CN116210764A - Egg white protein-based slow-release antibacterial coating for fruit preservation and preparation method thereof - Google Patents
Egg white protein-based slow-release antibacterial coating for fruit preservation and preparation method thereof Download PDFInfo
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- CN116210764A CN116210764A CN202310002086.0A CN202310002086A CN116210764A CN 116210764 A CN116210764 A CN 116210764A CN 202310002086 A CN202310002086 A CN 202310002086A CN 116210764 A CN116210764 A CN 116210764A
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- NCXMLFZGDNKEPB-FFPOYIOWSA-N natamycin Chemical compound O[C@H]1[C@@H](N)[C@H](O)[C@@H](C)O[C@H]1O[C@H]1/C=C/C=C/C=C/C=C/C[C@@H](C)OC(=O)/C=C/[C@H]2O[C@@H]2C[C@H](O)C[C@](O)(C[C@H](O)[C@H]2C(O)=O)O[C@H]2C1 NCXMLFZGDNKEPB-FFPOYIOWSA-N 0.000 description 1
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- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
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Classifications
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
- A23B7/00—Preservation or chemical ripening of fruit or vegetables
- A23B7/16—Coating with a protective layer; Compositions or apparatus therefor
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23B—PRESERVING, e.g. BY CANNING, MEAT, FISH, EGGS, FRUIT, VEGETABLES, EDIBLE SEEDS; CHEMICAL RIPENING OF FRUIT OR VEGETABLES; THE PRESERVED, RIPENED, OR CANNED PRODUCTS
- A23B7/00—Preservation or chemical ripening of fruit or vegetables
- A23B7/14—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10
- A23B7/153—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10 in the form of liquids or solids
- A23B7/154—Organic compounds; Microorganisms; Enzymes
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
- A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
- A23L5/20—Removal of unwanted matter, e.g. deodorisation or detoxification
- A23L5/27—Removal of unwanted matter, e.g. deodorisation or detoxification by chemical treatment, by adsorption or by absorption
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23V—INDEXING SCHEME RELATING TO FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES AND LACTIC OR PROPIONIC ACID BACTERIA USED IN FOODSTUFFS OR FOOD PREPARATION
- A23V2002/00—Food compositions, function of food ingredients or processes for food or foodstuffs
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/90—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in food processing or handling, e.g. food conservation
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Polymers & Plastics (AREA)
- Food Science & Technology (AREA)
- Zoology (AREA)
- Wood Science & Technology (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Microbiology (AREA)
- Health & Medical Sciences (AREA)
- Nutrition Science (AREA)
- Wrappers (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
Abstract
The invention provides an egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof, belonging to the technical field of natural high polymer materials for food packaging. According to the invention, thyme essential oil which is natural and safe and has excellent antibacterial effect is selected as a bacteriostatic agent, embedded in chitosan microspheres and used for stabilizing pickering emulsion with thyme essential oil as a partial disperse phase, and egg white protein is used as a main matrix to prepare a novel slow-release antibacterial coating. The antibacterial coating obtained by the method can effectively inhibit common food putrefying bacteria such as escherichia coli, staphylococcus aureus and the like for a long time, has a remarkable inhibition effect on characteristic mold in fruits and vegetables such as alternaria alternata, penicillium and the like, and can provide a food protein-based fresh-keeping packaging material with functional activity for the fields of fruit storage and fresh-keeping industry and packaging materials.
Description
Technical Field
The invention provides an egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof, belonging to the technical field of natural high polymer materials for food packaging.
Background
China is a large country for planting and trade of fruits and vegetables in the world. With the improvement of the living standard of people, people pursue the freshness of fruits, and sales of fruits in the reverse seasons rise year by year. Most fruits are harvested in 6 to 8 months, and fruits sold in reverse seasons are required to have a post-harvest fresh-keeping period of 2 to 4 months, so that the requirements on the fresh-keeping technology are higher. The fruit and vegetable has short shelf life after picking due to the influence of factors such as water transpiration and harmful microorganism invasion. The proper active package can slow down the change of the quality of fruits and vegetables by improving the gas environment around the fruits and vegetables, reducing the number of harmful microorganisms, slowing down enzymatic browning and the like, and prolong the shelf life of the fruits and vegetables. The current common fruit and vegetable fresh-keeping method has certain limitation on application due to the reasons of expensive equipment, high cost, technology and safety, so that people begin to focus on researching natural, safe, nontoxic, cheap and degradable fruit and vegetable fresh-keeping coatings in order to reduce environmental pollution and realize green health sustainable development, and the method gradually becomes a hot spot of current research.
Egg white proteins consist of free water (88%), protein (11%) and trace amounts of carbohydrates, fat and ash (1%). Among them, ovalbumin, ovotransferrin and lysozyme are main bioactive substances in egg white proteins, and have important roles in the fields of food medicine and the like. Egg white protein has the advantages of good amphipathy, low toxicity, self-assembly property, digestibility, rich nutritive value and the like, and is considered as a biological material with the most application prospect in a coating matrix. Egg white protein based coatings have good film forming properties, adhesion and the coatings are brighter and more transparent, while egg white protein based coatings are a good fat barrier and are also commonly used as carrier substrates for antibacterial and antioxidant agents. The related literature shows that the protein in the egg white protein can promote emulsion droplets to be closely stacked to form a stable elastic network structure, and the protein can be used as a film forming matrix to be added into food packaging materials to obviously improve the transparency of an emulsion coating and the adhesiveness between the emulsion coating and fruit and vegetable epidermis.
Pickering emulsions are emulsions stabilized by solid colloidal particles. Pickering emulsions stabilize emulsions by changing interfacial properties, or changing the rheological properties of the continuous phase, primarily by increasing steric hindrance compared to traditional emulsions. The solid particles used have certain wettability between the water phase and the oil phase, and can be adsorbed on an oil-water interface to form a denser particle film to prevent aggregation of emulsion liquid drops, so that the Pickering emulsion has higher environmental stability. However, the traditional pickering emulsion is stabilized by a surfactant small-molecule emulsifier, and has the problems of large consumption, large side effect, environmental pollution, high cost and the like; and most natural macromolecular substances have strong hydrophilicity and poor emulsifying property, the prepared emulsion is easy to phase inversion, and stable Pickering emulsion is difficult to prepare. Therefore, it is important to use food grade solid particles with good emulsifying properties for the preparation of pickering emulsions. Meanwhile, the Pickering emulsion can ensure the bioavailability of the bioactive substances, and is widely applied to the delivery and slow release of the bioactive substances.
The chitosan is the product obtained after N-deacetylation of chitin. Chitosan is the only natural polysaccharide found at home and abroad, and has alkaline pH and high availability. The chitosan has the advantages of good antibacterial property, emulsifying property, biodegradability, biocompatibility and the like, so that a plurality of high-efficiency active substances which are easy to volatilize, poor in stability and difficult to directly use are carried by the chitosan in the preparation process. Since the free amino groups of chitosan are easy to modify, there are also scholars to enhance the performance of chitosan as a drug-carrying material by means of a cross-linking agent. Meanwhile, the chitosan is reported to be added as an emulsifier to stabilize the Pickering emulsion to a certain extent, so that the chitosan is favored by scientific researchers.
Thyme essential oil has various natural active substances, the components of which are classified from compound types and can be classified into phenols, monoterpenes, esters and alcohols, and the components are extremely volatile and have different odors, so that the special pungent aroma of the thyme essential oil is formed. A large number of researches show that the thyme essential oil has a wide antibacterial spectrum and a certain inhibition effect on various food spoilage bacteria, and the main antibacterial active substances are thymol and carvacrol, so that the thyme essential oil is widely used as a natural antibacterial agent and the like. In the aspect of fruit and vegetable fresh-keeping, the thymol is used for fumigating and treating the apricot and plum fruits, so that the spoilage rate of the fruits can be effectively reduced, and other adverse effects on the fruits are avoided. Earlier studies showed that thyme essential oil had 100% inhibition of gray mold, rhizopus, alternaria and myxosporean in vitro tests. Wherein rhizopus can cause soft rot of melons and fruits, and Botrytis cinerea is also an important pathogenic bacterium in the process of storing fruits and vegetables. The thyme essential oil has strong antibacterial effect on food-borne bacteria such as staphylococcus aureus, escherichia coli, bacillus subtilis, alcaligenes eutrophus and the like, and has great potential in the aspect of fruit and vegetable fresh-keeping. However, due to the pungent odor of thyme essential oil, and the susceptibility to external environmental conditions such as light, temperature, etc., during storage, the thyme essential oil is extremely volatile or oxidized and degraded, which greatly limits the application of thyme essential oil in the food industry. The microsphere embedding technology is one of good measures for solving the problems, and can control the release of thyme essential oil to achieve efficient, stable and sustainable antibacterial effect.
According to the invention, thyme essential oil which is natural and safe and has excellent antibacterial effect is selected as a bacteriostatic agent, embedded in chitosan microspheres and used for stabilizing pickering emulsion with thyme essential oil as a partial disperse phase, and egg white protein is used as a main matrix to prepare a novel slow-release antibacterial coating. The Chinese patent CN115005268A discloses a composite antibacterial strawberry preservative solution and a preparation method thereof, wherein the composite antibacterial strawberry preservative solution comprises an antibacterial A solution, an antibacterial B solution and glycerin, the antibacterial A solution is an antibacterial solution containing konjak glucomannan, the antibacterial B solution is an antibacterial aqueous solution containing a firewood extract, and the antibacterial aqueous solution is a mixed aqueous solution of natamycin and potassium sorbate; chinese patent CN114304261a discloses a preparation method and application of preparing bacteriostatic composite coating liquid from gellan gum and tea polyphenol (and acetic acid) for preserving strawberry. The active substances or the bacteriostat are directly blended in the coating liquid, the guarantee of bacteriostasis and aging is not considered, and the bacteriostasis effect is inevitably greatly reduced along with the storage time, so that the actual fresh-keeping effect is affected.
Disclosure of Invention
The invention aims to provide a novel antibacterial coating which is natural and safe, wide in application range and long in antibacterial aging time, and a preparation method thereof, and the novel antibacterial coating is applied to the field of fresh-keeping packaging of perishable foods such as fruits and vegetables. In order to achieve the above object, the technical scheme of the present invention is as follows:
an egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof comprise the following steps:
(1) Preparation of chitosan solution: chitosan was dissolved in 1.0% acetic acid solution at room temperature and stirred overnight, and the ratio of Tween80 to chitosan was controlled to be 1:0.1 (w/w), stirring at 60 ℃ for 2h to obtain 1.0% chitosan solution as the aqueous phase of the emulsion;
(2) Dissolving thyme essential oil: thyme essential oil (0.04-0.12): 1 (w/v) is dissolved in absolute ethyl alcohol and is used as an oil phase for standby;
(3) Preparation of the emulsion: dropwise adding the oil phase prepared in the step (2) into the water phase prepared in the step (1), and homogenizing at 12000rpm for 10min to prepare an emulsion;
(4) Preparation of sodium tripolyphosphate solution: weighing a certain amount of sodium tripolyphosphate, and dissolving in deionized water for later use;
(5) Crosslinking of chitosan microspheres: dropwise adding the sodium tripolyphosphate solution prepared in the step (4) into the emulsion prepared in the step (3), controlling the ratio of chitosan to sodium tripolyphosphate to be 1 (0.15-0.75) (w/w), and uniformly stirring for 40min to crosslink the solution;
(6) And (3) centrifugal separation: centrifuging the product obtained in the step (5) at 4 ℃ at 10000 r for 30min, washing the precipitate with deionized water for 3 times, and dispersing in deionized water;
(7) And (3) freeze-drying: pre-freezing the solution obtained in the step (6) for 12 hours, and freeze-drying the solution at the temperature of minus 60 ℃ for 24 hours to obtain the chitosan microsphere embedded with thyme essential oil;
(8) Preparation of Pickering emulsion: dissolving the microsphere particles in the step (7) in deionized water, dropwise adding thyme essential oil and soybean oil with a certain proportion as a disperse phase, wherein the total addition amount of the disperse phase is 10%, the proportion of thyme essential oil and soybean oil is (1-4): (4-1) (v/v), homogenizing for 3min at 12000rpm at room temperature by using a high-speed homogenizer to obtain coarse emulsion, carrying out ultrasonic treatment on the coarse emulsion under the ice bath condition, wherein the ultrasonic power is 500W, the working time and the intermittent time are respectively 2s, and the actual ultrasonic treatment time is 5min, thus obtaining the pickering emulsion, and storing at 4 ℃;
(9) The preparation of the Pickering emulsion/egg white protein-based antibacterial coating liquid comprises the steps of adding the emulsion obtained in the step (8) into 2-5% of egg white protein solution according to a certain proportion, adding 1% of glycerol, and stirring for 1h at room temperature to obtain the coating liquid. Spraying it on the surface of fruit and vegetable with an electric spray gun with optimal coating amount of 0.1-0.5mL/cm 2 The fruit preservative is placed in a shady and ventilated place for airing, and the spoilage speed of the fruits can be obviously delayed.
Storage test:
uniformly spraying the Pickering emulsion/egg white protein-based antibacterial coating liquid obtained in the step (9) on strawberries (non-respiratory-transition type) and blueberries (respiratory-transition type), using the commercial fruit fresh-keeping coating liquid as a control, uniformly spraying the coating liquid on the strawberries and the blueberries, and keeping fresh for 0-15 days at room temperature.
The antibacterial principle of the pickering emulsion/egg white protein-based antibacterial coating liquid prepared by the invention mainly comprises the following steps:
(1) Phenolic substances in thyme essential oil can destroy the structure of germ cell walls or cell membranes, induce mycelium to dissolve, cause irreversible damage to microorganisms and finally cause death of the microorganisms;
(2) The organic components in the thyme essential oil can reduce the content of unsaturated fatty acid of microorganisms and reduce or inhibit the generation and germination of conidia by dissolving fatty substances, so that pathogenic bacteria lose the original functions, the generation of offspring is blocked, and the effect of inhibiting the growth and reproduction of microorganisms is achieved;
(3) The load protection of the chitosan on the thyme essential oil can enable the thyme essential oil to be released slowly, so that the antibacterial aging of the thyme essential oil is prolonged.
Experimental results: compared with the fruit and vegetable fresh-keeping coating liquid used in the control market, the Pickering emulsion/egg white protein-based antibacterial coating liquid has more remarkable effect of inhibiting escherichia coli and staphylococcus aureus, and the specific results are shown in table 1.
The beneficial effects of the invention are as follows:
according to the invention, thyme essential oil which is natural and safe and has excellent antibacterial effect is selected as a bacteriostatic agent, embedded in chitosan microspheres and used for stabilizing pickering emulsion with thyme essential oil as a partial disperse phase, and egg white protein is used as a main matrix to prepare a novel slow-release antibacterial coating. The antibacterial coating obtained by the method can effectively inhibit common food putrefying bacteria such as escherichia coli, staphylococcus aureus and the like for a long time, has a remarkable inhibition effect on characteristic mold in fruits and vegetables such as alternaria alternata, penicillium and the like, and can provide a food protein-based fresh-keeping packaging material with functional activity for the fields of fruit storage and fresh-keeping industry and packaging materials.
Detailed Description
Specific embodiments of the present invention are described in detail below:
an egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof comprise the following steps:
(1) Preparation of chitosan solution: chitosan was dissolved in 1.0% acetic acid solution at room temperature and stirred overnight, and the ratio of Tween80 to chitosan was controlled to be 1:0.1 (w/w), stirring at 60 ℃ for 2h to obtain 1.0% chitosan solution as the aqueous phase of the emulsion;
(2) Dissolving thyme essential oil: thyme essential oil (0.04-0.12): 1 (w/v) is dissolved in absolute ethyl alcohol and is used as an oil phase for standby;
(3) Preparation of the emulsion: dropwise adding the oil phase prepared in the step (2) into the water phase prepared in the step (1), and homogenizing at 12000rpm for 10min to prepare an emulsion;
(4) Preparation of sodium tripolyphosphate solution: weighing a certain amount of sodium tripolyphosphate, and dissolving in deionized water for later use;
(5) Crosslinking of chitosan microspheres: dropwise adding the sodium tripolyphosphate solution prepared in the step (4) into the emulsion prepared in the step (3), controlling the ratio of chitosan to sodium tripolyphosphate to be 1 (0.15-0.75) (w/w), and uniformly stirring for 40min to crosslink the solution;
(6) And (3) centrifugal separation: centrifuging the product obtained in the step (5) at 4 ℃ at 10000 r for 30min, washing the precipitate with deionized water for 3 times, and dispersing in deionized water;
(7) And (3) freeze-drying: pre-freezing the solution obtained in the step (6) for 12 hours, and freeze-drying the solution at the temperature of minus 60 ℃ for 24 hours to obtain the chitosan microsphere embedded with thyme essential oil;
(8) Preparation of Pickering emulsion: dissolving the microsphere particles in the step (7) in deionized water, dropwise adding thyme essential oil and soybean oil with a certain proportion as a disperse phase, wherein the total addition amount of the disperse phase is 10%, the proportion of thyme essential oil and soybean oil is (1-4): (4-1) (v/v), homogenizing for 3min at 12000rpm at room temperature by using a high-speed homogenizer to obtain coarse emulsion, carrying out ultrasonic treatment on the coarse emulsion under the ice bath condition, wherein the ultrasonic power is 500W, the working time and the intermittent time are respectively 2s, and the actual ultrasonic treatment time is 5min, thus obtaining the pickering emulsion, and storing at 4 ℃;
(9) The preparation of the Pickering emulsion/egg white protein-based antibacterial coating liquid comprises the steps of adding the emulsion obtained in the step (8) into 2-5% of egg white protein solution according to a certain proportion, adding 1% of glycerol, and stirring for 1h at room temperature to obtain the coating liquid.
Example 1: an egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof comprise the following steps:
(1) Preparation of chitosan solution: chitosan was dissolved in 1.0% acetic acid solution at room temperature and stirred overnight, and the ratio of Tween80 to chitosan was controlled to be 1:0.1 (w/w), stirring at 60 ℃ for 2h to obtain 1.0% chitosan solution as the aqueous phase of the emulsion;
(2) Dissolving thyme essential oil: thyme essential oil at 0.08:1 (w/v) is dissolved in absolute ethyl alcohol and is used as an oil phase for standby;
(3) Preparation of the emulsion: dropwise adding the oil phase prepared in the step (2) into the water phase prepared in the step (1), and homogenizing at 12000rpm for 10min to prepare an emulsion;
(4) Preparation of sodium tripolyphosphate solution: weighing a certain amount of sodium tripolyphosphate, and dissolving in deionized water for later use;
(5) Crosslinking of chitosan microspheres: dropwise adding the sodium tripolyphosphate solution prepared in the step (4) into the emulsion prepared in the step (3), controlling the ratio of chitosan to sodium tripolyphosphate to be 1:0.45 (w/w), and uniformly stirring for 40min to crosslink the sodium tripolyphosphate;
(6) And (3) centrifugal separation: centrifuging the product obtained in the step (5) at 4 ℃ at 10000 r for 30min, washing the precipitate with deionized water for 3 times, and dispersing in deionized water;
(7) And (3) freeze-drying: pre-freezing the solution obtained in the step (6) for 12 hours, and freeze-drying the solution at the temperature of minus 60 ℃ for 24 hours to obtain the chitosan microsphere embedded with thyme essential oil;
(8) Preparation of Pickering emulsion: dissolving the microsphere particles in the step (7) in deionized water, dropwise adding thyme essential oil and soybean oil in a certain proportion as a disperse phase, wherein the total addition amount of the disperse phase is 10%, homogenizing the thyme essential oil and the soybean oil for 3min at 12000rpm at room temperature by a high-speed homogenizer to obtain coarse emulsion, carrying out ultrasonic treatment on the coarse emulsion under the ice bath condition, wherein the ultrasonic power is 500W, the working time and the intermittent time are respectively 2s, and the actual ultrasonic treatment time is 5min, thus obtaining the pickering emulsion, and storing the pickering emulsion at 4 ℃;
(9) The preparation of the Pickering emulsion/egg white protein-based antibacterial coating liquid comprises the steps of adding the emulsion obtained in the step (8) into 2-5% of egg white protein solution according to a certain proportion, adding 1% of glycerol, and stirring for 1h at room temperature to obtain the coating liquid.
(10) Bacteriostasis experiment: cutting the sterile filter paper sheet into discs with the diameter of 10.00mm, soaking the discs in the sample solution obtained in the step (9) for 12 hours, and performing bacteriostasis experiments after 20 minutes of sterilization under ultraviolet light.
Colibacillus bacteriostasis experiment
100 mu L of the mixture is diluted to 10 5 The escherichia coli bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Antibacterial test of staphylococcus aureus
100 mu L of the mixture is diluted to 10 5 The staphylococcus aureus bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Example 2: an egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof comprise the following steps:
(1) Preparation of chitosan solution: dissolving chitosan in 1.0% acetic acid solution at room temperature, and stirring overnight to obtain 1.0% chitosan solution;
(2) Preparation of sodium tripolyphosphate solution: weighing a certain amount of sodium tripolyphosphate, and dissolving in deionized water for later use;
(3) Crosslinking of chitosan microspheres: dropwise adding the sodium tripolyphosphate solution prepared in the step (2) into the chitosan solution prepared in the step (1), controlling the ratio of chitosan to sodium tripolyphosphate to be 1:0.45 (w/w), and uniformly stirring for 40min to crosslink the chitosan solution;
(4) And (3) centrifugal separation: centrifugally separating the product of the step (3) at 10000 revolutions for 30min at 4 ℃, washing the precipitate with deionized water for 3 times, and dispersing in the deionized water;
(5) And (3) freeze-drying: pre-freezing the solution obtained in the step (4) for 12 hours, and freeze-drying the solution at the temperature of minus 60 ℃ for 24 hours to obtain the thyme essential oil-embedded chitosan microsphere;
(6) Preparation of Pickering emulsion: dissolving the microsphere particles in the step (5) in deionized water, dropwise adding soybean oil as a disperse phase, wherein the addition amount of the disperse phase is 10%, homogenizing at 12000rpm for 3min at room temperature by using a high-speed homogenizer to obtain coarse emulsion, carrying out ultrasonic treatment on the coarse emulsion under ice bath condition, wherein the ultrasonic power is 500W, the working time and the intermittent time are respectively 2s, and the actual ultrasonic treatment time is 5min, thus obtaining Pickering emulsion, and storing at 4 ℃;
(7) The preparation of the Pickering emulsion/egg white protein-based antibacterial coating liquid comprises the steps of adding the emulsion obtained in the step (6) into 2-5% of egg white protein solution according to a certain proportion, adding 1% of glycerol, and stirring for 1h at room temperature to obtain the coating liquid.
(8) Bacteriostasis experiment: cutting the sterile filter paper sheet into discs with the diameter of 10.00mm, soaking the discs in the sample solution obtained in the step (7) for 12 hours, and performing bacteriostasis experiments after 20 minutes of sterilization under ultraviolet light.
Colibacillus bacteriostasis experiment
100 mu L of the mixture is diluted to 10 5 The escherichia coli bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Antibacterial test of staphylococcus aureus
100 mu L of the mixture is diluted to 10 5 The staphylococcus aureus bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Example 3: an albumin-based coating and method of making the same comprising the steps of:
(1) The preparation of the egg white protein-based coating liquid comprises accurately weighing a certain amount of egg white protein, dissolving in deionized water, preparing 5% egg white protein solution, centrifuging for 10min at 6000r, adding 1% glycerol into the supernatant, and stirring at room temperature for 1h to obtain the coating liquid.
(2) Bacteriostasis experiment: cutting the sterile filter paper sheet into discs with the diameter of 10.00mm, soaking the discs in the sample solution obtained in the step (1) for 12 hours, and sterilizing the discs for 20 minutes under ultraviolet light, and then carrying out a bacteriostasis experiment.
Colibacillus bacteriostasis experiment
100 mu L of the mixture is diluted to 10 5 The escherichia coli bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Antibacterial test of staphylococcus aureus
100 mu L of the mixture is diluted to 10 5 The staphylococcus aureus bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Control group 1: the commercial fruit fresh-keeping coating comprises the following steps:
(1) The preparation of the commercial fruit fresh-keeping coating liquid comprises the steps of taking out a tablet, dissolving the tablet in 2L of deionized water, and obtaining a coating liquid sample of a control group.
(2) Bacteriostasis experiment: cutting the sterile filter paper sheet into discs with the diameter of 10.00mm, soaking the discs in the sample solution obtained in the step (1) for 12 hours, and sterilizing the discs for 20 minutes under ultraviolet light, and then carrying out a bacteriostasis experiment.
Colibacillus bacteriostasis experiment
100 mu L of the mixture is diluted to 10 5 The escherichia coli bacterial suspension with the CFU/mL is dripped into a sterile agar culture medium to be uniformly coated, a sterile filter paper sheet with the diameter of 10.00mm is paved on the surface of the culture medium, the culture medium is inverted and is cultured in a culture box with the temperature of 37 ℃ for 24 hours, and the diameter of a bacteriostasis ring of a coating sample is observed and recorded to detect the bacteriostasis effect of the coating sample.
Antibacterial test of staphylococcus aureus
100 mu L of the mixture is diluted to 10 5 Dripping CFU/mL staphylococcus aureus suspension into sterile agar culture medium, coating uniformly, spreading sterile filter paper sheet with diameter of 10.00mm on the surface of the culture medium, culturing in a 37 deg.C incubator for 24 hr, observing and recording the diameter of the antibacterial ring of the coating sample to detect its antibacterial effect。
Example 5: an application test of an egg white protein-based slow-release antibacterial coating for fruit preservation comprises the following steps:
(1) Preparation of chitosan solution: chitosan was dissolved in 1.0% acetic acid solution at room temperature and stirred overnight, and the ratio of Tween80 to chitosan was controlled to be 1:0.1 (w/w), stirring at 60 ℃ for 2h to obtain 1.0% chitosan solution as the aqueous phase of the emulsion;
(2) Dissolving thyme essential oil: thyme essential oil at 0.08:1 (w/v) is dissolved in absolute ethyl alcohol and is used as an oil phase for standby;
(3) Preparation of the emulsion: dropwise adding the oil phase prepared in the step (2) into the water phase prepared in the step (1), and homogenizing at 12000rpm for 10min to prepare an emulsion;
(4) Preparation of sodium tripolyphosphate solution: weighing a certain amount of sodium tripolyphosphate, and dissolving in deionized water for later use;
(5) Crosslinking of chitosan microspheres: dropwise adding the sodium tripolyphosphate solution prepared in the step (4) into the emulsion prepared in the step (3), controlling the ratio of chitosan to sodium tripolyphosphate to be 1:0.45 (w/w), and uniformly stirring for 40min to crosslink the sodium tripolyphosphate;
(6) And (3) centrifugal separation: centrifuging the product obtained in the step (5) at 4 ℃ at 10000 r for 30min, washing the precipitate with deionized water for 3 times, and dispersing in deionized water;
(7) And (3) freeze-drying: pre-freezing the solution obtained in the step (6) for 12 hours, and freeze-drying the solution at the temperature of minus 60 ℃ for 24 hours to obtain the chitosan microsphere embedded with thyme essential oil;
(8) Preparation of Pickering emulsion: dissolving the microsphere particles in the step (7) in deionized water, dropwise adding thyme essential oil and soybean oil in a certain proportion as a disperse phase, wherein the total addition amount of the disperse phase is 10%, homogenizing the thyme essential oil and the soybean oil for 3min at 12000rpm at room temperature by a high-speed homogenizer to obtain coarse emulsion, carrying out ultrasonic treatment on the coarse emulsion under the ice bath condition, wherein the ultrasonic power is 500W, the working time and the intermittent time are respectively 2s, and the actual ultrasonic treatment time is 5min, thus obtaining the pickering emulsion, and storing the pickering emulsion at 4 ℃;
(10) The preparation of the Pickering emulsion/egg white protein-based antibacterial coating liquid comprises the steps of adding the emulsion obtained in the step (8) into 2-5% of egg white protein solution according to a certain proportion, adding 1% of glycerol, and stirring for 1h at room temperature to obtain the coating liquid;
(11) Spraying the coating liquid obtained in the step (10) on the surfaces of blueberries and strawberries by using an electric spray gun, wherein the optimal coating amount is 0.1-0.5mL/cm 2 Airing in a cool and ventilated place, putting the treated blueberries and strawberries into a biochemical incubator, measuring the quantity of escherichia coli and staphylococcus aureus every 24 hours at the temperature of 20+/-0.1 ℃ and the humidity of 48+/-1%, and recording the detection result;
(12) Experimental results: compared with the control commercial fruit fresh-keeping coating liquid, the Pickering emulsion/egg white protein-based antibacterial coating liquid has better effect of inhibiting the growth of escherichia coli and staphylococcus aureus;
application tests prove that the Pickering emulsion/egg white protein-based antibacterial coating liquid can effectively inhibit the growth and propagation of microorganisms in the storage process of fruits, and the shelf life is prolonged by 3-5 days.
TABLE 1 diameter (mm) of inhibition zone for coating liquids of different examples
Note that: UC (unable to check out), undetected.
Claims (6)
1. An egg white protein-based slow-release antibacterial coating for fruit preservation and a preparation method thereof comprise the following steps:
(1) Preparation of chitosan solution: chitosan was dissolved in 1.0% acetic acid solution at room temperature and stirred overnight, and the ratio of Tween80 to chitosan was controlled to be 1:0.1 (w/w), stirring at 60 ℃ for 2h to obtain 1.0% chitosan solution as the aqueous phase of the emulsion;
(2) Dissolving thyme essential oil: dissolving thyme essential oil in absolute ethyl alcohol to serve as an oil phase for standby;
(3) Preparation of the emulsion: dropwise adding the oil phase prepared in the step (2) into the water phase prepared in the step (1), and homogenizing at 12000rpm for 10min to prepare an emulsion;
(4) Preparation of sodium tripolyphosphate solution: weighing a certain amount of sodium tripolyphosphate, and dissolving in deionized water for later use;
(5) Crosslinking of chitosan microspheres: dropwise adding the sodium tripolyphosphate solution prepared in the step (4) into the emulsion prepared in the step (3), and uniformly stirring for 40min to crosslink the sodium tripolyphosphate solution;
(6) And (3) centrifugal separation: centrifuging the product obtained in the step (5) at 4 ℃ at 10000 r for 30min, washing the precipitate with deionized water for 3 times, and dispersing in deionized water;
(7) And (3) freeze-drying: pre-freezing the solution obtained in the step (6) for 12 hours, and freeze-drying the solution at the temperature of minus 60 ℃ for 24 hours to obtain the chitosan microsphere embedded with thyme essential oil;
(8) Preparation of Pickering emulsion: dissolving the microsphere particles in the step (7) in deionized water, dropwise adding thyme essential oil and soybean oil with a certain proportion as a disperse phase, homogenizing at 12000rpm for 3min at room temperature by using a high-speed homogenizer to obtain coarse emulsion, carrying out ultrasonic treatment on the coarse emulsion under the ice bath condition, wherein the ultrasonic power is 500W, the working time and the intermittent time are respectively 2s, and the actual ultrasonic treatment time is 5min, thus obtaining Pickering emulsion, and storing at 4 ℃;
(9) The preparation of the Pickering emulsion/egg white protein-based antibacterial coating liquid comprises the steps of adding the emulsion obtained in the step (8) into 2-5% of egg white protein solution according to a certain proportion, adding 1% of glycerol, and stirring for 1h at room temperature to obtain the coating liquid. The electric spray gun is used for spraying the fruits and vegetables, and the fruits and vegetables are placed in a shady and ventilated place for airing, so that the putrefaction speed of the fruits and vegetables can be obviously delayed.
2. The egg white protein-based slow-release antibacterial coating for fruit preservation and the preparation method thereof according to claim 1, wherein thyme essential oil in the step (2) is prepared by the following steps (0.04-0.12): 1 (w/v) in absolute ethanol.
3. The slow-release egg white protein-based antibacterial coating for fruit preservation and the preparation method thereof according to claim 1, wherein the ratio of chitosan to sodium tripolyphosphate in the step (5) is controlled to be 1 (0.15-0.75) (w/w).
4. The slow-release egg white protein-based antibacterial coating for fruit preservation and the preparation method thereof according to claim 1, wherein the total addition amount of oil phase in the step (8) is 10%, and the ratio of thyme essential oil to soybean oil is (1-4): 4-1) (v/v).
5. The slow-release egg white protein-based antibacterial coating for fruit preservation and the preparation method thereof according to claim 1, wherein the optimal coating amount in the step (9) is 0.1-0.5mL/cm when the coating is sprayed by an electric spray gun 2 。
6. The egg white protein-based slow-release antibacterial coating for fruit preservation and the preparation method thereof as claimed in claim 1 are characterized in that chitosan microspheres embedded with thyme essential oil are used as emulsion stabilizers, and pickering antibacterial emulsion prepared by using thyme essential oil as an oil phase is wide in application range, and the antibacterial coating prepared by using egg white protein as a film forming matrix can be applied to the field of fruit and other perishable food preservation.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106835504A (en) * | 2017-02-16 | 2017-06-13 | 江苏大学 | A kind of nanofiber antibacterial film and its production and use |
| CN108783373A (en) * | 2018-04-03 | 2018-11-13 | 上海应用技术大学 | A kind of citral pickering emulsion and preparation method thereof |
| CN112314838A (en) * | 2020-10-29 | 2021-02-05 | 成都大学 | Antibacterial food fresh-keeping Pickering emulsion and preparation method thereof |
| CN113207956A (en) * | 2021-05-17 | 2021-08-06 | 上海扬彩生物科技有限公司 | Fruit and vegetable preservative and preparation method and application thereof |
| CN113243421A (en) * | 2021-06-18 | 2021-08-13 | 浙江省农业科学院 | Pickering emulsion and preparation method thereof |
| CN113367189A (en) * | 2021-05-21 | 2021-09-10 | 泉州师范学院 | Multifunctional edible preservative film material and preparation method thereof |
-
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106835504A (en) * | 2017-02-16 | 2017-06-13 | 江苏大学 | A kind of nanofiber antibacterial film and its production and use |
| CN108783373A (en) * | 2018-04-03 | 2018-11-13 | 上海应用技术大学 | A kind of citral pickering emulsion and preparation method thereof |
| CN112314838A (en) * | 2020-10-29 | 2021-02-05 | 成都大学 | Antibacterial food fresh-keeping Pickering emulsion and preparation method thereof |
| CN113207956A (en) * | 2021-05-17 | 2021-08-06 | 上海扬彩生物科技有限公司 | Fruit and vegetable preservative and preparation method and application thereof |
| CN113367189A (en) * | 2021-05-21 | 2021-09-10 | 泉州师范学院 | Multifunctional edible preservative film material and preparation method thereof |
| CN113243421A (en) * | 2021-06-18 | 2021-08-13 | 浙江省农业科学院 | Pickering emulsion and preparation method thereof |
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