Preparation method and application of high-bioavailability calcium ostreate powder

Abstract

A preparation method of high-bioavailability calcium ostreate powder is characterized in that efficient preparation of calcium ostreate powder is realized through scientific and reasonable treatment steps including cleaning, high-temperature calcination, crushing, acid mixing, filtering, drying and the like, the bioavailability of the calcium ostreate powder is remarkably improved, and the preparation method specifically comprises the following steps: a, cleaning and drying; b, calcining; c, crushing and sieving; d, acid mixing; e, performing biological activity treatment; and f, drying. The preparation method is simple, scientific and reasonable, the raw materials are rich and easy to obtain, the calcium ostrelate is prepared more efficiently, the bioavailability of the calcium ostrelate is remarkably improved by 50% or above, and the calcium ostrelate has unique advantages in application in the field of bone health, is a great innovation in improving the bone health level of the human body, and has wide application prospects. And the method has obvious social and economic benefits.

Description

Technical Field

[0001] The present invention relates to the field of article preparation, in particular to a preparation method and application of calcium oysterate powder with high bioavailability, which can be applied to the preparation of food, health food, medicine or other medical products beneficial to bone health. Background Art

[0002] Bone health has always been a topic of considerable concern in the field of human health management. Maintaining good bone density and structure is crucial for preventing osteoporosis, fractures, and other bone-related diseases. To meet the growing demand for human bone health, research and development of highly bioavailable calcium supplements is crucial. Oysters, the shells of the long oyster Ostrea gigas Thunberg, the Dalian Bay oyster Ostrea talienwhanensis Crosse, or the Omi oyster Ostrea rivularis Gould, all members of the family Ostreae, are produced annually in the millions of tons. As a dual-use medicinal and edible Chinese herbal medicine, they possess properties such as calming the nerves, nourishing yang and replenishing yin, and softening and dispersing nodules. Furthermore, oysters contain over 94.0% calcium carbonate (CaCO3), making them a renewable, natural calcium source. Oysters contain amino acids and numerous essential trace elements, are renewable and inexpensive, making them an ideal nutrient supplement. However, they are not currently used as a raw material for calcium supplements, limiting their application in the field of bone health. Current bone density supplements on the market suffer from complex preparation and low bioavailability, making them difficult to meet consumer demand for effective bone health products. The preparation of highly bioavailable oyster calcium faces numerous challenges, including ensuring the stability of the bioactive components in the oyster shell, the complexity of the preparation process, and improving absorption rates. Therefore, finding a new, efficient preparation method that overcomes the shortcomings of traditional methods has become a key technical issue in current research. Summary of the Invention

[0003] In view of the above situation, in order to overcome the defects of the existing technology, the purpose of the present invention is to provide a preparation method of calcium oysterate powder with high bioavailability and its application, which can effectively solve the problems of complex preparation, low bioavailability and difficulty in meeting the needs of existing products in the field of bone health.

[0004] To achieve the above objectives, the technical solution provided by the present invention is a method for preparing calcium oysterate powder with high bioavailability. The method achieves efficient preparation of calcium oysterate powder and significantly improves its bioavailability through scientific and reasonable processing steps, including cleaning, high-temperature calcination, crushing, acid mixing, filtration, and drying. The method specifically comprises the following steps:

[0005] a. Cleaning and drying: clean and dry the oyster shells for later use;

[0006] b. Calcination: The cleaned oyster shells were calcined at 550-650°C in a gradient manner, firstly heating to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then heating to the target temperature at a linear heating rate of 3°C / min and holding for 1-2 h, and then naturally cooling the oyster shells to room temperature;

[0007] c. Crushing and sieving: crush the calcined oyster shells and pass them through a 120-mesh sieve, then use an ultra-fine airflow grinder to grind them to D 90 ≤50μm, calcined oyster powder is obtained;

[0008] d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add food-grade acid dropwise at a rate of 0.5 ml / min at 40-60°C under strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:5-10, and the weight ratio of calcined oyster powder to food-grade acid is 1:1-2.2.

[0009] e. Bioactive treatment: add 0.001-0.03% of vitamin D3 and 0.05-0.1% of collagen peptide to the filtrate by weight, stir evenly, and obtain a mixed solution;

[0010] f. Drying: Dry the mixed solution to a powdery state to obtain calcium oysterate powder, which has a bioavailability increased by more than 50%.

[0011] Furthermore, the specific parameters of the gradient calcination in step b are: first heating to 300°C at a linear heating rate of 5°C / min and holding for 30 minutes, then heating to 600°C at a linear heating rate of 3°C / min and holding for 1.5 hours.

[0012] The drying method in step f is spray drying, maintaining the air inlet temperature at 155-165°C and the air outlet temperature at 60-70°C; or placing the mixed liquid in an oven and directly drying it at 60-70°C; or adopting a reduced pressure concentration drying method, drying it at 40-60°C and -0.08 to -0.1 MPa.

[0013] The operating parameters of the ultrafine airflow pulverizer in step c are: airflow pressure 0.8-1.2 MPa, pulverization temperature ≤ 40°C.

[0014] The food-grade organic acid in step d is one of lactic acid, malic acid, citric acid or tartaric acid, or a mixture of multiple acids in any proportion.

[0015] In the step e, the added amount of vitamin D3 is 0.001%-0.002%, and the added amount of collagen peptide is 0.06%-0.08%.

[0016] The particle size of the calcium oysterate powder is D 90 <50μm.

[0017] The calcium oysterate powder prepared by the method is used in the preparation of common foods, health foods, medicines, or other medical products for enhancing bone health. The health foods or medicines also contain vitamin D3 and collagen peptides to synergistically enhance calcium absorption and utilization. This can effectively increase bone density, prevent the occurrence of bone diseases, and assist in the treatment of bone-related disorders.

[0018] The medicine is a medically accepted tablet, capsule, granule, powder, oral liquid or film.

[0019] The preparation method of the present invention is simple, scientific and reasonable, and the raw materials are abundant and easily available, which makes the preparation of calcium oysterate more efficient and significantly improves the bioavailability of calcium oysterate. It has unique advantages in the application of the field of bone health, is a major innovation in improving the level of human bone health, and has significant social and economic benefits. DETAILED DESCRIPTION

[0020] The specific implementation methods of the present invention are described in detail below with reference to the examples.

[0021] The present invention is specifically implemented by the following examples.

[0022] Example 1

[0023] A method for preparing calcium oysterate powder with high bioavailability comprises the following steps:

[0024] a. Cleaning and drying: clean and dry the oyster shells for later use;

[0025] b. Calcination: The cleaned oyster shells were calcined at 550°C in a gradient process, firstly increasing the temperature to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then increasing the temperature to 550°C at a linear heating rate of 3°C / min and holding for 2 h, and then naturally cooling the oyster shells to room temperature;

[0026] c. Crushing and sieving: crush the calcined oyster shells and pass them through a 120-mesh sieve, then use an ultra-fine airflow grinder to grind them to D 90 ≤50μm, calcined oyster powder is obtained;

[0027] d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add acetic acid dropwise at a rate of 0.5 ml / min at 40°C with strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:5, and the weight ratio of calcined oyster powder to acetic acid is 1:1.

[0028] e. Bioactive treatment: add 0.001% vitamin D3 and 0.06% collagen peptide to the filtrate by weight, stir evenly, and obtain a mixed solution;

[0029] f. Drying: Place the mixed solution in an oven and dry it directly at 65°C until it becomes a powder to obtain calcium oysterate powder.

[0030] Example 2

[0031] A method for preparing calcium oysterate powder with high bioavailability comprises the following steps:

[0032] a. Cleaning and drying: clean and dry the oyster shells for later use;

[0033] b. Calcination: The cleaned oyster shells were calcined at 600°C in a gradient manner, firstly by increasing the temperature to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then increasing the temperature to 600°C at a linear heating rate of 3°C / min and holding for 1.5 h, and then naturally cooling the oyster shells to room temperature;

[0034] c. Grinding and sieving: Grind the calcined oyster shells and pass them through a 120-mesh sieve, then grind them using an ultra-fine airflow mill until D90 is ≤ 50 μm to obtain calcined oyster powder;

[0035] d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add lactic acid dropwise at a rate of 0.5 ml / min at 60°C under strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:5, and the weight ratio of calcined oyster powder to lactic acid is 1:2.2.

[0036] e. Bioactive treatment: add 0.002% of vitamin D3 and 0.08% of collagen peptide by weight of the filtrate to the filtrate, stir evenly, and obtain a mixed solution;

[0037] f. Drying: spray the mixed solution to dryness, maintaining the air inlet temperature at 165°C and the air outlet temperature at 70°C to obtain calcium oysterate powder.

[0038] Example 3

[0039] A method for preparing calcium oysterate powder with high bioavailability comprises the following steps:

[0040] a. Cleaning and drying: clean and dry the oyster shells for later use;

[0041] b. Calcination: The cleaned oyster shells were calcined at 650°C in a gradient process, firstly increasing the temperature to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then increasing the temperature to 650°C at a linear heating rate of 3°C / min and holding for 1 h, and then naturally cooling the oyster shells to room temperature;

[0042] c. Grinding and sieving: Grind the calcined oyster shells and pass them through a 120-mesh sieve, then grind them using an ultra-fine airflow mill until D90 is ≤ 50 μm to obtain calcined oyster powder;

[0043] d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add malic acid dropwise at 50°C under strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:8, and the weight ratio of calcined oyster powder to malic acid is 1:1.6.

[0044] e. Bioactive treatment: add 0.001% vitamin D3 and 0.07% collagen peptide to the filtrate by weight, stir evenly, and obtain a mixed solution;

[0045] f. Drying: The mixed solution is dried at 50°C and -0.08 to -0.1 MPa by means of reduced pressure concentration and drying until it becomes powdery to obtain calcium oysterate powder.

[0046] Example 4

[0047] A method for preparing calcium oysterate powder with high bioavailability comprises the following steps:

[0048] a. Cleaning and drying: clean and dry the oyster shells for later use;

[0049] b. Calcination: The cleaned oyster shells were calcined at 630°C in a gradient manner, firstly by increasing the temperature to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then increasing the temperature to 630°C at a linear heating rate of 3°C / min and holding for 1 h, and then naturally cooling the oyster shells to room temperature;

[0050] c. Crushing and sieving: crush the calcined oyster shells and pass them through a 120-mesh sieve, then use an ultra-fine airflow grinder to grind them to D 90 ≤50μm, calcined oyster powder is obtained;

[0051] d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add tartaric acid dropwise at a rate of 0.5 ml / min at 55°C under strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:8, and the weight ratio of calcined oyster powder to tartaric acid is 1:1.8.

[0052] e. Bioactive treatment: add 0.01% vitamin D3 and 0.05% collagen peptide to the filtrate by weight, stir evenly, and obtain a mixed solution;

[0053] f. Drying: spray the mixed solution to dryness, maintaining the air inlet temperature at 165°C and the air outlet temperature at 75°C to obtain calcium oysterate powder.

[0054] Example 5

[0055] A method for preparing calcium oysterate powder with high bioavailability comprises the following steps:

[0056] a. Cleaning and drying: clean and dry the oyster shells for later use;

[0057] b. Calcination: The cleaned oyster shells were calcined at 580°C in a gradient process, firstly increasing the temperature to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then increasing the temperature to 580°C at a linear heating rate of 3°C / min and holding for 2 h, and then naturally cooling the oyster shells to room temperature;

[0058] c. Crushing and sieving: crush the calcined oyster shells and pass them through a 120-mesh sieve, then use an ultra-fine airflow grinder to grind them to D 90 ≤50μm, calcined oyster powder is obtained;

[0059] d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add citric acid dropwise at a rate of 0.5 ml / min at 45°C under strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:6, and the weight ratio of calcined oyster powder to citric acid is 1:1.4.

[0060] e. Bioactive treatment: add 0.03% vitamin D3 and 0.09% collagen peptide to the filtrate by weight, stir evenly, and obtain a mixed solution;

[0061] f. Drying: Place the mixed solution in an oven and dry it directly at 70°C until it becomes a powder to obtain calcium oysterate powder.

[0062] The present invention discloses a method for preparing calcium oysterate powder with high bioavailability. By using special treatment steps such as cleaning, high-temperature calcination, crushing, and acid mixing, the preparation of calcium oysterate is more efficient, the content of bioactive ingredients is increased, and the bioavailability of calcium oysterate is significantly improved. The results are very good. The relevant experimental data are as follows:

[0063] 1. Preparation of oyster calcium powder

[0064] Weigh an appropriate amount of raw oysters, wash and dry them, weigh 1000g and place them at 600℃ for gradient calcination. First, heat the temperature to 300℃ at a linear heating rate of 5℃ / min and hold for 30min, then heat the temperature to 600℃ at a linear heating rate of 3℃ / min and hold for 1.5h. Then, cool the oyster shells naturally to room temperature, crush the calcined oyster shells and pass them through a 120-mesh sieve, and then use an ultrafine airflow mill to crush them to D90 ≤50μm, thus obtaining calcined oyster powder. Weigh 500g of calcined oyster powder, add 2.5kg of water, stir for 10min, adjust the temperature, and when the reaction liquid temperature rises to 60°C, add 1.12kg of 80% lactic acid dropwise under vigorous stirring. After the lactic acid addition is complete, continue stirring for 30min after the bubbles disappear, then filter while hot. Add 0.002% vitamin D3 and 0.08% collagen peptide by weight of the filtrate to the filtrate, stir evenly, and obtain a mixed solution. Dry to obtain 785g of calcium oysterate powder.

[0065] 2. Process comparison experiment

[0066] 2.1 Comparative study on the processing of raw oysters, calcined oysters and calcined oysters:

[0067] Take three portions of oysters, each weighing 200g. The first portion remains unprocessed and is the raw oyster. The other two portions are calcined at 600°C in a gradient process. One portion is removed immediately after calcination and poured into a tray filled with cold water. After smoke ceases, the upper layer of water is poured out and the oyster is dried in a 105°C oven for 2 hours. The oyster is removed and allowed to cool to room temperature to obtain the calcined oyster. The other portion is cooled directly to room temperature after removal to obtain the calcined oyster. The three portions of oysters are crushed and passed through a 120-mesh sieve. The crushing and sieving yields are calculated for each portion, as shown in Table 1.

[0068] Table 1 Comparative investigation results of raw oyster, calcined oyster and calcined oyster

[0069] Serial number Sample name Calcination / calcination quenching rate / % Crushing and screening yield / % Difficulty of crushing and screening 1 Raw oysters / 86.09 difficult 2 Calcined oyster 96.42 89.56 generally 3 Calcined oysters 96.59 92.23 generally

[0070] From the above, it can be seen that calcining oysters does help to crush and screen, and can improve the screening yield; calcining and quenching oysters does not lead to a decrease in yield, and its screening yield is somewhat higher than that of unquenched calcined oysters. However, considering that adding process steps will lead to increased production costs and increase the risk of dissolution of trace substances in oysters, the oysters are chosen to be forged.

[0071] 2.2 Calcination temperature investigation experiment

[0072] Weigh 3 portions of cleaned oysters, 50g each, and calcine them at 550℃, 600℃, and 650℃ respectively.

[0073] After 1.5 hours, take out the oysters, let them cool and observe the calcination effect. The ones with "crisp texture, grayish white color and layered cross section" are the best. The results are shown in Table 2.

[0074] Table 2 Calcination temperature investigation results

[0075]

[0076] From the above, it can be seen that the calcination temperature has basically no effect on the yield of the calcination process, but when the calcination temperature is 550℃, the calcined oysters are slightly hard. In order to ensure that the oysters are fully calcined and easy to crush, the optimal calcination temperature is determined to be 600℃.

[0077] 2.3 Calcination time investigation experiment

[0078] Three portions of cleaned oysters were weighed, each 50 g, and calcined at 600 °C for 1.0 h, 1.5 h, and 2.0 h, respectively. After cooling, the calcined oysters were observed. The best ones were "crisp, off-white, and layered in cross section". The results are shown in Table 3.

[0079] Table 3 Calcination time investigation results

[0080]

[0081] From the above, it can be seen that under the same calcination temperature conditions, different calcination times have basically no effect on the yield of the calcination process. However, when the calcination temperature is 1 hour, the calcined oysters are slightly hard. In order to ensure that the oysters are fully calcined and save costs, the optimal calcination time is determined to be 1.5 hours.

[0082] 2.4 Experimental study on the ratio of calcined oyster powder and lactic acid

[0083] The reaction of calcined oyster powder with lactic acid to form calcium lactate is essentially a process in which one molecule of calcium carbonate reacts with two molecules of lactic acid to form one molecule of calcium lactate and release carbon dioxide. The molar ratios of calcium carbonate to lactic acid (calcium carbonate:lactic acid) were 1:1.6, 1:1.8, 1:2.0, and 1:2.2, respectively. Weigh 1.0 g of calcined oyster powder (calcined oyster powder contains 100% calcium carbonate, and each 1 g of oyster powder contains 0.01 mol of calcium carbonate), 4 parts, add 30 g of water to each, and stir evenly. Then, under strong stirring, add 1.80 g, 2.03 g, 2.25 g, and 2.48 g of 80% lactic acid in sequence (equivalent to 0.016 mol, 0.018 mol, 0.020 mol, and 0.022 mol of lactic acid, respectively. After the lactic acid is weighed, add 10 g of water to dilute them). After the lactic acid is added dropwise, continue stirring for 30 minutes and filter while hot. Wash the filter residue with 5 g of water. Concentrate the filtrate under reduced pressure at 40°C to near dryness, then dry it in a constant temperature drying oven at 80°C. Collect the dried product and weigh it. [The data listed in the table below are the weights of the products equivalent to anhydrous calcium lactate, the same below. After the product was dried, samples were taken to determine the loss on drying (refer to Appendix A.6 of GB 25555-2010) and the yields were calculated. The results are shown in Table 4.

[0084] Table 4 Investigation results of the feeding ratio of calcined oyster powder and lactic acid

[0085] Serial number Feed ratio 80% lactic acid / g Amount of water added / g Finished product appearance Product amount / g Yield / % 1 1:1.6 1.80 40 Light yellowish white granules 1.80 82.62 2 1:1.8 2.03 40 Light yellowish white granules 2.02 92.69 3 1:2.0 2.25 40 Light yellowish white granules 2.11 96.97 4 1:2.2 2.48 40 Light yellowish white granules 2.18 99.98

[0086] From the above, it can be seen that with the increase of lactic acid dosage, the yield of the product (measured in moles of calcium) gradually increases. However, considering that the cost of lactic acid raw materials is higher than that of oysters, and there is a risk of acidification of the product when the acid is excessive, the optimal molar ratio of oyster powder to lactic acid is determined to be 1:2.0.

[0087] 2.5 Experimental study on the mixing temperature of calcined oyster powder and acid and optimization of solvent dosage

[0088] Weigh 2.0g of calcined oyster powder into four portions, add a certain amount of water to each portion, and stir on a thermostatic magnetic stirrer at different temperatures for 10 minutes. Then, while vigorously stirring, add 4.5g of 80% lactic acid dropwise to each portion. After the bubbles disappear, continue stirring for 30 minutes. Stop stirring, filter under reduced pressure, and wash the residue with 5g of hot water. The filtrate is concentrated under reduced pressure at 40°C to near dryness and then dried in a thermostatic drying oven at 80°C. The dried product is collected, weighed, and the yield is calculated. The results are shown in Table 5.

[0089] Table 5 Investigation of oyster and acid mixing temperature and optimization of solvent dosage

[0090] Serial number Temperature / ℃ First water addition amount / g Secondary water addition amount / g Product amount / g Yield / % Experimental phenomenon 1 40 15.00 5.00 4.11 94.27 normal 2 60 15.00 5.00 4.14 94.95 normal 3 40 10.00 0 / / The reaction liquid gradually solidifies 4 60 10.00 0 4.06 93.12 normal

[0091] As shown above, at a temperature of 60°C, both material-liquid ratios of 1:10 and 1:5 reacted normally, with no significant change in yield. At a temperature of 40°C and a material-liquid ratio of 1:5, the reaction solution solidified, and the reaction terminated. To reduce the difficulty of solvent recovery and production costs, the proposed reaction conditions were a temperature of 60°C and a material-liquid ratio of 1:5.

[0092] 3. Nutrient composition and harmful element determination experiment of raw oyster, calcined oyster and calcined oyster calcium powder

[0093] Raw oysters, calcined oysters and calcined oysterate calcium powder were sent to a third-party testing agency (Puni Testing) to measure the contents of 14 trace elements (iron, copper, zinc, cobalt, manganese, chromium, selenium, iodine, nickel, fluorine, molybdenum, vanadium, tin, silicon) and pollutants (lead, total arsenic, total mercury, cadmium) and total amino acids. The results are shown in Table 6.

[0094] Table 6 Nutrient composition and harmful element determination results of raw oyster, calcined oyster and calcined oyster calcium powder

[0095]

[0096]

[0097] As can be seen above, calcined oysters contain higher levels of total calcium lactate than raw and calcined oysters, and are also higher in the nutrients iron, zinc, manganese, and selenium. Harmful element levels are low, falling below the limits set by current national food safety standards. Total amino acid analysis revealed a 0.031% content in raw oysters, while calcined and calcined oysters contained no detectable levels of total amino acids due to the destruction of amino acids by high temperatures. In summary, calcined oyster calcium lactate powder, due to its higher calcium and nutrient content, is more beneficial for increasing bone density, preventing bone diseases, and assisting in the treatment of bone-related conditions.

[0098] 4. Bioavailability Determination Experiment of Calcium Oysterate

[0099] 70 4-week-old SPF SD rats were adaptively fed for one week and then fasted for 12 hours and randomly divided into 7 groups according to body weight, with 10 rats in each group. All groups drank deionized water and were fed low-calcium feed (100 mg / 100 g) and were free to eat. The model group was gavaged with deionized water, and the other groups were gavaged with calcium solution (calculated based on the calcium dose, which was 133.3 mg / kg, equivalent to 10 times the recommended amount for an adult with 60 kg body weight. The samples were dried at 105°C for 2 hours before use, and the calcium lactate content in the oyster calcium powder was 86%). The gavage volume for rats was 7 mL / kg. The gavage process lasted for a total of 4 weeks. After the experiment, arterial blood was taken from the rats, allowed to stand at 4°C for 0.5 hours, and centrifuged at 10,000 r / min at 4°C to obtain the upper serum. The serum calcium content was determined using a biochemical automatic analyzer. The results are shown in Table 7 below:

[0100] Table 7 Various calcium bioavailability determination results

[0101] Sample name Blood calcium concentration (mmol / L) Model Group <![CDATA[1.717±0.029 a ]]> Oyster powder <![CDATA[2.012±0.031 b ]]> calcium carbonate <![CDATA[2.633±0.031 c ]]> Calcium oysterate powder <![CDATA[3.028±0.046 d ]]> calcium acetate <![CDATA[2.878±0.031 e ]]> calcium malate <![CDATA[2.737±0.033 f ]]> calcium tartrate <![CDATA[2.744±0.024 f ]]> calcium citrate <![CDATA[2.735±0.030 f ]]>

[0102] Note: The same superscript letters indicate no significant difference (P>0.05).

[0103] The results showed that supplementation with the above six calcium preparations could significantly increase the concentration of calcium in rat serum. The effect of organic calcium preparations was better than that of the calcium carbonate group. Among various organic calcium preparations, calcium acetate and calcium oysterate were better at increasing serum calcium concentration, among which calcium oysterate was the best (P < 0.05).

[0104] 5. Experimental study on the effect of calcium oysterate powder on bone density

[0105] Sixty four-week-old SPF Sprague-Dawley rats were fed adaptively for one week and then fasted for 12 hours. Afterward, they were randomly divided according to body weight into a blank control group, a model group, a calcium carbonate-positive group, and low-, medium-, and high-dose groups of calcium oysterate powder, with 10 rats in each group. All groups drank deionized water. Except for the blank control group, all other groups were fed a low-calcium diet (100 mg / 100 g). The rats were gavaged at a dose of 7 mL / kg. The low-, medium-, and high-dose groups of calcium oysterate powder were administered at doses of 66.7 mg / kg, 133.3 mg / kg, and 266.7 mg / kg, respectively (calculated based on calcium dose, equivalent to 5, 10, and 20 times the recommended adult dose per 60 kg body weight, respectively. The samples were dried at 105°C for 2 hours before use, and their calcium lactate content was calculated as 86%). The calcium content of the gavage fluid in the calcium carbonate-positive group was the same as that in the high-dose group. The gavage process lasted for a total of four weeks. After 4 weeks, rats were anesthetized with an intraperitoneal injection of 1% sodium pentobarbital (dose 40 mg / kg). The right femur of the rats was removed and the bone density of the distal femur was measured. The results are as follows:

[0106] Table 8 Effect of calcium oysterate on bone density

[0107]

[0108]

[0109] Note: Compared with the model group, ** indicates P < 0.01, * indicates P < 0.05; compared with the calcium carbonate group, △ indicates P < 0.05.

[0110] The results showed that the bone density of the distal end of the femur in all dose groups of calcium oysterate powder was significantly higher than that in the model group (P < 0.01), and its effect in increasing bone density was better than that of calcium carbonate (P < 0.05), suggesting that calcium oysterate powder can promote bone formation in rats.

[0111] VI. Conclusion

[0112] The present invention provides a method for preparing calcium oysterate powder with high bioavailability, which is simple, scientific and reasonable, and has abundant and easy-to-get raw materials. By scientific and reasonable processing steps, the bioavailability of calcium oysterate is significantly improved, thereby having unique advantages in the field of bone health. By processing steps such as cleaning, high-temperature calcination, crushing, and acid mixing, the preparation of calcium oysterate is made more efficient and the content of bioactive ingredients is increased. By adopting steps such as high-temperature calcination and crushing at specific temperatures and times, the maximum preservation of key components in calcium oysterate is ensured, and by mixing oyster powder with specific food-grade acid (such as lactic acid), the absorption of bioactive ingredients is effectively promoted, and the bioavailability of the product is improved, and the bioavailability is significantly higher than that of other calcium types. The present invention is not only applicable to ordinary foods, but also can be used for health products, medicines or other medical uses, and provides a flexible application solution for calcium oysterate with high bioavailability in different fields. The unique preparation method and multiple advantages of the present invention make the obtained products more adaptable to market demand, provide innovative technical solutions and new technical roads for improving human bone health, and have significant social and economic benefits.

[0113] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing calcium oysterate powder with high bioavailability, characterized in that: The following steps are involved: a. Cleaning and drying: clean and dry the oyster shells for later use; b. Calcination: The cleaned oyster shells were calcined at 550-650°C in a gradient manner, firstly heating to 300°C at a linear heating rate of 5°C / min and holding for 30 min, then heating to the target temperature at a linear heating rate of 3°C / min and holding for 1-2 h, and then naturally cooling the oyster shells to room temperature; c. Crushing and sieving: crush the calcined oyster shells and pass them through a 120-mesh sieve, then use an ultra-fine airflow grinder to grind them to D 90 ≤100μm, calcined oyster powder is obtained; d. Acid mixing: Add water to the crushed calcined oyster powder and stir for 10 minutes. Add food-grade acid dropwise at a rate of 0.5 ml / min at 40-60°C under strong stirring. Continue stirring for 30 minutes after the bubbles disappear, and then filter while hot. The weight ratio of calcined oyster powder to water is 1:5-10, and the weight ratio of calcined oyster powder to food-grade acid is 1:1-2.

2. e. Bioactive treatment: add 0.001-0.03% of vitamin D3 and 0.05-0.1% of collagen peptide to the filtrate by weight, stir evenly, and obtain a mixed solution; f. Drying: Dry the mixed solution to a powdery state to obtain calcium oysterate powder, which increases the bioavailability by more than 50%.

2. The method for preparing the high bioavailability calcium oysterate powder according to claim 1, wherein The specific parameters of the gradient calcination in step b are: first heating to 300°C at a linear heating rate of 5°C / min and holding for 30 minutes, then heating to 600°C at a linear heating rate of 3°C / min and holding for 1.5 hours.

3. The method for preparing the calcium oysterate powder with high bioavailability according to claim 1, wherein The drying method in step f is spray drying, maintaining the air inlet temperature at 155-165°C and the air outlet temperature at 60-70°C; or placing the mixed liquid in an oven and directly drying it at 60-70°C; or adopting a reduced pressure concentration drying method, drying it at 40-60°C and -0.08 to -0.1 MPa.

4. The method for preparing the high bioavailability calcium oysterate powder according to claim 1, wherein The operating parameters of the ultrafine airflow pulverizer in step c are: airflow pressure 0.8-1.2 MPa, pulverization temperature ≤ 40°C.

5. The method for preparing calcium oysterate powder with high bioavailability according to claim 1, characterized in that the food-grade organic acid in step d is one of lactic acid, malic acid, citric acid or tartaric acid, or a mixture of multiple acids in any proportion.

6. The method for preparing the high bioavailability calcium oysterate powder according to claim 1, wherein In the step e, the added amount of vitamin D3 is 0.001%-0.002%, and the added amount of collagen peptide is 0.06%-0.08%.

7. The method for preparing the calcium oysterate powder with high bioavailability according to claim 1, wherein The particle size D of the calcium oysterate powder 90 <50μm.

8. Use of the calcium oysterate powder prepared by the method according to any one of claims 1 to 7 in the preparation of common foods, health foods, medicines or other medical products for enhancing bone health.

9. The use according to claim 8, characterized in that The medicine is a medically accepted tablet, capsule, granule, powder, oral liquid or film.

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