188results about How to "Prevent oxidation and discoloration" patented technology

The invention discloses a production method of fermented beef jerky. The production method is characterized by comprising the steps of: cutting fresh beef into 3-4cm strips, soaking the strips by a mixing solution of CaCl2, composite phosphate and ginger juice for a whole night, adding glucose and a fermenting agent in the mixture, fermenting for 8 hours and roasting for 12 hours, boiling in boiling water and roasting for 1 hour, and implementing vacuum packaging and high-pressure sterilization to obtain the fermented beef jerky. The production method makes use of the acid production capacity of acid kumiss from natural fermentation and lactobacillus which is excellent in growth property, and is easy to control a fermentation process and short in fermentation cycle; the production method changes conventional processes of boiling twice, frying and the like, so that the deterioration of a later product due to over oxidation in the frying process is avoided and the shelf life is prolonged; and by adding a tendering pickling process and the fermentation process, the fermented beef jerky is unique in flavor, and has soft lactic acid taste and good color, reflects the fermentation property of lactobacillus, is soft and tender in texture, and is applicable to people of all ages.

The invention relates to a making method of instant squid food. The making method comprises the steps of pretreatment, soaking, tenderization, stewing, flavoring, baking and package. The making method has the advantages that before squids are made, the squid meat is soaked in tea polyphenol solution, residual formaldehyde can be removed, and meanwhile, the squid meat can be prevented from discoloring through oxidation; before the squid meat stewing, the squid meat is subjected to tenderization treatment so that the original muscular tissue structure of the squid meat is destroyed, the made instant squid food has good mouth feeling, excellent taste and good palatability, and the selection of mass consumers is met; and the storage of the used tea polyphenol and papain is rich, the cost of raw materials is low, the raw materials are easy to obtain, in addition, the extraction process is simple, and the production cost is low.

An instant granular solid green tea with unique tea smell is prepared from natural green tea through proportionally extracting in water at 75-95 deg.C, adding carambola juice and beta-cyclodextrin, stirring, concentrating and freeze-drying. It is rich in nutrients including amino acids, tea polyphenol, flavone, VC and trace elements.

The invention relates to honey-waxberry yoghourt and a production method thereof. The honey-waxberry yoghourt is characterized by comprising a component A, a component B and a component C, wherein the component A is milk; the component B comprises the following components according to the weight percent of the component A: 4%-8% of honey water solution, 8%-24% of waxberry juice and 4%-8% of cane sugar; the component C is strain powder, and the adding amount of the strain powder is equal to 2%-3% of the component A according to weight percent. According to the production method, the honey, the waxberry and the milk are processed into a yoghourt beverage in certain proportion, the nutrition and the taste are integrated, the honey-waxberry yoghourt has the nutrition and healthcare functions of the honey, the waxberry and the yoghourt, the assortment of yoghourt products are enriched, and particularly, the market blank of honey-waxberry yoghourt is made up. Specifically, the honey-waxberry yoghourt has the advantages that the color is uniform and is pale violet red, the aroma of the waxberry and the honey and the milk fragrance are properly coordinated, the sweetness is moderate, the taste is fine, the honey-waxberry yoghourt is in a uniform curdled milk state, and no or few whey is separated out.

The present invention relates to a medlar health-care preserved fruit and a method of manufacturing the same, the product is composed of (by weight parts of raw material in finished product) 80 to 95% of medlar dried fruit, 2 to 15% of fruit juice, 0.3 to 5.0% of compatibility medicinal materials soaking juice, 0.1 to3.5% of citric acid, 0.1 to 1.0% of VC, the rest is pure water. The finished product is made by filtrating and edulcorating, purifying, dried fruit softening, stock leaked by medicament, mixing and agitating, stock leaked by fruit juice, antisticking process, sterilizing and low temperation drying of the medlar dried fruit.

The invention provides a stabilizing agent used for nonaqueous electrolytic solution, and the stabilizing agent is composed of phosphite ester compound and amine compound. The invention also provides the nonaqueous electrolytic solution containing the stabilizing agent. The nonaqueous electrolytic solution contains 85-90 percent (weight) of organic solvent, 8-14 percent (weight) of lithium salt and 0.1-5 percent (weight) of the stabilizing agent. In the stabilizing agent of the invention, the phosphite ester compound can be oxidized preferentially to play a role of protecting other effective components in the nonaqueous electrolytic solution; and the amine compound can catch active protons in the nonaqueous electrolytic solution and can restrain the decomposition of LiPF6 and reduce the HF content of electrolytic solution. The phosphite ester compound and the amine compound are matched for use to prevent the acidity of the nonaqueous electrolytic solution from being overhigh and prevent the nonaqueous electrolytic solution from being oxidized to change the color so as to well stabilize the nonaqueous electrolytic solution, thereby the nonaqueous electrolytic solution containing the stabilizing agent can keep stable for a long time.

The invention discloses a water-soluble nickel protective agent as well as a preparation method and a use method thereof. The preparation method comprises the steps of: dissolving 0.5-1.5 percent by weight of a film forming substance into 14-34 percent of cosurfactant to prepare a solution A; dissolving 4-9 percent of surfactant into the balance of water to prepare a solution B; and adding the solution A into the solution B for micro-emulsification, and cooling to obtain the water-soluble nickel protective agent. The use method comprises the steps of: heating the water-soluble nickel protective agent to 60-80 DEG C, placing a clean and dry workpiece into the heated the water-soluble nickel protective agent, dipping for 2-10min at 60-80 DEG C, taking out, airing, packing and warehousing. The water-soluble nickel protective agent has the advantages of strong corrosion resistance, stable electric property, safety, environmental-friendliness and low cost.

The invention discloses a preparation method of an optical transparent two-sided sticky tape. The preparation method is characterized by comprising the following steps: adding butyl acrylate, iso-octyl acrylate, ethyl methacrylate, functional monomers, glycidyl methacrylate, solvent I and an initiator to a reaction kettle to carry out copolymerization for 4-6h under the protection of nitrogen, thus obtaining acrylate prepolymer resin; mixing the acrylate prepolymer resin with a curing agent and a diluting solvent to obtain an acrylate optical glue; uniformly spreading the acrylate optical glue on polyester release film A with a comma blade by a coating machine and then feeding the polyester release film A coated with the acrylate optical glue into a six-section drying channel at a linear velocity of 5-15m / min, wherein the length of the drying channel is 20-25m and the temperature of the drying channel is 65-100 DEG C; compounding the polyester release film A and polyester release film B which are the same in width under the pressure of a compression roller being 0.4MPa; curing in a 40-45 DEG C drying room, thus obtaining the optical transparent two-sided sticky tape. The optical transparent two-sided sticky tape has extremely low viscosity and excellent performance.

A copper foil having a high etching factor, enabling formation of fine patterns excellent in linearity of bottom lines of circuit patterns and without leaving particles of copper foil forming the circuit patterns in the resin, free from a drop in bond strength between the copper foil and resin substrate due to the processing for formation of solder balls, excellent in visibility, and excellent in mounting of ICs on fine patterns, comprising a copper foil on at least one surface of which is provided an alloy fine roughening particle layer comprised of a copper-cobalt-nickel alloy with contents of cobalt and nickel equal to or greater than that of copper, specifically a copper foil on the surface of the copper foil for bonding with the resin substrate of which is provided an alloy fine roughening particle layer comprised of 5 to 12 mg / dm2 copper, 6 to 13 mg / dm2 cobalt, and 5 to 12 mg / dm2 nickel, wherein the alloy fine roughening particle layer provided on the copper foil surface may be treated for stainproof or may be treated by a silane coupling agent.

The invention discloses a preparation method of a high-precision rolled copper foil for a lithium battery. The preparation method is characterized in that I, technological steps and technological parameters of rolling of a copper foil rolling machine are improved according to a copper foil rolling theory, a 0.15-mm copper foil parent material is prepared into a 0.0097-mm rolled copper foil through five passes of rolling, the rolled copper foil is tested through a bending resistance testing machine and resists 784 times of bending on average, and the bending resistance requirement (the bending resistance time is larger than 600) of the rolled copper foil for the lithium battery is met; and II, chromium plating and zinc plating surface treatment is added after rolling forming is carried out and before the rolled copper foil is applied to the lithium battery, and the technological steps and technological parameters of chromium plating and zinc plating are optimized, so that the rolled copper foil subjected to rolling forming is prevented from oxidizing and discoloring, the corrosion resistance is improved, and the rolled copper foil does not oxidize and discolor when the rolled copper foil is stored for a long time at the normal temperature and is placed at the high temperature of 180 DEG C for 30 minutes.

The invention relates to a metal zipper, the manufacture technology and a sealing and treating machine for the oil on the surface of the metal zipper, belonging to the technical field of daily necessities. A layer of oil is covered on the surface of the metal zipper; the oil comprises double-component epoxy resin varnish, epoxy curing agent and epoxide diluent with the weight ratio of 1:1 to 1.5:2.5 to 3.5. The metal zipper has the functions of rusting prevention, color losing resistance and anti-oxidizing discoloration with the advantages of good rigidity, friction resistance, scratch resistance and chemical corrosion resistance.

The invention discloses a water-soluble magnesium alloy machining fluid.The water-soluble magnesium alloy machining fluid is prepared from, by weight, 40-50% of base oil or oiliness agent, 5-15% of an anionic surfactant, 0.5-3% of a nonionic surfactant, 3-6% of a black metal sustained-release agent, 5-10% of a coupling agent, 0.5-2% of a copper alloy corrosion inhibitor, 2-8% of a magnesium / aluminum alloy corrosion inhibitor, 1-3% of a bactericide, 0.2-1% of an antifoaming agent and 3-12% of pure water.The water-soluble magnesium alloy machining fluid is high in universality, suitable for various metals, particularly applicable to machining of magnesium alloy and magnesium-aluminum alloy parts, excellent in corrosion resistance effect on magnesium alloy, long in efficacy lasting time and effective in prevention of oxidative discoloration of sensitive magnesium alloy and magnesium-aluminum alloy and inhibition of hydrogen generation and magnesium ion dissolution.In addition, the water-soluble magnesium alloy machining fluid has excellent lubricating performance and anti-rusting performance, remarkable hard water resistance and the like, long in service life, free of toxic and harmful substances such as nitrites and phenols and beneficial to environment and health.

The invention discloses an electroless tin plating formula for a printed circuit board. The formula comprises the following components with the following concentrations: 10-30g / L of stannous ions, 70-130g / L of thiourea, 30-70g / L of methanesulfonic acid, 30-60g / L of citric acid, 20-50g / L of tetrasodium iminodisuccinate, 10-30g / L of carbohydrazide, 10-50mg / L of interfacial agent, 0.05-0.15g / L of bismuth acetate and 20-40g / L of polyamino polyether methylene phosphonate, wherein the component solutions are uniformly mixed and then prepared into an electroless tin plating solution; and the electroless tin plating solution has the following characteristics: tin is stable in tin deposition rate, bivalent tin is not liable to be oxidized into tetravalent tin, and the solution is high in stability. The formula disclosed by the invention contains many complexing agents, the stannous ions are not liable to be oxidized into tetravalent tin, the oxidization of oxygen dissolved in the plating solution can be cancelled by virtue of a reducing agent, the plating solution contains bismuth acetate, a plating layer is a tin-bismuth alloy, and the alloyed plating layer is not liable to grow tin whiskers; and moreover, the electroless tin plating solution has the following characteristics: tin is stable in tin deposition rate, bivalent tin is not liable to be oxidized into tetravalent tin, and the solution is high in stability.

The invention discloses a soaking treatment method for oil repellency and antioxidation of a copper net or foamy copper. The soaking treatment method comprises the following steps of: soaking the copper net or the foamy copper in a mixed solution including the components of 1.0mol / L-2.0mol / L of hydrochloric acid, 2g / L-5g / L of a surfactant, 1g / L-3g / L of fluorosilane and alcohol in concentration, wherein the water-bath heating temperature is 30 DEG C to 90 DEG C, the soaking time is 5 minutes to 30 minutes; washing the soaked and treated copper net or foamy copper by deionized water, and putting the washed copper net or foamy copper to an oven for curing for 0.5 hour to 1.5 hours under the temperature of 150 DEG C to 250 DEG C; and taking out the cured copper net or foamy copper to obtain the bright oil-repellent anti-oxidant copper net or foamy copper. The soaking treatment method disclosed by the invention can be used for effectively preventing the formation of an oxide layer.

The invention relates to a method for repairing cracks in an installing support of a combustion box. According to the method for repairing the cracks in the installing support of the combustion box, a base body is heated in an electric arc mode, a welding current is adjusted, the purpose of having control over the heat input quantity is achieved, namely, a parent material is prevented from melting, and can be fully heated, so that it is ensured that spreading wetting is fully carried out on a BNi-2 welding wire after the BNi-2 welding wire is melted, when welding is carried out, inert gas is fed into a welding zone, a weld surface is prevented from oxidation discoloration or burning loss, fluorescent inspection is carried out on the weld surface after welding is carried out, and the weld surface is free of the defects such as the cracks or air holes. A welding tool is omitted, production efficiency is improved, and the cost is reduced.

The invention provides a light-colored cardanol alkyl ether epoxy curing agent and a preparation method thereof, the cardanol alkyl ether epoxy curing agent prepared by the method, and a cured object formed by the curing agent and an epoxy resin. The preparing method comprises the steps of: mixing 1 mol of cardanol alkyl ether and 1-3 mol of polyamine; then adding 1- 3 mol of formaldehyde in batch, and controlling a reaction temperature between 80 DEG C and 90 DEG C and reacting for 4 hours; next, heating to 100-120 DEG C and evaporating water generated by reaction; at last, retaining at 80-120 DEG C, distilling at a reduced pressure till no moisture is evaporated; and obtaining the cardanol alkyl ether epoxy curing agent through Mannich reaction. The curing agent obtained by the invention is relatively light in color and non-discoloring after long-time storage; in addition, mixture of the curing agent and the epoxy resin encounters phase separation in curing, so that the impact strength of the cured object is improved, and the flexibility of material is reinforced.

The invention discloses a material particle screening device for a plastic extrusion granulation system. The material particle screening device comprises a rack, a motor, a sieve, a material bin and damping springs, wherein the sieve is fixedly arranged on the upper side of the material bin, a vibrator is installed between the rack and the sieve, at least two damping springs are installed at the bottom of the material bin, and an air blowing device is installed on the rack on the upper side of the sieve. According to the material particle screening device, the temperature of plastic particles can be reduced, oxidation stain or mutual bonding is avoided, meanwhile, the dust flowing is accelerated, sieve holes are prevented from being blocked, the screening efficiency and the production efficiency are improved while the quality of material particles is ensured.

The invention discloses a method for preparing a vitamin C tablet. The method comprises the following steps of: a, weighting the following raw materials: vitamin C, microcrystalline cellulose, hyprolose and sodium carboxymethyl starch; b, weighting 3 to 10g of octadecanol, adding the octadecanol into 100 ml of 80 to 95 percent of ethanol solution, and stirring the mixture to dissolve so as to prepare inclusion liquor; c, screening the vitamin C with a 100-mesh screen, putting the vitamin C into a fluidized drying bed or a stirrer, spraying the inclusion liquor in a volume mass ratio of 0.1:1 under the state of stirring, drying the mixture, and controlling the temperature to be between 45 and 55 DEG C; and d, putting the dried vitamin C into the stirrer, spraying the inclusion liquor in a volume mass ratio of 0.05-0.1:1 under the state of stirring, drying the mixture, uniformly mixing the included vitamin C and the remaining raw materials, and tabletting the mixture. Compared with the conventional wet granulation process, the method can improve production efficiency by 3 to 5 times and saves energy resources.

The invention discloses a light-diffusion environment-friendly and inflaming retarding polycarbonate based composition for LED (Light-Emitting Diode) illumination and a preparation method thereof. The composition is prepared from the following raw materials in parts by weight of: 50-90 parts of diphenol A aromatic polycarbonate A, 1-40 parts of diphenol A aromatic polycarbonate B, 0.005-2 parts of light dispersant A, 0.05-1 part of light dispersant B, 0.01-2 parts of fire retardant, 0-2 parts of antioxidant A, 0-2 parts of antioxidant B and 0-2 parts of antioxidant C. The composition disclosed by the invention has excellent mechanical property and machining performance, has higher light transmittance and haze, and has a good inflaming retarding effect.

The invention relates to a processing technology of fried cakes of lotus roots. During the processing, lotus roots are firstly subjected to dip processing through citric acid and vitamin C, and then sodium hexametahposphate and sodium (potassium) citrate are added to perform subsequent processing. The processing technology adopts 0.03 to 0.5 percent of citric acid and 0.03 to 0.5 percent of vitamin C to control the pH of dipping liquid, so as to prevent the lotus roots from being oxidized and discolored, and 0.03 to 0.1 percent of sodium hexametahposphate and 0.05 to 5.0 percent of sodium (potassium) citrate are added to be resistant of oxidation, so as to prevent the lotus roots from being discolored during processing and cooking processes, and further, the natural dye-forming reaction of food reaches better effect during the frying process and products can properly embody characteristics of lotus roots, and color and flavor characteristics of lotus roots are obvious and different from those of other food. Sodium hexametahposphate and 0.05 to 5.0 percent of sodium citrate can prevent the brown stain of lotus roots at high temperature frying state, and metallic iron and manganese ion of sodium hexametahposphat and sodium citrate are generally believed to have strengthened complexing action and to prevent brown stain.

The invention discloses combined lemon and flower dry tea, which comprises the following ingredients based on mass ratio: 1-30% of lemon slice, 5-40% of single flower, 10-45% of medlar, 1-8% of aspartame and 2-80% of added materials, wherein the added materials can be any one or the mixture of more than two of water soluble starch, lemon essential oil, citric acid, glucose, honey, xylitol and Vc (Vitamin C) powder; and the single flower can be dried flower which is obtained by drying any one of honeysuckle, chrysanthemum, arabian jasmine flower, rose, greenish lily flower, lemon flower and carnation. By adopting the dry tea form, external sugar impregnation liquid infiltrates pulp, and various enzymes in the lemon slice are destroyed to prevent tannin substances in the lemon slice against oxidation and discolouration under the action of oxidase and peroxidase, which is conductive to the freshness keeping of the lemon slice.

The invention provides a processing method of dry potato chips. The processing method comprises five working procedures of selecting raw materials, washing and peeling the raw materials, slicing and immersing the peeled materials, drying the sliced materials at a low temperature, and bagging and sterilizing the products. The processing method has the beneficial effects that potatoes are sliced and then are immediately put into an immersing solution so as to effectively prevent the dry potato chips from oxidization and color change; meanwhile, the dry potato chips can absorb effective components of Chinese herbal medicines in the immersing solution, so that the dry potato chips have a Chinese herbal medicine flavor, the quality guarantee period of the dry potato chips can be prolonged under the precondition of not adding chemical additives, and the dry potato chips can be stored for more than half a year at room temperature; when being eaten, the dry potato chips can be processed by methods of steaming, frying by oil, cooking for soup and the like; the dry potato chips have a mellow mouth feel and are convenient and sanitary, and nutrition ingredients of the dry potato chips are not lost; the processing method is simple and is easy to operate; and automatic line production and large-scale industrialization of the dry potato chips can be realized, and the requirements on increasing living quality and food diversification of people are met.

The invention discloses printing paste used for gold powder printing of stone wall paper and a preparation method. The printing paste is prepared by carrying out the following steps: emulsifying 2.0-2.2 parts by mass of 1,4-butanediol dimethacrylate, 1.0-1.1 parts by mass of itaconic acid, 130-140 parts by mass of ethyl acrylate, 31-32 parts by mass of butyl acrylate, 6.4-6.6 parts by mass of hydroxyethyl methylacrylate, 27-28 parts by mass of methyl methacrylate, 4.0-4.2 parts by mass of 2-(methacryloyloxy)ethyl acetoacetate, 32-33 parts by mass of styrene, 2-2.3 parts by mass of fatty alcohol-polyoxyethylene ether 23E9 and 230-250 parts by mass of deionized water, and initiating polymerization; compounding 20-25 parts by mass of a mixed solution of sorbitol and benzotriazole, 20-22 parts by mass of an associative leveling rheological agent and 10-15 parts by mass of an acrylic dispersant, and mixing. The printing paste in high in transparency, glossiness and fastness, and is resistant to air oxidation.

The present invention discloses a sliced dried beef fermentation method using yogurt fermentation by-products of whey as a fermentation agent. The preparation method includes the following steps: cutting beef into strips, pickling the beef strips, and fermenting the pickled beef strips, adding flavorings and yogurt fermentation obtained by-products of whey in the fermented beef strips, vacuum rolling the treated beef strips, and then fermenting the rolled beef strips, baking the fermented beef strips, oil-frying the baked beef strips, etc. The fresh whey containing lactic acid bacteria is used as a fermentation agent for the first time for the fermentation of sliced dried beef, so that the sliced dried beef produced by the technology not only retains the basic characteristics of the traditional sliced dried beef, but also enables obvious improvements in product texture, color and luster, taste, flavor, nutritional value and shelf life.

The invention relates to deep processing mechanical equipment for fresh Chinese yam slices and a deep processing method thereof. The deep processing mechanical equipment comprises a slicing turntable, a conveyer belt and a steam pipeline. The deep processing method comprises the following steps of: arranging the slicing turntable in a clean water pond; cleaning and peeling fresh Chinese yam strips, and then putting the Chinese yam strips into a feeding barrel; driving the slicing turntable by a first motor to perform slicing in the clean water; and conveying the Chinese yam slices at a discharge hole to the steam pipeline through the conveyer belt driven by a second motor, and steaming and drying the Chinese yam slices through the steam pipeline introduced with steam of 120 to 135 DEG C. The deep processing mechanical equipment and the deep processing method have the advantages of coking resistance, taste preservation and fresh, white and uniform color of the processed Chinese yam slices, high yield, short production time, reduction in energy consumption and processing cost saving.

The invention relates to a grape biological fresh-keeping agent which comprises 1-8 g of sodium chloride, 1-6 g of calcium chloride, 3-9 g of chitosan, 0.1-0.5 g of nisin, 1-10 g of beta-1,3-glucanase, 15-40 g of B-CHD bacillus fermentation liquor, and 1 L of normal temperature sterile water; the preparation method comprises the following steps: adding 1-8 g of sodium chloride, 1-6 g of calcium chloride, 3-9 g of chitosan, 1-10 g of beta-1,3-glucanase, 0.1-0.5 g of nisin with a concentration unit of 75 units / 150 ul into 1 L of normal temperature sterile water, stirring to completely dissolve; then adding 15-40 g of B-CHD bacillus fermentation liquor. The advantages of the invention are that the product is free of pollution, low in cost, safe, and nutritious, has multifunctional characteristics of obviously reducing grape fruit decay and threshing, preventing oxidation and coloration, and preventing fiber decomposition and softening, is suitable for storage and fresh keeping after grape picking, and is an economical and ideal biological fresh-keeping agent.

The invention discloses a novel antimicrobial sponge and a preparation method thereof, and the sponge comprises the following components in parts by weight: 100 parts of polypolyol, 45 to 68 parts ofpolyisocyanate, 1.1 to 2.4 parts of a foam stabilizer, 0.8 to 1.5 parts of an amine catalyst, 5 to 13 parts of a foaming agent and 3 to 8 parts of an antibacterial microcapsule. The antibacterial microcapsule includes nano silver, helichrysum extract and tea polyphenol. According to the invention, by adding the nano silver and the helichrysum extract as antibacterial agents in the sponge materials, and combining with different antibacterial characteristics of different antibacterial agents, the materials are compounded to fully exert antimicrobial advantages thereof. At the same time, the helichrysum extract, the tea polyphenol and the nano silver are encapsulated in a microencapsulated structure, enabling the natural antibacterial agent to be slowly released by the embedding effect of themicrocapsule, thereby realizing the enduring antibacterial effect while preventing the nan silver from oxidation stain, and the addition of the antibacterial microcapsule does not affect the resilience of the sponge material.

The invention discloses stable and efficient veterinary oxytetracycline hydrochloride soluble powder and a preparing technology thereof. The veterinary oxytetracycline hydrochloride soluble powder which is quick in absorption, efficient, stable and safe in using and the preparing technology of the veterinary oxytetracycline hydrochloride soluble powder are provided. The veterinary oxytetracycline hydrochloride soluble powder is composed of, by weight, 15-55% of oxytetracycline hydrochloride, 0.2-3.0% of sodium dodecyl sulfate salt, 0.1-1.0% of ethylenediamine tetraacetic acid disodium salt and the balance of glucosum anhydricum. According to the preparing technology of the stable and efficient veterinary oxytetracycline hydrochloride soluble powder, the oxytetracycline hydrochloride is used as raw materials, the sodium dodecyl sulfate salt is added to be used as a sorbefacient, the ethylenediamine tetraacetic acid disodium salt is used as antioxygen and a chelating agent, and accordingly the stability and the high efficiency of the oxytetracycline hydrochloride soluble powder are guaranteed.

The invention provides a preparation method of a pure natural dried osmanthus. The preparation method comprises the following steps: (1) harvesting fresh osmanthus; (2) room temperature tedding: air drying dew and water on the surfaces of the fresh osmanthus in a cold, ventilated, room-temperature and aseptic condition, and removing impurities; (3) ultra low temperature quick-freezing storage: placing the osmanthus which have been processed in the step (2), into low-temperature freezing food containers in an aseptic condition, and placing the containers into a freezer with a temperature in the range of -22 DEG C to -18 DEG C; (4) low-temperature vacuum drying: drying the osmanthus by sublimation technology in the vacuum condition with the negative pressure of -0.04 to -0.06 MPa and the temperature of 10-30 DEG C until the water content of the osmanthus is less than or equal to 5%; (5) medium-temperature baking: placing the processed osmanthus into a drying device at 40-50 DEG C, heating and turning over until the water content is less than 3%, so as to prepare the pure natural dried osmanthus. The invention also discloses the pure natural dried osmanthus which is prepared by the above preparation method. The invention especially solves the problems such as fresh flower discoloration and capacity restriction.

The invention relates to an aralia mandshurica green-protecting compounded agent and belongs to the field of agricultural product processing. The invention develops a food-grade compounded green-protecting agent specially used for aralia mandshurica and aims at solving the problem that the aralia mandshurica can get yellow easily and is not applicable to long-term storage and the current situation that a green-protecting agent containing heavy metal ions is mainly adopted for green protecting in the fruit and vegetable fresh-keeping industry. The aralia mandshurica blanched by virtue of the aralia mandshurica green-protecting compounded agent is emerald green in overall, full in appearance and long in preservation time. The green-protecting compounded agent provided by the invention has the advantages that on the basis that three green-protecting agents, namely vitamin C, cysteine and sodium sulfite, respectively fully play roles, citric acid and calcium chloride are added to enhance the synergistic green-protecting effect, so that chlorophyll of the aralia mandshurica is effectively protected, and the chlorophyll loss ratio is reduced; and no heavy metal ion is added, so that the green-protecting compounded agent serves as a green, safe and efficient green-protecting method, and a basis can be provided for development of the industries such as aralia mandshurica green-protecting and fresh-keeping, green processing of aralia mandshurica and development of related green foods.