11 results about "Lipase preparation" patented technology

The present invention discloses a method and application for simultaneously reducing polycyclic aromatic hydrocarbons in tobacco leaves and cigarette smoke, as well as a cigarette, which relates to the technical field of harm reduction in tobacco processing. The method includes: preparing a lipase solution; uniformly spraying the lipase solution on both the front and back sides of the tobacco leaves to be treated; subjecting the tobacco leaves sprayed with the lipase solution to constant temperature and humidity treatment, and the content of polycyclic aromatic hydrocarbons in the tobacco leaves after lipase treatment is reduced; cutting the tobacco leaves treated with lipase into shreds, and inactivating the lipase in the shredded tobacco leaves treated with lipase; rolling the inactivated shredded tobacco into cigarette sticks, and the content of polycyclic aromatic hydrocarbons in the smoke after combustion is reduced. The method is applicable to low-grade flue-cured tobacco or cut tobacco after threshing and redrying. The cigarette includes shredded tobacco obtained by lipase treatment. The method of the present invention is simple and easy to operate. After treatment with lipase preparation, it can specifically reduce the content of PAHs in tobacco leaves and cigarette smoke, especially the content of fluoranthene, and can significantly improve the safety of tobacco with a high fluoranthene content.

The invention belongs to the technical field of laundry detergents, and particularly relates to a phosphorus-free laundry detergent based on an enzyme preparation and a preparation method of the phosphorus-free laundry detergent. The non-phosphorus laundry detergent based on the enzyme preparation is prepared from the following components in percentage by mass: 10 to 15 percent of anionic surfactant, 4 to 8 percent of nonionic surfactant, 1 to 3 percent of zwitterionic surfactant, 0.1 to 0.5 percent of papain preparation, 0.1 to 0.5 percent of lipase preparation, 1 to 3 percent of propylene glycol, 2 to 4 percent of trisodium citrate, 0.02 to 0.04 percent of polyether defoaming agent, 0.10 to 0.15 percent of citric acid and the balance of water. The laundry detergent prepared by the invention is strong in dirt-removing power and high in storage stability.

This invention discloses a method for preparing millet lipase, belonging to the fields of bioengineering and deep processing of agricultural products. The method uses millet flour as raw material, extracts a crude enzyme solution using a buffer solution, and further constructs a polyethylene glycol-inorganic salt aqueous two-phase system to achieve targeted distribution of the millet lipase, completing rapid enrichment and preliminary purification. Subsequently, polyethylene glycol and inorganic salts are removed from the system by ultrafiltration or dialysis, and molecular sieve chromatography is used for fine purification when necessary to obtain a high specific activity millet lipase preparation. Experimental results show that compared with the traditional ammonium sulfate fractionation precipitation method, the method of this invention significantly shortens the processing time, improves the recovery rate and purification fold of the lipase, and has mild operating conditions and good reproducibility, demonstrating good potential for industrial application.

The application belongs to the technical field of oil and fat chemistry, and particularly relates to a diglyceride oil capable of preventing fatty liver, a preparation method and application of the diglyceride oil, and the preparation method comprises the following steps: (1) mixing raw oil with glycerol, adding a lipase preparation, and performing enzymatic reaction in a solvent-free system; the content of monoglyceride in the raw oil is 40-80 wt%; (2) separating the reaction product of step (1), collecting the upper oil phase, and then performing secondary molecular distillation purification on the oil phase to obtain an oil product with a diglyceride content of greater than or equal to 80 wt%. The technical scheme of the application uses raw oil with a monoglyceride component content greater than 40% as raw material to synthesize an oil product with a high diglyceride content, and the amount of the lipase preparation added is low, so that the production cost can be effectively reduced, and the obtained product has high diglyceride and sterol contents and has a significant effect in preventing fatty liver.

The invention discloses a double-bacterium synergistic fermentation enzyme modified cheese flavoring agent and a preparation method thereof, and the double-bacterium synergistic fermentation enzyme modified cheese flavoring agent is prepared from the following raw materials in parts by mass: 10-20 parts of milk powder, 40-50 parts of anhydrous butter, 0.5-1.5 parts of an emulsifier, 0.1-1.0 part of a protease preparation, 0.1-1.0 part of a lipase preparation, 5-15 parts of a microbial fermentation agent and the balance of water, the microbial fermentation agent is composed of lactobacillus helveticus and saccharomycetes, and the saccharomycetes comprise one of kluyveromyces marxianus, kluyveromyces lactis and candida lactis. Ethyl ester compounds are dynamically generated through esterification reaction of ethyl alcohol generated through yeast metabolism and carboxylic acid synthesized by lactic acid bacteria, the natural cheese characteristic flavor with rich levels is formed, and the obtained final product is soft in flavor, free of irritation and rich and natural in fragrance.

The invention relates to the technical field of grease chemistry, in particular to diglyceride oil capable of preventing fatty liver and a preparation method and application thereof.The preparation method of the diglyceride oil comprises the following steps that 1, raw material oil and glycerinum are mixed, a lipase preparation is added, and an enzymolysis reaction is conducted in a solvent-free system; the content of monoglyceride in the raw oil is 40-80 wt%; and (2) separating the reaction product in the step (1), collecting an upper-layer oil phase, and then carrying out secondary molecular distillation purification on the oil phase to obtain a grease product with the diglyceride content of more than or equal to 80wt%. According to the technical scheme, the raw material oil with the monoglyceride component content larger than 40% is adopted as the raw material to synthesize the oil product with the high diglyceride content, the addition amount of the lipase preparation is low, the production cost can be effectively reduced, the diglyceride content and the sterol content in the obtained product are high, and the obvious effect is achieved in the aspect of preventing the fatty liver.

The invention belongs to the technical field of biological catalysis and enzyme engineering, and particularly relates to a preparation method of covalent immobilized lipase based on amino functionalization MOF (Metal Organic Framework) and application of the covalent immobilized lipase in synthesis of diglyceride. The invention discloses a method for cross-linking and immobilizing CALB lipase on a zirconium-based metal organic framework NH2-UiO-66 by adopting glutaraldehyde as a cross-linking agent, the obtained immobilized lipase is defined as CALB-coated GA-NH2-UiO-66, and the immobilized lipase is applied to catalytic esterification synthesis of diglyceride. The oleic acid conversion rate is determined by adopting an acid value, and the composition of a product is analyzed by HPLC-ELSD. The immobilized lipase CALB (at) GA-NH2-UiO-66 disclosed by the invention has the advantages of high stability, reusability, high catalytic efficiency and diglyceride selectivity. The high DAG production significantly mitigates downstream purge burden. A promising solution is provided for industrial production of DAG, and a deep insight is provided for a fixing mechanism of a functionalized metal-organic framework.

The invention belongs to the technical field of biological catalysis, and particularly relates to a preparation method of immobilized lipase and application of the immobilized lipase in catalytic synthesis of glyceride, the preparation method comprises the following steps: (1) surface modification: immersing a pretreated carrier in 80-300 parts by weight of a silanization solution for reaction to obtain functional resin; (2) enzyme immobilization: putting the functionalized resin into an enzyme solution, and oscillating and adsorbing to form an enzyme-resin compound; and (3) post-treatment: washing the enzyme-resin compound with 300-600 parts by weight of a phosphate buffer solution, and drying until the water content is less than or equal to 5% to obtain a finished product of the immobilized lipase. The immobilized lipase is used for catalytic synthesis of glyceride, and the glyceride comprises diglyceride and triglyceride. The enzyme stability is improved by combining covalent modification on the surface of the carrier with a protective auxiliary agent, the composition of a glyceride product is accurately regulated and controlled by utilizing a temperature-vacuum synergistic mechanism, and the reaction kinetic performance is enhanced by virtue of a composite dewatering system.

The application discloses a preparation method of immobilized lipase and application of the immobilized lipase in catalysis of 1,3-glycerol diglyceride synthesis. The preparation method comprises the following steps: (1) preparation of a template; (2) immobilization of lipase; and (3) removal of the template. The prepared immobilized enzyme is used for catalyzing conversion of TAG of vegetable oil into DAG, and the selectivity of 1,3-DAG can be remarkably improved, and the proportion of 1,3-DAG in the product is 80% to 90%.

The present invention belongs to the field of bioengineering technology and relates to a lipase, a gene encoding the lipase, a recombinant expression vector and a recombinant expression transformant containing the lipase gene, a method for preparing the lipase, and a method for preparing methyl epoxy stearate using the lipase. Compared with the prior art, the lipase of the present invention has high activity and good stability. The enzyme is used to catalyze hydrogen peroxide and n-heptanoic acid to form peroxycarboxylic acid, which is then reacted with methyl oleate to generate methyl epoxy stearate. This avoids the large demand for strong acids and metal catalysts and the complex reaction apparatus in conventional chemical catalysis methods. The process is simple, the process is environmentally friendly, and there is good prospect in the industrial production of methyl epoxy stearate.

The invention discloses a preparation method of biomass diesel oil immobilized lipase, and belongs to the technical field of lipase immobilization. The preparation method specifically comprises the following steps: (1) drying polystyrene resin, and adding methanol for swelling, suction filtration, washing and drying to obtain pretreated resin; (2) adding L-lysine, L-arginine, L-histidine or L-cysteine into the enzyme solution of the biomass diesel lipase, and stirring for dissolving, so as to obtain a pretreated enzyme solution; and (3) adding the pretreated enzyme liquid into the pretreated resin for adsorption, suction filtration, washing and drying. According to the biomass diesel oil immobilized lipase prepared by the invention, the content of free FFA in a biomass diesel oil reaction can be reduced to 0.5% or below, the cycle use frequency exceeds 14 times, the biomass diesel oil immobilized lipase has the characteristics of simple preparation process, excellent catalytic performance, greatly improved stability and the like, and the production cost is greatly reduced.