CN101177494A - Method for preparing chitosan complex film using glycerin and stearic acid as plasticizer - Google Patents
Method for preparing chitosan complex film using glycerin and stearic acid as plasticizer Download PDFInfo
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- CN101177494A CN101177494A CNA2007100600513A CN200710060051A CN101177494A CN 101177494 A CN101177494 A CN 101177494A CN A2007100600513 A CNA2007100600513 A CN A2007100600513A CN 200710060051 A CN200710060051 A CN 200710060051A CN 101177494 A CN101177494 A CN 101177494A
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Abstract
The invention discloses a preparation method for chitosan composite membrane, which aims at providing a preparation method for the composite membrane with great toughness and less water and air permeability. The invention comprises the following steps that: the chitosan is dissolved by dilute acetum; the feed liquid ratio of the chitosan and the dilute acetum is 1:40 to 100 (weight/volume), and the chitosan is added with plasticiser, and then water-bath heating is implemented so as to make the chitosan dissolve completely, after that, the room temperature is lowered, so that the membrane solution is obtained; the plasticiser is a combination of the glycerin which accounts for 0.2 percent to 1.0 percent of the acetum in volume percent and the stearic acid which accounts for 0.3 percent to 0.8 percent of the acetum in mass percent. The prepared membrane solution is filtered for removing impurity, and is deaerated for half an hour, and then the membrane solution is poured into a clean glass plate, and is dried to form a membrane at the constant temperature of 40 to 80 DEG C; after the membrane is formed, and then stripping is implemented for generating the chitosan composite membrane. The invention adopts the glycerol and the stearic acid as the plasticiser, the composite membrane is prepared through the use selection, and the composite membrane not only has certain toughness and can keep a lower water and air permeability.
Description
Technical field
The invention belongs to food product pack and preservation technique field, in particular, relating to a kind of is the preparation method of the chitosan complex film of softening agent with glycerine and stearic acid.
Background technology
Chitosan is to be made by the chitin deacetylase base, and chitin extensively is present in the crust of Crustaceans shrimp, crab, the crust of insect, and in cell walls of fungi (yeast, mould) and the cell walls of plant (mushroom), its content on earth is only second to Mierocrystalline cellulose.Studies show that in a large number both at home and abroad, chitin and chitosan are nontoxic, it is foodstuff additive for U.S. food and medical and sanitary control office (FDA) approved, therefore, chitosan is nontoxic and safe natural high moleculer eompound, and is a kind of functional polymer compound, has special amino, hydroxyl functional group on the molecular chain, therefore come compared with many synthetic macromolecular compounds, be more suitable for using in foodstuffs industry.Chitosan mainly contains aspect following three in Application in Food Industry: the first, and the treatment agent of liquid.As reduce total solids content in the liquid, from waste water, reclaim protein, drink water purification, the clarification of beverage and drinks etc.; The second, foodstuff additive.Control as the food configuration shape improves flavours in food products, improves the flowability of food, and the control viscosity increases fibre content etc.; The 3rd, functional materials.As bacteriostasis, preservation agent, diet food, wrapping material or trapped material, also can be used as slow-release material etc.
Present packaging material for food mostly is a plastic membrane product, because plastics film may be harmful, causes " white pollution " after discarding, so many countries are are all competitively researching and developing biodegradable even the edible food packaging material.Along with the develop rapidly of present foodstuffs industry and the people enhancing to environmental protection consciousness, a kind of new packaging material one edible packaging that can solve contradiction between wrapping material and the environment is fully shown one's talent.Edible packaging has obtained extensive concern both domestic and external with its abundant raw material, characteristics such as complete, edible and nuisanceless.Edible packing membrane is also more and more paid attention to as a kind of wrapping material.Edible film can be divided into polyose, protein, lipid and composite membrane class according to film forming material.The polyose edible film has chitosan, starch, sodium alginate, Rhizoma amorphophalli glucomannan and derivative thereof.And chitosan obtains extensive concern as the potential film forming component because of it has good health care function, bacteriostasis property, machinery and penetrating quality.So the edibility chitosan film has very big application prospect in food product pack and fresh-keeping aspect.The research of chitosan film relates to membrane sepn, edible film, biological degradable membrane, medical film, coating-film fresh-keeping, composite membrane etc., and the film-forming properties of chitosan has been applied in industrial circles such as weaving, printing and dyeing, papermaking, medicine, food.Chitosan removes has film-forming properties, also has antibiotic preservative activity and biological degradability, holds out broad prospects aspect Freshkeeping Packaging.
As the edible fresh-keeping packing film, requirement should have the favorable mechanical performance, and good obstruct and penetrating quality are arranged again.Softening agent is the principal element that influences film properties, softening agent add the microstructure that affiliation changes film, thereby influence the machinery and the penetrating quality of film.The adding of softening agent avoids film to produce macropore and crack, and the integrity of film is strengthened.
Only use single softening agent mostly among the at present relevant preparation method of chitosan complex film, promptly glycerine or stearic acid though glycerine can reduce the tensile strength of film, have increased the ventilation property of film; And add the ventilation property that stearic acid can reduce film, but toughness reduces the tensile strength increase.On the 9th phase of the calendar year 2001 Food science magazine, in " research of chitosan film forming characteristics " literary composition that lucky big people such as grade delivers, proposed to make film not only have certain toughness as softening agent and can also keep low water-permeable and air permeable with glycerine and stearic acid combination, but just to the direction of having researched and proposed of film forming characteristics, do not provide suitable glycerine and stearic consumption in this article.Therefore, selecting the consumption of suitable manufacturing methods for use is the key of the chitosan complex film for preparing.
Summary of the invention
The present invention is in order to overcome weak point of the prior art, the preparation method of the chitosan complex film that a kind of toughness is big, water-permeable and air permeable is little to be provided.
The present invention is achieved through the following technical solutions:
The preparation method of chitosan complex film of the present invention is to be film forming material with the chitosan, and it is dissolved in rare acetum, adds glycerine and stearic acid as softening agent, casting film-forming on sheet glass then, solvent evaporated, drying and forming-film, take off from sheet glass, promptly obtain chitosan complex film.Specifically comprise the steps:
A kind of preparation method of chitosan complex film is characterized in that, comprises the steps:
(1) film liquid preparation: with rare acetum dissolving chitosan, the solid-liquid ratio of chitosan and acetum is 1: 40～100 (weight/volume), adds softening agent again, is heated to dissolving fully in 50～70 ℃ of water-baths, cools off room temperature then, makes film liquid; Described softening agent is that the volume percent that accounts for acetum is 0.2～1.0% glycerine and the stearic combination that accounts for acetum mass percent 0.3～0.8%.
(2) film forming: the above-mentioned film liquid for preparing is filtered, remove impurity, and suction filtration outgases half an hour under 0.1～0.5Mpa vacuum tightness, then film liquid is poured on the clean sheet glass, 40～80 ℃ of following freeze-day with constant temperature film forming; After the film forming, take off film, obtain chitosan complex film.
Wherein the volume by volume concentration of dilute acetic acid solution can select 1%～3% for use.
The present invention has following technique effect:
The present invention uses glycerine and stearic acid as softening agent, and by the selection to its consumption, the composite membrane of preparation not only has certain toughness, can also keep lower water-permeable and air permeable.
Can be used as the wrapping material of food by the chitosan complex film of method of the present invention preparation, give full play to the health care and the bacteria resistance function of chitosan.
Embodiment
Below in conjunction with specific embodiment to the detailed description of the invention.
The chitosan, acetic acid, glycerine, the stearic acid that use all are food grade.Be used to prepare the chitosan of film, at first require to be dissolved in diluted acid.Chitosan is made by chitin deacetylase, and deacetylation is little, and chitosan just is insoluble to diluted acid, and the present invention can make the chitosan dissolving just passable to the selection of deacetylating degree of chitosan as long as deacetylation reaches.Generally speaking, deacetylation reaches more than 55%, and chitosan just can be dissolved in the diluted acid.Chitosan in the embodiment of the invention is the product that Jinan Haidebei Marine Organism Engineering Co., Ltd. produces, and its deacetylation is 85.8%.
Embodiment 1
Taking by weighing chitosan 1g, to be dissolved in the 100mL volume by volume concentration be in 1% the acetum, adds 0.2ml glycerine, 0.6g stearic acid, is heated to dissolving fully in 70 ℃ of water-baths, and cool to room temperature is made film liquid.With the above-mentioned film liquid filtered through gauze for preparing, remove impurity, and at 0.1MPa vacuum lower pumping 0.5h, the solution of getting 50ml then is poured on the sheet glass uniformly, and drying and forming-film in 40 ℃ of thermostatic drying chambers is after the film forming, carefully take off film with clean blade, obtain chitosan complex film.
Embodiment 2
Taking by weighing chitosan 1.25g, to be dissolved in the 100mL volume by volume concentration be in 1.5% the acetum, adds 0.4ml glycerine, 0.4g stearic acid, is heated to dissolving fully in 70 ℃ of water-baths, and cool to room temperature is made film liquid.With the above-mentioned film liquid filtered through gauze for preparing, remove impurity, and at 0.1MPa vacuum lower pumping 0.5h, the solution of getting 50ml then is poured on the sheet glass uniformly, and drying and forming-film in 60 ℃ of thermostatic drying chambers is after the film forming, carefully take off film with clean blade, obtain chitosan complex film.
Embodiment 3
Taking by weighing chitosan 1.5g, to be dissolved in the 100mL volume by volume concentration be in 1% the acetum, adds 0.4ml glycerine, 0.5g stearic acid, is heated to dissolving fully in 70 ℃ of water-baths, and cool to room temperature is made film liquid.With the above-mentioned film liquid filtered through gauze for preparing, remove impurity, and at 0.1MPa vacuum lower pumping 0.5h, the solution of getting 50ml then is poured on the sheet glass uniformly, and drying and forming-film in 60 ℃ of thermostatic drying chambers is after the film forming, carefully take off film with clean blade, obtain chitosan complex film.
Embodiment 4
Taking by weighing chitosan 2g, to be dissolved in the 100mL volume by volume concentration be in 2% the acetum, adds 0.2ml glycerine, 0.8g stearic acid, is heated to dissolving fully in 50 ℃ of water-baths, and cool to room temperature is made film liquid.With the above-mentioned film liquid filtered through gauze for preparing, remove impurity, and at 0.3MPa vacuum lower pumping 0.5h, the solution of getting 50ml then is poured on the sheet glass uniformly, and drying and forming-film in 40 ℃ of thermostatic drying chambers is after the film forming, carefully take off film with clean blade, obtain chitosan complex film.
Embodiment 5
Taking by weighing chitosan 2.5g, to be dissolved in the 100mL volume by volume concentration be in 3% the acetum, adds 1.0ml glycerine, 0.3g stearic acid, is heated to dissolving fully in 60 ℃ of water-baths, and cool to room temperature is made film liquid.With the above-mentioned film liquid filtered through gauze for preparing, remove impurity, and at 0.5MPa vacuum lower pumping 0.5h, the solution of getting 50ml then is poured on the sheet glass uniformly, and drying and forming-film in 80 ℃ of thermostatic drying chambers is after the film forming, carefully take off film with clean blade, obtain chitosan complex film.
Above-mentioned chitosan complex film, its machinery and penetrating quality are as shown in table 1 after measured.
Table 1 chitosan complex film performance
| Tensile strength (MPa) | Elongation (%) | Water-permeable (gmm/m 2d mmHg) | Ventilation property (mlm/m 2d kpa) | |
| Embodiment 1 | 11.259 | 6.25 | 0.3626 | 0.0435 |
| Embodiment 2 | 9.832 | 8.75 | 0.3917 | 0.0523 |
| Embodiment 3 | 15.387 | 12.25 | 0.4253 | 0.0972 |
| Embodiment 4 | 13.268 | 5.25 | 0.2394 | 0.0264 |
| Embodiment 5 | 8.362 | 16.75 | 0.5389 | 0.1025 |
| LDEP | 17.8 | 206.5 | 0.011 | 7.4×10 -4 |
| HDEP | 28.7 | 155.4 | 0.007 | 7.4×10 -4 |
As can be seen from the above table, the film properties of the chitosan complex film of method preparation of the present invention is compared with traditional LDEP and HDEP, and tensile strength and LDEP are close, and are lower than the tensile strength of HDEP film; Elongation at break is lower than LDEP film and HDEP film, and water-permeable and air permeable also is higher than LDEP film and HDEP film respectively.In sum, chitosan complex film of the present invention has certain tensile strength and toughness, also has certain water-permeable and air permeable, can be used as the food fresh keeping packing film.
To relate to a kind of be that the preparation method of the chitosan complex film of softening agent has carried out special description with glycerine and stearic acid to disclosed although with reference to embodiment, embodiment described above is illustrative and not restrictive, under the situation that does not break away from the spirit and scope of the present invention, all variations and modification are all within the scope of the present invention.
Claims (2)
1. one kind is the preparation method of the chitosan complex film of softening agent with glycerine and stearic acid, it is characterized in that, comprises the steps:
(1) film liquid preparation: with rare acetum dissolving chitosan, the solid-liquid ratio of chitosan and acetum is 1: 40～100 (weight/volume), adds softening agent again, is heated to dissolving fully in 50～70 ℃ of water-baths, is cooled to room temperature then, makes film liquid; Described softening agent is that the volume percent that accounts for acetum be 0.2～1.0% glycerine with accounting for the acetum mass percent is 0.3～0.8% stearic combination;
(2) film forming: the above-mentioned film liquid for preparing is filtered, remove impurity, and suction filtration outgases half an hour under 0.1～0.5Mpa vacuum tightness, then film liquid is poured on the clean sheet glass, 40～80 ℃ of following freeze-day with constant temperature film forming; After the film forming, take off film, obtain chitosan complex film.
2. according to claim 1 is the preparation method of the chitosan complex film of softening agent with glycerine and stearic acid, it is characterized in that the volume by volume concentration of dilute acetic acid solution is 1%～3%.
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| CN102249396A (en) * | 2010-05-18 | 2011-11-23 | 中国水利水电科学研究院 | Biologically slow filtering filler and manufacturing method thereof |
| CN102504351A (en) * | 2011-11-03 | 2012-06-20 | 中山火炬职业技术学院 | Chitosan composite preservative film and preparation process thereof |
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| CN104145987B (en) * | 2014-08-08 | 2016-06-29 | 广西大学 | The preparation of ethephon controllable sustained-release material and application |
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