Compositions for enhancing immunity, lyophilized compositions, lyophilized milk nuggets, and methods of making the same

Abstract

The application discloses an immunity-enhancing composition, a freeze-dried composition, a freeze-dried milk block and a preparation method thereof, and belongs to the field of food. The immunity-enhancing composition is prepared by reasonably compounding lactoferrin, N-acetylneuraminic acid, PQQ, oat beta-glucan and taurine, fully volatilizing the synergistic effect among the components, and has excellent immunity-enhancing effect on the body. The immunity-enhancing composition can be used for preparing freeze-dried food such as freeze-dried milk blocks and freeze-dried powder, and can endow the food with additional functions and help to improve the added value of the food and develop new markets.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of food technology, and relates to an immune-enhancing composition, a freeze-dried composition, a freeze-dried milk block and a preparation method thereof. BACKGROUND

[0002] Immunity is the body's own defense mechanism, and is the ability of the body to recognize and eliminate any foreign invaders (viruses, bacteria, etc.), to process aged, damaged, dead, and degenerated cells, and to recognize and process mutant cells and virus-infected cells in the body. Nowadays, people's life rhythm is accelerated, and the working intensity is high, and irregular diet and sleep can easily lead to a decline in the immune function of the body, and can easily cause abnormality such as lack of spirit, fatigue, sweating, repeated colds, and infections. With the improvement of living standards, people gradually pay attention to nutrition and health care, and therefore, it is necessary to develop an immune-enhancing composition. SUMMARY

[0003] Based on the defects of the prior art, the present application aims to provide an immune-enhancing composition, a freeze-dried composition, a freeze-dried milk block and a preparation method thereof, and the obtained immune-enhancing composition has excellent immune function enhancement.

[0004] In order to achieve the above-mentioned purpose, the present application provides an immune-enhancing composition, which comprises the following components in parts by weight: lactoferrin 1-7 parts, N-acetylneuraminic acid 1-7 parts, pyrroloquinoline quinone disodium salt 0.16-0.48 parts, oat beta-glucan 42-105 parts, and taurine 1-7 parts.

[0005] Lactoferrin has multiple biological activities such as antibacterial, antiviral, anti-inflammatory, anticancer, and antioxidant activities, and plays an important role in the immune system. It mainly acts on immune cells and immune factors to exert immune regulation, and effectively inhibits the formation of bacterial biofilm through iron chelation to prevent bacteria from combining with cells to exert antibacterial action.

[0006] N-acetylneuraminic acid regulates various response activities of the immune system, so that immune cells maintain normal activity, protect the cell surface, and eliminate pathogens. It can also promote the absorption of vitamins and minerals.

[0007] Taurine is a good immune stabilizer and membrane stabilizer, and enables cells to exert normal physiological functions. Taurine also has a certain protective effect on lymphocytes, can promote lymphocyte proliferation and antibody production, and can promote macrophages to produce interleukin I and enhance the phagocytosis and bactericidal function of neutrophils, thereby improving the specific immune function of humans and animals. In addition, taurine can also relieve physical fatigue symptoms.

[0008] Pyrroloquinoline quinone disodium salt (PQQ) is a negatively charged, water-soluble complex with redox function, which can play a role as a vitamin or bioactive substance. When the body lacks PQQ, a series of problems such as growth disorders, immune dysfunction, decreased reproductive capacity, and reduced respiratory entropy may occur. The human intestinal flora cannot synthesize PQQ or the amount of PQQ synthesized is far from meeting the needs of the body, and the PQQ in the body is mainly obtained exogenously through the dietary route. Supplementing PQQ has potential health benefits, such as improving metabolic flexibility, immunity, neuroprotection, and relieving inflammation.

[0009] Oat β-glucan is mainly distributed in the cell walls of aleuron, sub-aleuron and endosperm tissue, and is composed of pyranose glucose units connected by β-(1→3) and β-(1→4) glycosidic bonds. Oat β-glucan can bind to the surface receptors of immune cells, activate and regulate humoral immunity and cellular immunity. Oat β-glucan can regulate the activity of macrophages, T lymphocytes and the complement system, and regulate natural immune response and enhance adaptability by stimulating the activity of T lymphocytes.

[0010] The immune-enhancing composition can resist infection, reduce inflammation, enhance immune cell activity, and enhance the body's resistance to disease under the combined action of lactoferrin, N-acetylneuraminic acid, PQQ, oat β-glucan and taurine. The five components work together in multiple directions to achieve the effect of synergistically enhancing the body's immune function, thereby achieving excellent immune-enhancing efficacy. The absence of any one of the above five components will significantly weaken the immune-enhancing effect.

[0011] In an embodiment, the immune-enhancing composition includes the following components by weight: lactoferrin 3.5-5 parts, N-acetylneuraminic acid 3.5-5 parts, pyrroloquinoline quinone disodium salt 0.32-0.42 parts, oat β-glucan 70-85 parts, and taurine 3.5-5 parts. In another embodiment, the immune-enhancing composition includes the following components by weight: lactoferrin 3.5 parts, N-acetylneuraminic acid 3.5 parts, pyrroloquinoline quinone disodium salt 0.32 parts, oat β-glucan 70 parts, and taurine 3.5 parts.

[0012] When the immune-enhancing composition includes the following components by weight: lactoferrin 3.5-5 parts, N-acetylneuraminic acid 3.5-5 parts, pyrroloquinoline quinone disodium salt 0.32-0.42 parts, oat β-glucan 70-85 parts, and taurine 3.5-5 parts, the immune-enhancing effect is better. To reduce production costs, the immune-enhancing composition includes the following components by weight: lactoferrin 3.5 parts, N-acetylneuraminic acid 3.5 parts, pyrroloquinoline quinone disodium salt 0.32 parts, oat β-glucan 70 parts, and taurine 3.5 parts.

[0013] The present application provides a freeze-dried composition comprising the above-mentioned immune-enhancing composition. Freeze-drying, i.e. vacuum freeze-drying technology, reduces the moisture in the material by freezing the material below the freezing point, freezing the water in the material into small ice crystals, and sublimating the water from the solid to the gaseous state under vacuum conditions, thereby reducing the moisture in the material to obtain dry material. Freeze-drying can effectively protect heat-sensitive materials with less loss of nutritional ingredients, retain the original flavor of the material, and maintain the original form of the material, with good rehydration and easy dissolution.

[0014] The freeze-dried composition has excellent immune-enhancing effects due to the presence of the above-mentioned immune-enhancing composition. In one embodiment, the mass fraction of the immune-enhancing composition in the freeze-dried composition is more than 20%.

[0015] In one embodiment, the freeze-dried composition comprises at least one of freeze-dried milk blocks, freeze-dried powder, etc.

[0016] The present application also provides a freeze-dried milk block comprising the following components by weight: lactoferrin 1-7 parts, N-acetylneuraminic acid 1-7 parts, pyrroloquinoline quinone disodium salt 0.16-0.48 parts, oat beta-glucan 42-105 parts, taurine 1-7 parts, whey protein 20-50 parts, whole milk powder 30-60 parts, fruits 10-40 parts, pregelatinized starch 10-25 parts, fructose syrup 15-30 parts, soluble dietary fiber 10-30 parts, vitamin C 1-7 parts, acidity regulator 0.3-1.2 parts, coloring agent 1-20 parts, emulsifier 5-15 parts, thickening agent 0.1-3 parts, wherein the fruits comprise at least one of fruit particles and fruit extract.

[0017] The freeze-dried milk block, under the combined action of lactoferrin, N-acetylneuraminic acid, taurine, PQQ, oat beta-glucan, etc., can resist infection, reduce inflammation, enhance immune cell activity, and enhance the body's resistance to disease, with multiple synergistic effects to enhance the body's immune function. In addition, the freeze-dried milk block is sweet and tasty, with a crispy texture, good rehydration, and melts in the mouth. Moreover, it is prepared by freeze-drying technology, avoiding the inactivation of active substances such as lactoferrin (which gradually denatures and loses activity at 66-69°C under pH 6.6 conditions).

[0018] The freeze-dried milk block contains sugar and flavoring substances in the fruit, wherein the sugar can act as a binder to prevent the powder from being sprayed in the mouth; fructose syrup is both a sweetener and a binder to prevent the powder from being sprayed in the mouth; vitamin C mainly plays a color protection role; oat beta-glucan can also be used as a partial filler; soluble dietary fiber, which has no sweetness, is both a solid filler and a binder; whey protein is a filler; whole milk powder is a filler and provides oil; and an emulsifier is used to disperse the oil in the whole milk powder, facilitating demolding in the later stage.

[0019] The freeze-dried milk block has a mass fraction of fat controlled within a range of 4% to 12% by using the specific formula described above, so as to avoid the mass fraction of fat being too low to cause difficulty in demolding, a granular texture of the product, and the mass fraction of fat being too high to cause the formation of an oil layer that is too thick on the surface, the internal water not being easy to evaporate, the sample not being easy to freeze-dry, or a large air hole being formed on the surface to damage the integrity of the product, the internal collapse of the product, and the like, so that the obtained freeze-dried milk block is not easy to stick to the mold, has good formability, is not easy to powder, and has internal collapse and the like.

[0020] In an embodiment, the freeze-dried milk block comprises the following components by weight: lactoferrin 3.5-5 parts, N-acetylneuraminic acid 3.5-5 parts, pyrroloquinoline quinone disodium salt 0.32-0.42 parts, oat beta-glucan 70-85 parts, taurine 3.5-5 parts, whey protein 25-35 parts, whole milk powder 40-50 parts, fruit 20-30 parts, pre-gelatinized starch 12-20 parts, fructose syrup 20-26 parts, soluble dietary fiber 17-29 parts, vitamin C 2-5 parts, acidity regulator 0.5-0.8 parts, coloring agent 6-15 parts, emulsifier 7-13 parts, and thickening agent 0.2-0.8 parts, so as to obtain better immune-enhancing efficacy.

[0021] In an embodiment, the freeze-dried milk block comprises the following components by weight: lactoferrin 3.5 parts, N-acetylneuraminic acid 3.5 parts, pyrroloquinoline quinone disodium salt 0.32 parts, oat beta-glucan 70 parts, taurine 3.5 parts, whey protein 30 parts, whole milk powder 45 parts, fruit 25 parts, pre-gelatinized starch 16 parts, fructose syrup 24 parts, soluble dietary fiber 21 parts, vitamin C 3.5 parts, acidity regulator 0.6 parts, coloring agent 12 parts, emulsifier 9 parts, and thickening agent 0.6 parts, so as to obtain better immune-enhancing efficacy of the body at a lower production cost.

[0022] In an embodiment, at least one of the following conditions is met:

[0023] a) the acidity regulator comprises at least one of sodium citrate, potassium hydroxide, and potassium citrate;

[0024] b) the colorant comprises at least one of purple carrot juice, red beet powder, red yeast red;

[0025] c) the emulsifier comprises at least one of citric acid fatty acid glyceride, phospholipid, mono, di-glyceride fatty acid ester;

[0026] d) the thickening agent comprises at least one of xanthan gum, konjac powder;

[0027] e) the soluble dietary fiber comprises at least one of fructo-oligosaccharide, inulin, malto-oligosaccharide, resistant dextrin.

[0028] It should be noted that when the colorant is a liquid, the weight parts of the colorant are calculated based on the weight of the dry matter contained therein.

[0029] In an embodiment, the fruit extract is derived from at least one of fruit pulp, fruit concentrate, fruit ferment, etc.

[0030] The present application also provides a method for preparing the freeze-dried milk block, comprising the following steps:

[0031] The pregelatinized starch and the thickening agent are weighed according to the formula and mixed, added to purified water, and stirred until completely dissolved to obtain a first solution;

[0032] The N-acetylneuraminic acid is weighed according to the formula and added to purified water, and the pH value is adjusted to 4-4.5 by adding an acidity regulator to obtain a second solution;

[0033] The fructose syrup, fruit, vitamin C, and soluble dietary fiber are weighed according to the formula and added to the second solution, purified water is added, and the pH value is adjusted to 4.5-5.5 by adding an acidity regulator to obtain a third solution;

[0034] The emulsifier, pyrroloquinoline quinone disodium salt, and taurine are weighed according to the formula and added to the third solution, and stirred until dissolved to obtain a fourth solution;

[0035] The whole milk powder, whey protein, lactoferrin, and colorant are weighed according to the formula and added to the fourth solution, stirred, and then the first solution is added and stirred to obtain a fifth solution;

[0036] The oat beta-glucan is weighed according to the formula and added to the fifth solution, stirred, and homogenized with a colloid mill to obtain a sixth solution with a solid content of 23wt%-33wt%;

[0037] The sixth solution is poured into a mold and leveled off;

[0038] The mold containing the solution is pre-frozen to obtain a pre-frozen sample;

[0039] The pre-frozen sample is vacuum freeze-dried, and the highest temperature in the freeze-drying process is controlled to be not more than 60℃, to obtain freeze-dried milk blocks.

[0040] N-acetylneuraminic acid has strong acidity, and a 2wt% aqueous solution thereof has a pH value of 1.8-2.3 at room temperature. Adding it at a low temperature to a formula easily causes irreversible precipitation of casein in the material, and causes the solution to be stratified during the pre-freezing process of the mold. By controlling the addition amount of the casein-containing raw material and changing the addition order of the raw material, the precipitation of casein is avoided, and a stable solution system is ensured.

[0041] The sixth liquid solid content is controlled to be in the range of 23wt%-33wt%, so as to avoid too low solid content leading to collapse or too high solid content leading to easy pulverization, so that the taste is similar to that of dry milk powder.

[0042] In some embodiments, the weight of purified water used for preparing the first solution is 8 times the total weight of the pregelatinized starch and the thickening agent;

[0043] The weight of purified water used for preparing the second solution is 50 times the weight of N-acetylneuraminic acid.

[0044] In some embodiments, at least one of the following conditions is met:

[0045] 1) The temperature of the purified water used is 4-10℃;

[0046] 2) The processing before pre-freezing of the mold containing the solution is carried out in an environment of 4-10℃ (to control microorganisms in the environment);

[0047] 3) During preparation of the fifth solution, the whole milk powder, whey protein, lactoferrin and colorant are weighed according to the formula and added to the fourth solution, stirred at a speed of 20-40rpm / min for 10min, then the first solution is added, and the stirring is continued for 15min to obtain the fifth solution;

[0048] 4) The number of homogenization times of the colloidal mill is 2 times;

[0049] 5) The capacity of the mold is 2mL-5mL;

[0050] 6) The vacuum freeze-drying is carried out until the moisture content is not higher than 3.7wt%;

[0051] 7) The vacuum freeze-drying program is as follows: 25℃ for 1h, 24℃-55℃ for 2h, 55℃ for 4h, 50℃ for 5h, and 45℃ for 2h.

[0052] Compared with the prior art, the application has the following beneficial effects:

[0053] (1) The application fully develops the synergistic effect of lactoferrin, N-acetylneuraminic acid, PQQ, oat beta-glucan and taurine by reasonably compounding them, so that the obtained product has excellent immune-enhancing effect;

[0054] (2) The immune-enhancing composition has excellent immune-enhancing effect, and can be used to prepare freeze-dried food such as freeze-dried milk block and freeze-dried powder, endow the food with additional functions, and help to improve the added value and open up new markets. DETAILED DESCRIPTION

[0055] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific examples and comparative examples, the purpose of which is to understand the content of the present application in detail, rather than to limit the present application. All other examples obtained by those skilled in the art without creative labor fall within the protection scope of the present application. The experimental reagents and instruments involved in the implementation of the present application are common reagents and instruments unless otherwise specified.

[0056] Examples 1-6 and Comparative Examples 1-5

[0057] Both provide a freeze-dried composition, the composition of the raw materials for preparing the freeze-dried composition is shown in Table 1, and the preparation method comprises the following steps:

[0058] The pregelatinized starch and thickening agent are weighed according to the formula and mixed, and then added to purified water (7℃) with a weight of 8 times the total weight of the two, stirred until completely dissolved, to obtain a first solution;

[0059] N-acetylneuraminic acid is weighed according to the formula and added to purified water (7℃) with a weight of 50 times, and then an acidity regulator is added to adjust the pH value to 4-4.5 to obtain a second solution;

[0060] Fruit glucose syrup, fruit concentrate juice and vitamin C are weighed according to the formula and added to the second solution, the remaining purified water is added, and then an acidity regulator is added to adjust the pH value to 4.5-5.5 to obtain a third solution;

[0061] The emulsifier, pyrroloquinoline quinone disodium salt and taurine are weighed according to the formula and added to the third solution, and stirred until dissolved to obtain a fourth solution;

[0062] The whole milk powder, whey protein, lactoferrin and colorant are weighed according to the formula and added to the fourth solution, and stirred at 30 rpm / min for 10 min, then the first solution is added, and the stirring is continued for 15 min to obtain a fifth solution;

[0063] The oat beta-glucan is weighed according to the formula and added to the fifth solution, and stirred and homogenized twice with a colloid mill to obtain a sixth solution;

[0064] The above operations are all carried out in a 5℃ environment.

[0065] The sixth solution is pre-frozen to obtain a pre-frozen sample.

[0066] The pre-frozen sample is vacuum freeze-dried to obtain a freeze-dried product with a moisture content of not higher than 3.7wt%, wherein the vacuum freeze-drying procedure is as follows: 25℃ for 1h, 24℃-55℃ for 2h, 55℃ for 4h, 50℃ for 5h, and 45℃ for 2h.

[0067] The solid content in the concentrated fruit juice is 50wt%.

[0068] The same raw materials are used in each example, i.e., the same product of the same specification and model from the same manufacturer.

[0069] Table 1 Raw material formulation (weight parts) of the freeze-dried compositions of Examples 1-6 and Comparative Examples 1-5

[0070]

[0071]

[0072]

[0073] The freeze-dried milk blocks obtained in each example and comparative example are subjected to efficacy evaluation, and the specific method is as follows.

[0074] Test method: According to the evaluation method of the immunity enhancement function in the Health Food Function Evaluation Procedure and Test Method issued by the Ministry of Health, the delayed-type hypersensitivity (DTH) of mice induced by dinitrofluorobenzene (DNFB) is used to evaluate the cellular immune function, the serum hemolysin determination-half hemolysis value (HC 50 ) is used to evaluate the humoral immune function, and the mouse peritoneal macrophage phagocytosis of chicken red blood cells is used to evaluate the monocyte-macrophage function. By comparing whether the test group and the control group have significant difference (P<0.05), it is determined whether the test result is positive, so as to screen the best composition.

[0075] Experimental animals: SPF grade CI / F1 healthy female mice with a body weight of 18-22g, provided by Hunan Slike Jingda Experimental Animal Co., Ltd., with the experimental animal production license number: SCXK(Xiang)2019-0004. The animals are adaptively fed in the animal room environment for 5 days before the experiment, with an environmental temperature of 20-25℃ and a relative humidity of 40-70%.

[0076] Sample and dosage: The test substance was the lyophilized composition prepared in Examples 1-6 and Comparative Examples 1-5. The recommended human dosage was 4 g / person / day (based on a body weight of 60 kg), and the animal experimental dosage was 0.67 g / kg-bw / d (10 times the recommended human dosage). A control group was set up in which the test substance was replaced by 0 g / kg-bw / d of sterile water. The test substance was prepared in sterile water to a concentration of 67 mg / mL, and the corresponding dosage of the test substance was orally administered to mice once a day. The gavage volume for mice was 0.1 mL / 10 g-bw. Each test group consisted of 10 mice, and the immune function indicators were determined after 30 days of continuous gavage.

[0077] (1) Delayed-type hypersensitivity (DTH) in mice induced by dinitrofluorobenzene (DNFB) - ear swelling method

[0078] After the animals in each experimental group were continuously gavaged for one month, the abdominal fur was shaved with a shaver to a range of about 3 cm x 3 cm, and 10 mg / mL DNFB (50 μL of solution was uniformly applied) was used for sensitization. Five days later, 10 μL of 10 mg / mL DNFB solution was uniformly applied to the right ear (both sides) of the mice for challenge. The mice were sacrificed by cervical dislocation 24 h after the challenge, and the left and right ear shells were cut off. The ear pieces with a diameter of 8 mm were removed with a puncher, and the weight was measured.

[0079] Ear weight difference (mg) = right ear weight (mg) - left ear weight (mg)

[0080] The degree of DTH was represented by the difference between the weights of the left and right ears. If the weight difference in the test sample group was significantly higher than that in the control group, the test result was determined to be positive.

[0081] After the mice were orally administered different test samples for one month, the DNFB-induced DTH test in mice was performed by the ear swelling method, the ear shell weight gain was calculated, and the homogeneity of variance was tested. The results were statistically processed by the method of pairwise comparison of means between multiple test groups and one control group in the single-factor variance analysis method, and the results are shown in Table 2. As can be seen from the results in Table 2, the ear shell weight gain in each group of examples was higher than that in the control group, and the difference was statistically significant (P<0.05), indicating that each group of examples had a cell immune enhancing effect. The ear shell weight gain in each group of comparative examples was also higher than that in the control group, and only comparative example 5 had a statistically significant difference (P<0.05), and the others did not have a statistically significant difference. Compared with other examples, the ear shell weight gain in examples 3 and 6 was more.

[0082] Table 2 Effect of test samples on DNFB-induced DTH in mice

[0083] Group Number of animals Dose (g / kg·bw / d) Ear shell weight gain (mg) Control group 10 - 9.88±1.4 Example 1 10 0.67 11.5 ± 1.9 ** ]] Example 2 10 0.67 11.6 ± 1.6 ** <!-- 7 -->]]> Example 3 10 0.67 12.3 ± 2.0 ** ]] Example 4 10 0.67 11.8 ± 1.7 ** ]] Example 5 10 0.67 11.7 ± 1.6 ** ]] Example 6 10 0.67 12.6 ± 1.7 ** ]] Comparative Example 1 10 0.67 11.2±1.8 Comparative Example 2 10 0.67 10.8±2.0 Comparative Example 3 10 0.67 11.0±2.2 Comparative Example 4 10 0.67 10.9±2.1 Comparative Example 5 10 0.67 11.4 ± 2.0 * ]]

[0084] Note: compared with the control group, * P<0.05,** P<0.01

[0085] (2) Serum hemolysin assay - half hemolysis value (HC 50 )

[0086] After the animals in the test sample group were continuously gavaged for one month, a 2% (v / v) suspension of sheep red blood cells (SRBC) was prepared and each mouse was injected intraperitoneally with 0.2 mL. Four days later, blood was collected from the orbital plexus of the mice into centrifuge tubes, which were left to stand for 1 h, and then centrifuged at 2000 r / min for 10 min. The serum was separated and collected. After the serum was diluted 200 times, the optical density value at the half hemolysis of the sample tube and the SRBC was determined according to the test method. The amount of hemolysin was expressed as the half hemolysis value (HC 50 ).

[0087]

[0088] The amount of hemolysin was expressed as the half hemolysis value (HC 50 ), and the HC 50 of the test sample group was significantly higher than the HC 50 of the control group, indicating that the test result was positive.

[0089] After the test sample was orally administered for one month, the half hemolysis value (HC50) of the serum of the mice was determined by the half hemolysis value method, and homogeneity of variance test was performed. After the homogeneity of variance requirement was met, statistical processing was performed by the method of pairwise comparison of means between multiple test groups and one control group in the single factor analysis of variance. The results are shown in Table 3. As can be seen from the results in Table 3, the HC 50 of each group of examples was higher than that of the control group, and the difference was statistically significant (P<0.05), indicating that each group of examples had the effect of enhancing humoral immunity; the HC 50 of each group of the comparative examples was also higher than that of the control group, but the difference was not statistically significant; compared with other examples, the HC 50 of Example 3 and Example 6 was higher.

[0090] Table 3 Effect of test sample on HC 50 of mice

[0091] Group Number of animals Dose (g / kg·bw / d) HC 50 ]]> Control group 10 - 77±11.4 Example 1 10 0.67 91 ± 16.6 ** ]] Example 2 10 0.67 92 ± 15.6 ** ]] Example 3 10 0.67 95 ± 15.7 ** ]] Example 4 10 0.67 93 ± 16.9 ** ]] Example 5 10 0.67 93 ± 14.9 ** ]] Example 6 10 0.67 99 ± 15.2 ** ]] Comparative Example 1 10 0.67 86±16.1 Comparative Example 2 10 0.67 90±17.7 Comparative Example 3 10 0.67 86±16.3 Comparative Example 4 10 0.67 88.1±15.6 Comparative Example 5 10 0.67 87±16.4

[0092] Note: compared with the control group, * P<0.05, ** P<0.01

[0093] (3) Mouse peritoneal macrophage phagocytosis of chicken red blood cell experiment - drop method

[0094] Activation of mouse macrophage: 4 days before the experiment, each mouse was injected intraperitoneally with 0.2 mL of 2% packed sheep blood red cells. The mice were killed by cervical dislocation, and 4 mL of Hank's solution with calf serum was injected intraperitoneally per mouse, and the abdomen was gently massaged 20 times to wash out the peritoneal macrophages. Then, the abdominal wall was cut open, and 2 mL of peritoneal washing solution was sucked into a test tube (or using a syringe). 0.5 mL of the peritoneal washing solution was sucked into a 1 mL pipette and added to a test tube containing 0.5 mL of a 1% chicken red blood cell suspension, and mixed well. 0.5 mL of the mixed solution was sucked into a syringe (with a large needle) and added to the agar ring on the slide. Incubate in an incubator at 37°C for 15-20 minutes. After incubation, the unattached cells were quickly washed away with normal saline, fixed in methanol for 1 minute, and stained with Giemsa solution for 15 minutes. Rinse with distilled water, dry, and count the phagocytic rate and phagocytic index under a 40x microscope. The phagocytic rate is the percentage of macrophages that phagocytose chicken red blood cells per 100 macrophages, and the phagocytic index is the average number of chicken red blood cells phagocytosed per macrophage.

[0095]

[0096]

[0097] The phagocytic percentage or phagocytic index of the test sample group was significantly different from that of the control group, and the experimental results were determined to be positive.

[0098] After oral administration of the test sample for one month, the mouse peritoneal macrophage chicken red blood cell phagocytosis experiment was performed using the drop method, the phagocytic index and phagocytic percentage were calculated, and the phagocytic percentage was converted to sin -1 p 1 / 2 (P is the phagocytic percentage, expressed as a decimal) was converted and subjected to homogeneity of variance test. The phagocytic percentage and phagocytic index met the requirements of homogeneity of variance, and were statistically processed using the pairwise comparison method of single factor variance analysis for the mean of multiple test groups and one control group. The results are shown in Table 4. As can be seen from the results in Table 4, the phagocytic percentage and phagocytic index of the mouse peritoneal macrophages of each group of examples were higher than those of the control group, and the difference was statistically significant (P<0.05), indicating that each group of examples enhanced the phagocytosis of mononuclear macrophages; the phagocytic percentage and phagocytic index of each group of comparative examples were also higher than those of the control group, but the difference was not statistically significant; compared with other examples, the phagocytic percentage and phagocytic index of examples 3 and 6 were higher.

[0099] Table 4 Effect of test sample on phagocytic percentage and phagocytic index of mouse peritoneal macrophages phagocytizing chicken red blood cells

[0100] Group Number of animals Dose (g / kg·bw / d) Phagocytosis percentage (%) Phagocytosis index Control group 10 - 22.5±2.2 0.30±0.038 Example 1 10 0.67 25.2 ± 2.8 ** ]] 0.35 ± 0.047 ** ]] Example 2 10 0.67 25.0 ± 2.7 ** ]] 0.34 ± 0.033 ** ]] Example 3 10 0.67 25.6 ± 2.6 ** ]] 0.36 ± 0.048 ** ]] Example 4 10 0.67 24.8 ± 2.4 ** ]] 0.34 ± 0.037 ** ]] Example 5 10 0.67 25.3 ± 2.7 ** ]] 0.35 ± 0.043 ** ]] Example 6 10 0.67 27.0 ± 3.1 ** ]] 0.37 ± 0.045 ** ]] Comparative Example 1 10 0.67 24.7±4.2 0.33±0.047 Comparative Example 2 10 0.67 24.2±3.5 0.32±0.038 Comparative Example 3 10 0.67 24.8 ± 3.1 * ]] 0.34±0.052 Comparative Example 4 10 0.67 24.4±2.8 0.33±0.051 Comparative Example 5 10 0.67 24.0±3.2 0.32±0.043

[0101] Note: compared with the control group, * P < 0.05, ** P < 0.01

[0102] The test was carried out by orally administering the test substances prepared by different methods to mice at 10 times the recommended human dose for one month, and the cell immune function, humoral immune function, and monocyte-macrophage function were determined. The results showed that the weight gain of each group of examples was higher than that of the control group, the serum hemolysis value (HC 50 ) was higher than that of the control group, and the phagocytosis percentage and phagocytosis index of mouse peritoneal macrophages were higher than those of the control group, and the differences were statistically significant (P < 0.05). According to the requirements of the Technical Specifications for Health Food Inspection and Evaluation, each example group has the function of enhancing immunity; compared with the control group, the differences in each test of the comparative examples were not statistically significant. It can be seen that the lactoferrin in the freeze-dried milk block cannot be replaced by whey protein similar to it, and oat β-glucan cannot be replaced by polydextrose similar to it. In addition, lactoferrin, N-acetylneuraminic acid, taurine, PQQ, and oat β-glucan are indispensable, otherwise the enhanced immunity will decrease. The test results of example 3 and example 6 are better than those of other examples. Although the test results of example 6 are better than those of example 3, the raw material cost of example 6 is higher than that of example 3, and therefore the preferred product is example 3.

[0103] Examples 7-12

[0104] Each provides a freeze-dried milk block. The composition of the preparation raw materials of these freeze-dried milk blocks is shown in Table 5, and the preparation method comprises the following steps:

[0105] The pregelatinized starch and thickening agent are weighed according to the formula and mixed, and then added to purified water (7℃) with a weight of 8 times the total weight of the two, stirred until completely dissolved, to obtain a first solution;

[0106] N-acetylneuraminic acid is weighed according to the formula and added to purified water (7℃) with a weight of 50 times, and then an acidity regulator is added to adjust the pH value to 4-4.5 to obtain a second solution;

[0107] Fruit glucose syrup, fruit concentrate juice, and vitamin C are weighed according to the formula and added to the second solution, the remaining purified water is added, and then an acidity regulator is added to adjust the pH value to 4.5-5.5 to obtain a third solution;

[0108] The emulsifier, pyrroloquinoline quinone disodium salt, and taurine are weighed according to the formula and added to the third solution, and stirred until dissolved to obtain a fourth solution;

[0109] The full-fat milk powder, whey protein, lactoferrin and colorant are weighed according to the formula and added to the fourth solution, which is stirred at 30 rpm / min for 10 min, and then the first solution is added and stirring is continued for 15 min to obtain a fifth solution;

[0110] The oat beta-glucan is weighed according to the formula and added to the fifth solution, which is stirred and homogenized twice with a colloid mill to obtain a sixth solution with a solid content of 23wt%-33wt%;

[0111] The sixth solution is poured into a mold with a capacity of 3 mL and is scraped flat;

[0112] The above operations are all carried out in an environment of 5°C;

[0113] The solution-containing mold is pre-frozen to obtain a pre-frozen sample;

[0114] The pre-frozen sample is vacuum freeze-dried to obtain a freeze-dried milk block with a moisture content of not more than 3.7wt%, wherein the vacuum freeze-drying program is as follows: 25°C for 1h, 24°C-55°C for 2h, 55°C for 4h, 50°C for 5h, and 45°C for 2h.

[0115] The solid content in the above concentrated fruit juice is 50wt%.

[0116] Table 2 Raw material formula (weight parts) of the freeze-dried milk block in Examples 7-12

[0117]

[0118] In the preparation process of the freeze-dried milk block in Examples 7-12, the obtained solutions are not prone to stratification, the fat mass fraction in the obtained freeze-dried milk block is in the range of 4%-12%, the freeze-dried milk block is easy to be demoulded, has good formability, is sweet and sour, has a crisp taste, has good rehydration, and melts in the mouth.

[0119] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A freeze-dried milk block, characterized in that, It is made from the following components in parts by weight: 1-7 parts lactoferrin, 1-7 parts N-acetylneuraminic acid, 0.16-0.48 parts disodium pyrroloquinoline quinone, 42-105 parts oat β-glucan, 1-7 parts taurine, 20-50 parts whey protein, 30-60 parts whole milk powder, 10-40 parts fruit, 10-25 parts pregelatinized starch, 15-30 parts fructose syrup, 10-30 parts soluble dietary fiber, 1-7 parts vitamin C, 0.3-1.2 parts acidity regulator, 1-20 parts colorant, 5-15 parts emulsifier, 0.1-3 parts thickener, with the balance being water. The fruit is at least one of fruit granules or fruit extract; the fat content in the freeze-dried milk block is 4%-12% by mass.

2. The freeze-dried milk block as described in claim 1, characterized in that, It is made from the following components in parts by weight: lactoferrin 3.5-5 parts, N-acetylneuraminic acid 3.5-5 parts, disodium pyrroloquinoline quinone 0.32-0.42 parts, oat β-glucan 70-85 parts, taurine 3.5-5 parts, whey protein 25-35 parts, whole milk powder 40-50 parts, fruit 20-30 parts, pregelatinized starch 12-20 parts, fructose syrup 20-26 parts, soluble dietary fiber 17-29 parts, vitamin C 2-5 parts, acidity regulator 0.5-0.8 parts, colorant 6-15 parts, emulsifier 7-13 parts, thickener 0.2-0.8 parts, with the balance being water.

3. The freeze-dried milk block as described in claim 2, characterized in that, It is made from the following components in parts by weight: 3.5 parts lactoferrin, 3.5 parts N-acetylneuraminic acid, 0.32 parts disodium pyrroloquinoline quinone, 70 parts oat β-glucan, 3.5 parts taurine, 30 parts whey protein, 45 parts whole milk powder, 25 parts fruit, 16 parts pregelatinized starch, 24 parts fructose syrup, 21 parts soluble dietary fiber, 3.5 parts vitamin C, 0.6 parts acidity regulator, 12 parts colorant, 9 parts emulsifier, 0.6 parts thickener, and the balance being water.

4. The freeze-dried milk curd as described in any one of claims 1 to 3, characterized in that, At least one of the following conditions must be met: a) The acidity regulator includes at least one of sodium citrate, potassium hydroxide, potassium citrate, and citric acid; b) The colorant includes at least one of purple carrot juice, red beet powder, tomato red, and red yeast rice; c) The emulsifier includes at least one of citrate fatty acid glycerides, phospholipids, and mono- and diglycerides of fatty acids; d) The thickener includes at least one of xanthan gum and konjac flour; e) The soluble dietary fiber includes at least one of fructooligosaccharides, inulin, maltodextrin, and resistant dextrin.

5. A method for preparing freeze-dried milk blocks as described in any one of claims 1-4, characterized in that, Includes the following steps: Weigh out the pregelatinized starch and thickener according to the formula, mix them, add them to purified water, and stir until completely dissolved to obtain the first solution; Weigh out N-acetylneuraminic acid according to the formula, add it to purified water, and then add an acidity regulator to adjust the pH value to 4-4.5 to obtain the second solution; Weigh out the fructose syrup, fruit, vitamin C, and soluble dietary fiber according to the formula and add them to the second solution. Add purified water and then add an acidity regulator to adjust the pH value to 4.5-5.5 to obtain the third solution. Weigh out the emulsifier, disodium pyrroloquinoline quinone, and taurine according to the formula, add them to the third solution, and stir until dissolved to obtain the fourth solution; Weigh out whole milk powder, whey protein, lactoferrin, and colorant according to the formula, add them to the fourth solution, stir, then add the first solution, stir, and obtain the fifth solution; Weigh out oat β-glucan according to the formula and add it to the fifth solution. Stir and homogenize with a colloid mill to obtain a sixth solution with a solid content between 23wt% and 33wt%. The sixth solution is poured into the mold and leveled. The mold containing the solution was pre-frozen to obtain the pre-frozen sample; The pre-frozen sample was subjected to vacuum freeze-drying, with the maximum temperature controlled not to exceed 60°C during the freeze-drying process, to obtain freeze-dried milk blocks.

Images