Method for extracting pure calcium from mangosteen shells

Abstract

The invention discloses a pure calcium extraction method of mangosteen shells, and relates to the technical field of calcium extraction, and the extraction steps are as follows: S1, material preparation and pretreatment: mangosteen shells are prepared, washed and dried, the mangosteen shells are put into liquid nitrogen to be quickly frozen, and then crushed and refined into powder particles to obtain crushed materials; s2, screening microorganisms for fermentation, carrying out experimental analysis on microbial strains based on a plate streaking method, screening proper microorganisms based on data calculation, carrying out activation culture on the lactic acid bacteria to prepare a bacterial suspension, inoculating the crushed materials into the bacterial suspension, carrying out fermentation treatment, and regularly observing the fermentation condition. According to the method, a high-purity pure calcium product is finally obtained through multi-stage purification steps, the problems that cell wall structures are difficult to fully destroy and calcium elements are difficult to effectively dissolve out in conventional acid leaching and alkali extraction methods are solved, the extraction efficiency is improved, and consumed raw materials are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of calcium extraction, and in particular to a method for extracting pure calcium from mangosteen shells. Background Art

[0002] As a tropical fruit, mangosteen’s shell is often discarded as waste after consumption. However, mangosteen shell actually contains rich nutrients and a variety of bioactive substances, such as dietary fiber, flavonoids, polysaccharides and calcium, which have been proven to have antioxidant and anti-inflammatory physiological activities. As people pay more and more attention to health, calcium, as an important mineral element necessary for the human body, plays a key role in maintaining bone health, nerve conduction, muscle contraction and many other physiological functions. The market demand for calcium supplements and various calcium-containing products continues to grow. Traditional calcium sources mainly come from minerals and animal bones, but these sources have certain limitations. For example, calcium from minerals may require complex purification processes due to the presence of heavy metal impurities, and calcium from animal bones may involve the risk of animal disease transmission and limited acceptance by some people due to religious beliefs and eating habits. The calcium contained in mangosteen shell can supplement people’s needs for calcium. In the prior art of purification technology for mangosteen shell, since the cell wall of mangosteen shell forms a natural barrier to the calcium element inside, it is difficult for conventional acid leaching and alkali extraction methods to fully destroy the cell wall structure and effectively dissolve the calcium element, resulting in low extraction efficiency. A large amount of raw materials is required to obtain a small amount of calcium, which undoubtedly increases the cost and does not conform to the principle of efficient utilization of resources, resulting in low efficiency of calcium extraction. In this regard, we propose a method for extracting pure calcium from mangosteen shell. Summary of the invention

[0003] In order to solve the above technical problems, a method for extracting pure calcium from mangosteen shell is provided. The technical solution solves the above problem of low extraction efficiency.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is: a method for extracting pure calcium from mangosteen shell, the extraction steps are: S1. Material preparation and pretreatment: prepare mangosteen shells, wash and dry them, quickly freeze the mangosteen shells in liquid nitrogen, and then crush them into powder particles to obtain crushed materials; S2, screening microbial fermentation, experimentally analyzing the microbial strains based on the plate streak method, screening out suitable microorganisms based on data calculation, the microorganisms are lactic acid bacteria, activating and culturing the lactic acid bacteria, preparing a bacterial suspension, inoculating the crushed materials into the bacterial suspension, performing fermentation treatment, and regularly observing the fermentation status; S3, filtering, filtering the fermentation product through filter paper to obtain a filtrate of soluble calcium salt; S4, precipitation conversion, adding a precipitant to the calcium ion filtrate, stirring and reacting to generate calcium carbonate precipitate; S5, filtering and washing, filtering the precipitate to filter out the calcium carbonate precipitate, and washing the calcium carbonate precipitate with distilled water; S6. calcining the washed calcium carbonate precipitate to purify the calcium to obtain calcium oxide, which is then reduced to pure calcium by electrolysis.

[0005] Preferably, in step S1, the collected mangosteen shells are placed in a container and soaked in clean water for 2 hours. After soaking, the outer surface of the mangosteen shells is wiped, and the washed mangosteen shells are spread in a well-ventilated and dry environment for drying. The ambient temperature is 15-25° C. After waiting for complete drying, the mangosteen shells are placed in a liquid nitrogen container in batches, and after they are completely immersed in liquid nitrogen, they are taken out from the liquid nitrogen, and the frozen mangosteen shells are transferred to a pulverizing device for crushing. Through impact and cutting, external force is applied to the mangosteen shells, and they are refined into powder particles.

[0006] Preferably, in the step S2, the plate streaking method step is performed by obtaining a sample of the crushed material, dividing the culture dish with a marker pen to form parallel samples, placing the crushed material sample in the parallel sample corresponding to the culture dish, performing corresponding culture observations, checking the culture effect, recording the data, counting the number of colonies and the distribution of microorganisms, and comprehensively analyzing to obtain the best microorganism for culturing mangosteen shell.

[0007] Preferably, the colony count calculation formula is:

[0008] Where N ij is the colony data counted on the jth parallel sample plate of the i-th microbial strain, m is the parallel sample set for the strain, j is the number of the parallel sample, N i is the average colony count; Calculate the standard deviation SD of the colony count i , to measure the discreteness of the data, the calculation formula is:

[0009] Among them SD i is the standard deviation of the colony count; And calculate the average score S of the parallel sample colony distribution of each microbial species i , the calculation formula is:

[0010] Where S ij is the score value, S i As the average score, construct a comprehensive evaluation index E iTo judge which microorganism is the best for cultivating mangosteen shell, by comparing the comprehensive evaluation index E corresponding to different microbial strains i Value, E i The strain with the largest value was judged as the best microbial strain for culturing mangosteen shell.

[0011] Preferably, in step S2, the lactic acid bacteria are placed in an incubator, the incubation temperature is set to 30-45°C, and the incubation time is 12-24 hours. The morphology of the lactic acid bacteria in the incubator is observed, and after the lactic acid bacteria become turbid, it is determined that the activation of the lactic acid bacteria is complete, and a bacterial suspension is prepared. The lactic acid bacteria are centrifuged at a speed of 3000-5000rpm and a centrifugation time of 5-10min. After the operation is completed, sterile physiological saline is added to prepare a bacterial suspension.

[0012] Preferably, in step S2, the fermentation treatment is carried out by taking out the crushed material, placing it in a fermentation tank, and pouring in the bacterial suspension for fermentation treatment. The fermentation time is 2 days, the fermentation temperature is 25-35°C, and regular observation is carried out to judge the fermentation status by sensory organs, and the fermentation is waited for completion.

[0013] Preferably, in step S3, the fermentation product is filtered through filter paper for more than 4 times to remove solid impurities in the fermentation product.

[0014] Preferably, in step S4, the precipitant is a sodium carbonate solution, and the sodium carbonate solution is added dropwise to the calcium ion filtrate, and the dropping process is continuously stirred to react, wherein the reaction equation is:

[0015] After stopping the addition of the precipitant, the liquid was allowed to stand for 2 hours.

[0016] Preferably, in step S5, the filtration is performed through medium-speed qualitative filter paper, and the number of filtrations is greater than 2 times; the washing is performed by dropping distilled water into the calcium carbonate precipitate and stirring the precipitate to adsorb impurities in the distilled water. After the stirring is completed, the mixture is allowed to stand for 2 hours, and the distilled water is poured out to complete the washing.

[0017] Preferably, in step S6, the high temperature calcination is carried out by volatilization through the difference in stability between calcium oxide and impurities at high temperature to achieve a purification effect, and calcium carbonate is decomposed into calcium oxide and carbon dioxide, and carbon dioxide gas escapes, thereby removing calcium carbonate impurities; the reaction equation is:

[0018] The calcination temperature is 800-1000°C; the electrolysis method prepares an electrolyte, electrolyzes calcium oxide, and collects pure calcium.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The invention extracts pure calcium by adopting a microbial fermentation method. Before the extraction, the mangosteen shell is placed in liquid nitrogen for rapid freezing and is crushed, so that the crushing efficiency can be effectively improved, and the crushed particles can be made more uniform and fine, which is more in line with the requirements of the subsequent microbial fermentation link on the material particle size, and is beneficial to increasing the contact area between the material and the microorganism and the reaction reagent. After multiple stages of purification steps, a high-purity pure calcium product is finally obtained, and the problem that conventional acid leaching and alkali extraction methods are difficult to fully destroy the cell wall structure and effectively dissolve the calcium element is avoided, the extraction efficiency is improved, and the consumed raw materials are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of the pure calcium extraction steps of the present invention. DETAILED DESCRIPTION

[0021] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0022] A method for extracting pure calcium from mangosteen shells, comprising the following steps: S1. Material preparation and pretreatment: prepare mangosteen shells, wash and dry them, quickly freeze the mangosteen shells in liquid nitrogen, and then crush them into powder particles to obtain crushed materials; S2, screening microbial fermentation, experimentally analyzing the microbial strains based on the plate streak method, screening out suitable microorganisms based on data calculation, the microorganisms are lactic acid bacteria, activating and culturing the lactic acid bacteria, preparing a bacterial suspension, inoculating the crushed materials into the bacterial suspension, performing fermentation treatment, and regularly observing the fermentation status; S3, filtering, filtering the fermentation product through filter paper to obtain a filtrate of soluble calcium salt; S4, precipitation conversion, adding a precipitant to the calcium ion filtrate, stirring and reacting to generate calcium carbonate precipitate; S5, filtering and washing, filtering the precipitate to filter out the calcium carbonate precipitate, and washing the calcium carbonate precipitate with distilled water; S6. calcining the washed calcium carbonate precipitate to purify the calcium to obtain calcium oxide, which is then reduced to pure calcium by electrolysis.

[0023] In step S1, the collected mangosteen shells are placed in a container and soaked in clean water for 2 hours. After the soaking is completed, the outer surface of the mangosteen shells is wiped, and the washed mangosteen shells are spread in a well-ventilated and dry environment for drying. The ambient temperature is 15-25° C. After waiting for complete drying, the mangosteen shells are placed in a liquid nitrogen container in batches. After they are completely immersed in liquid nitrogen, they are taken out from the liquid nitrogen, and the frozen mangosteen shells are transferred to a crushing device for crushing. Through impact and cutting, external force is applied to the mangosteen shells, and they are refined into powder particles.

[0024] The mangosteen shell of the present application has a certain toughness and fiber structure. When it is crushed at room temperature, a large mechanical force is required, and it is difficult to crush it to a very fine degree. The temperature of liquid nitrogen is extremely low. After the mangosteen shell is placed in liquid nitrogen and quickly frozen, its texture will become extremely brittle and hard, just like glass. In the subsequent crushing process, only a small external force is needed to break it into fine particles, which greatly improves the crushing efficiency, and can make the crushed particles more uniform and fine, which is more in line with the requirements of the subsequent microbial fermentation link for the particle size of the material, and is conducive to increasing the contact area between the material and the microorganism and the reaction reagent; after the mangosteen shell is crushed into powder particles, in the subsequent microbial fermentation process to extract calcium, the microorganism can more fully contact with various parts of the mangosteen shell, and the enzyme metabolites secreted by it can also better act on the calcium-containing components inside the mangosteen shell, so that the calcium element is released more effectively; similarly, when chemical reagents are added for precipitation conversion operation, the contact area between the reagent and the mangosteen shell powder is increased, and the reaction will be more sufficient and rapid, which is conducive to improving the efficiency and effect of calcium extraction.

[0025] In the plate streaking method step in step S2, a sample of the crushed material is obtained, and a culture dish is divided and separated by a marker pen to form parallel samples. The crushed material sample is placed in the parallel samples corresponding to the culture dish, and corresponding culture observations are performed to check the culture effect, record the data, count the number of colonies and the distribution of microorganisms, and comprehensively analyze to obtain the best microorganism for culturing mangosteen shell.

[0026] By obtaining samples of crushed materials, the present application can directly conduct microbial analysis on the mangosteen shell material to be processed, so that the obtained results are more in line with the actual application scenario of subsequent fermentation and calcium extraction, because the microorganisms contained in these samples are originally present in the natural environment of mangosteen shell. Analyzing them helps to understand the characteristics of the microbial community of mangosteen shell itself, and provide a real and reliable basis for the subsequent screening of suitable microorganisms.

[0027] The colony count calculation formula is:

[0028] Where N ijis the colony data counted on the jth parallel sample plate of the i-th microbial strain, m is the parallel sample set for the strain, j is the number of the parallel sample, N i is the average colony count; Calculate the standard deviation SD of the colony count i , to measure the discreteness of the data, the calculation formula is:

[0029] Among them SD i is the standard deviation of the colony count; And calculate the average score S of the parallel sample colony distribution of each microbial species i , the calculation formula is:

[0030] Where S ij is the score value, S i As the average score, construct a comprehensive evaluation index E i To judge which microorganism is the best for cultivating mangosteen shell, by comparing the comprehensive evaluation index E corresponding to different microbial strains i Value, E i The strain with the largest value was judged as the best microbial strain for culturing mangosteen shell.

[0031] The application calculates the average colony count, which can objectively present the reproductive capacity of each microbial species in the environment of crushed mangosteen shell materials from a quantitative perspective. The higher the average colony count, the higher the efficiency of the microorganism in growing and reproducing by utilizing the nutrients in mangosteen shell under given culture conditions; the standard deviation can reflect the fluctuation of the colony count between parallel samples. A smaller standard deviation indicates that the colony count data obtained from each parallel sample are more concentrated and stable, which means that the growth of the microbial species during the experiment is less affected by external accidental factors, and the reliability of the experimental results is higher. On the contrary, a larger standard deviation indicates that the data is highly discrete, and the growth of the microorganism may be sensitive to environmental factors, or the consistency of the experimental operation is difficult to ensure. Such microorganisms may be difficult to function stably in practical applications. By calculating the standard deviation, it is possible to assist in judging the quality of the experimental data, and then more scientifically screen out microbial species that not only have suitable reproductive capacity but also have good growth stability.

[0032] In step S2, the lactic acid bacteria are placed in an incubator, the incubation temperature is set to 30-45°C, and the incubation time is 12-24 hours. The morphology of the lactic acid bacteria in the incubator is observed. After the lactic acid bacteria become turbid, it is determined that the activation of the lactic acid bacteria is completed, and a bacterial suspension is prepared. The lactic acid bacteria are centrifuged at a speed of 3000-5000rpm and a centrifugation time of 5-10min. After the operation is completed, sterile physiological saline is added to prepare a bacterial suspension.

[0033] The culture temperature is set at 30-45°C in the present application because this temperature range is close to the optimum temperature range for the growth and reproduction of lactic acid bacteria. Lactic acid bacteria are mesophilic bacteria. Under such temperature conditions, the activities of various enzymes in their bodies can be maintained at a high level. For example, key enzymes involved in the physiological processes of carbohydrate metabolism and protein synthesis can efficiently catalyze the corresponding biochemical reactions at a suitable temperature, so that lactic acid bacteria can quickly utilize the nutrients in the culture medium for growth and reproduction, thereby ensuring their growth activity and reserving a sufficient number of bacterial cells with good activity for subsequent fermentation operations.

[0034] In step S2, the fermentation treatment is carried out by taking out the crushed material, placing it in a fermentation tank, and pouring in the bacterial suspension for fermentation. The fermentation time is 2 days, the fermentation temperature is 25-35°C, and regular observation is carried out to judge the fermentation status through sensory perception, and wait for the fermentation to be completed.

[0035] The present application places the taken out crushed material in a fermentation tank, and then pours the bacterial suspension into it, so that the two can be fully mixed evenly through stirring operation, and regular observation can be carried out to understand various changes in the fermentation process in real time, observe the changes in the appearance of the fermented material, and see if there are any color changes, gas production phenomena, and changes in the texture of the material. This ensures the effect and quality of fermenting the crushed mangosteen shell material using lactic acid bacteria from multiple aspects.

[0036] In step S3, the fermentation product is filtered through filter paper for more than 4 times to remove solid impurities in the fermentation product.

[0037] The fermentation product of the present application often contains many solid impurities, such as mangosteen shell residues that have not been fully fermented and decomposed, microbial cells, and some precipitated substances that may be produced during the fermentation process. By filtering with filter paper multiple times, these solid impurities can be more thoroughly separated from the system, making the final filtrate clearer and purer.

[0038] In step S4, the precipitant is a sodium carbonate solution, and the sodium carbonate solution is added dropwise to the calcium ion filtrate, and the addition process is continuously stirred to react, wherein the reaction equation is:

[0039] After stopping the addition of the precipitant, the liquid was allowed to stand for 2 hours.

[0040] In the present application, stirring is continuously performed during the process of dripping the sodium carbonate solution into the calcium ion filtrate. Stirring can make the dripped sodium carbonate solution quickly and evenly dispersed in the entire filtrate system, and the generated calcium carbonate precipitate is allowed to fully settle to the bottom of the container under the action of gravity. During filtration, the upper relatively clear filtrate can be directly poured out, which reduces the burden on the filter paper and speeds up the filtration speed.

[0041] In step S5, the filtration is performed through medium-speed qualitative filter paper, and the number of filtrations is greater than 2 times; the washing is performed by dropping distilled water into the calcium carbonate precipitate and stirring the precipitate to adsorb impurities in the distilled water. After the stirring is completed, the mixture is allowed to stand for 2 hours, and the distilled water is poured out to complete the washing.

[0042] The medium-speed qualitative filter paper in the present application has a suitable pore size, which can effectively intercept solid impurity particles in the calcium carbonate precipitate and some other insoluble substances that may be mixed in, and selectively remove impurities on the surface of the precipitate without damaging the calcium carbonate itself, thereby further improving the purity of the calcium carbonate precipitate and making it more in line with the subsequent requirements for high-purity calcium products.

[0043] In step S6, the high temperature calcination is carried out by volatilization through the difference in stability between calcium oxide and impurities at high temperature to achieve the purification effect. Calcium carbonate will decompose into calcium oxide and carbon dioxide, and carbon dioxide gas will escape, thereby removing calcium carbonate impurities; the reaction equation is:

[0044] The calcination temperature is 800-1000°C; the electrolysis method prepares an electrolyte, electrolyzes calcium oxide, and collects pure calcium.

[0045] The present application cleverly utilizes the difference in stability between calcium oxide and impurities at high temperatures to achieve a purification effect. Many impurities will volatilize or undergo chemical reactions to be converted into gaseous substances and escape under such high temperature conditions. Relatively pure calcium oxide products can be obtained without complicated separation operations, thereby simplifying the process and avoiding the contamination of calcium oxide by impurities during subsequent processing, thereby facilitating subsequent electrolysis of calcium oxide for further purification.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A method for extracting pure calcium from mangosteen shell, characterized in that: The extraction steps are: S1. Material preparation and pretreatment: prepare mangosteen shells, wash and dry them, quickly freeze the mangosteen shells in liquid nitrogen, and then crush them into powder particles to obtain crushed materials; S2, screening microbial fermentation, experimentally analyzing the microbial strains based on the plate streak method, screening out suitable microorganisms based on data calculation, the microorganisms are lactic acid bacteria, activating and culturing the lactic acid bacteria, preparing a bacterial suspension, inoculating the crushed materials into the bacterial suspension, performing fermentation treatment, and regularly observing the fermentation status; S3, filtering, filtering the fermentation product through filter paper to obtain a filtrate of soluble calcium salt; S4, precipitation conversion, adding a precipitant to the calcium ion filtrate, stirring and reacting to generate calcium carbonate precipitate; S5, filtering and washing, filtering the precipitate to filter out the calcium carbonate precipitate, and washing the calcium carbonate precipitate with distilled water; S6. calcining the washed calcium carbonate precipitate to purify the calcium to obtain calcium oxide, which is then reduced to pure calcium by electrolysis.

2. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S1, the collected mangosteen shells are placed in a container and soaked in clean water for 2 hours. After the soaking is completed, the outer surface of the mangosteen shells is wiped, and the washed mangosteen shells are spread in a well-ventilated and dry environment for drying. The ambient temperature is 15-25° C. After waiting for complete drying, the mangosteen shells are placed in a liquid nitrogen container in batches. After they are completely immersed in liquid nitrogen, they are taken out from the liquid nitrogen, and the frozen mangosteen shells are transferred to a crushing device for crushing. Through impact and cutting, external force is applied to the mangosteen shells, and they are refined into powder particles.

3. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In the plate streaking method step in step S2, a sample of the crushed material is obtained, and a culture dish is divided and separated by a marker pen to form parallel samples. The crushed material sample is placed in the parallel samples corresponding to the culture dish, and corresponding culture observations are performed to check the culture effect, record the data, count the number of colonies and the distribution of microorganisms, and comprehensively analyze to obtain the best microorganism for culturing mangosteen shell.

4. The method for extracting pure calcium from mangosteen shell according to claim 3, characterized in that: The colony count calculation formula is: Where N ij is the colony data counted on the jth parallel sample plate of the i-th microbial strain, m is the parallel sample set for the strain, j is the number of the parallel sample, N i is the average colony count; Calculate the standard deviation SD of the colony count i , to measure the discreteness of the data, the calculation formula is: Among them SD i is the standard deviation of the colony count And calculate the average score S of the parallel sample colony distribution of each microbial species i , the calculation formula is: Where S ij is the score value, S i As the average score, construct a comprehensive evaluation index E i To judge which microorganism is the best for cultivating mangosteen shell, by comparing the comprehensive evaluation index E corresponding to different microbial strains i Value, E i The strain with the largest value was judged as the best microbial strain for culturing mangosteen shell.

5. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S2, the lactic acid bacteria are placed in an incubator, the incubation temperature is set to 30-45°C, and the incubation time is 12-24 hours. The morphology of the lactic acid bacteria in the incubator is observed. After the lactic acid bacteria become turbid, it is determined that the activation of the lactic acid bacteria is completed, and a bacterial suspension is prepared. The lactic acid bacteria are centrifuged at a speed of 3000-5000rpm and a centrifugation time of 5-10min. After the operation is completed, sterile physiological saline is added to prepare a bacterial suspension.

6. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S2, the fermentation treatment is carried out by taking out the crushed material, placing it in a fermentation tank, and pouring in the bacterial suspension for fermentation. The fermentation time is 2 days, the fermentation temperature is 25-35°C, and regular observation is carried out to judge the fermentation status through sensory perception, and wait for the fermentation to be completed.

7. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S3, the fermentation product is filtered through filter paper for more than 4 times to remove solid impurities in the fermentation product.

8. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S4, the precipitant is a sodium carbonate solution, and the sodium carbonate solution is added dropwise to the calcium ion filtrate, and the addition process is continuously stirred to react, wherein the reaction equation is: After stopping the addition of the precipitant, the liquid was allowed to stand for 2 hours.

9. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S5, the filtration is performed through medium-speed qualitative filter paper, and the number of filtrations is greater than 2 times; the washing is performed by dropping distilled water into the calcium carbonate precipitate and stirring the precipitate to adsorb impurities in the distilled water. After the stirring is completed, the mixture is allowed to stand for 2 hours, and the distilled water is poured out to complete the washing.

10. The method for extracting pure calcium from mangosteen shell according to claim 1, characterized in that: In step S6, the high temperature calcination is carried out by volatilization through the difference in stability between calcium oxide and impurities at high temperature to achieve the purification effect. Calcium carbonate will decompose into calcium oxide and carbon dioxide, and carbon dioxide gas will escape, thereby removing calcium carbonate impurities; the reaction equation is: The calcination temperature is 800-1000°C; the electrolysis method prepares an electrolyte, electrolyzes calcium oxide, and collects pure calcium.

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