136 results about "Polyphenol oxidase" patented technology

The invention provides a streptomyces, which is named as Streptomyces sp. And is registered and preserved in Guangdong Microbial Culture Collection Center, and the preservation number is GDMCC No: 65917. The invention also provides a fermentation broth of the streptomyces, and an ethanol extract and a crude extract of the fermentation broth. The novel streptomyces, the crude extract thereof and the like have broad-spectrum antibacterial activity, have a good antagonistic effect on various pathogenic bacteria such as banana long leaf spot germs and banana colletotrichum gloeosporioides, can enable hyphae of the banana colletotrichum gloeosporioides to shrink, deform and break, inhibit spore germination of the banana colletotrichum gloeosporioides, and have a good anti-bacterial effect on the banana colletotrichum gloeosporioides. According to the present invention, with the application of the bacterial strain, the colletotrichum gloeosporioides spores are shrunk and broken, the growth of the colletotrichum gloeosporioides is inhibited, the peroxidase activity, the polyperoxidase activity, the CAT activity and the like in the banana peel can be improved, and the bacterial strain is the potential biological agent for the prevention and control of the colletotrichum gloeosporioides diseases, and has wide development space and good development and application prospects.

The present invention discloses a flue-curing method for reducing ash on upper tobacco leaves. The method shortens the yellowing time at or before 38°C, maintains the same dry-bulb and wet-bulb temperatures at 40°C, stops the circulating fan, reduces the temperature and humidity difference between different tobacco layers in the flue-curing barn, then lowers the wet-bulb temperature. This process is repeated to cause the tobacco leaves to soften, wilt, and turn yellow. The dry-bulb temperature is then raised to 44°C, causing the main ribs to soften. The high temperature is then returned to 42°C, and the wet-bulb temperature is lowered by 1-2°C at 42°C to control the water loss of the tobacco leaves to 40-45%, inhibiting the activity of polyphenol oxidase and promoting yellowing. The dry-bulb and wet-bulb temperatures are then lowered by 1-2°C at the initial color setting stage, slowing the heating rate. A medium temperature, medium humidity, and slow heating are used for color setting in the middle color setting stage. The temperature is then slowly increased in the later color setting stage. The flue-curing time at a steady temperature of 54°C is extended to increase the water loss and dryness of the tobacco leaves. The wet-bulb temperature is increased during the dry rib drying stage. This method can significantly reduce the occurrence of ash on tobacco leaves and improve the appearance quality of the upper tobacco leaves after curing.

The invention discloses a preparation method and application of high-fiber low-GI-value biscuits, and the preparation method comprises the following steps: S1: carrying out superheated steam treatment on sea rice bran to obtain stabilized sea rice bran; s2, inoculating probiotics into the stabilized sea rice bran obtained in the step S1, and fermenting to obtain fermented sea rice bran; and S3, uniformly mixing the fermented sea rice bran obtained in the step S2 with auxiliary materials, and baking to obtain the high-fiber low-GI-value biscuits, the fermented sea rice bran accounts for 12-18% of the mass of the high-fiber low-GI-value biscuit on a dry basis, and the GI value of the biscuit is 30-48. According to the preparation method provided by the invention, the sea rice bran is treated through superheated steam processing and probiotic fermentation, and lipase, polyphenol oxidase and peroxidase of the sea rice bran are inactivated, so that the sea rice bran is stable in quality and improved in flavor, the content of total phenols capable of inhibiting amylase activity is increased, and the variety of deeply-processed sea rice products is enriched.

The invention provides a tobacco polyphenol oxidase gene NtPPO15 and application of the tobacco polyphenol oxidase gene NtPPO15 in inhibiting browning of tobacco and improving ripening resistance and baking resistance of the tobacco. According to the invention, a key gene NtPPO15 related to tobacco browning and baking resistance is screened through experiments, the activity of an NtPPO15 promoter and a gene expression site are further explored by constructing a GUS dyeing vector, and the function of the gene is deeply studied through gene editing and overexpression. Experiments prove that the NtPPO15 gene provided by the invention is a key gene related to browning in a tobacco maturing and baking process, and by regulating and controlling the expression quantity of the NtPPO15 gene, the browning of the tobacco can be controlled, the maturing resistance and baking resistance of the tobacco can be improved, the quality of a tobacco product can be improved, the harvesting frequency can be reduced, and the economic benefit can be greatly improved; and the method can also be used for screening tobacco varieties with excellent quality, so that the method has a good and wide market application prospect.

The invention belongs to the field of electrochemical gas sensors, and particularly relates to a phenol gas sensor based on quantum dots and a preparation method of the phenol gas sensor. The gas sensor comprises a quantum dot sensing film, polyphenol oxidase on the surface of the quantum dot sensing film and an enzyme stabilizing composite reagent covering the polyphenol oxidase, benzoquinone is formed on the basis that phenol is oxidized through molecular oxygen on the basis of the polyphenol oxidase, the enzyme-substrate efficient specific catalysis effect is achieved, and the content of the polyphenol oxidase in the gas sensor is increased. The polyphenol oxidase-based quantum dot phenol gas sensor is designed. The sensor is high in phenol gas detection specificity and sensitivity.

The invention discloses a method for inhibiting browning of apple juice through combination of ultrahigh pressure and medicinal and edible substances, and belongs to the technical field of fruit processing. In order to solve the problems of color deterioration, nutrition loss and flavor loss caused by enzymatic browning in the processing and storage processes of non-concentrated and reduced apple juice, the technical scheme is characterized in that fresh apples, gastrodia elata and phyllanthus emblica are respectively prepared into juice, gastrodia elata juice and phyllanthus emblica juice are added into the apple juice according to a ratio, and the juice is added into the apple juice according to a ratio. The raw materials are stirred, mixed, packaged and packaged, then subjected to ultrahigh pressure treatment with specific parameters at a constant temperature, and finally subjected to low-temperature storage. The preparation method can effectively inhibit the activity of polyphenol oxidase and peroxidase, delay the browning process and remarkably improve the oxidation resistance of fruit juice, and is mainly used for quality maintenance and browning inhibition of natural and additive-free apple juice and other fruit and vegetable juice.

A method for preparing theasinensin A (TSA) by means of a low-temperature enzyme process. The method comprises using a plant polyphenol oxidase enzyme extract or polyphenol oxidase enzyme formulation as an enzyme source, using epigallocatechin gallate (EGCG) as a substrate, using as a reaction system a buffer solution having a certain pH value, and performing an enzymatic reaction at a low temperature and subsequent steps such as column chromatography, distillation and concentration, liquid phase preparation, and freeze drying, thereby synthesizing TSA in a directional enzymatic manner. The method achieves EGCG enzymatic oxidation at a low temperature and obtains dimeric TSA by means of a conversion reaction, laying a theoretical and practical basis for green, safe, efficient and large-scale industrial production and utilization of TSA.

The invention provides an application of inhibiting or knocking out a tobacco polyphenol oxidase gene NtPPO12 in inhibiting tobacco browning. The important gene NtPPO12 related to tobacco browning is screened out through transcriptome sequencing and molecular biological experiments, the NtPPO12 promoter activity and the gene expression site are further verified, and the gene function is deeply studied through gene editing and overexpression. Molecular biology experiments prove that the NtPPO12 gene provided by the invention is a key gene related to browning in the tobacco maturing and baking process, and the browning degree of tobacco can be controlled by regulating the expression quantity of the NtPPO12 gene, so that the maturing resistance and baking resistance of tobacco are improved, the harvesting frequency is reduced, the baking characteristic is improved, and the yield of tobacco is improved. Therefore, the method has a wide market application prospect.

The invention discloses a synergetic color protection method for hot-processed eggplants. The eggplants are inhibited from browning through combination of multiple technologies. The method comprises the following steps: pretreatment, preparation of a color protection solution (compounding of ascorbic acid, tea polyphenol and calcium chloride, ultrasonic high and low temperature circulating blanching, pulse vacuum treatment and gradient temperature control secondary enzyme deactivation. After being treated by the method disclosed by the invention, the polyphenoloxidase (PPO) activity can be synergistically inhibited, the cell permeability and the anti-oxidation effect can be regulated and controlled, and the color difference delta E value (less than 5.0) can be obviously reduced. The method is suitable for color protection pretreatment of eggplant processing forms such as hot drying, hot frying and hot steaming, the color protection efficiency is greatly improved, no synthetic preservative needs to be added, and a possible way is provided for deep development of eggplants in the field of prefabricated vegetables.

The invention provides an acrylamide generation inhibitor and a method for inhibiting acrylamide generation. The acrylamide inhibitor is syringic acid, vanillic acid or sinapic acid. The syringic acid and the vanillic acid can passivate polyphenol oxidase in the food processing process and prevent polyphenol oxidase from oxidizing polyphenol in food into quinone, and the sinapic acid can directly inhibit quinone generated by oxidizing polyphenol, so that the content of Maillard reaction substrates is reduced, and the yield of the Maillard reaction products is improved. The structure of quinone is extremely similar to that of an intermediate product dicarbonyl compound in a path for producing acrylamide through Maillard reaction, so that quinone and asparagine can be subjected to Maillard reaction under a high-temperature condition to generate acrylamide. Therefore, the Maillard reaction is prevented by passivating the activity of polyphenol oxidase or inhibiting the generation of quinone oxidized by polyphenol, the generation of 2A cancerogen acrylamide easily generated in the high-temperature food processing process is further inhibited, the purpose of healthy diet is achieved, and a new thought is provided for controlling the generation of acrylamide in the food processing process.

The present application provides an application of inhibiting or knocking out tobacco polyphenol oxidase gene NtPPO12 in inhibiting tobacco browning. The present application screens an important gene NtPPO12 related to tobacco browning through transcriptome sequencing and molecular biology experiments, further verifies the promoter activity and gene expression site of NtPPO12, and deeply researches the function of the gene through gene editing and overexpression. The present application proves by molecular biology experiments that the NtPPO12 gene provided by the present application is a key gene related to browning in the mature curing process of tobacco, and by regulating the expression amount of the NtPPO12 gene, the browning degree of tobacco can be controlled, and the tobacco maturity and curing resistance can be improved, which is beneficial to reducing the picking frequency, improving the curing characteristics, and improving the appearance and internal quality of tobacco leaves, so it has a broad market application prospect.

The invention discloses fresh wet noodles adopting fermented soybean milk as a preservative and a processing method of the fresh wet noodles. According to the fresh wet noodles, fermented soybean milk prepared from streptococcus thermophilus 937 serves as a preservative, firstly, 100 parts of plain flour, 30 parts of fermented soybean milk, 8.25 parts of water and 1.5 parts of salt are mixed to form dough, and then the dough is fermented, pressed, cut into strips, sealed and refrigerated. According to the invention, the fermented soybean milk is used as a preservative, and the addition of the fermented soybean milk improves the strength of the noodles, enhances the viscoelasticity of the noodles, improves the sensory quality and taste of the fresh wet noodles, makes up for the deficiency of lysine in wheat, and can effectively inhibit the activity of polyphenol oxidase in the fresh wet noodles, slow down the browning rate and prolong the shelf life of the fresh wet noodles.

The invention discloses lactobacillus casei capable of improving the flavor of a tea beverage through fermentation and application of the lactobacillus casei. The lactobacillus casei is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation number of the lactobacillus casei is CGMCC No.32672, and the preservation date of the lactobacillus casei is November 18, 2024. The lactobacillus casei can be used for producing extracellular beta-glucosidase, polyphenol oxidase and peroxidase; when being used for fermentation, the fermentation broth can improve the flavor and color of a tea beverage, increase the content of organic acid, reduce the bitter taste of the tea beverage, generate new volatile aroma substances such as nerolidol, isobutanol, ethyl hexanoate, ethyl 3-hexenoate, ethyl caprylate, ethyl 2-hexenoate and the like, and enrich the aroma substance composition of the tea beverage. The invention provides a novel tea beverage production process which has the advantages of simplicity and convenience in operation, low cost, remarkable effect and the like, and is suitable for industrial production.

The application discloses a kind of high-activity polyphenol oxidase and preparation method thereof, belong to nano mimic enzyme synthesis technical field.The polyphenol oxidase of the application is with copper ion as active center, 2-methyl imidazole and guanylate disodium as organic ligand.Preparation method thereof includes the following steps: guanylate disodium solution is added to copper chloride solution under stirring condition, to obtain first mixed solution;First mixed solution is slowly added to 2-methyl imidazole solution under stirring condition, to obtain second mixed solution;Second mixed solution is centrifuged after ultrasonic at room temperature, to obtain brown precipitate, and the polyphenol oxidase is prepared by washing and drying brown precipitate.The mimic enzyme prepared by the application has higher catalytic performance, better stability and feasibility of large-scale preparation compared with natural enzyme, and will have broad application prospect in the field of biosensor.

The invention discloses a method for inhibiting polyphenol oxidase in fruit and vegetable products. The method for inhibiting polyphenol oxidase in the fruit and vegetable product comprises the following step: treating an intermediate product or a finished product of the fruit and vegetable product by using dihydroquercetin so as to inhibit the activity of polyphenol oxidase. The natural component dihydroquercetin is adopted as a natural inhibitor, the PPO enzyme activity of fruit and vegetable products can be inhibited, sensory and flavor deterioration caused by enzymatic browning is relieved, the acceptability of consumers is greatly improved, and waste of precious food resources and economic losses of production links such as storage, transportation and processing are expected to be reduced.

The present invention relates to a method for freezing and refrigerating chestnut kernels for preservation, and the specific method includes: sterilizing the chestnut kernels with a composite specific bactericide in coordination with slightly acidic electrolyzed water after pre-treatment of the chestnut kernels, then color-protecting the chestnut kernels with L-cysteine ​​in combination with cold shock treatment, and finally slightly freezing and air conditioning after treating the chestnut kernels with chitosan coating. The present invention uses a specific bactericide needle combined with the synergistic effect of slightly acidic electrolyzed water to completely kill the pathogenic bacteria of chestnuts during storage; L-cys is used to change the molecular spatial structure of PPO that causes browning during chestnut kernel storage, thereby achieving the purpose of inhibiting PPO activity; a microenvironment with high CO2 and low O2 is formed on the surface of the fruit by using a chitosan coating treatment method, and combined with cold shock treatment, the respiration intensity can be reduced to inhibit the activity of PPO polyphenol oxidase and POD peroxidase, while also inhibiting the activity of PAL phenylalanine ammonia lyase, thereby reducing the synthesis of phenolic substances.

The invention provides a cooking method and device, a readable storage medium and cooking equipment. The cooking method is applied to the cooking equipment, and the cooking method comprises the following steps: on the basis that the cooking temperature in a cooking cavity is within a first temperature range and lasts for a first duration, stopping heating the cooking cavity; on the basis that the cooking temperature is lowered to a first temperature threshold value, the cooking cavity is heated, so that the cooking temperature is within a second temperature range; and heating the cooking cavity until the target liquid in the cooking cavity is in a boiling state on the basis that the cooking temperature is within a second temperature range and lasts for a second duration. According to the method, oxidation of polyphenol oxidase in the food materials on polyphenol nutritional ingredients is reduced, loss of the polyphenol nutritional ingredients caused by the high cooking temperature is reduced, and the content of the polyphenol nutritional ingredients in the cooked food is further increased.

The present application relates to asparagus tissue culture technical field, specifically to a kind of asparagus tissue culture rapid propagation seedling cultivation method.A kind of asparagus tissue culture rapid propagation seedling cultivation method, comprising: the disinfection and browning prevention treatment of explant, preparation of composite antibacterial agent, preparation of culture medium, asparagus explant culture and transplanting.The present application adopts ozone fumigation to combine ultraviolet light disinfection, synergistic sterilization, covers surface and deep layer, reduces explant injury and browning.Browning prevention agent inhibits polyphenol oxidase, removes free radicals, reduces browning, promotes axillary bud germination.Add composite antibacterial agent in induction culture medium, destroys microbial cell membrane, has antibacterial and antioxidant effects, and guarantees explant growth.Compound rooting agent contains activated carbon, chitosan and sucrose, adsorbs harmful substances, stimulates root differentiation and provides energy, improves rooting rate and plant robustness.Overall, it improves the success rate of asparagus tissue culture.

Compositions and methods for the production of L-glufosinate are provided. The method involves converting racemic glufosinate to the L-glufosinate enantiomer or converting PPO to L-glufosinate in an efficient manner. In particular, the method involves the specific amination of PPO to L-glufosinate, using L-glutamate, racemic glutamate, or another amine source as an amine donor. PPO can be obtained by the oxidative deamination of D-glufosinate to PRO (2-oxo-4-(hydroxy (methyl) phosphinoyl) butyric acid) or generated via chemical synthesis. PPO is then converted to L-glufosinate using a transaminase in the presence of an amine donor. When the amine donor donates an amine to PPO. L-glufosinate and a reaction by product are formed. Because the PPO remaining represents a yield loss of L-glufosinate, it is desirable to minimize the amount of PPO remaining in the reaction mixture. Degradation, other chemical modification, extraction, sequestration, binding, or other methods to reduce the effective concentration of the by-product. i.e., the corresponding alpha ketoacid or ketone to the chosen amine donor will shift the reaction equilibrium toward L-glufosinate, thereby reducing the amount of PPO and increasing the yield of L-glufosinate. Therefore, the methods described herein involve the conversion or elimination of the alpha ketoacid or ketone by-product to another product to shift the equilibrium towards L-glufosinate.

The invention discloses application of pseudopenicillin variotii in preparation of a resistance inducer for preventing and treating plant diseases, and belongs to the technical field of plant protection. The invention provides an application of Panax variotii in prevention and treatment of plant diseases, the application concentration of the Panax variotii is 0.1 microgram / mL-1 microgram / mL, a plant resistance inducer containing the Panax variotii can be sprayed on plant leaves or fruit surfaces and has a remarkable prevention effect on anthrax leaf blight, and the higher the concentration is, the better the prevention effect is; the pseudopenicillin variotii can promote synthesis or activity improvement of catalase, peroxidase, polyphenol oxidase, glutathione S-transferase and superoxide dismutase in apple bodies, and also can remarkably induce up-regulation expression of disease-resistant related genes such as MdPR2 and MdPR5, so that the disease resistance, the antioxidant level and the plant immunity of apples are enhanced; a novel and efficient plant resistance inducer application scheme is provided for apple disease control and physiological regulation.

The invention belongs to the field of crop heredity, and relates to application of a polyphenol oxidase gene. The invention discloses an InDel marker for rice brown glume traits, a regulatory gene and application of the InDel marker and the regulatory gene. Based on a brown glume mutant material in the background of Hunan early indica 42, genetic analysis shows that the mutation is dominant mutation, single-gene control and gene positioning find that the mutant gene is a polyphenol oxidase encoding gene (MSULocus is LOCOs04g53300), and the exon region of the mutant gene is deleted by 6bp (GCGACT), so that the material shows brown glume; the gene is knocked out from a brown glume mutant, and the glume color becomes normal; the method has the advantages that the GCGACTs are used as the raw materials, the GCGACTs are accurately edited in the wild type materials, the corresponding 6bp deletion (GCGACT) materials are obtained, the glumes of the GCGACTs are brown, and new gene resources and methods are provided for quickly and directionally cultivating novel rice materials and rice materials suitable for mechanized seed production of hybrid rice.

The invention relates to the technical field of seasoning sauce preparation, in particular to a composite enzymatic hydrolysis aroma enhancement preparation method of seasoning sauce, which comprises the following steps: soaking shiitake mushroom particles in a composite buffer solution to obtain a solid A and a flavor liquid B, mixing the solid A with deionized water, grinding into a homogenate, performing three times of enzymatic hydrolysis to obtain an enzymatic hydrolysate C, and adding the sterilized supernate D, the solid A and the flavor liquid B into other stir-fried raw materials to obtain the seasoning sauce with obvious shiitake mushroom flavor and sufficient fragrance. Cellulase in the composite buffer solution can quickly decompose a cellulose skeleton of a cell wall, so that polyphenol oxidase can enter cells conveniently, an enzymatic browning reaction is catalyzed, a Maillard reaction is facilitated, and various flavor substances are generated; and after the three-step enzymolysis reaction, protein in the shiitake mushrooms is hydrolyzed into small molecular amino acids, so that the fresh and sweet flavor is effectively increased, the shiitake mushroom flavor is more obvious, and the method has a wide application prospect.

The application discloses application of NtPPO7 gene in regulating chlorogenic acid content in tobacco leaves and tobacco variety cultivation, and belongs to the technical field of plant genetic engineering. The cDNA of leaves of common tobacco at different periods is used as a template, and a homologous gene of polyphenol oxidase of tobacco is cloned by using PCR technology, and is named as NtPPO7. It is found through cloning of the NtPPO7 gene and construction and analysis of an expression vector that overexpression of the gene in tobacco plants can significantly reduce the content of chlorogenic acid in mature tobacco leaves, which indicates that the NtPPO7 gene has an important role in regulation of chlorogenic acid in mature tobacco leaves. The application enriches the polyphenol oxidase gene family of tobacco, and lays a foundation for in-depth study of the polyphenol oxidase gene family in tobacco. Meanwhile, the application lays a foundation for elucidating a molecular regulation mechanism of chlorogenic acid biosynthesis in tobacco leaves, and provides a new precise regulation gene for regulation of the content of chlorogenic acid in tobacco leaves.

The invention relates to the technical field of tea processing, in particular to a black tea fermentation regulation and control method and equipment based on a multienzyme synergistic effect, and the method comprises the following steps: S1, mixing enzymes such as polyphenol oxidase and peroxidase, adding trehalose, trisodium citrate and vitamin C, fixing the volume with a phosphate buffer solution, and activating in a water bath at 30 DEG C to obtain a compound enzyme solution; s2, withering the fresh leaves until the water content is 60-65%, performing UV-C intermittent irradiation, and performing gradient rolling to obtain rolled leaves; s3, spraying enzyme liquid which accounts for 1.5-2.0% of the weight of the rolled leaves, and performing ultrasonic-assisted permeation; s4, performing three-stage temperature-controlled fermentation, stirring every 30 minutes, introducing ozone air, and adding a pulsed magnetic field every hour; s5, detecting the conversion rate of tea polyphenol, theaflavin and the like, and terminating fermentation after reaching the standard; s6, performing microwave fixation after hot air treatment; and S7, drying in sections until the water content is 5-6% to obtain a finished product. According to the method, the tea polyphenol conversion efficiency and theaflavin generation balance of the black tea are improved, aroma substances are reserved, and the functional activity is enhanced; the process stability is optimized, the energy consumption and pollution are reduced, and the black tea quality and industrial benefits are improved.

The invention provides a slicing preservation method for fruits and vegetables, which comprises the following steps: firstly, cleaning, peeling, denucleating and deseeding complete fruits and vegetables, and then slicing the fruits and vegetables in a low-temperature environment by using a disinfected cutter; completely immersing the obtained slices in a composite fresh-keeping solution for treatment; taking out the treated slices, using filtered and sterilized low-temperature high-speed air flow to blow away residual liquid on the surfaces, and then sealing the slices and a modified atmosphere preservative in a high-barrier packaging bag; the packaged fruit and vegetable slices are placed in a low-temperature environment to be stored and transported; the low-temperature composite fresh-keeping liquid containing the edible calcium salt, the antioxidant and the pH regulator is adopted for treating the slices, juice loss and tissue softening caused by cutting are reduced, meanwhile, the low-pH environment and the antioxidant act jointly, the activity of polyphenol oxidase and other enzymes is greatly inhibited, and therefore enzymatic browning is prevented, and the fresh-keeping effect is good. And the fresh appearance color of the product is kept.

The invention provides a tea leaf freezing, withering and rolling process parameter determination method and a preparation method, relates to the technical field of tea leaf preparation, and aims to solve the problem of poor tea leaf quality caused by non-uniform withering and finished product appearance in a traditional process. According to the method, a technological parameter control algorithm is introduced, key technological parameters are subjected to collaborative optimization, the phenomenon of traditional uneven withering is improved, and the identifiability of a three-technological-parameter coupling relation is improved, so that the rapid contact reaction of polyphenol compounds and polyphenol oxidase is promoted, and the tea quality is effectively improved. The optimal key process parameters determined on the basis of the method are applied to the preparation process of the pointed Taiping Kui black tea, the effective index content and withering uniformity can be remarkably improved, the tea strip forming rate and moderate overflow of tea juice are ensured to support flavor formation, and the parameters of each step are controllable to ensure the stable quality of a finished product.

This invention discloses tobacco polyphenol oxidase NtPPO6, its encoding gene, gene editing vector, and applications. The nucleotide sequence of the tobacco polyphenol oxidase encoding gene NtPPO6 of this invention is: (1) the nucleotide sequence shown in SEQ ID NO.1; or (2) the nucleotide sequence shown in SEQ ID NO.1, after substitution and / or deletion and / or addition of one or more nucleotides, expressing a protein with the same function. Detection revealed that knocking out the NtPPO6 gene in tobacco significantly reduces the activity of polyphenol oxidase in tobacco plants and increases the chlorogenic acid content in tobacco plants; moreover, tobacco plants with the NtPPO6 gene knocked out show increased plant height, reduced average leaf size, and increased maximum leaf width in the middle, width of the top leaf, and length of the top leaf.

The invention belongs to the technical field of intelligent food packaging films, and particularly relates to a preparation method and application of a biomass-based active packaging film. According to the film, a double-network skeleton is constructed by using wood nano cellulose / sodium alginate, so that the film is endowed with excellent flexibility, ultraviolet shielding property and antibacterial activity; furthermore, zein nanoparticles loaded with curcumin are uniformly embedded into the matrix, so that ammonia-sensitive color development and curcumin slow release synergism are realized. Due to the introduction of the curcumin-zein nanoparticles, the mechanical strength, the water-oxygen barrier property, the oxidation resistance and the antibacterial property of the film are further remarkably improved, and reversible color change occurs in the presence of NH3, so that the meat product decay visual detection is realized. Fresh shrimps are packaged with the film and stored at 4 DEG C, the activity of polyphenol oxidase can be remarkably inhibited, blackening and microbial proliferation are delayed, and a green, visible and controllable multifunctional packaging strategy is provided for a meat supply chain.

The application belongs to the technical field of biological fermentation, and relates to a bacillus subtilis SXZY-03 and application of the bacillus subtilis SXZY-03 in tobacco leaf fermentation. Bacillus subtilis The bacillus subtilis SXZY-03 is separated from the surface of tobacco leaves (CCTCC NO: M 2025150), and the strain is fermented to prepare a biological preparation containing the bacillus subtilis SXZY-03; after activation and concentration optimization of copper sulfate, manganese sulfate and ferric sulfate, polyphenol oxidase enzyme activities reach 112.59, 69.26 and 51.26 U·mL ‑1 respectively; the biological preparation is applied to tobacco shred fermentation, polyphenols are degraded, tobacco aroma quality is effectively improved, irritation is reduced, and aftertaste is improved. The technology provides a green and environment-friendly solution for tobacco quality upgrading, and meets the high-quality development direction of the industry.

The invention discloses an efficient and universal tissue culture anti-browning method for sugarcane plants, and belongs to the technical field of tissue culture. According to the invention, the potassium cinnamate is used as an anti-browning active substance for the first time and is used in plant tissue culture pretreatment and induction culture treatment, and a synergistic strategy of low-temperature pretreatment, explant potassium cinnamate soaking and culture medium addition is introduced, so that a remarkable beneficial effect is achieved in sugarcane plant tissue culture anti-browning. Through synergistic application of low-temperature pretreatment and potassium cinnamate, the activity of polyphenol oxidase is inhibited in a targeted manner, and browning is effectively blocked. According to the method, the browning rate of different germplasm sugarcane plants is remarkably reduced, the regeneration efficiency is synchronously improved, the genotype dependence of a traditional browning resisting technology is successfully overcome, and an efficient and universal solution is provided for development and utilization of sugarcane germplasm resources.