63 results about "Palmitoleic acid" patented technology

The invention belongs to the technical field of preparation of modified cellulose carboxymethyl cellulose and nano-emulsion, and particularly relates to a preparation method of novel amphiphilic cellulose carboxymethyl cellulose palmitate, which comprises the following steps: S1, preparing palmitoleic acid from palm oil as a raw material, and further preparing palmitoleic acid into palmitoleic anhydride; and S2, reacting palmitoleic anhydride obtained in the step S1 with carboxymethyl cellulose, and purifying after the reaction is finished to obtain the carboxymethyl cellulose palmitate. According to the preparation method, ester bonds on palmitoleic acid anhydride and hydroxyl groups on carboxymethyl cellulose are replaced by utilizing the prepared novel palmitoleic acid anhydride derivative through ester exchange reaction, so that the amphipathic carboxymethyl cellulose palmitate is obtained. The novel amphiphilic cellulose carboxymethyl cellulose palmitate synthesized by the invention is green in reaction process and high in reaction activity of palmitic anhydride, and provides a basis for subsequent application in the aspect of self-assembly entrapment.

The invention discloses an application of silkworm fatty acid dehydrogenase Bmdesat13 in enzymatic catalytic generation of trans-palmitoleic acid and a method thereof, the silkworm fatty acid dehydrogenase Bmdesat13 gene ORF sequence is cloned from silkworms, and a brewer's yeast eukaryotic expression system is used for heterologous expression of Bmdesat13, so that the trans-palmitoleic acid is obtained. An enzyme activity product which can be synthesized by the gene in a yeast positive recombinant engineering strain is identified to be trans-9-hexadecenoic acid (trans-palmitoleic acid) through GC-MS (gas chromatography-mass spectrometry), so that theoretical and technical supports are provided for mass production of trans-palmitoleic acid.

An Alzheimer's disease biomarker based on a brain metabolite and a use thereof. The biomarker comprises any one or a combination of at least two of palmitic acid, DHA, gallic acid, 11Z,14Z,17Z-eicosatrienoic acid, glycodeoxycholic acid, palmitoleic acid, linoleic acid, erucic acid, petroselinic acid, and arachidonic acid. The level of a metabolite is detected to assist in early diagnosis of the Alzheimer's disease, thus facilitating rapid detection; in addition, the present invention has the characteristics of timeliness, convenience, high specificity and high sensitivity.

The invention provides a weather-resistant polyester FDY (Fully Drawn Yarn) oil agent and a preparation method thereof, and the weather-resistant polyester FDY oil agent comprises the following components in parts by weight: 58-62 parts of a composite smoothing agent, 16-20 parts of an emulsifier, 5-9 parts of an antistatic agent, 3-7 parts of a penetrant and 6-10 parts of deionized water, wherein the composite smoothing agent is prepared from palmitoleic acid glyceride, polyglycerol-6 oleate and pentaerythritol tetraol-4EO-triisostearate according to the mass ratio of (30 to 40) to (10 to 15) to (8 to 12). According to the invention, the palmitoleic acid glyceride, the polyglycerol-6 oleate and the pentaerythritol-4EO-triisostearate are reasonably compounded, so that the emulsion stability of the treating agent at low temperature can be remarkably improved, and the finally prepared oil agent has good heat resistance and can ensure the stability of the production process.

The application provides a recombinant Yarrowia lipolytica capable of producing palmitoleic acid at a high yield, a construction method and application thereof, and belongs to the technical field of bioengineering. Yarrowia lipolytica The recombinant Yarrowia lipolytica is obtained by knocking out peroxisome biogenesis factor 10 and triacylglycerol lipase 4 in the genome of Yarrowia lipolytica and inserting an acetyl-CoA carboxylase, a Δ9 desaturase, an acetyl-CoA diacylglycerol acyltransferase, a glycerol-3-phosphate acyltransferase, a lysophosphatidylcholine acyltransferase and a phosphatidylcholine:diacylglycerol acyltransferase gene expression cassette. Experiment proves that the recombinant Yarrowia lipolytica can efficiently ferment and produce palmitoleic acid, and realizes efficient synthesis of the natural product palmitoleic acid from plants in Yarrowia lipolytica.

The invention discloses an application of fat powder as a chicken feed raw material in replacing corn and improving fatty acid composition of eggs. The fat powder accounts for 2-6% of the feed; the dosage ratio of unsaturated fatty acid to saturated fatty acid is 2.7-3.83; in the fat powder, the saturated fatty acid accounts for 70-135 mg / g; 270 to 365 parts of unsaturated fatty acid; the unsaturated fatty acid comprises 1.03 to 2.56 parts of palmitoleic acid; 90.8 to 124 parts of oleic acid; 164 to 216 parts of linoleic acid; 0.819 to 1 part of eicosaenoic acid; 10 to 15.9 parts of alpha-linolenic acid; ePA (ethylene propylene diene monomer) is 1.49 to 3.24; and DHA (docosahexaenoic acid) 1.62- By adopting the scheme of finely blending the fat powder to replace corn and improve the fatty acid composition of eggs, the egg quality of laying hens can be obviously improved, and the feed cost is obviously improved.

The present invention belongs to the technical field of genetic engineering, and particularly relates to an GmHMGS application of a gene and a recombinant overexpression vector in regulating the fatty acid content of plants, and the GmHMGS nucleotide sequence of the gene is shown as SEQ ID NO.1. The present invention uses an overexpression vector of an exogenous gene sequence to introduce the GmHMGS gene shown as SEQ ID NO.1 into plants for overexpression GmHMGS of the gene, and the plants show that the contents of palmitoleic acid, arachidonic acid, docosanoic acid and erucic acid are significantly higher than those of the wild type; at the same time, the contents of stearic acid, oleic acid and linolenic acid are significantly reduced. The present invention regulates the GmHMGS expression of the gene in plants and then uses it to cultivate new plant varieties with adjustable fatty acid content, which provides a new idea for cultivating new crop varieties and has great application value in molecular breeding.

The application belongs to the technical field of bio-based packaging materials, and particularly relates to a novel double-layer composite film and application thereof. The novel double-layer composite film comprises the following steps: reacting palmitic anhydride and carboxymethyl cellulose to obtain carboxymethyl cellulose palmitate; adding a pH-sensitive natural dye indicator to obtain carboxymethyl cellulose palmitate nanoemulsion containing a pH-sensitive substance; then loading a natural polymer material to prepare a film material; finally adding the film material to the carboxymethyl cellulose palmitate to prepare a composite film, thereby obtaining the novel double-layer composite film. The double-layer composite film can be self-emulsified without adding a surfactant, and has the ability to load functional indicator (pH-sensitive color indicator) substances; meanwhile, the barrier performance of the film material, such as a chitosan film, to water vapor and oxygen is improved, and the double-layer composite film has a very promising application in food or fruit preservation. The method provided by the application is not only green in raw materials, but also uses a flow casting method, which can be applied to industrial production and has a good application prospect.

The invention belongs to the technical field of agricultural pest control, and particularly relates to a novel drosophila melanogaster attractant and a preparation method and application thereof. The invention discloses a novel drosophila melanogaster attractant which comprises the following components in percentage by mass: 10%-20% of brown sugar, 1%-5% of acetic acid, 1%-5% of ethanol, 1%-5% of phenethyl alcohol, 0.5%-2.0% of oleic acid, 0.1%-1% of palmitoleic acid, 0.1%-0.5% of sodium benzoate, 0.2%-0.5% of ascorbic acid, 0.2%-0.3% of sodium carboxymethyl cellulose, 0.5%-1.0% of sodium dodecyl benzene sulfonate and the balance of water. Field test results show that the novel drosophila melanogaster attractant is high in trapping rate of drosophila melanogaster on fruit crops, the used raw materials are low in price, the preparation process is simple, the dosage form is a liquid dosage form, field application is facilitated, the novel drosophila melanogaster attractant can be widely applied to prevention and control of field drosophila melanogaster, and the market prospect is good.

This application discloses a corrosion and scale inhibitor and its preparation method. On one hand, this application provides a corrosion and scale inhibitor, wherein the mass ratio of each component of the corrosion and scale inhibitor includes: 60-70 parts of palmitoleic acid-acrylic acid-lignin sulfonic acid copolymer and 30-40 parts of maleic acid-acrylic acid-EDTA copolymer. On the other hand, this application provides a method for preparing the above-mentioned corrosion and scale inhibitor, including the following steps: S1, preparing palmitoleic acid-acrylic acid-lignin sulfonic acid copolymer; S2, preparing maleic acid-acrylic acid-EDTA copolymer; S3, weighing each component according to the formula, mixing thoroughly, and obtaining the corrosion and scale inhibitor. The application exhibits good environmental friendliness, excellent scale inhibition effect against calcium and magnesium ions, good dispersibility, and excellent corrosion inhibition effect.

The purpose of this invention is to provide an oil-in-water emulsion and a foamable oil-in-water emulsion with minimized thickening and solidification during refrigerated storage.　This oil-in-water emulsion contains oil / fat having a weight ratio S2Po / S2M of 0.03 or more. S2Po is a triglyceride in which two Ss and one Po are bonded, and S2M is a triglyceride in which two Ss and one M are bonded. Here, S denotes a 16-22 C saturated fatty acid, M denotes a 16-22 C monovalent unsaturated fatty acid, and Po denotes a palmitoleic acid (C16: 1 (n-7)).

Disclosed is a compound essential oil for improving dull skin, which comprises the following components: oleic acid, linoleic acid, palmitic acid, stearic acid, limonene, α-pinene, linalool, palmitoleic acid, eicosanoic acid, squalene, α-copaene, cis-11-eicosenoic acid, β-pinene, trans-caryophyllene, 3-thujene, camphene, behenic acid, myristic acid, p-cymene, (+)-δ-cadinene, menthol, linolenic acid, caprylic acid, menthone, capric acid, sabinene, and myrcene. The compound essential oil has excellent effects of skin whitening, brightening, and moistening.

The present invention is a novel approach to treating, and even preventing, upper respiratory infections its related symptoms caused by influenza or other lipid-enveloped viruses infiltration and infection in vivo, comprising administering as a gargling agent one or more of clove (plant parts or oil), black tea (with or without caffeine), at least one fatty acid and / or its mono- or di-glyceride form, such as without limitation, coconut water (milk, cream, oil, etc.), caprylic acid, lauric acid (and glycerol monolaurate), monolaurin, myristic acid, oleic acid, palmitoleic acid, or stearic acid, citron, lemon, lime, plant acids (citric acid, etc.), food grade acids (acetic, lactic, malic, oxalic, benzoic, quinic, tannic, and others and / or their sodium salts), vinegar (apple cider, white, balsamic, red wine, wine, etc.), garlic, gangmei root, Sambucus nigra (elderberry), Pelargonium sidoides and or any extract thereof (African geranium), cranberry or pomegranate juice, zinc, saponified lipid (soap), non-toxic detergent, or vitamin C.

The present application belongs to the field of microbial fermentation technology, and specifically relates to a strain of Bacillus paramycoides and its application in the preparation of palmitoleic acid. The Bacillus paramycoides SS6 is a Bacillus paramycoides strain. Bacillus paramycoides , deposited in the China General Microbiological Culture Collection on October 28, 2024, with the deposit number: CGMCC No.32390; the address of the deposit unit: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; palmitic acid can be obtained by fermenting sugarcane juice with it; after subsequent extraction, it can be used for industrial production.

The application belongs to the technical field of microbial fermentation, and discloses a method for improving the production of palm oleic acid in Schizochytrium sp. by fermentation regulation and application. In the fermentation process of Schizochytrium sp., one or more combined regulation strategies of controlling the fermentation temperature, optimizing the carbon-nitrogen ratio of the fermentation medium and adjusting the pH value of the fermentation liquid are adopted to change the metabolic flow direction, so as to improve the accumulation of palm oleic acid C16:1 in oil. Compared with genetic engineering modification, the method does not need complex genetic operation and has high safety. Through verification of a 5L fermentation tank, the proportion of palm oleic acid in oil can be significantly increased from less than 1% in conventional fermentation to 16.12%, and the oil yield is stable, so that the method has good industrial application potential.

Compound essential oil for alleviating skin aging and a preparation method therefor. The compound essential oil comprises the following components in parts by weight: 60-70 parts of oleic acid, 10-20 parts of linoleic acid, 10-20 parts of palmitic acid, 1-10 parts of stearic acid, 0.1-0.8 parts of cis-11-eicosenoic acid, 0.1-0.8 parts of α-copaene, 0.1-0.6 parts of linolenic acid, 0.1-0.5 parts of α-pinene, 0.1-0.5 parts of trans-caryophyllene, 0.1-0.5 parts of eicosanoic acid, 0.1-0.4 parts of linalool, 0.01-0.4 parts of (+)-δ-cadinene, 0.01-0.3 parts of limonene, 0.01-0.3 parts of behenic acid, 0.01-0.3 parts of palmitoleic acid, 0.01-0.3 parts of β-cedrene, 0.01-0.2 parts of tetracosanoic acid, 0.01-0.2 parts of β-pinene, 0.01-0.1 parts of 3-thujene, 0.01-0.1 parts of myristic acid, 0.01-0.1 parts of α-humulene, 0.01-0.1 parts of (-)-α-gurjunene, 0.01-0.1 parts of α-cedrene, and 0.01-0.1 parts of p-cymene. The compound essential oil is derived from natural and green raw materials, can effectively avoid side effects while treating skin aging, and thus has good safety.

The invention relates to the technical field of pharmaceutical preparations, and discloses a double-effect capsule-in-capsule capsule of seabuckthorn seed oil and fruit oil and a preparation method of the double-effect capsule-in-capsule capsule of the seabuckthorn seed oil and the fruit oil, the double-effect capsule-in-capsule capsule of the seabuckthorn seed oil and the fruit oil comprises an inner capsule and an outer capsule, the inner capsule contains the seabuckthorn seed oil, the outer capsule contains the seabuckthorn fruit oil, and the mass ratio of the seabuckthorn seed oil to the seabuckthorn fruit oil is 1: 9-3: 7; the sea buckthorn seed oil contains 50%-70% of linoleic acid, 10%-30% of linolenic acid and 5%-15% of oleic acid; the sea buckthorn fruit oil contains 20%-40% of palmitoleic acid, 20%-40% of oleic acid and 50-300 mg / kg of carotenoid; the inner capsule shell is composed of gelatin, glycerin and purified water; the outer capsule shell is composed of gelatin, glycerin, purified water and food coloring. Through an original bag-in-bag space partition structure, the sea buckthorn seed oil with relatively active chemical properties is encapsulated in the inner bag, and then the sea buckthorn fruit oil is placed in the outer bag, so that effective physical isolation of two kinds of functional grease is realized.

The purpose of the present invention is to address the problem of providing a new oil and fat composition that is suitable for use in chocolate and that is substantially free from lauric acid. The oil and fat composition satisfies the following (i) and (ii). (i) The weight ratio (P2Po / P2M) of the content of a triglyceride (P2Po) to which two palmitic acid (P) moieties and one palmitoleic acid (Po) moiety are bound with respect to the content of a triglyceride (P2M) to which two palmitic acid (P) moieties and one monovalent unsaturated fatty acid (M) moiety having 16-24 carbon atoms are bound is 0.04 or more. (ii) The content of a triglyceride (S3) to which three saturated fatty acid (S) moieties having 16-24 carbon atoms are bound is 1.5%-13% by weight.

The invention discloses a Nitzschia algae that accumulates palmitoleic acid in high yield and its application. The Nitzschia algae (Nitzschi as.) Y3 is deposited with a number of CCTCCM2023030Y3, and the deposit address is Wuhan University, No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province; the Nitzschia algae (Nitzschi as.) Y3 is observed under a microscope as a single-cell structure, the cell is spindle-shaped, the two ends are symmetrical, 24 to 31 μm long, 6 to 7 μm wide, and the cell proliferates by longitudinal division. The Nitzschia algae (Nitzschi as.) Y3 has a simple and reasonable fatty acid composition and can be used for the production of high-quality biodiesel; palmitoleic acid can account for 60 to 70% of the total fatty acids, which is beneficial to the extraction and purification of palmitoleic acid, and can be used to produce palmitoleic acid-related health products, foods, medicines, etc.; it can be cultured using pickling wastewater, salt lakes or seawater, and has good temperature and pH adaptability, can be simply and economically cultured for the production of palmitoleic acid, and is beneficial to reducing production costs.

The invention discloses a positive ion saliva metabolite marker related to brain glioma, a product and application of the positive ion saliva metabolite marker, and relates to the field of biological medicine. The positive ion saliva metabolite marker is prepared from one or more of glyceryl monolinoleate, 1-palmitic acid-2-oleic acid-3-linoleic acid glyceryl, 2, 6-dimethoxyphenol, 20-hydroxyarachidonic acid, 3, 5-dihydroxybenzyl alcohol, rapeseed sterol, histidyl alanyl lysine, pethidine and palmitoleic acid glycolamide. The invention provides a kit which comprises a detection reagent for detecting the positive ion saliva metabolite marker. The invention provides a computer program product related to brain glioma. The product provided by the invention has good feasibility and accuracy, can effectively evaluate the risk of brain glioma, and provides a new tool for clinical diagnosis.

The invention discloses a composite protective agent, a preparation method of active dry yeast, the active dry yeast and application, and belongs to the technical field of bioengineering and fermented food. The composite protective agent comprises a first-phase biological enhancer and a second-phase film-forming protective agent, the first-phase biological enhancer comprises palmitoleic acid and trehalose; the second-phase film-forming protective agent comprises trehalose; the first-phase biological enhancer is added when the yeast grows into the logarithmic growth later stage or the residual sugar of the fermentation liquor is reduced to 40-60% of the residual sugar of the initial fermentation liquor; and the second-phase film-forming protective agent is added before drying. The active dry yeast protective agent is applied to the aspect of active dry yeast preparation, the problem that an existing active dry yeast protective agent for the beer industry cannot prevent leakage of intracellular substances (such as K < + > and nucleotide) is solved, the ultra-high viable bacterium rate of 95% or above can be achieved, and the foam stability and ester flavor of beer are remarkably improved.

The application discloses application of white atractylodes rhizome in increasing content of fatty acids in eggs, and further discloses a method for increasing content of fatty acids in eggs, which is to feed laying hens with additives prepared from white atractylodes rhizome. The application can effectively increase content of fatty acids such as palmitic acid, palmitoleic acid, oleic acid, stearic acid, arachidic acid, alpha-linolenic acid and DHA in eggs by feeding laying hens with additives prepared from white atractylodes rhizome, but the change of content of cholesterols is not obvious, so that the additive is a very ideal nutritional additive, and provides a simple and convenient method for obtaining high-fatty-acid and low-cholesterol eggs.

The purpose of the present invention is to provide an oil-and-fat composition which is a non-trans acid and a non-lauric acid suitable for use in various oily food products. This oil-and-fat composition satisfies all of the following. · The content of stearic acid in the constituent fatty acid composition is 3-40 mass%. · The content mass ratio of stearic acid with respect to palmitic acid in the constituent fatty acid composition is 0.09-5.0. · The content of S3 is 1-15 mass%. · The content mass ratio of SSU with respect to S2U is 0.3 or more. · The content mass ratio of S2Po with respect to S2U is 0.01 or more. Here, S represents a saturated fatty acid having 16 carbon atoms or more, U represents an unsaturated fatty acid having 16 carbon atoms or more, Po represents palmitoleic acid, S2U represents a triglyceride in which 2 molecules of S is bonded to 1 molecule of U, S3 represents a triglyceride in which 3 molecules of S are bonded, S2Po represents a triglyceride in which 2 molecules of S are bonded to 1 molecule of Po, and SSU is an asymmetric triglyceride in which S is bonded to position 2, and S and U are bonded to positions 1 and 3.

The invention relates to the technical field of microorganisms, and discloses a pre-culture solution for improving the survival rate of saccharomyces boulardii under in-vitro simulated gastrointestinal stress conditions and application of the pre-culture solution. Each liter of the pre-culture solution contains the following components: 8-12 g of yeast extract, 18-22 g of peptone, 18-22 g of glucose, 3-7 g of characteristic casein, 0.01 [mu] g of palmitoleic acid and the balance of water, and the pH value of the pre-culture solution is 5.8-6.2; the characteristic casein is casein coated with astaxanthin. According to the method disclosed by the invention, the saccharomyces boulardii is inoculated into the pre-culture solution of the characteristic casein and palmitoleic acid which are externally supplemented and coated with the astaxanthin for pre-culture, so that the saccharomyces boulardii can keep a relatively high survival rate under the action of stress factors such as low pH value of gastrointestinal tracts, cholate and digestive enzymes; a suitable growth environment can be provided for saccharomyces boulardii, and growth and reproduction of the saccharomyces boulardii are promoted, so that the biomass is increased, and the survival rate of the saccharomyces boulardii is increased.

The invention discloses application of palmitoleic acid in preparation of a medicine for protecting nerves and treating cerebral ischemia-reperfusion injury, and belongs to the field of biological medicine. Animal experiments prove the neuroprotective effect of palmitoleic acid on cerebral ischemia-reperfusion injury for the first time. By establishing a mouse cerebral ischemia reperfusion injury model, the palmitoleic acid is found to be capable of remarkably improving neurological impairment and reducing the volume and area of cerebral infarction, which indicates that the palmitoleic acid can be used for effectively limiting ischemic necrosis of brain tissues. According to the application, the research limitation that palmitoleic acid is traditionally applied to metabolic diseases is broken through, a brand new treatment strategy is provided for solving clinical ischemic stroke reperfusion injury, a solid foundation is laid for developing novel neuroprotective drugs, and important clinical application value and development prospects are shown in the aspect of improving prognosis of stroke patients.

The purpose of the present invention is to address the problem of providing an oil and fat composition which is free of trans acid and lauric acid, and is suitable for use in various oily foods. An oil and fat composition according to the present invention satisfies all of the following conditions: ･ In a constituent fatty acid composition, the content of palmitic acid is 30-70 mass% ･ In the constituent fatty acid composition, the content of unsaturated fatty acid is 20-60 mass% and the content of S3 is 1-15 mass% ･ The content mass ratio of SSU to S2U is 0.5 or more ･ The content mass ratio of S2Po to S2U is 0.01 or more S represents a saturated fatty acid having 16 or more carbon atoms, U represents an unsaturated fatty acid having 16 or more carbon atoms, Po represents palmitoleic acid, S2U represents a triglyceride in which two S molecules and one U molecule are bonded, S3 represents a triglyceride in which three S molecules are bonded, S2Po represents a triglyceride in which two S molecules and one Po molecule are bonded, and SSU represents an asymmetric triglyceride in which S is bonded at the 2-position, and S and U are bonded at the 1- and 3-positions.

The application discloses a kind of compound insect oil and its application in cardiovascular and cerebrovascular repair, the compound insect oil is composed of palmitoleic acid-enriched pentatomidae oil and olive oil, wherein the content of palmitoleic acid in palmitoleic acid-enriched pentatomidae oil is ≥20g / 100g.The application obtains pentatomidae crude oil by supercritical CO2 extraction, then directional enrichment is carried out by low-temperature distillation and molecular rectification, the content of palmitoleic acid is increased to more than 20g / 100g, then the enriched pentatomidae oil is compounded with olive oil, and the compound insect oil is prepared by low-temperature homogenization emulsification, deodorization, sterilization process.The compound insect oil prepared by the application can significantly reduce the levels of TC, TG and LDL-C, while significantly increasing the level of HDL-C, showing excellent hypolipidemic effect.In addition, the compound insect oil can also significantly reduce the level of endothelin-1 and increase the level of nitric oxide, effectively improve the function of vascular endothelium, and can be used for the prevention and adjuvant therapy of cardiovascular and cerebrovascular diseases, with good application prospect.

The invention relates to the cross technical field of biotechnology and daily chemicals, and particularly discloses a natural plant composition for removing odors of old people, which comprises ligusticum root extract, eupatorium extract, tea extract, rosemary leaf extract, nigella nigra seed oil, tea tree oil, polygonum cuspidatum root extract and agastache rugosus extract. Through the synergistic effect of all the components, the composition inhibits release of palmitoleic acid from the upstream, performs anti-oxidation and antibacterial intervention in the midstream, decomposes odor molecules from the downstream, assists in repairing the skin microenvironment, forms an intervention network covering the whole path of generation of the old-age odor, can efficiently remove the old-age odor, and has a good application prospect in related odor removal products.

The invention belongs to the technical field of bio-based packaging materials, and particularly relates to a novel double-layer composite film and application thereof. The preparation method of the novel double-layer composite membrane comprises the following steps: reacting palmitoleic anhydride with carboxymethyl cellulose to obtain carboxymethyl cellulose palmitate; then adding a pH sensitive natural dye indicator to obtain a nano emulsion containing pH sensitive carboxymethyl cellulose palmitate; then loading a natural polymer material to prepare a film-forming material; and finally, on the basis of cellulose palmitate film forming, adding the film forming material to prepare a composite film, thereby obtaining the novel double-layer composite film. The double-layer composite film can be self-emulsified without additionally adding a surfactant, and has the capability of loading functional indication (pH sensitive color indication) substances; meanwhile, the water vapor and oxygen barrier property of a coating material, such as a chitosan film, is improved, and the coating material has a very good prospect in food or fruit fresh-keeping application. According to the method provided by the invention, raw materials are green, and a tape casting method is adopted, so that the method can be applied to industrial production and has a good application prospect.