed into fine particles within 3 minutes.

[0022] Furthermore, the total phenolic content of the blueberry Euglena milk tablets is ≥80 mg GAE / 100g, the scavenging rate of DPPH free radicals is ≥65%, and the scavenging rate of ABTS free radicals is ≥70%.

[0023] Thirdly, the present invention also discloses the application of the above-mentioned blueberry Euglena milk tablets in the preparation of functional foods.

[0024] Furthermore, the application includes: using the blueberry Euglena milk tablets as a daily nutritional supplement for people who need to supplement anthocyanins and Euglena polysaccharides; during in vitro simulated digestion, the anthocyanin retention rate of the milk tablets is more than 30% higher than that of traditional blueberry milk tablets, which can effectively exert antioxidant and intestinal flora regulation functions.

[0025] Furthermore, in the aforementioned application, the blueberry Euglena milk tablets exhibit an anthocyanin release rate of ≥75% and a Euglena polysaccharide retention rate of ≥85% in in vitro simulated digestion, demonstrating good bioavailability.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention employs high-pressure microfluidic homogenization combined with enzymatic hydrolysis using cellulase and pectinase to increase the polysaccharide retention rate of Euglena to over 87%, while significantly eliminating the fishy odor of Euglena. Using fish gelatin powder as a natural binder, supplemented by static curing, gradient low-temperature drying (35-40℃ hot air + 45-50℃ vacuum), and constant temperature and humidity conditioning, the product achieves an anthocyanin retention rate of over 90%, with a hardness controlled at 65-75N, a disintegration time ≤5 minutes, and a 30-day moisture absorption rate of less than 2.5%. Compared to untreated Euglena, the polysaccharide retention rate is increased by approximately 26 percentage points; compared to high-temperature drying at 60℃, the anthocyanin retention rate is increased by approximately 35 percentage points. In vitro simulated digestion experiments show that the total anthocyanin release rate of the product of this invention reaches 84.7%, significantly higher than the 51.7% of the control sample. The relative standard deviation of three batches in scaled-up production is less than 5%, indicating good process reproducibility. The product of this invention has clean ingredients, does not contain additives such as non-dairy creamer, and has the advantages of high retention of active ingredients, good sensory quality and stable shelf life. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the method for producing blueberry Euglena milk tablets according to the present invention; Figure 2 The graph shows the comparison of anthocyanin retention rate and fishy smell score under different process conditions. The horizontal axis represents, in order: Example 1, Comparative Example 1 (without enzymatic hydrolysis), Comparative Example 2 (high temperature drying), and CN105076442A control. Figure 3 Line graphs showing the hardness and disintegration time equilibrium index of different samples. The equilibrium index is defined as the ratio of hardness (N) to disintegration time (min). The horizontal axis represents, in order: Example 1, Comparative Example 2 (high temperature drying), Comparative Example 3 (without gelatin powder), and commercially available blueberry milk tablets; Figure 4The graph shows the anthocyanin release rate of different samples after simulated in vitro digestion, including three curves: gastric phase release rate, intestinal phase release rate, and total release rate. The horizontal axis represents, in order: Example 1, Comparative Example 1 (unenzymatic hydrolysis), Comparative Example 2 (high-temperature drying), and commercially available blueberry milk tablets. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.

[0029] Table 1: Main Raw Materials

[0030] Example 1

[0031] This embodiment provides a method for preparing blueberry Euglena milk tablets, such as... Figure 1 The process, as shown, includes the following steps: S1. Preparation of Euglena powder: Fresh Euglena gracilis mud was selected, and impurities were removed by repeatedly washing it three times with pure water. The mud was then processed three times with a high-pressure micro-jet homogenizer at a pressure of 120 MPa to break the cell walls. Subsequently, it was spray-dried with an inlet air temperature of 170℃ and an outlet air temperature of 80℃ to collect Euglena gracilis powder.

[0032] S2, Enzymatic hydrolysis: Take 5g of Euglena powder obtained in step S1, mix it with 30g of honey, and add 0.2g of a compound enzyme. The compound enzyme is a mixture of cellulase and pectinase in a 1:1 mass ratio, and its total enzyme activity concentration in the hydrolysate is 1200 U / mL. Add purified water to a total volume of 100mL, and hydrolyze at 45℃ for 30min to obtain the hydrolysate.

[0033] S3, Stabilization treatment of blueberry juice: Take 50g of blueberry juice, add 1.5g of inulin, and homogenize twice using a high-pressure microfluidic homogenizer at 90MPa pressure to obtain stabilized blueberry juice.

[0034] S4. Preparation of fish glue adhesive: Take 7g of gelatin powder, dissolve it in 35g of blueberry juice, heat it in a water bath to 45℃ and stir until dissolved to obtain gelatin adhesive liquid.

[0035] S5. Preparation of compound nutrient solution: Mix the enzymatic hydrolysate obtained in step S2, the stabilized blueberry juice obtained in step S3, the fish glue adhesive obtained in step S4, and the remaining 5g of honey evenly to obtain a compound nutrient solution.

[0036] S6. Wet granulation: Mix 80g of cornstarch and 20g of milk powder evenly to obtain the main powder. Slowly add the compound nutrient solution to the main powder while stirring until it becomes flocculent. Knead by hand until it reaches the state of "forming a ball when squeezed but crumbling when lightly pressed". Spread the wet granules evenly in a stainless steel pan and let them stand at 4℃ for 3 hours to mature.

[0037] S7, Gradient Drying: The matured wet granules were first dried with hot air at 38°C and 35% relative humidity for 1.5 hours, and then transferred to a vacuum drying oven and dried at 48°C and -0.09MPa vacuum for 0.8 hours. The moisture content was measured to be 6.5%.

[0038] S8. Tableting and Curing: After drying, the granules are sieved through a 20-mesh sieve and sized. A rotary tablet press is used to adjust the tablet weight to 4g, and the tablets are tested and adjusted until the hardness is moderate (they can be broken with fingers). After formal tableting, the tablets are placed in a constant temperature and humidity chamber at 22℃ and 55% relative humidity for 18 hours for curing, and then sealed and packaged.

[0039] The resulting blueberry Euglena milk tablets are light purple in appearance, with a smooth surface, uniform particles, a delicate taste, a sweet and sour flavor, and no fishy smell of Euglena.

[0040] Example 2

[0041] This embodiment is basically the same as Embodiment 1, except for the adjustment of raw material ratios and some process parameters: The ingredient ratio is as follows: 48g blueberry juice, 32g honey, 4.5g Euglena powder, 78g corn starch, 19g milk powder, 6.5g gelatin powder, 1.2g inulin, and 0.15g compound enzyme. The high-pressure micro-jet homogenization pressure in S1 is 100MPa, and the treatment is repeated twice. The enzymatic hydrolysis temperature in S2 was 42℃, the enzymatic hydrolysis time was 35 min, and the total enzyme activity concentration of the complex enzyme was 800 U / mL. The high-pressure homogenization pressure in S3 is 85 MPa; The static curing temperature in S6 is 6℃, and the curing time is 2.5 hours; The first stage of hot air drying in S7 is at a temperature of 35℃ for 1.8 hours; the second stage is at a temperature of 46℃, a vacuum degree of -0.08MPa, and a time of 0.6 hours. The curing temperature in S8 is 23℃, the relative humidity is 56%, and the curing time is 20 hours.

[0042] Example 3

[0043] This embodiment is basically the same as Embodiment 1, except that: After S8 tableting, the process also includes a coating solution spraying step: beeswax, hydroxypropyl starch and water are mixed in a mass ratio of 1:5:20, heated to 60°C and stirred evenly, and then sprayed onto the tablet surface using a coating pan, with the coating weight gain controlled at 2-3%.

[0044] The remaining steps are the same as in Example 1.

[0045] Comparative Example 1 No enzymatic hydrolysis was used.

[0046] This comparative example is basically the same as Example 1, except that step S2 is omitted, that is, enzymatic hydrolysis is not performed, and Euglena powder is directly mixed with honey for subsequent preparation.

[0047] Specific adjustments: Mix 5g of Euglena powder with 30g of honey directly without adding compound enzymes, stir at 45℃ for 30 minutes, and then mix with the liquid obtained in steps S3 and S4.

[0048] Comparative Example 2 Traditional high-temperature drying is used.

[0049] This comparative example is basically the same as Example 1, except that step S7 uses traditional high-temperature drying: the wet particles are directly dried with hot air at 60°C for 2 hours, without gradient drying or vacuum drying.

[0050] Comparative Example 3 No gelatin powder was used.

[0051] This comparative example is basically the same as Example 1, except that step S4 is omitted, gelatin powder is not added, blueberry juice is directly mixed with other liquids, and the amount of corn starch is increased accordingly to adjust the molding properties.

[0052] Specific adjustments: gelatin powder is removed, and the amount of corn starch is adjusted to 87g.

[0053] Comparative Example 4 No static ripening treatment was performed.

[0054] This comparative example is basically the same as Example 1, except that in step S6, after the soft material is prepared, it is directly subjected to gradient drying without undergoing a 4°C static curing treatment.

[0055] Comparative Example 5 No maintenance was performed.

[0056] This comparative example is basically the same as Example 1, except that after tableting in step S8, the tablets are directly sealed and packaged without undergoing constant temperature and humidity curing.

[0057] Test Example 1 Anthocyanin retention rate and total phenolic content determination Referring to NY / T 2640-2014 "Determination of Anthocyanins in Plant-Derived Foods by High Performance Liquid Chromatography" and the Folin-Ciocalteu method, the anthocyanin retention rate and total phenolic content of the blueberry Euglena milk tablets prepared in Examples 1-3 and Comparative Examples 1-5 were determined. The anthocyanin retention rate was calculated as the ratio of the anthocyanin content in the processed product to the theoretical feed amount. The results are shown in Table 2.

[0058] Table 2. Results of anthocyanin retention rate and total phenol content determination for different samples.

[0059]

[0060] The results showed that the anthocyanin retention rate of Examples 1-3 was over 90%, and the total phenol content was over 120 mg GAE / 100g. Comparative Example 2 (high-temperature drying) had an anthocyanin retention rate of only 58.6%, and the total phenol content was significantly reduced, indicating that high-temperature treatment severely damaged heat-sensitive components. Comparative Example 1 (unenzymatically hydrolyzed) had an anthocyanin retention rate of 85.3%, slightly lower than the examples, possibly due to insufficiently released bound anthocyanins. The anthocyanin retention rates of Comparative Examples 3-5 were close to those of the examples, indicating that gelatin powder, static curing, and maintenance treatment had little effect on anthocyanin retention, but had a significant impact on other properties.

[0061] Test Example 2 Determination of Euglena polysaccharide retention rate The retention rate of Euglena gracilis polysaccharide (β-1,3-glucan) in the blueberry Euglena gracilis milk tablets prepared in Examples 1-3 and Comparative Examples 1-5 was determined using high performance liquid chromatography (HPLC). The retention rate was calculated as the ratio of Euglena gracilis polysaccharide content in the processed product to the theoretical feed amount. The results are shown in Table 3.

[0062] Table 3. Results of polysaccharide retention rate determination for different samples of Euglena.

[0063]

[0064] in conclusion: The results showed that the polysaccharide retention rates of Euglena in Examples 1-3 were all close to 90%. In contrast, the polysaccharide retention rate of Comparative Example 1 (unenzymatically hydrolyzed) was only 62.4%, indicating that the intracellular polysaccharides in Euglena powder without enzymatic hydrolysis were difficult to release effectively during subsequent processing, resulting in a significant reduction in product content. The retention rates of Comparative Examples 2-5 were similar to those of the examples, indicating that enzymatic hydrolysis is a key step affecting the retention of Euglena polysaccharides.

[0065] Test Example 3 Texture properties and disintegration time determination The hardness of the samples was determined using a texture analyzer (TA-XT Plus) (probe diameter 5 mm, compression distance 5 mm, test speed 1 mm / s); the disintegration time of the samples was determined according to the "Disintegration Time Test Method" in Part IV of the 2020 edition of the Chinese Pharmacopoeia (medium: purified water at 37℃, using the basket method). The results are shown in Table 4.

[0066] Table 4. Results of structural characteristics and disintegration time determination for different types of products.

[0067]

[0068] The results showed that Examples 1-3 had moderate hardness (65-75N), were easily dissolved in the mouth, and had a disintegration time of less than 5 minutes. Comparative Example 2 (high-temperature drying) had significantly higher hardness (135N), with a disintegration time extended to 8.2 minutes, and a hard shell formed on the surface. Comparative Example 3 (without gelatin powder) had moderate hardness but disintegrated too quickly (completely disintegrating in 12.5 minutes), but actual testing revealed poor tableting properties and easy fragmentation; its moisture absorption rate was highest (4.8%) after 30 days of storage. Comparative Example 5 (without curing) had low initial hardness, but its moisture absorption rate increased significantly after storage, indicating that curing treatment plays an important role in product stability.

[0069] Test Example 4 Sensory quality evaluation Fifteen trained food sensory evaluation professionals were invited to conduct sensory evaluations of the blueberry Euglena milk tablets prepared in Examples 1-3 and Comparative Examples 1-5. Evaluation indicators included color, texture, sweetness, fishy smell, and overall acceptability, using a 10-point scale (10 being the optimal score). The results were averaged and are shown in Table 5.

[0070] Table 5 Sensory evaluation results (scores) for different samples

[0071] The results showed that Examples 1-3 had high sensory scores across all categories, with an overall acceptance rate above 8.3. Comparative Example 1 (unenzymatically hydrolyzed) scored only 4.2 for fishy odor, with a pronounced Euglena odor that severely impacted its overall acceptance rate (5.8). Comparative Example 2 (high-temperature drying) had a low taste score (6.5), possibly related to surface hardening. Comparative Example 3 (without gelatin powder) had a low color score (6.8), and its surface was rough and brittle during tableting, affecting its overall acceptance rate. Comparative Examples 4-5 had sensory scores close to those of the Examples, indicating that the effects of static curing and maintenance on sensory quality were relatively small.

[0072] Test Example 5 To verify whether the present invention has overcome the technical difficulty of achieving both high activity retention and good sensory qualities, the anthocyanin retention rate and fishy smell score of Example 1, Comparative Example 1 (unenzymatic hydrolysis), Comparative Example 2 (high temperature drying) and the control sample prepared according to the method of Example 1 of CN105076442A were simultaneously determined.

[0073] Preparation method of reference sample CN105076442A: Take blueberry pomace (the pomace remaining after blueberry juice extraction), dry and pulverize it, take 70g of blueberry pomace powder and mix it evenly with 30g of milk powder to obtain a base material; add 10g of vegetable fat powder to the base material, dissolve 8g of fructoside sugar and 0.1g of citric acid in water and add them to the base material, mix thoroughly to make a soft material; compress it into tablets using a tablet press; put the tablets in a drying oven and dry them at 60℃ for 2 hours; the result is obtained.

[0074] Test results are as follows Figure 2 As shown in Table 6.

[0075] Table 6 Comparison of anthocyanin retention rate and fishy smell score under different processing conditions

[0076] The results showed that Comparative Example 2 (high-temperature drying) had an anthocyanin retention rate of only 58.6%, while the control (CN105076442A) had a retention rate of 55.2%. Although the fishy smell was acceptable, both suffered from severe loss of active ingredients. Comparative Example 1 (unhydrolyzed) had an anthocyanin retention rate of 85.3%, which was acceptable, but the fishy smell score was only 4.2, making it sensorily unacceptable. Example 1 achieved both a high retention rate of 93.5% and a high fishy smell score of 8.5, successfully breaking through the technical bottleneck that prevented both from being achieved simultaneously.

[0077] Test Example 6 A comparison of the balance between disintegration time and hardness The hardness and disintegration time of Example 1, Comparative Example 2 (high-temperature drying), Comparative Example 3 (without gelatin powder), and a commercially available brand of blueberry milk tablets were measured, and the balance index (hardness / disintegration time, with a higher value indicating better balance) was calculated. The results are shown in Table 7 and... Figure 3 .

[0078] Table 7 Relationship between hardness and disintegration time of different samples

[0079] The balance index of Example 1 was 22.5, which was significantly higher than that of Comparative Example 2 (16.5), Comparative Example 3 (8.8) and commercially available products (9.9), indicating that the present invention achieves rapid disintegration while ensuring moderate hardness, overcoming the defect of traditional processes where hardness and disintegration are difficult to balance.

[0080] Test Example 7 Long-term storage stability testing (accelerated testing) To investigate the shelf-life stability of the products, Example 1, Comparative Example 2 (high-temperature drying), and Comparative Example 3 (without gelatin powder) were placed in a constant temperature and humidity chamber (38°C, 75% relative humidity). Samples were taken at 0 days, 30 days, and 60 days to determine the anthocyanin retention rate, hardness change rate, and sensory scores. The results are shown in Table 8.

[0081] Table 8. Changes in product performance under accelerated testing conditions

[0082] After 60 days, Example 1 still maintained an anthocyanin retention rate of 81.5%, with a hardness change rate of only +8.3% and a sensory score of 7.6. Comparative Example 2 showed an anthocyanin retention rate that decreased to 42.3%, and Comparative Example 3 showed a sensory score that decreased to 5.2 and exhibited severe moisture absorption. This demonstrates that the product of this invention possesses excellent long-term storage stability.

[0083] Test Example 8 Anthocyanin release rate (bioaccessibility) after simulated in vitro digestion Following the method of an in vitro static simulated digestion model, the anthocyanin release rates of Example 1, Comparative Example 1 (unenzymatic digestion), Comparative Example 2 (high-temperature drying), and commercially available blueberry milk tablets in simulated gastric and intestinal fluids were determined. Simulated gastric fluid preparation: 2.0 g NaCl and 3.2 g pepsin were added, and the pH was adjusted to 2.0 with hydrochloric acid, then brought to a final volume of 1 L. Simulated intestinal fluid preparation: 6.8 g KH₂PO₄ and 10.0 g trypsin were added, and the pH was adjusted to 6.8 with NaOH, then brought to a final volume of 1 L. Each sample was added to simulated gastric fluid (37°C, 120 rpm shaking for 2 hours), centrifuged, and the supernatant was used to determine the anthocyanin release. Gastric residue was transferred to simulated intestinal fluid for further digestion for 2 hours, and the intestinal release rate was determined using the same method. Results are shown in Table 9. Figure 4 .

[0084] Table 9 Comparison of anthocyanin release rates after simulated in vitro digestion

[0085] The total release rate of Example 1 reached 84.7%, which is significantly higher than that of Comparative Example 1 (63.9%), Comparative Example 2 (55.5%), and commercially available products (51.7%). This indicates that the enzymatic hydrolysis and cell wall disruption treatment of the present invention not only releases Euglena polysaccharides but also improves the bioavailability of anthocyanins.

[0086] Test Example 9 Multi-batch scale-up production reproducibility test To verify the industrial stability of the technical solution of this invention, three batches of scaled-up production (1000 tablets per batch) were carried out according to the formulation and process of Example 1, and key quality indicators were measured. The results are shown in Table 10.

[0087] Table 10 Comparison of Indicators of Three Batches of Products

[0088] The relative standard deviation (RSD) of all indicators is less than 5%, indicating that the technical solution of the present invention has good batch-to-batch consistency and industrial reproducibility, and is suitable for large-scale production.

[0089] Summary: Based on the test results of Test Examples 1-9 above, the following conclusions can be drawn: 1. Retention of active ingredients: The anthocyanin retention rate of Examples 1-3 is ≥90% and the polysaccharide retention rate of Euglena is ≥87%, which is significantly better than the unenzymatic hydrolysis comparative examples (85.3% and 62.4%, respectively) and the high-temperature drying comparative examples (58.6% and 86.1%, respectively).

[0090] 2. Sensory quality: The fishy smell scores of Examples 1-3 were all ≥8.2 points, and the overall acceptability was ≥8.3 points; the fishy smell score of the unenzymatically hydrolyzed comparative example was only 4.2 points, indicating that the enzymatic hydrolysis treatment effectively eliminated the fishy smell of Euglena.

[0091] 3. Texture and disintegration: Example 1 had a hardness of 72 N, a disintegration time of 3.2 min, and an equilibrium index of 22.5; while the high-temperature drying comparison example had an excessively high hardness (135 N) and the gelatin-free comparison example had an excessively slow disintegration time (12.5 min), indicating that the present invention takes into account both formability and solubility.

[0092] 4. Storage stability: After 60 days of accelerated testing, Example 1 still retained 81.5% of anthocyanins, with a hardness change rate of +8.3% and a sensory score of 7.6; the comparison example without gelatin powder severely absorbed moisture and deteriorated after 30 days.

[0093] 5. Bioavailability: In in vitro simulated digestion, the total anthocyanin release rate of Example 1 was 84.7%, which was significantly higher than that of the unenzymatically hydrolyzed control group (63.9%) and commercially available products (51.7%).

[0094] 6. Process reproducibility: The key indicator RSD of the three batches of scale-up production was less than 5%, indicating that the process is stable and controllable.

[0095] In summary, this invention, through enzymatic hydrolysis, gelatin powder bonding, gradient drying, and curing processes, outperforms existing technologies and comparative examples in retaining heat-sensitive components, eliminating the fishy smell of Euglena, improving disintegration performance, and enhancing storage stability. The technical effects are clear.

[0096] The above are merely a few preferred embodiments of the present invention, described in a relatively specific and detailed manner, but 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 all fall within the protection scope of the present invention.

Claims

1. A method for producing blueberry Euglena milk tablets, characterized in that, Includes the following steps: S1. Preparation of Euglena powder: Euglena gracilis, a slender algae, was selected, washed, homogenized and broken down by high-pressure micro-jet, and spray-dried to obtain Euglena powder; S2, Enzymatic hydrolysis: The Euglena powder obtained in step S1 is mixed with honey and a compound enzyme, and enzymatically hydrolyzed at 40-50℃ for 20-40 minutes to obtain an enzymatic hydrolysate; the compound enzyme includes cellulase and pectinase, and the total enzyme activity concentration of the compound enzyme in the enzymatic hydrolysate is 500-2000 U / mL. S3, Stabilization treatment of blueberry juice: Blueberry juice is mixed with a stabilizer and homogenized under high pressure to obtain stabilized blueberry juice. S4. Preparation of fish glue adhesive: Dissolve gelatin powder in some blueberry juice and heat to 40-50℃ to dissolve, thus obtaining gelatin adhesive liquid; S5. Preparation of compound nutrient solution: Mix the enzymatic hydrolysate obtained in step S2, the stabilized blueberry juice obtained in step S3, the gelatin binder obtained in step S4, and the remaining honey evenly to obtain a compound nutrient solution. S6. Wet granulation: Corn starch and milk powder are mixed to obtain the main powder. The compound nutrient solution is slowly added to the main powder and stirred to form a soft material. After granulation, wet granules are obtained. S7, Gradient Drying: The wet granules are first dried with hot air at 35-40℃, and then dried under vacuum at 45-50℃, with the moisture content controlled to be ≤8%. S8. Tableting and Curing: After drying, the granules are sized, compressed, and then the resulting tablets are placed in an environment with a temperature of 20-25℃ and a relative humidity of 52%-58% for 12-24 hours to obtain blueberry Euglena milk tablets.

2. The method according to claim 1, characterized in that, In step S1, the high-pressure microjet homogenization pressure is 100-150MPa, and the number of treatments is 2-3; the inlet air temperature of the spray drying is 160-180℃, and the outlet air temperature is 70-85℃.

3. The method according to claim 1, characterized in that, In step S2, the mass ratio of Euglena powder to honey is 1:2 to 1:

4.

4. The method according to claim 1, characterized in that, In step S3, the stabilizer is selected from one or more of inulin, flaxseed gum, and gum arabic, and its addition amount is 1-3% of the weight of blueberry juice; the high-pressure homogenization pressure is 80-100 MPa.

5. The method according to claim 1, characterized in that, In step S6, after preparing the soft material, the wet granules are further subjected to a step of standing and maturing at 4-10°C for 2-4 hours.

6. The method according to claim 1, characterized in that, In step S7, the first stage of hot air drying has a relative humidity of 30-40% and a drying time of 1-2 hours; the second stage of vacuum drying has a vacuum degree of -0.08 to -0.1 MPa and a drying time of 0.5-1 hours.

7. The method according to claim 1, characterized in that, The raw materials consist of the following components in parts by weight: 45-55 parts blueberry juice, 30-35 parts honey, 4-6 parts Euglena powder, 75-85 parts corn starch, 18-22 parts milk powder, 6-8 parts gelatin powder, 1-3 parts stabilizer, and 0.1-0.3 parts compound enzyme.

8. The method according to claim 1, characterized in that, After tableting in step S8, the process further includes spraying a coating solution onto the tablet surface. The coating solution is composed of beeswax, hydroxypropyl starch, and water in a mass ratio of 1:5:

20.

9. A blueberry Euglena milk tablet, characterized in that, It is prepared by the manufacturing method described in any one of claims 1 to 8.

10. The blueberry Euglena milk tablets according to claim 9, characterized in that, The milk tablets have an anthocyanin retention rate of ≥90%, a moisture content of 5-8%, and a hardness of 50-90N.

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