阅读说明：本技术 一种海藻酸钠保鲜膜及其制备方法和应用 (A kind of sodium alginate preservative film and its preparation method and application ) 是由 陈敬鑫 米红波 励建荣 吴安康 杨明亮 于 2019-09-09 设计创作，主要内容包括：本发明属于可食性保鲜膜制备技术领域,尤其涉及一种海藻酸钠保鲜膜及其制备方法和应用。本发明使用多胺对海藻酸钠膜液进行预交联,能够有效提高单一海藻酸钠膜的拉伸强度和断裂伸长率,改善了海藻酸钠膜的机械性能；实施例表明,相对于单一海藻酸钠膜,本发明制备的海藻酸钠保鲜膜的拉伸强度可提高近20％,断裂伸长率可提高近200％。本发明将百里香酚添加到海藻酸钠保鲜膜中,得到的海藻酸钠保鲜膜具有较好的抑菌和抗氧化效果,将该海藻酸钠保鲜膜作为新鲜或鲜切果蔬的包装材料,可有效延缓新鲜或鲜切果蔬的衰老,延长其贮藏期,为海藻酸钠可食性保鲜膜的制备提供了新思路。(The invention belongs to edible freshness-keeping thin coat preparation technical fields more particularly to a kind of sodium alginate preservative film and its preparation method and application.The present invention carries out precrosslink to sodium alginate film liquid using polyamines, can effectively improve the tensile strength and elongation at break of single sodium alginate film, improve the mechanical performance of sodium alginate film；Embodiment shows that, relative to single sodium alginate film, the tensile strength of sodium alginate preservative film prepared by the present invention can be improved nearly 20%, and elongation at break can be improved nearly 200%.Thymol is added in sodium alginate preservative film by the present invention, obtained sodium alginate preservative film has preferable antibacterial and antioxidant effect, using the sodium alginate preservative film as fresh or fresh-cut fruit and vegetable packaging material, fresh or fresh-cut fruit and vegetable aging can effectively be delayed, extend its storage period, the preparation for sodium alginate edible freshness-keeping thin coat provides new approaches.)

1. a kind of preparation method of sodium alginate preservative film, which comprises the following steps:

Sodium alginate film liquid is mixed with glycerol, obtains the first film liquid；

First film liquid is mixed with Thymol and polyamines, obtains the second film liquid；

Second film liquid is formed a film, gained film is placed in calcium chloride solution, carries out calcium crosslinking, obtains sodium alginate guarantor Fresh film.

2. preparation method according to claim 1, which is characterized in that the mass concentration of the sodium alginate film liquid is 1%.

3. preparation method according to claim 1, which is characterized in that mass concentration of the glycerol in the first film liquid be 1%.

4. preparation method according to claim 1, which is characterized in that quality of the Thymol in the second film liquid is dense Degree is 0.1%~1.0%.

5. preparation method according to claim 1, which is characterized in that the polyamines is putrescine, cadaverine, spermidine and spermine One or more of, concentration of the polyamines in the second film liquid is 0.01~0.1mol/L.

6. preparation method according to claim 1, which is characterized in that the method for the film forming is the tape casting；Described in completion After film forming, further includes: by gained film 15~20h of naturally dry at room temperature.

7. preparation method according to claim 1, which is characterized in that the mass concentration of the calcium chloride solution be 1~ 2%；The glycerol for being 3~5% containing mass fraction in the calcium chloride solution.

8. preparation method according to claim 1, which is characterized in that the calcium cross-linked temperature is room temperature, and the calcium is handed over The time of connection is 10~15min.

9. the sodium alginate preservative film that any one of claim 1~8 preparation method is prepared.

10. application of the sodium alginate preservative film described in claim 9 in fresh or fresh-cut fruit and vegetable packaging material.

Technical field

The present invention relates to edible freshness-keeping thin coat preparation technical field more particularly to a kind of sodium alginate preservative film and its preparations Methods and applications.

Background technique

Sodium alginate is linearly total made of being keyed as beta-D-mannuronic acid and α-L- guluronic acid by (1 → 4) Polymers is a kind of natural polysaccharide, has good biocompatibility, biodegradability and has no toxic side effect, food, Medicine, weaving, chemical field are widely applied.Containing free hydroxyl and carboxyl in sodium alginate, with Ca²⁺、Zn²⁺Deng Reaction can be crosslinked and form alginate not soluble in water, this provides advantage to the preparation of sodium alginate preservative film.

Application No. is the patents of CN201310069715.8 to disclose a kind of food packaging high-intensitive antibiotic property alginic acid Sodium film and preparation method thereof will mix first, three sodium hexametaphosphates are then added dropwise, prepare shell in chitosan, benzalkonium chloride dissolution Glycan-benzalkonium chloride nanosphere；Gained nanosphere is added in nano-cellulose solution, it is poly- that nano-cellulose/shell is made Sugar-benzalkonium chloride compound；Compound is finally added to the sodium alginate that high-intensitive high antibiotic property is prepared in sodium alginate Food package film.Application No. is the patent of CN201810508790.2, to disclose a kind of sodium alginate-chitosan bilayer edible Sodium alginate, emulsifier, glycerol and natural antibacterial agent are prepared into sodium alginate film first by film and preparation method and application, Then it will be cast one layer of chitosan film on film, is finally crosslinked with calcium chloride solution, obtains sodium alginate-chitosan multilayer edible Property film.Application No. is the patents of CN201711246613.3 to disclose a kind of preparation method of nontoxic degradable preservative film, will be extra large Mosanom film liquid mixes dispersion with caryophyllus oil ethanol solution and obtains caryophyllus oil-sodium alginate film liquid, it is pressed with chitosan film liquid Certain proportion mixing, incorporation agar powder obtain coagulant liquid, are then coated on the poly (methyl methacrylate) plate containing LDPE/EVA laminated film On, dry after compression, cooling obtains nontoxic degradable preservative film.Application No. is the patents of CN201810508790.2 to disclose one Kind edibility film and preparation method thereof, using chitosan and sodium alginate film liquid, is prepared edible using LBL self-assembly method Composite membrane, and ferulic acid is crosslinked in composite membrane, which has certain preservation to fruit.

To sum up, mostly improve the characteristic of single sodium alginate film using chitosan and sodium alginate formation composite membrane at present, The preparation section of film is not only increased, and chitosan and sodium alginate are polysaccharide molecule, film quality is more crisp, limits its film machine The further improvement of tool performance, influences its service life.

Summary of the invention

It is prepared the purpose of the present invention is to provide a kind of sodium alginate preservative film and its preparation method and application, this method Sodium alginate preservative film has excellent mechanical performance and preferable fungistatic effect.

In order to achieve the above-mentioned object of the invention, the present invention the following technical schemes are provided:

The present invention provides a kind of preparation methods of sodium alginate preservative film, comprising the following steps:

Sodium alginate film liquid is mixed with glycerol, obtains the first film liquid；

First film liquid is mixed with Thymol and polyamines, obtains the second film liquid；

Second film liquid is formed a film, gained film is placed in calcium chloride solution, calcium crosslinking is carried out, obtains alginic acid Sodium preservative film.

Preferably, the mass concentration of the sodium alginate film liquid is 1%.

Preferably, mass concentration of the glycerol in the first film liquid is 1%.

Preferably, mass concentration of the Thymol in the second film liquid is 0.1%~1.0%.

Preferably, the polyamines is one or more of putrescine, cadaverine, spermidine and spermine, and the polyamines is second Concentration in film liquid is 0.01~0.1mol/L.

Preferably, the method for the film forming is the tape casting；After completing the film forming, further includes: at room temperature by gained film 15~20h of naturally dry.

Preferably, the mass concentration of the calcium chloride solution is 1~2%；Contain mass fraction in the calcium chloride solution For 3~5% glycerol.

Preferably, the calcium cross-linked temperature is room temperature, and the calcium cross-linked time is 10~15min.

The present invention provides the sodium alginate preservative films that preparation method described in above-mentioned technical proposal is prepared.

The present invention provides sodium alginate preservative films described in above-mentioned technical proposal in fresh or fresh-cut fruit and vegetable packaging material Application.

The present invention provides a kind of preparation methods of sodium alginate preservative film, comprising the following steps: by sodium alginate film liquid It is mixed with glycerol, obtains the first film liquid；First film liquid is mixed with Thymol and polyamines, obtains the second film liquid；By institute It states the second film liquid to form a film, gained film is placed in calcium chloride solution, carry out calcium crosslinking, obtain sodium alginate preservative film.

The present invention carries out precrosslink to sodium alginate film liquid using polyamines, can effectively improve the drawing of single sodium alginate film Intensity and elongation at break are stretched, and then improves the mechanical performance of sodium alginate film.Embodiment shows relative to single sodium alginate Film, the tensile strength of sodium alginate preservative film prepared by the present invention can be improved nearly 20%, and elongation at break can be improved nearly 200%.

Thymol is added in sodium alginate preservative film by the present invention, and obtained sodium alginate preservative film has preferable Antibacterial and antioxidant effect can effectively delay new using the sodium alginate preservative film as fresh or fresh-cut fruit and vegetable packaging material Fresh or fresh-cut fruit and vegetable aging, extends its storage period, provides new thinking for the preparation of sodium alginate edible freshness-keeping thin coat.

Specific embodiment

The present invention provides a kind of preparation methods of sodium alginate preservative film, comprising the following steps:

Sodium alginate film liquid is mixed with glycerol, obtains the first film liquid；

First film liquid is mixed with Thymol and polyamines, obtains the second film liquid；

Second film liquid is formed a film, gained film is placed in calcium chloride solution, calcium crosslinking is carried out, obtains alginic acid Sodium preservative film.

In the present invention, if without specified otherwise, the required raw material for preparing is commercial goods well known to those skilled in the art.

The present invention mixes sodium alginate film liquid with glycerol, obtains the first film liquid.In the present invention, the sodium alginate film The preparation method of liquid is preferred are as follows: sodium alginate powder is dissolved in pure water, obtains sodium alginate film liquid.In the present invention, described The temperature of dissolution is preferably 60 DEG C, and the dissolution preferably carries out under agitation, and the present invention does not have the revolving speed of the stirring Special restriction can dissolve sodium alginate powder complete.In the present invention, the quality of the sodium alginate film liquid is dense Degree preferably 1%.In the present invention, the mixing preferably carries out under agitation, and the present invention does not have the revolving speed of the stirring There is special restriction, sodium alginate film liquid can be uniformly mixed with glycerol.In the present invention, the glycerol is in the first film Mass concentration in liquid is preferably 1%.The present invention uses glycerol as plasticizer, can further enhance sodium alginate preservative film Mechanical strength.

After obtaining the first film liquid, the present invention mixes first film liquid with Thymol and polyamines, obtains the second film liquid. In the present invention, Thymol and polyamines preferably under agitation, are sequentially added described first by the mixed process In film liquid, the present invention does not have special restriction to the revolving speed of the stirring, can mix the first film liquid with Thymol and polyamines It closes uniform.

In the present invention, mass concentration of the Thymol in the second film liquid is preferably 0.1~1.0%, more preferably It is 0.2~0.8%, most preferably 0.5~0.6%.In the present invention, Thymol has stronger inhibition to bacterium and fungi Effect, can further enhance the bacteriostasis and antioxidant effect of sodium alginate preservative film.

In the present invention, the polyamines is preferably one or more of putrescine, cadaverine, spermidine and spermine, described more Concentration of the amine in the second film liquid is preferably 0.01~0.1mol/L, more preferably 0.02~0.08mol/L, most preferably 0.03 ~0.06mol/L.In the present invention, polyamines is occurred quiet by the free carboxy (negative electrical charge) of amino (positive charge) and sodium alginate Electric interactions can improve the film forming characteristics of sodium alginate.

After obtaining the second film liquid, the present invention forms a film second film liquid, and gained film is placed in calcium chloride solution, Calcium crosslinking is carried out, sodium alginate preservative film is obtained.In the present invention, the method for the film forming is preferably the tape casting, specifically will Second film liquid is poured on glass or acrylic board, then by gained film 15~20h of naturally dry at room temperature.

In the present invention, the mass concentration of the calcium chloride solution is preferably 1~2%, and more preferably 1.5%；The chlorine Change and preferably comprise the glycerol that mass fraction is 3~5% in calcium solution, the present invention adds glycerol in calcium chloride solution and can prevent Loss of the glycerol in calcium cross-linking process on film, that is, avoid the glycerol on film excessively soluble in water.In the present invention, the calcium The temperature of crosslinking is preferably room temperature, and the calcium cross-linked time is preferably 10~15min, more preferably 12~14min.

After completing calcium crosslinking, present invention preferably uses 20~30mL glycerine water solution, (qualities of glycerin content is preferably 3%~5%) rinse gained film surface, be subsequently placed in relative humidity be 50%, naturally dry 48 in the environment of temperature is 25 DEG C~ 72h obtains sodium alginate preservative film.

In calcium cross-linking process, calcium ion is swapped with the sodium ion on sodium alginate, and calcium ion and two carboxyls exist It interacts under electrostatic interaction, to play the purpose of crosslinking.

The present invention provides the sodium alginate preservative films that preparation method described in above-mentioned technical proposal is prepared.In the present invention In, the sodium alginate preservative film belongs to edible freshness-keeping thin coat, wherein polyamines and Thymol are added with, using polyamines to seaweed Sour sodium film liquid carries out precrosslink, then carries out calcium crosslinking, can effectively improve the tensile strength and fracture of sodium alginate preservative film Elongation, Thymol can enhance sodium alginate preservative film to the inhibiting effect of fruits and vegetables putrefactive microorganisms.Therefore, institute of the present invention Sodium alginate preservative film is stated with excellent mechanical performance and good fungistatic effect.In the present invention, the sodium alginate is protected Fresh film with a thickness of 0.019~0.022mm.

The present invention provides sodium alginate preservative films described in above-mentioned technical proposal in fresh or fresh-cut fruit and vegetable packaging material Application.The present invention is not special to application method of the sodium alginate preservative film in fresh or fresh-cut fruit and vegetable packaging material Restriction, select method well known to those skilled in the art.

Below in conjunction with the embodiment in the present invention, the technical solution in the present invention is clearly and completely described.It is aobvious So, described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Based on the reality in the present invention Example is applied, every other embodiment obtained by those of ordinary skill in the art without making creative efforts all belongs to In the scope of protection of the invention.