What are the benefits of extracting maggot protein from ceramic membrane?

What are the benefits of extracting maggot protein from ceramic membrane?

With the rapid development of the breeding industry and the feed industry, the demand for animal protein in China is also increasing. At present, the main source of animal protein in China is fishmeal. Domestic fishmeal cannot meet the market demand, so it needs to import a large amount of fishmeal every year. The fly maggot dry base contains 54% fly 5%, fat 10%-14%, chitin 8%-10% and rich in vitamins, trace elements, etc. The nutrients are more comprehensive, and the total amino acid is 2.3 times that of fish meal. Methionine and lysine were 2.7 times and 2.6 times higher than fish meal, respectively. In addition, the breeding ability of flies is very strong. It is estimated that a pair of flies can breed 266 billion flies in 4 months and weigh more than 600 tons. Therefore, the maggot protein can be used as a high-quality protein feed instead of fish meal.

According to research, the maggot protein powder has antibacterial, antiviral and free radical scavenging effects. The use of maggots to develop protein powders and amino acid products can meet the needs of specific populations that need to supplement high-quality protein or amino acids, and can also be an important source of protein. Therefore, it is very necessary and practical to study the deep processing technology of maggot protein products and increase the added value of products.

Chinese patent CN1415757A discloses a method for extracting protein and chitin from maggots by enzymatic hydrolysis and chitosan using chitin. The filtrate and the residue are obtained by washing the fly maggot, crushing and enzymatically dissolving the filtrate. The protein is obtained by flavoring, concentration and spray drying, and the protein yield of the method is higher than 60%. Patent CN1377898A discloses a method for extracting chitin and biological protein powder, which is obtained by soaking, filtering, acid soaking, washing and drying to obtain protein powder. Although the protein extracted by the above method retains its biological activity, it is filtered by a filter cloth, the filtration precision is not high, and the finished product contains many ineffective impurity components, so the purity is not high, and in addition, all of the fly maggots are Proteins are extracted, but not all proteins are absorbed by the body, so a method of extracting proteins that are highly pure and capable of being extracted by the body is developed.

specific contents

The invention provides a method for extracting and purifying a fly maggot protein, which needs to increase the content and purity of the extracted protein, reduce the bitterness of the separated protein, and has simple operation, small pollution, and is suitable for large-scale production. Mainly through the separation of ceramic membrane microfiltration and ultrafiltration membrane separation and purification operations, the specific technical solutions adopted are as follows:

A method for extracting maggot protein using a ceramic membrane, comprising the following steps:

The first step is to wash, dry and grind the fly maggot into a powder;

In the second step, the fly maggot powder is hydrolyzed by enzymatic hydrolysis, and then the enzyme is killed;

In the third step, after filtering the hydrolyzate through the coarse filter, the filtrate is filtered by the ceramic microfiltration membrane; in the fourth step, the permeate of the microfiltration membrane is filtered through the ceramic ultrafiltration membrane;

In the fifth step, the concentrated solution of the ultrafiltration membrane is dried to obtain maggot protein;

In the sixth step, the permeate of the ultrafiltration membrane is concentrated and dried by a nanofiltration membrane to obtain a polypeptide, an amino acid, and a small molecule protein.

The extraction method mainly hydrolyzes the macromolecules of maggots by enzymatic hydrolysis, making them more easily separated, purified, and more easily absorbed by the human body. In addition, due to the production of a part of polypeptides and amino acids in the hydrolysis process, this part of the hydrolyzate It has its specific use, and this part of the hydrolyzate has a more pronounced bitter taste, which needs to be separated from the protein to improve the quality of the product. The present invention extracts it by concentration and drying by nanofiltration. The parameters of the hydrolysis process include the type of enzyme, the amount of enzyme, the hydrolysis temperature and the hydrolysis time. The hydrolysis process will affect the degree of hydrolysis of the protein, the presence and absence of bitterness, the process parameters of microfiltration and ultrafiltration, and the product. The yield and the like. If the degree of hydrolysis is high, the bitterness of the hydrolyzate will be heavier, and the protein will be hydrolyzed and the yield will be low. On the contrary, if the degree of hydrolysis is insufficient, the protein will not be completely hydrolyzed, and more protein will be microfiltered. The ultrafiltration membrane is polluted, and the process parameters of hydrolysis are closely related to the choice of ceramic membrane. It is necessary to determine the optimal ceramic membrane type to adapt to different hydrolysis processes. The preferred hydrolysis parameter is: the mass ratio of the maggot meal to water is preferably 1:20-1:30; the enzyme used for hydrolysis is preferably one of trypsin, papain, alkaline protease, hydrolysis temperature 45-55 °C, hydrolysis time 50-70 minutes.

In the third step, the hydrolyzate first needs to remove the large particle impurities through the coarse filter, which is mainly fly maggot, which can prevent the contamination of the microfiltration membrane and improve the purity of the product. The coarse filter can be a conventional filter cloth or sand. Filtering, etc. The microfiltration membrane further filters the filtrate to remove the gum, oil and the like in the hydrolyzate, thereby improving the purity of the product, reducing the oil content and ash in the product; and being highly hydrophilic due to the surface property of the ceramic membrane, hydrolysis The oil and fat in the post material have strong repulsive force on the surface of the ceramic membrane, are not easy to penetrate the membrane layer, have high rejection rate, and are not easy to form pollution on the surface, easy to clean and regenerate. After extensive experimentation, the average pore size of the microfiltration membrane is preferably in the range of 200-500 nm. If the pore diameter is too large, the purity of the product is lowered, and the impurities such as ash and grease are too high. If the pore diameter is too small, the filtration flux will be increased. Decreased, and a portion of the protein is trapped, resulting in a decrease in product yield. The material of the ceramic microfiltration membrane is preferably one of alumina, zirconia, and titania. In the microfiltration process, the choice of transmembrane pressure difference has an interactive relationship with the average pore size, filtration flux and product purity of the microfiltration membrane. If the pressure difference across the membrane is too large, a part of the colloid will be worn after being pressed. The membrane pores reach the permeate side, which affects the purity of the product. If the membrane pressure difference is filtered, the filtration flux will be too small. After a lot of experiments, the preferred transmembrane pressure difference is 0.05-0.3 MPa. The change in pH during filtration interacts with the charge generated by the protein, affecting the form of the protein present, which in turn affects the filtration flux and protein rejection, with a preferred pH range of 6.0-7.0. The membrane flow rate affects the filtration flux, with a preferred range of I-5 m/s. The filtration temperature is preferably from 40 to 500 ° C, and the concentration ratio is preferably from 6 to 8 times the concentration of the feed liquid.

In the fourth step, the function of ultrafiltration is to achieve the concentration of hydrolyzed protein and the separation from peptides and amino acids. Since peptides and amino acids have a certain bitter taste, it is necessary to optimize the process parameters of ultrafiltration, if the average of ultrafiltration membranes If the pore size is too large, the protein will not be completely trapped, resulting in loss of product recovery. If the average of the ultrafiltration membrane is too small, it will not only cause the filtration flux to be too small, but also have industrial practical value, and will lead to groups of peptides and amino acids. The fraction is trapped, which will cause bitterness of the recovered protein; the transmembrane pressure difference of ultrafiltration also needs a lot of experiments. The average pore diameter of the ultrafiltration membrane is preferably 20-50 nm, and the material of the ceramic ultrafiltration membrane is selected from zirconia and titania. One kind. In the process of ultrafiltration, the transmembrane pressure difference also has an effect on the yield and content of the product. Since the protein is a macromolecular substance with a certain compressive property, if the transmembrane pressure difference is too large, a part of the macromolecular protein will be permeated. The membrane pore enters the permeate side. If the transmembrane pressure difference is too small, the filtration flux will be too small. After a large number of experiments, the transmembrane pressure difference is preferably 0.2-0.4 MPa. The change in pH during the filtration process interacts with the charge generated by the protein, affecting the form of the protein and the polypeptide, which in turn affects the filtration flux and protein rejection, and the permeability of the polypeptide. The preferred pH range is 5.0. -6.0. The membrane flow velocity will affect the filtration flux. Due to the ultrafiltration protein process, the surface contamination of the ceramic membrane is mainly caused by adsorption pollution and membrane pore blockage. The influence of membrane flow velocity on the filtration flux is relatively small. The large membrane flow rate has a limited increase in flux, with a preferred range of I-3 m/s. The filtration temperature is preferably 40 to 50 ° C, and the concentration ratio is preferably 5 to 7 times the concentration of the liquid.

As a preferred method of the present method, spray drying is employed in the fifth step, and the operation time is short, which ensures that the protein is not destroyed during the drying process.