CN111387279A - Preparation method and application of ethylene composite absorbent - Google Patents
Preparation method and application of ethylene composite absorbent Download PDFInfo
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- CN111387279A CN111387279A CN202010235274.4A CN202010235274A CN111387279A CN 111387279 A CN111387279 A CN 111387279A CN 202010235274 A CN202010235274 A CN 202010235274A CN 111387279 A CN111387279 A CN 111387279A
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- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 title claims abstract description 78
- 239000005977 Ethylene Substances 0.000 title claims abstract description 78
- 239000002250 absorbent Substances 0.000 title claims abstract description 52
- 230000002745 absorbent Effects 0.000 title claims abstract description 52
- 239000002131 composite material Substances 0.000 title claims abstract description 50
- 238000002360 preparation method Methods 0.000 title claims abstract description 30
- 229920001661 Chitosan Polymers 0.000 claims abstract description 78
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 66
- 239000004343 Calcium peroxide Substances 0.000 claims abstract description 40
- LHJQIRIGXXHNLA-UHFFFAOYSA-N calcium peroxide Chemical compound [Ca+2].[O-][O-] LHJQIRIGXXHNLA-UHFFFAOYSA-N 0.000 claims abstract description 40
- 235000019402 calcium peroxide Nutrition 0.000 claims abstract description 40
- 239000012286 potassium permanganate Substances 0.000 claims abstract description 35
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- 239000000243 solution Substances 0.000 claims description 74
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 claims description 32
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- 238000003756 stirring Methods 0.000 claims description 20
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- 239000011259 mixed solution Substances 0.000 claims description 12
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 10
- 239000007864 aqueous solution Substances 0.000 claims description 10
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- 238000000034 method Methods 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 8
- 238000002791 soaking Methods 0.000 claims description 8
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 7
- 239000004327 boric acid Substances 0.000 claims description 7
- 229960000583 acetic acid Drugs 0.000 claims description 5
- 238000001816 cooling Methods 0.000 claims description 5
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- 238000010438 heat treatment Methods 0.000 claims description 5
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- 239000007788 liquid Substances 0.000 claims description 5
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- 230000000694 effects Effects 0.000 abstract description 29
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- 238000010521 absorption reaction Methods 0.000 abstract description 5
- 230000002035 prolonged effect Effects 0.000 abstract description 4
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 abstract description 3
- 230000000844 anti-bacterial effect Effects 0.000 abstract description 3
- 230000002349 favourable effect Effects 0.000 abstract description 3
- 239000007800 oxidant agent Substances 0.000 abstract description 3
- 230000001590 oxidative effect Effects 0.000 abstract description 3
- 239000011148 porous material Substances 0.000 abstract description 3
- 238000006864 oxidative decomposition reaction Methods 0.000 abstract description 2
- 235000013399 edible fruits Nutrition 0.000 description 24
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- 240000003040 Solanum lycopersicum var. cerasiforme Species 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000004677 Nylon Substances 0.000 description 8
- 238000011068 loading method Methods 0.000 description 8
- 229920001778 nylon Polymers 0.000 description 8
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- 230000029058 respiratory gaseous exchange Effects 0.000 description 7
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- SHDPRTQPPWIEJG-UHFFFAOYSA-N 1-methylcyclopropene Chemical compound CC1=CC1 SHDPRTQPPWIEJG-UHFFFAOYSA-N 0.000 description 6
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- 235000021016 apples Nutrition 0.000 description 5
- 239000003755 preservative agent Substances 0.000 description 5
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- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 4
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- UPYKUZBSLRQECL-UKMVMLAPSA-N Lycopene Natural products CC(=C/C=C/C=C(C)/C=C/C=C(C)/C=C/C1C(=C)CCCC1(C)C)C=CC=C(/C)C=CC2C(=C)CCCC2(C)C UPYKUZBSLRQECL-UKMVMLAPSA-N 0.000 description 3
- JEVVKJMRZMXFBT-XWDZUXABSA-N Lycophyll Natural products OC/C(=C/CC/C(=C\C=C\C(=C/C=C/C(=C\C=C\C=C(/C=C/C=C(\C=C\C=C(/CC/C=C(/CO)\C)\C)/C)\C)/C)\C)/C)/C JEVVKJMRZMXFBT-XWDZUXABSA-N 0.000 description 3
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- OAIJSZIZWZSQBC-GYZMGTAESA-N lycopene Chemical compound CC(C)=CCC\C(C)=C\C=C\C(\C)=C\C=C\C(\C)=C\C=C\C=C(/C)\C=C\C=C(/C)\C=C\C=C(/C)CCC=C(C)C OAIJSZIZWZSQBC-GYZMGTAESA-N 0.000 description 3
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- ZCIHMQAPACOQHT-ZGMPDRQDSA-N trans-isorenieratene Natural products CC(=C/C=C/C=C(C)/C=C/C=C(C)/C=C/c1c(C)ccc(C)c1C)C=CC=C(/C)C=Cc2c(C)ccc(C)c2C ZCIHMQAPACOQHT-ZGMPDRQDSA-N 0.000 description 3
- ZZZCUOFIHGPKAK-UHFFFAOYSA-N D-erythro-ascorbic acid Natural products OCC1OC(=O)C(O)=C1O ZZZCUOFIHGPKAK-UHFFFAOYSA-N 0.000 description 2
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- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 2
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- 229940088597 hormone Drugs 0.000 description 2
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- 239000011718 vitamin C Substances 0.000 description 2
- 244000298697 Actinidia deliciosa Species 0.000 description 1
- 235000009436 Actinidia deliciosa Nutrition 0.000 description 1
- 244000144730 Amygdalus persica Species 0.000 description 1
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- 235000006040 Prunus persica var persica Nutrition 0.000 description 1
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- 238000005411 Van der Waals force Methods 0.000 description 1
- 238000007259 addition reaction Methods 0.000 description 1
- 239000002156 adsorbate Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000008953 bacterial degradation Effects 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 235000021015 bananas Nutrition 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
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- 235000019398 chlorine dioxide Nutrition 0.000 description 1
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- 201000010099 disease Diseases 0.000 description 1
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- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-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
- A23B7/14—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10
- A23B7/144—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10 in the form of gases, e.g. fumigation; Compositions or apparatus therefor
- A23B7/152—Preserving or ripening with chemicals not covered by groups A23B7/08 or A23B7/10 in the form of gases, e.g. fumigation; Compositions or apparatus therefor in a controlled atmosphere comprising other gases in addition to CO2, N2, O2 or H2O ; Elimination of such other gases
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- Storage Of Fruits Or Vegetables (AREA)
Abstract
The invention discloses a preparation method of an ethylene composite absorbent, which utilizes the oxidative decomposition effect of potassium permanganate and calcium peroxide and the adsorption effect of acidified active carbon to prepare potassium permanganate active carbon adsorbed oxidant and calcium peroxide particles coated by nano chitosan, the specific surface area and pore volume of the acidified active carbon are increased, the ethylene adsorption capacity is increased, and the acid groups on the surface are favorable for the oxidation effect of potassium permanganate; the calcium peroxide coated by the nano chitosan plays a role in protecting calcium peroxide, achieves the purposes of slow release oxidation of the calcium peroxide and prolonged use, and plays a role in delaying mildew on the fresh keeping of fruits and vegetables due to the antibacterial effect of the nano chitosan; the two materials are independently packaged and cooperate with ethylene oxide, so that a good ethylene absorption effect is achieved, and the ethylene absorption effect is good for the ethylene with the low nanogram level; the composite absorbent has good market application prospect when being used for fruit and vegetable preservation.
Description
Technical Field
The invention belongs to the technical field of agricultural fruit and vegetable fresh-keeping, and particularly relates to a preparation method of an ethylene composite absorbent and application of the ethylene composite absorbent in fruit and vegetable fresh-keeping.
Background
Ethylene is a fruit and vegetable ripening hormone, when the concentration of the ethylene is 0.1 mu L/L, the fruit and vegetable can be induced to ripen more quickly, the rotting loss rate of the fruit and vegetable in developed countries is less than 7%, while the fruit and vegetable rot loss rate in China is generally 20% -30%, the economic loss is as high as 750 million yuan/year, and timely and effective removal of the ethylene released by the fruit and vegetable in the storage and transportation processes is a key for solving the problem.
Currently, ethylene removal agents are mainly used to remove ethylene. Ethylene removers can be classified into physical adsorption, chemical adsorption and bacterial degradation according to the working principle. The physical adsorbent is mainly used for adsorbing ethylene based on Van der Waals force, and the adsorption effect is weak, easy to desorb, nonselective for adsorbate, limited in adsorption amount and required to be replaced frequently. The bacterial remover has poor capability and low speed of removing ethylene, is greatly influenced by the environmental humidity, and is not generally used for keeping fruits and vegetables fresh. The chemical adsorbent is mainly used for removing ethylene through chemical reaction, and can be classified into a catalytic reaction type, an oxidation reaction type and an addition reaction type according to the principle of the reaction with ethylene. The oxidation type ethylene remover has the obvious advantages of strong ethylene removing capacity and high speed, and common oxidants include potassium permanganate, chlorine dioxide, calcium peroxide and the like. Wherein, the potassium permanganate has strong oxidizing property, and the ethylene removal is more thorough. At present, potassium permanganate type ethylene remover is usually prepared by loading potassium permanganate on inert materials with large specific surface areas, such as activated carbon, molecular sieve, alumina and the like, and because the surface of a carrier is inert, the loading capacity is limited, and the ethylene removal efficiency is reduced.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation method of an ethylene composite absorbent, the invention utilizes the oxidative decomposition effect of potassium permanganate and calcium peroxide and the adsorption effect of acidified active carbon to prepare a calcium peroxide nano material loaded with potassium permanganate active carbon to adsorb an oxidant and coated by nano chitosan, the specific surface area and the pore volume of the acidified active carbon are increased, the ethylene adsorption capacity is increased, and the acid groups on the surface are favorable for the oxidation effect of potassium permanganate; the calcium peroxide coated by the nano chitosan plays a role in protecting calcium peroxide, achieves the purposes of slow release oxidation of the calcium peroxide and prolonged use, and plays a role in delaying mildew on the fresh keeping of fruits and vegetables due to the antibacterial effect of the nano chitosan; the two materials are independently packaged and cooperate with ethylene oxide, so that a good effect of absorbing ethylene can be achieved, and the two materials have a good absorption effect on the ethylene with the level as low as nanogram; the composite absorbent is used for keeping fruits and vegetables fresh, and effectively prolongs the shelf life of the fruits and vegetables.
The preparation method of the ethylene composite absorbent comprises the following steps:
(1) preparation of potassium permanganate loaded active carbon
Putting the activated carbon in 0.1-0.2 mol/L HCl or HNO3Soaking the acidified activated carbon in a potassium permanganate solution of 0.4-0.6 mol/L for 12-24 h, filtering and drying to obtain the potassium permanganate-loaded activated carbon;
(2) preparation of Chitosan nanoparticle suspension
Dissolving chitosan in a glacial acetic acid solution with the volume concentration of 1-2%, stirring for 1-2 h, adjusting the pH value to 4.5-5.5, and filtering with a 0.45-micrometer filter membrane to remove insoluble impurities in the solution to obtain a chitosan solution; adding a sodium tripolyphosphate aqueous solution filtered by a 0.45-micrometer filter membrane into the chitosan solution, and continuously stirring for 10-20 min to obtain a chitosan nanoparticle suspension;
(3) preparation of nano chitosan coated calcium peroxide particles
Adding calcium peroxide into a mixed solution of a sodium alginate solution and the chitosan nanoparticle suspension liquid obtained in the step (2) at 70-80 ℃, uniformly stirring, granulating and drying to obtain calcium peroxide particles coated with nano chitosan;
(4) preparation of ethylene composite absorbent
And (3) respectively packaging the potassium permanganate loaded active carbon obtained in the step (1) and the nano chitosan coated calcium peroxide particles obtained in the step (3) into bags by using non-woven fabrics or air-permeable plastic paper films to obtain the ethylene composite absorbent.
The concentration of the chitosan solution is 0.8mg/m L-3.5 mg/m L, the concentration of the sodium tripolyphosphate aqueous solution is 0.75mg/m L-2.0 mg/m L, and the volume ratio of the chitosan solution to the sodium tripolyphosphate aqueous solution is 3-8: 1.
The mass ratio of the mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution to the calcium peroxide is 75-80: 25-20.
The mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution is prepared by adding sodium alginate into distilled water to prepare a sodium alginate solution with the mass volume concentration of 1-3% under the constant-temperature heating condition of 60-70 ℃, fully stirring, adding boric acid, completely dissolving, cooling, and uniformly mixing the chitosan nanoparticle suspension and the sodium alginate solution according to the volume ratio of the chitosan nanoparticle suspension to the sodium alginate solution of 2-3: 1.
The addition amount of the boric acid is 0.5-1% of the mass of the ethylene composite absorbent.
The invention also aims to apply the ethylene composite absorbent prepared by the method in the preservation of fruits and vegetables, wherein the fruits and vegetables comprise climacteric fruits and vegetables, such as mangoes, bananas, apples, peaches, plums, persimmons, tomatoes, custards, guavas, papayas, kiwi fruits, figs and the like.
The invention has the advantages that:
1. after the activated carbon is subjected to acidification treatment, the specific surface area and the pore volume of the prepared potassium permanganate-loaded activated carbon are increased, meanwhile, the activated carbon surface is provided with active groups such as-OH and the like, the ethylene adsorption capacity is increased, and the acid groups on the surface are favorable for the oxidation of potassium permanganate;
2. the calcium peroxide particles coated with the nano chitosan prepared by the invention have the advantages that firstly, the nano chitosan coats the calcium peroxide, the calcium peroxide and other reducing agents are protected, and the purposes of slow release oxidation of the calcium peroxide and prolonged use are achieved; the antibacterial effect of the two nano chitosan plays roles in resisting bacteria and delaying mildew of fruits and vegetables;
3. the ethylene composite absorbent prepared by the invention consists of two ethylene absorbents, the absorption principle is that ethylene generated in the storage process of fruits and vegetables is oxidized, but the generation effects of materials are different; the two materials are independently packaged, cooperate with ethylene oxide and have good absorption effect on ethylene with the level as low as nanogram; the composite absorbent is used for keeping fruits and vegetables fresh, and effectively prolongs the shelf life of the fruits and vegetables.
Detailed Description
The technical solution of the present invention is further described in detail by the following examples, but the scope of the present invention is not limited thereto.
Example 1: preparation of ethylene composite absorbent and application of ethylene composite absorbent in apple preservation
(1) Preparation of potassium permanganate loaded active carbon
Soaking 100g of activated carbon in 300m L0.1.1 mol/L HCl solution for 2h, then placing the activated carbon in water bath at room temperature for 12h, washing the activated carbon with distilled water until the washing liquid is neutral, filtering, and drying at 100 ℃ for 3h to obtain acidified activated carbon, soaking the acidified activated carbon in 300m L0.5.5 mol/L potassium permanganate solution for 24h, filtering, and naturally drying to obtain the potassium permanganate loaded activated carbon;
(2) preparation of Chitosan nanoparticle suspension
Dissolving 0.80g of chitosan in a glacial acetic acid solution with the volume concentration of 1000m L and the concentration of 1% to prepare a solution with the concentration of 0.80mg/m L, stirring for 1h, adjusting the pH value to 5.0 by using 0.1 mol/L NaOH, filtering the solution by using a 0.45-micron filter membrane to remove insoluble impurities in the solution to prepare a chitosan solution, dissolving 0.75g of sodium tripolyphosphate in 1000m L distilled water to prepare a 0.75mg/m L aqueous solution, filtering by using a 0.45-micron filter membrane to prepare a sodium tripolyphosphate solution, transferring 60m L chitosan solution into a 500m L flask, quickly adding 10m L sodium tripolyphosphate solution on a magnetic stirrer with the rotating speed of 600r/min, and continuously stirring for 10min to obtain a chitosan nanoparticle suspension;
(3) preparation of nano chitosan coated calcium peroxide particles
Under the constant-temperature heating condition of 60 ℃, adding sodium alginate into distilled water to prepare a sodium alginate solution with the mass volume concentration of 2%, fully stirring, adding boric acid (the addition amount is 0.5% of the mass of the ethylene composite absorbent), completely dissolving, cooling, and uniformly mixing the chitosan nanoparticle suspension and the sodium alginate solution according to the volume ratio of 2:1 of the chitosan nanoparticle suspension to the sodium alginate solution to prepare a mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution;
adding 75g of calcium peroxide into a mixed solution of 25g of chitosan nanoparticle suspension and sodium alginate solution, controlling the temperature at 70 ℃, stirring, mixing, granulating and naturally drying to obtain calcium peroxide particles coated with nano chitosan;
(4) respectively packaging the potassium permanganate loaded active carbon obtained in the step (1) and the nano chitosan coated calcium peroxide particles obtained in the step (3) into bags by using non-woven fabrics, wherein the weight of each bag is 100g, so as to obtain the ethylene composite absorbent;
(5) apple preservation experiment
Setting 3 processing groups, ① processing with ethylene composite absorbent, namely, loading 10kg Fuji apples into a carton lined with microporous bags, then respectively placing 1 bag of nano chitosan-coated calcium peroxide particles and 1 bag of loaded potassium permanganate activated carbon into the bottom and the middle of a box body, fastening the microporous bags by using a nylon rope, sealing the box by using an adhesive tape, and recording the result as EA, ② 1-MCP processing, namely, loading 10kg Fuji apples into the carton lined with the microporous bags, then immediately placing 1 small bag of 1-MCP (1 mu L/L) into the middle of the box body after being wetted by distilled water, fastening the microporous bags by using the nylon rope, sealing the box by using the adhesive tape, and recording the sealed box as 1-MCP, ③ contrast processing, namely, directly fastening the microporous bags by using the nylon rope, sealing the box by using the adhesive tape, recording the sealed box as CK, after loading 10kg Fuji apples into the carton lined with the microporous bags, placing the carton into the carton without any nylon rope, directly, and then measuring the content, hardness, surface of the fruits, and the fruit release rate of the fruits are measured at the temperature of 20 +/-1 ℃ and relative humidity, 85% -90%, and the environmental conditions of the table, and the table are measured, and the table 5, and the;
TABLE 1 different treatments on apple firmness (kg/cm) at different times2) Influence of
TABLE 2 Effect of different treatments on apple soluble solids (%) content at different times
TABLE 3 Effect of different treatments on apple titratable acid content (%) at different times
Table 4: effect of different treatments on apple respiration intensity (mg/(kg. h)) at different times
TABLE 5 Effect of different treatments on apple ethylene Release Rate (. mu. L/(kg. h)) at different times
Table 6: effect of different treatments on apple rot (%) at different times
The respiration is an effective metabolic process of organism for carrying out life activities and is one of the most key physiological activities after fruit and vegetable picking, but the respiration consumes organic nutrients accumulated in the fruit and vegetable bodies, and reduces the fruit quality and the storage property. Ethylene is one of important plant endogenous hormones, and can promote the after-ripening and aging process of fruits and vegetables. The ethylene composite absorbent prepared by the invention can prevent the generation of endogenous ethylene by combining with an ethylene receptor, so as to achieve the effect of regulating and controlling fruit respiration, thereby delaying the fruit senescence. Hardness, titratable acid and soluble solid are important indexes for measuring the quality of fruits in the storage process; the experimental results show that: compared with CK, 1-MCP and the ethylene composite absorbent treatment of the embodiment can maintain the apple to have higher hardness in a 30-day storage period, inhibit fruit softening in the storage process and delay the ripening and aging process of the apple. Titratable acid and soluble solid are used as important nutrient components in the fruit, and the change of the content of the titratable acid and the soluble solid reflects not only the nutrient value of the fruit but also the direct reaction of the storage condition of the fruit. The experimental result shows that the 1-MCP and the ethylene composite absorbent prepared by the embodiment can effectively delay the reduction of the titratable acid content of the apples and inhibit the increase of soluble solid matters and the rotting rate, and the ethylene composite absorbent prepared by the embodiment has better treatment effect than the 1-MCP and is an excellent ethylene absorbent.
Example 2: preparation of ethylene composite absorbent and application of ethylene composite absorbent in mango preservation
(1) Preparation of loaded potassium permanganate activated carbon
100g of activated carbon is put into 400m of L0.15.15 mol/L HNO3Soaking the solution for 2h, placing the solution in water bath at room temperature, oscillating for 20h, washing with distilled water until the washing liquid is neutral, filtering, drying at 90 ℃ for 6h to obtain acidified active carbon, soaking the acidified active carbon in 300m L0.6 mol/L potassium permanganate solution for 12h, filtering, and naturally drying to obtain potassium permanganate-loaded active carbon;
(2) preparation of Chitosan nanoparticle suspension
Dissolving 1.0g of chitosan in 1000m L of 1.5 percent glacial acetic acid solution to prepare a solution with the concentration of 1.0mg/m L, stirring for 2 hours, adjusting the pH value to 5.5 by using 0.1 mol/L NaOH, filtering the solution by using a 0.45 mu m filter membrane to remove insoluble impurities in the solution to prepare a chitosan solution, dissolving 1.5g of sodium tripolyphosphate in 1000m L distilled water to prepare a 1.5mg/m L aqueous solution, filtering the aqueous solution by using a 0.45 mu m filter membrane to prepare a sodium tripolyphosphate solution, transferring the 60m L chitosan solution into a 500m L flask, quickly adding the 8m L sodium tripolyphosphate solution on a magnetic stirrer with the rotating speed of 600r/min, and continuously stirring for 15min to obtain the chitosan nanoparticle suspension;
(3) preparation of nano chitosan coated calcium peroxide particles
Under the constant-temperature heating condition of 70 ℃, adding sodium alginate into distilled water to prepare a sodium alginate solution with the mass volume concentration of 2.5%, fully stirring, adding boric acid (the addition amount is 1% of the mass of the ethylene composite absorbent), completely dissolving, cooling, and uniformly mixing the chitosan nanoparticle suspension and the sodium alginate solution according to the volume ratio of 3:1 of the chitosan nanoparticle suspension to the sodium alginate solution to prepare a mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution;
adding 78g of calcium peroxide into a mixed solution of 22g of chitosan nanoparticle suspension and sodium alginate solution, controlling the temperature to be 80 ℃, stirring, mixing, granulating and drying to obtain calcium peroxide particles coated with nano chitosan;
(4) preparation of ethylene composite absorbent
Respectively packaging the potassium permanganate loaded active carbon obtained in the step (1) and the nano chitosan coated calcium peroxide particles obtained in the step (3) into bags by using air-permeable plastic paper films, wherein the weight of each bag is 100g, so as to obtain the ethylene composite absorbent;
(5) mango preservation experiment
① selecting fresh mango 10kg with uniform size, consistent maturity, no damage and no disease and insect, placing the mango 10kg into a carton lined with a microporous bag, then placing 1 bag of nano chitosan-coated calcium peroxide particles and 1 bag of loaded potassium permanganate activated carbon into the bottom and the middle of a box body respectively, then binding the microporous bag with a nylon rope, sealing the box with an adhesive tape, and recording as EA, ② contrast treatment, namely, after 10kg of mango is placed into the carton lined with the microporous bag, directly binding the microporous bag with the nylon rope without any preservative, sealing the box with the adhesive tape, recording as CK, carrying out sensory index evaluation for 15 days, and measuring good fruit rate and weight loss rate of the mango 35 days, wherein the results are shown in tables 7, 8 and 9;
TABLE 7 sensory evaluation table for 15-day storage of mangoes
As can be seen from Table 8, the good fruit rate of the mangoes treated by the ethylene composite absorbent is obviously higher than that of the control group; after the mango is treated by the ethylene composite absorbent, the good fruit rate of the mango is still 100% after the mango is stored for 28 days, rotten fruit appears when the mango is stored for 14 days in a control group, and the good fruit rate is further reduced to 0 when the mango is stored for 35 days;
TABLE 8 influence of different preservative films on good mango yield
Table 9 results of weight loss rate change during fruit storage show: after the treatment of the ethylene composite absorbent, the weight loss rate of the fruit and vegetable preservative is 4.7 percent and the control group is 8.0 percent after the fruit and vegetable preservative is stored for 35 days at normal temperature; the ethylene composite absorbent treatment has a good effect on mango preservation;
TABLE 9 influence of fruit and vegetable antistaling agent on weight loss rate of mango
Example 3: preparation of ethylene composite absorbent and application of ethylene composite absorbent in green pepper preservation
(1) Preparation of loaded potassium permanganate activated carbon
Putting 100g of activated carbon into 500m L0.2 mol/L HNO3Soaking the solution for 2h, placing the solution in water bath at room temperature, oscillating for 15h, washing with distilled water until the washing liquid is neutral, filtering, drying at 110 ℃ for 4h to obtain acidified active carbon, soaking the acidified active carbon in 400m L0.4 mol/L potassium permanganate solution for 20h, filtering, and drying to obtain potassium permanganate-loaded active carbon;
(2) preparation of Chitosan nanoparticle suspension
Dissolving 2.0g of chitosan into 1% glacial acetic acid solution of 1000m L to prepare solution with the concentration of 2.0mg/m L, stirring for 1.5h, adjusting the pH value to 4.5 by using 0.1 mol/L NaOH, filtering the solution by using a 0.45-micron filter membrane to remove insoluble impurities in the solution to prepare chitosan solution, dissolving 2.0g of sodium tripolyphosphate into 1000m L distilled water to prepare 2.0mg/m L aqueous solution, filtering by using a 0.45-micron filter membrane to prepare sodium tripolyphosphate solution, transferring 25m L chitosan solution into a 500m L flask, quickly adding 8m L sodium tripolyphosphate solution on a magnetic stirrer with the rotating speed of 600/min, and continuously stirring for 20min to obtain chitosan nanoparticle suspension;
(3) preparation of nano chitosan coated calcium peroxide particles
Under the constant-temperature heating condition of 65 ℃, adding sodium alginate into distilled water to prepare a sodium alginate solution with the mass volume concentration of 1%, fully stirring, adding boric acid (the addition amount is 0.8% of the mass of the ethylene composite absorbent), completely dissolving, cooling, and uniformly mixing the chitosan nanoparticle suspension and the sodium alginate solution according to the volume ratio of the chitosan nanoparticle suspension to the sodium alginate solution of 2.5:1 to prepare a mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution;
adding 80g of calcium peroxide into a mixed solution of 20g of chitosan nanoparticle suspension and sodium alginate solution, controlling the temperature to be 75 ℃, stirring, mixing, granulating and drying to obtain calcium peroxide particles coated with nano chitosan;
(4) preparation of ethylene composite absorbent
Respectively packaging the potassium permanganate loaded active carbon obtained in the step (1) and the nano chitosan coated calcium peroxide particles obtained in the step (3) into bags by using non-woven fabrics or air-permeable plastic paper films, wherein the weight of each bag is 100g, so as to obtain the ethylene composite absorbent;
(5) cherry tomato preservation experiment
The method comprises the following steps of setting 2 treatments, namely ① ethylene composite absorbent treatment, namely, loading 10kg of cherry tomatoes into a carton lined with a microporous bag, then respectively loading 1 bag of nano chitosan-coated calcium peroxide particles and 1 bag of potassium permanganate-loaded activated carbon into the bottom and the middle of a box body, then tightly binding the microporous bag by using a nylon rope, sealing the box by using an adhesive tape to obtain EA, carrying out ② comparison treatment, namely, loading 10kg of cherry tomatoes into the carton lined with the microporous bag, directly binding the microporous bag by using the nylon rope without adding any preservative, sealing the box by using an adhesive tape to obtain CK, storing the box at the normal temperature of 20 +/-1 ℃ and the relative humidity of 85-90% under the environmental conditions of 1 time per 3 days, measuring the fruit storage hardness, the soluble solid content, the titratable acid content, the lycopene content, the vitamin C content, the respiration strength and the ethylene release rate, and simultaneously observing the fruit rotting conditions, wherein the results are shown in tables 10, 11, 12, 13, 14 and 6.
TABLE 10 different treatments on cherry tomato firmness (kg/cm) at different times2) Influence of
TABLE 11 Effect of different treatments on cherry tomato soluble solids content (%) at different times
TABLE 12 Effect of different treatments on the titratable acid content (%) of cherry tomatoes at different times
TABLE 13 Effect of different treatments on vitamin C content (mg/100 g) of cherry tomatoes at different times
TABLE 14 Effect of different treatments on cherry lycopene content (mg/100 g) at different times
TABLE 15 Effect of different treatments on cherry tomato respiration intensity (mg/(kg. h)) at different times
TABLE 16 Effect of different treatments on cherry tomato decay Rate (%) at different times
The results show that the ethylene composite absorbent prepared by the embodiment can better inhibit the reduction of fruit hardness, reduce the respiration intensity of fruits, maintain the soluble solid content, titratable acid content, VC content and lycopene content of the fruits and reduce the rotting rate of the tomatoes after being used for treating the cherry tomatoes; on the premise of not losing the quality, the fresh-keeping effect of the fruits can be obviously enhanced, the shelf life of the picked fruits is prolonged, and the product has a great application prospect in fresh keeping of the fruits and the vegetables.
Claims (6)
1. The preparation method of the ethylene composite absorbent is characterized by comprising the following steps:
(1) preparation of potassium permanganate loaded active carbon
Putting the activated carbon in 0.1-0.2 mol/L HCl or HNO3Soaking the acidified activated carbon in a potassium permanganate solution of 0.4-0.6 mol/L for 12-24 h, filtering and drying to obtain the potassium permanganate-loaded activated carbon;
(2) preparation of Chitosan nanoparticle suspension
Dissolving chitosan in a glacial acetic acid solution with the volume concentration of 1-2%, stirring for 1-2 h, adjusting the pH value to 4.5-5.5, and filtering with a 0.45-micrometer filter membrane to remove insoluble impurities in the solution to obtain a chitosan solution; adding a sodium tripolyphosphate aqueous solution filtered by a 0.45-micrometer filter membrane into the chitosan solution, and continuously stirring for 10-20 min to obtain a chitosan nanoparticle suspension;
(3) preparation of nano chitosan coated calcium peroxide particles
Adding calcium peroxide into a mixed solution of a sodium alginate solution and the chitosan nanoparticle suspension liquid obtained in the step (2) at 70-80 ℃, uniformly stirring, granulating and drying to obtain calcium peroxide particles coated with nano chitosan;
(4) preparation of ethylene composite absorbent
And (3) respectively packaging the potassium permanganate loaded active carbon obtained in the step (1) and the nano chitosan coated calcium peroxide particles obtained in the step (3) into bags by using non-woven fabrics or air-permeable plastic paper films to obtain the ethylene composite absorbent.
2. The preparation method of the ethylene composite absorbent as claimed in claim 1, wherein the concentration of the chitosan solution is 0.8mg/m L-3.5 mg/m L, the concentration of the sodium tripolyphosphate aqueous solution is 0.75mg/m L-2.0 mg/m L, and the volume ratio of the chitosan solution to the sodium tripolyphosphate aqueous solution is 3-8: 1.
3. The method for preparing the ethylene composite absorbent according to claim 2, wherein: the mass ratio of the mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution to the calcium peroxide is 75-80: 25-20.
4. The method for preparing the ethylene composite absorbent according to claim 3, wherein: the mixed solution of the chitosan nanoparticle suspension and the sodium alginate solution is prepared by adding sodium alginate into distilled water to prepare a sodium alginate solution with the mass volume concentration of 1-3% under the constant-temperature heating condition of 60-70 ℃, fully stirring, adding boric acid, completely dissolving, cooling, and uniformly mixing the chitosan nanoparticle suspension and the sodium alginate solution according to the volume ratio of the chitosan nanoparticle suspension to the sodium alginate solution of 2-3: 1.
5. The method for preparing the ethylene composite absorbent according to claim 4, wherein: the addition amount of the boric acid is 0.5-1% of the mass of the ethylene composite absorbent.
6. The use of the ethylene composite absorbent prepared by the method for preparing the ethylene composite absorbent according to any one of claims 1 to 5 in the preservation of fruits and vegetables, which is characterized in that: the fruit and vegetable include climacteric fruit and vegetable.
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| CN114158671A (en) * | 2021-11-02 | 2022-03-11 | 云南省农业科学院农产品加工研究所 | Edible rose petal preservation method |
| CN114698687A (en) * | 2022-04-24 | 2022-07-05 | 杭州干将实业有限公司 | Multi-effect fruit and vegetable preservative and preparation method thereof |
| CN115138339A (en) * | 2022-07-25 | 2022-10-04 | 贵州省地质矿产勘查开发局一0五地质大队 | Montmorillonite-chitosan-hydroxyl iron composite material and preparation method thereof |
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