56 results about "Food engineering" patented technology

The invention relates to the technical field of food engineering, and discloses a colorimetric principle-based fried food Maillard reaction product concentration analysis model and frying equipment, and the colorimetric principle-based fried food Maillard reaction product concentration analysis model and frying equipment are established through three steps of experimental design, data acquisition and model construction. According to the concentration analysis model for the Maillard reaction product of the fried food based on the colorimetric principle and the frying equipment, in order to accurately judge the optimal frying end point of the fried food, improve the percent of pass of the fried food and adapt to industrial production, a linear analysis model based on R, G and B values of mobile phone imaging and the absorbance of the Maillard reaction product is established; the deep-frying end point judgment value is determined in combination with sensory evaluation, the optimal deep-frying end point of the deep-fried food can be judged, data are rapidly obtained through standardized mobile phone imaging parameters and substituted into a preset model for calculation, instant monitoring and judgment of the optimal deep-frying end point can be achieved, the qualified rate of the deep-fried food is increased, and the method is suitable for industrial production.

The invention belongs to the field of food engineering and traditional Chinese medicine functional foods, and discloses a preparation method of a tremella and ginseng composite freeze-dried product, which comprises the following steps: S1, preparing a decoction, weighing poria cocos, Chinese yam and other medicinal materials and ginseng slices according to a ratio, soaking, taking out the ginseng slices for later use, decocting the remaining medicinal materials, and filtering to obtain the decoction; s2, preparing a radix ophiopogonis zymolyte, namely crushing radix ophiopogonis, dissolving, adding a compound enzyme (cellulase: pectinase = 2: 1) for enzymolysis, and performing enzyme deactivation and concentration to obtain the zymolyte; s3, the tremella is boiled to produce glue, the soaked tremella and the medicine soup are mixed and boiled, and the radix ophiopogonis zymolyte, the ginseng powder and the sweetening agent are added; s4, molding and filling into a mold: filling the white fungus thick soup into the mold, and embedding the soaked ginseng slices, Chinese wolfberry fruits and red date slices; and S5, freeze-drying and packaging, namely sealing after pre-freezing and sublimation drying. According to the preparation method, the rehydration time of the product is less than or equal to 67 seconds, the retention rate of ginsenoside is greater than or equal to 90% and the distribution of ingredients is uniform and visual through segmented ginseng treatment (slice embedding and powder supplementing), radix ophiopogonis enzymolysis and process parameter standardization, so that the preparation method is suitable for industrial production of health-care foods and ready-to-eat foods.

This invention discloses a method for producing high-quality sodium caseinate, belonging to the field of food engineering technology. The method includes enzymatic modification, low-temperature alkali conversion, ceramic membrane microfiltration, ultrafiltration desalting and concentration, homogenized spray drying, and fluidized bed agglomeration granulation. Enzymatic modification uses a complex enzyme of endopeptide and phosphatase to hydrolyze bitter peptides and phytic acid at 45–55℃; low-temperature alkali conversion involves gradient alkali addition at 15–25℃ to avoid thermal damage and Maillard reactions; ultrafiltration employs equal-volume dialysis, with water added until the conductivity is ≤500 μS / cm, desalting and removing small-molecule bitterness; finally, agglomeration granulation is achieved by fluidized bed spraying with 0.1%–0.5% lecithin. This invention completely abandons the acid precipitation-alkali dissolution process, coupling enzymatic modification with all-physical membrane separation and purification to produce sodium caseinate that is white in color, pure in flavor, dissolves rapidly in cold water in ≤30 seconds, has an ash content ≤3.5%, reduces wastewater discharge by more than 90%, is environmentally friendly, and suitable for large-scale production.

The invention relates to a preparation method of ultrathin two-dimensional cobalt oxide rich in oxygen vacancies and an application of the ultrathin two-dimensional cobalt oxide rich in oxygen vacancies in food total antioxidant capacity detection, and belongs to the fields of low-dimensional nano materials, biological mimic enzyme catalysis and analytical chemistry. According to the preparation method, cobalt acetylacetonate and hexadecyl trimethyl ammonium bromide are adopted as raw materials, and the ultrathin two-dimensional cobalt oxide nano-enzyme rich in oxygen vacancies is prepared through a hydrothermal reaction and high-temperature pyrolysis. The obtained ultrathin two-dimensional cobalt oxide nano-enzyme rich in oxygen vacancies has excellent peroxidase-like catalytic activity and selectivity. The oxygen-vacancy-rich metal oxide has the advantages of high stability, easy mass production and low preparation cost, and is expected to be widely used in the fields of biosensing, agriculture, food engineering, catalysis and the like.

The invention discloses a novel vegetable food engineering pesticide residue detection device in the technical field of residue detection, the novel vegetable food engineering pesticide residue detection device comprises a detection box body, a quantification mechanism and a stirring mechanism, the quantification mechanism comprises a water level pipe, the water level pipe is arranged in the detection box body, and strip-shaped plates are arranged on the two sides of the inner wall of the water level pipe; a plurality of clamping grooves are formed in the outer portions of the strip-shaped plates, a movable plate is movably arranged in the water level pipe, fixing rods are symmetrically arranged at the top of the movable plate, inner spring pipes are arranged in the fixing rods, inserting rods are arranged at the free ends of the inner spring pipes, movable rods are arranged at the tops of the inserting rods, and an elastic rope is arranged between the two movable rods; the elastic rope drives the two movable rods to move, the movable rods drive the inserting rods to move in the moving process, at the moment, the height of the movable plate can be adjusted, after the movable plate is adjusted to the proper position, the pulling force on the elastic rope is released, and at the moment, the inserting rods are reset through the elastic force of the inner spring pipes to enter the clamping grooves.

The utility model relates to food fresh -keeping tool technical field discloses a kind of food engineering fresh -keeping tools, including fresh-keeping box body, the inside both sides of fresh-keeping box body are slidably installed with movable seat, and food placing plate is slidably installed between movable seat, the inner wall both sides of fresh-keeping box body are fixed with fixed plate in relative position, and the inside of fixed plate is equipped with limit clamping groove, the movable seat and the fixed plate front and back wall are fixed with the elastic limit plate of sticking together use in sticking together surface of fresh-keeping box body inner wall, and the position of elastic limit plate relative limit clamping groove is fixed with the limit clamping head of clamping in limit clamping groove inside use, the side face of fixed plate away from fresh-keeping box body inner wall is equipped with locating groove, the top of movable seat is fixed with locating lock head by fixed elastic plate, the technical solution is better to the spacing between food placing plate upper and lower better fast adjustment, it is convenient to place and use to a variety of volume food.

The present application relates to a kind of by knocking out Bacillus subtilis SacB gene constructed chassis strain and its application, belong to genetic engineering, enzyme engineering and food engineering technical field.The present application is by SacB gene on the genome of Bacillus subtilis Knocking out, obtain a kind of can efficiently express aminopeptidase, alkaline protease Bacillus subtilis expression system, lay the foundation for the efficient expression of protein, promote the efficient expression and industrial production of aminopeptidase, alkaline protease.The chassis strain described above, in the case of carrying aminopeptidase, alkaline protease expression cassette, respectively, 48H shake flask fermentation, fermentation broth aminopeptidase enzyme activity is as high as 1666.7U / mL, with the enzyme activity of starting strain as contrast, enzyme activity is increased by about 30%;Fermentation broth alkaline protease enzyme activity is as high as 6348U / mL, with the enzyme activity of starting strain as contrast, enzyme activity is increased by about 20%.

The invention discloses a polymorphic medicinal and edible stasis removing composition based on AI optimization and a classic famous prescription as well as a preparation method and application thereof, and relates to the technical field of medicinal and edible homology. The food is prepared from the following raw materials in parts by weight through artificial intelligence algorithm optimization determination: 6-12 parts of kelp, 6-12 parts of hawthorn, 3-6 parts of platycodon grandiflorum, 3-6 parts of pericarpium citri reticulatae, 6-12 parts of poria cocos and 3-6 parts of liquorice. The composition is prepared from kelp, hawthorn, platycodon grandiflorum, pericarpium citri reticulatae, poria cocos and liquorice according to a specific proportion, and is obtained by cutting and optimizing'seaweed jade pot soup 'and'cassia twig and poria cocos pills' through a deep learning algorithm. The traditional Chinese medicine theory is combined with the modern artificial intelligence and food engineering technology, a series of products with the remarkable auxiliary stasis removing effect and excellent taste and convenience are created, and the problems that traditional Chinese medicine is poor in taste and not portable, and modern functional food is unclear in effect are solved; an innovative solution is provided for daily prevention and conditioning of the nodular diseases.

The invention belongs to the technical field of food engineering, and discloses a wheat processing parameter determination method based on multi-modal vision, which comprises the following steps: step 1, determining three-dimensional morphological characteristics of wheat grains; 2, measuring the wheat suspension speed; step 3, extracting wheat color features; and step 4, determining wheat processing parameters. The method breaks through the limitation of two-dimensional image analysis, and adopts a multi-vision three-dimensional reconstruction technology to accurately obtain three-dimensional morphological parameters such as particle volume, sphericity and surface roughness.

The invention relates to the technical field of bioengineering and food engineering, in particular to a method for improving directional conversion of perigord truffle fatty acid into EPA and application of the perigord truffle fatty acid into the EPA. According to the system, a natural enzyme system and active ingredients in a nannochloropsis oculata lysate are fully utilized as biological catalytic components, and the physical strengthening effect of multi-frequency ultrasound is combined; under mild conditions, the unsaturated efficiency of fatty acid and the generation rate of EPA in a reaction system are remarkably improved. According to the method, perigord truffle is subjected to ethanol extraction, lipid components of perigord truffle are fully released, and the perigord truffle and a microalgae lysate have a synergistic effect, so that a composite reaction system with biological catalysis and physical promotion functions is constructed. The method is simple and controllable in process, has the advantages of being short in reaction time, low in energy consumption, environmentally friendly and the like, and meanwhile achieves the dual purposes of high-value utilization of perigord truffle resources and sustainable production of EPA. According to the method, an innovative solution is provided for high-value utilization of perigord truffle resources.

This utility model relates to the fields of food engineering and biotechnology, and discloses an ultrasonic-assisted defrosting device for pet food. It includes a shell, a control screen, a protective door, and a heating component. The control screen is fixedly connected to the surface of the shell, and the protective door is installed on the surface of the shell. The heating component is installed on the inner wall of the shell, and the inner wall of the shell has an installation structure including a sliding groove. A slider is slidably connected to the inner wall of the sliding groove, and a fixing rod is fixedly connected to the inner wall of the sliding groove. The arc surface of the fixing rod is slidably connected to the surface of the slider, and a placement plate is fixedly connected to the surface of the slider. A handle is fixedly connected to the surface of the placement plate. This utility model solves the problem in existing ultrasonic-assisted defrosting devices for pet food where, when the food is placed inside the device, it is often difficult to dry in layers, affecting the degree of drying and thus the working efficiency of the device.

The invention discloses high-quality physalis pubescens concentrated juice, a preparation method thereof and a physalis pubescens compound beverage containing the high-quality physalis pubescens concentrated juice, and relates to the technical field of food engineering. The preparation method comprises composite enzymolysis before concentration, a color protection process in an enzymolysis process, a clarification process before concentration and a concentration process. In the process optimization process, evaluation is carried out by taking the juice yield, the browning degree, the light transmittance and the high concentration efficiency as evaluation indexes, and a good preparation process is obtained. Besides, the prepared physalis pubescens concentrated juice and raspberry juice are mixed, meanwhile, cane sugar, citric acid and a stabilizer CNC-Na are added, the physalis pubescens-raspberry compound juice is prepared, the physalis pubescens-raspberry compound juice is good in color and luster state and sour and sweet in taste, the physalis pubescens and raspberries are coordinated in taste, the tissue state is uniform and stable, and layering and foreign matter are avoided.

The utility model relates to food engineering technical field, and disclose a kind of snake quick drying device, including heating tank, heating tank outside connection heat tracing jacket, heating tank tail end connects ultrasonic tank head end, ultrasonic tank tail end connects cooling tank head end, cooling tank one side connection magnetocaloric refrigeration structure, heating tank, ultrasonic tank and cooling tank inside are provided with conveyor belt and are set up collection box to the cooling tank outside with the extension of conveyor belt end, heating tank, ultrasonic tank and cooling tank bottom are equipped with drain device, the conveyor belt is set in the middle of each tank body connected, and the conveyor belt end is also equipped with collection box. The utility model solves the core defects of the existing snake drying technology, such as high temperature resulting in quality deterioration, surface crust hindering dehydration, residual heat leading to secondary damage and intermittent production low efficiency high consumption, by innovative integration of gentle radiation heating, circumferential ultrasonic deep layer wall breaking dehydration and rotating magnet refrigeration active quenching technology.

This invention discloses a method for preparing diglycerides using an immobilized enzyme from ultrafine pulverized plant protein, relating to the field of food engineering technology. The method employs a high-energy media mill to co-mill plant protein and chitosan to prepare a composite material with a porous network structure. This composite material is then mixed with a lipase solution to immobilize the lipase within the composite material, obtaining an immobilized enzyme. This immobilized enzyme is used as an emulsifier, and vegetable oil as a reaction substrate is added. A Pickering emulsion is prepared using a high-speed shear mill, followed by catalytic hydrolysis of the vegetable oil in a constant-temperature water bath to obtain the diglyceride product. This system improves enzyme catalytic efficiency, achieving a diglyceride content of over 45% after 30 minutes of reaction, and maintaining over 40% even after eight repetitions. The immobilized enzyme carrier of this invention uses inexpensive natural food raw materials, is simple to prepare, highly safe, produces minimal pollution, and allows for continuous production. Furthermore, the prepared Pickering emulsion exhibits good stability, which is beneficial for the clean production of diglycerides and has excellent industrialization potential.

This invention discloses a pretreatment modification method for dietary fiber in ready-to-eat Polygonatum sibiricum, belonging to the field of food engineering technology. S1: Place the Polygonatum sibiricum raw material in a steam flash explosion device, introduce saturated steam at a pressure of 1.2-1.6 MPa and a temperature of 180-200℃, maintain pressure for 90-150 seconds, then release pressure to atmospheric pressure to obtain flash-exploded Polygonatum sibiricum material; S2: Mix the flash-exploded Polygonatum sibiricum material with water to form a slurry, and sequentially perform enzymatic hydrolysis of endo-cellulosic composite cellulose, hemicellulose, and debranched cellulose, with enzyme inactivation treatment after each hydrolysis step to obtain enzymatically hydrolyzed Polygonatum slurry. This invention shortens the traditional 15-day production cycle to less than 24 hours, realizing a shift from natural experience to digital intelligent manufacturing. The batch-to-batch stability of key indicators is far superior to that of traditional processes, laying a technical foundation for industrialized and standardized production.

The utility model belongs to the technical field of food engineering, and particularly relates to a glue pudding separating device which comprises a plate body, a placing support is fixedly installed on the inner surface of the plate body, a limiting frame is arranged above the plate body, an auxiliary separating assembly is arranged below the limiting frame, and the auxiliary separating assembly comprises a pressing rod. The pressing rod is fixedly connected to the lower side of the limiting frame, the bottom of the pressing rod is fixedly connected with a first round rod, the first round rod is slidably connected into a straight notch, and the straight notch is formed in the outer wall of the straight rod. According to the glue pudding separating device, the limiting frame is pressed to drive the pressing rod, the straight rod, the vertical rod and other workpieces to be used in cooperation, the ejector rod on the sliding plate ejects glue pudding and assists the glue pudding to be separated from the containing opening, the simple mechanical structure is utilized in the design, the downward pressing action of the limiting frame is converted into ejection separating force on the glue pudding, operation is convenient and efficient, and practicability is high. The rice dumpling separation difficulty is effectively reduced, and the separation efficiency is improved.

The invention discloses EGCG (epigallocatechin gallate) composite core-shell nanoparticles as well as a preparation method and application thereof, and belongs to the technical field of food engineering. The EGCG composite core-shell nanoparticle comprises an inner core formed by EGCG and corn protein, and mango pectin and an extracellular polysaccharide layer which are coated on the outer surface of the inner core, the preparation method comprises the following steps: (1) dissolving corn protein in an alcohol-containing solution, stirring, and adding EGCG; (2) adding into water, stirring, and carrying out reduced-pressure rotary evaporation to remove alcohol; (3) adding mango pectin and exopolysaccharide into water, stirring, and performing ultrasonic treatment; and (4) mixing, stirring, carrying out refrigerated centrifugation to remove the precipitate, and carrying out vacuum freeze drying. After the EGCG composite core-shell nanoparticles are applied to bread, high antioxidant activity can be maintained in the storage period, the peroxide value and the total number of bacterial colonies are reduced, and it is indicated that the EGCG composite core-shell nanoparticles are beneficial for delaying degradation of active ingredients and inhibiting lipid oxidation and microbial growth.

The invention discloses a coffee olive solid beverage and a preparation method thereof, and relates to the technical field of food engineering.The coffee olive solid beverage specifically comprises coffee powder, olive capsule particles, gas capsule particles and maltodextrin, the olive capsule particles comprise olive powder and capsule shells wrapping the olive powder, and the capsule shells comprise sweetening agents, spices, starch and plasticizers; the gas capsule particle comprises a sealed shell and food-grade gas wrapped in the sealed shell, and the components of the sealed shell are the same as those of the capsule shell. The arrangement mode that the olive powder extract and the coffee powder are separated is adopted, the situation that the olive powder extract and the coffee powder react due to direct contact in the product storage period can be effectively avoided, and the quality stability of the coffee and olive solid beverage in the storage period is guaranteed; by adding the olive powder extract into the capsule shell and confining coffee fragrance, the beverage can gradually release coffee fragrance and olive powder extract fragrance in the brewing process, and drinking sensory experience is optimized.

This application discloses a composite aerogel for controlling Nisin release, its preparation method, and its application, relating to the field of food engineering technology. By selecting chitosan nanoparticles and nanocellulose as two loading materials, Nisin is dual-loaded to improve the Nisin loading rate. The composite aerogel obtained by freeze-drying has a three-dimensional porous network structure inside, which can provide channels for Nisin delivery and release, prolong the Nisin release cycle, and realize the sustained and controlled release of Nisin.

The utility model relates to the cross field of food engineering and mechanical manufacturing discloses a food processing and packaging device, including mounting panel, the outer wall fixed connection of mounting panel has a plurality of fixed blocks, the inner wall fixed connection of a plurality of fixed blocks all has the slide rod, the outer wall sliding connection of slide rod has a plurality of sliding blocks, the outer wall fixed connection of a plurality of sliding blocks all has fixed plate no.

The application relates to a method for bioconversion of naringenin to produce apigenin and dihydroquercetin, belonging to the field of biotechnology and food engineering, and comprising the following steps: (1) screening and mutagenic breeding of high-yield strains; (2) high-density fermentation for converting naringenin into apigenin and dihydroquercetin; and (3) extraction and refining to obtain high-purity apigenin and dihydroquercetin. Rhodococcus opacus OMK-104 bioconversion of cheap and easily available naringenin into high-value apigenin and dihydroquercetin has high conversion rate and high titer of apigenin and dihydroquercetin, and has a positive effect on reducing the production cost of apigenin and dihydroquercetin and promoting large-scale commercial application of apigenin and dihydroquercetin.

This utility model discloses an automatic nutritional meal preparation and dispensing device, belonging to the field of food engineering technology. It includes a support frame and a nutritional meal preparation box. Two side plates are fixedly connected to the top of the support frame. A main control panel is fixedly connected to the surface of one of the side plates. A conveyor belt is fixedly connected to the top of the support frame. A first motor is fixedly connected to the surface of one of the side plates. An isolation frame is fixedly connected to the top of the two side plates. A dispensing box is fixedly connected to the top of the isolation frame. This utility model, by setting a transmission structure composed of a third motor, a worm gear, internal and external worm wheels, transmission gears, and a transmission rack, can achieve synchronous opening and closing of the sensing sealing plate with a single drive source, realizing synchronous dispensing of multiple cuisines. This simplifies the equipment structure, reduces costs, and ensures the stability of the opening and closing action, effectively breaking through the limitations of the traditional single filling mode and significantly improving dispensing efficiency.

The invention discloses an in-situ resource conversion and food structure generation system for an extreme physical environment, belongs to the technical field of intersection of extreme environmental engineering and food engineering, and aims to solve the problems that food supply depends on external transportation for a long time and the anti-risk capability of a traditional agricultural system is insufficient in the extreme physical environment. The system comprises a resource acquisition module, a resource conversion module, a food structure generation module and a system operation control module. The system generates food base components by obtaining environmental in-situ resources, using biotransformation links, non-biotransformation links, or a combination thereof, and using physical conditions in an extreme environment as processing boundary conditions to perform structured, conformal, or ingestible treatment on the food base components or biological products, such that the food base components or biological products are obtained. And a structured food for human ingestion is generated. The system operation control module dynamically adjusts operation parameters according to a resource state, an energy state or a module operation state, triggers a degradation operation strategy under an abnormal or limited working condition, and preferentially maintains continuous supply of basic food. According to the invention, long-term operation can be realized without external continuous material supply, and the system is suitable for non-earth or non-earth-like extreme physical environments.

The invention relates to the technical field of food engineering and chemical separation, and discloses a lactose solution decoloring method based on strongly acidic macroporous adsorption resin, which comprises the following steps: pretreating strongly acidic macroporous adsorption resin with sulfonic acid groups; enabling a lactose solution to be decolored with the mass concentration of 30-50% to flow through the pretreated resin at the volume flow rate of 1.0-2.0 BV / h under the conditions that the pH value is 3.0-6.0 and the temperature is 70-90 DEG C, and carrying out adsorption decoloring; regeneration treatment is carried out on the resin saturated through adsorption, and the regeneration treatment sequentially comprises hot water flushing, alkaline solution elution and acid solution treatment. The decolorization process can be performed at high temperature, so that the problem of blockage of a pipeline or a column bed caused by easy crystallization of the high-concentration lactose solution at low temperature is effectively avoided, efficient decolorization and deproteinization of the lactose solution are realized, and meanwhile, the method has the technical effects that the lactose loss rate is low, and the resin can be recycled.

The invention discloses a method for improving starch 3D printing characteristics and product retrogradation performance, and belongs to the crossing field of food engineering, 3D printing materials and food processing technologies. Dispersing high-amylose corn starch in water to prepare a starch suspension, and performing gelatinization treatment; adding an edible rose polyphenol extract into the gelatinized starch solution, uniformly stirring, and carrying out multi-mode ultrasonic treatment on the starch and rose polyphenol mixture to obtain a rose polyphenol-high amylose corn starch compound; adding hydrophilic colloid into the compound, uniformly stirring, and cooling to room temperature to form modified starch gel; and 3D printing is conducted on the starch gel, and a 3D printing product is obtained. The problems that starch is poor in 3D printing performance and digestion performance and printed products are fast in retrogradation are effectively solved, a core material solution is provided for developing personalized 3D printing food which is high in performance, nutritional, healthy and long in shelf life, and a new technical approach is provided for functional 3D printing food.

The present application discloses a method for reducing cholesterol in beef tallow and use thereof, and relates to the field of food engineering technology. The present application effectively reduces the cholesterol content in beef tallow by adsorbing cholesterol in the beef tallow using β-cyclodextrin and pectin-crosslinked or chitosan-crosslinked β-cyclodextrin complex. In terms of flavor performance, after treatment with the pectin-crosslinked β-cyclodextrin complex, the beef tallow shows significant improvement over untreated beef tallow and beef tallow treated with the chitosan-crosslinked β-cyclodextrin complex. The use of β-cyclodextrin and pectin- or chitosan-crosslinked complex can adjust the hardness of beef tallow, and the prepared beef tallow can be applied in a wider range of scenarios.

The present application belongs to the technical field of bioengineering and food engineering, and discloses a method for improving the content of DHA, the ratio of DHA / DPA and the proportion of sn-2 DHA in the fermentation product of Schizochytrium sp., a product and application, wherein the oil-producing Schizochytrium sp. is subjected to fed-batch fermentation culture, and shikonin is added during the fermentation culture. The present application provides a fermentation strategy for producing high-quality DHA algal oil by using Schizochytrium sp., wherein shikonin is added to the fermentation medium of Schizochytrium sp., so that the Schizochytrium sp. obtains lipids with high DHA ratio, high DHA / DPA ratio and high sn-2 DHA proportion. The obtained Schizochytrium sp. lipids not only have a significantly improved total DHA content compared with traditional fermentation strategies, but also have a significantly improved DHA / DPA ratio and sn-2 DHA proportion.

The invention provides a double-field regulation and control 3D printing head and a control method thereof, and relates to the technical field of three-dimensional printing, the double-field regulation and control 3D printing head comprises a reaction chamber and a mixing chamber at the downstream of the reaction chamber, and the reaction chamber and the mixing chamber are communicated through a plurality of channels. A pair of parallel electrode plates are arranged in the reaction chamber and connected to a power supply unit, and materials are subjected to ohmic heating by applying alternating-current voltage or electrolyzed in the reaction chamber by applying direct-current voltage to form pH gradient distribution, so that collaborative regulation and control of a temperature field and a chemical field are integrally realized. By controlling an electric control valve arranged on the channel and a pump at the discharge port of the mixing chamber, the material in the target pH region in the reaction chamber can be conveyed to the mixing chamber, so that the pH value of the material in the mixing chamber is adjusted, and the material is finally extruded. The invention further correspondingly provides a control method of the printing head, the problems that in-situ curing response is slow and precision is low in traditional printing are solved through the scheme, rapid and accurate in-situ regulation and control over the material state are achieved, and the printing head is particularly suitable for the fields of biomedicine, food engineering and the like.

This invention belongs to the field of microbial fermentation and food engineering technology, and discloses a fermentation method and application for enhancing the DHA production capacity of *Schizochytrium* phospholipids. *Schizochytrium* is fermented for 32-60 hours, with optimized addition of organic nitrogen sources and phosphates during the fermentation process. The seed culture medium formulation for *Schizochytrium* remains unchanged; only the fermentation medium formulation is modified. This invention provides a fermentation strategy to enhance the DHA production capacity of *Schizochytrium* phospholipids by optimizing the organic nitrogen sources and phosphates in the fermentation medium, enabling *Schizochytrium* to obtain a higher content of DHA phospholipids. The obtained *Schizochytrium* oil not only has a significantly higher total DHA content than traditional fermentation strategies, but also a significantly higher proportion of DHA phospholipids. Applying this method to the preparation of *Schizochytrium* algal powder yields *Schizochytrium* algal powder rich in DHA phospholipids, which is more beneficial for its application in aquatic feed.

The invention provides chitosan for food packaging, a preparation method of the chitosan and a preparation method of a food packaging film, and belongs to the field of food engineering.The preparation method of the chitosan comprises the steps that natural pigment is added into N, N-dimethylformamide, stirring is conducted till the natural pigment is completely dissolved, and a pigment solution is obtained; dissolving chitosan in a glacial acetic acid aqueous solution, and fully swelling to form a transparent solution; dropwise adding the pigment solution into the transparent solution at room temperature, and uniformly stirring and mixing to obtain a mixture; adding a sufficient amount of a formaldehyde solution into the mixture until the reaction is completed, dropwise adding a sodium hydroxide solution to enable a product to form a precipitate, collecting the precipitate, and washing and freeze-drying the precipitate to obtain chitosan powder; wherein the natural pigment comprises curcumin and alizarin. The chitosan prepared by the method can improve the dispersibility of natural pigments in a film, improve the fixation mode of the pigments, avoid migration and loss, improve the light and heat stability of the natural pigments, improve the structural stability and mechanical properties of the film, and realize the double functions of preservation and indication.