CN106819076A - A kind of preparation method of the bacteriostasis, preservation plastics based on natural polysaccharide particle - Google Patents

Abstract

The invention relates to a preparation method of an antibacterial and fresh-keeping coating agent based on natural polysaccharide particles. The natural polysaccharide particles are dispersed in water to obtain a natural polysaccharide particle solution; an oxidizing agent is added to the polysaccharide particle solution to dissolve the hydroxyl groups on the surface of the natural polysaccharide particles. Selective oxidation obtains the oxidized natural polysaccharide particle solution; the compound nisin with antibacterial activity is added in the natural polysaccharide particle solution, and after the reaction, the salt in the reaction system is removed by dialysis bag dialysis with a cut-off of 3000 to obtain pH Bacteria fresh-keeping coating agent. The antibacterial and fresh-keeping coating agent prepared by the invention is sprayed on the surface of dairy products and is easy to dry naturally to form a film, and the performance is stable after film formation; it is harmless to the human body, safe and non-toxic; also due to the unique structure of natural polysaccharide particles, it can improve food quality. aroma and flavor. The invention has simple process and low cost, and can replace existing chemical preservatives and be applied in the field of antiseptic and fresh preservation in food processing.

Description

A preparation method of antibacterial and fresh-keeping coating agent based on natural polysaccharide particles

technical field

The invention relates to a preparation method of an antibacterial and fresh-keeping coating agent based on natural polysaccharide particles.

Background technique

Polysaccharides such as starch and cellulose are macromolecular renewable substances that widely exist in nature. Because of their abundant sources, environmental friendliness, and good biological safety, they have broad application prospects in many fields. However, because starch and cellulose do not have antibacterial activity, their application in materials such as functional packaging or functional fibers is limited.

In order to endow starch and cellulose with certain antibacterial properties, researchers introduced inorganic nanoparticles such as silver, copper, titanium dioxide, and cuprous oxide into starch or cellulose material substrates through certain physical or chemical methods to endow them with antibacterial properties. function; some researchers also mixed cellulose with chitosan and its quaternary ammonium salt, quaternary phosphonium antibacterial agent, halide amine and other organic compound antibacterial agents to prepare composite materials with antibacterial function; there are also researchers who directly Derivatization of starch or cellulose to prepare cellulose derivatives with antibacterial function. However, the starch or cellulose antibacterial functional material prepared by the above method has certain safety because of the antibacterial agent used, and the prepared antibacterial material cannot be used in the field of food packaging, especially as an edible coating film packaging material.

In addition, there is still a major problem in the preparation of edible cellulose antibacterial agents, which is the dissolution of cellulose. Since cellulose is difficult to dissolve in common solvents, the commonly used methods require the use of organic solvents or a large amount of acid and alkali. , the post-processing process is complicated, and new hazards will be introduced, and the prepared bacteriostatic material has a large safety hazard when it is used as a food packaging material. Starch and derivatized cellulose can give it a certain antibacterial property, but its solvent resistance will be affected. When used as an antibacterial agent, the antibacterial layer will fall off due to the humidity and solvent of the environment. . Therefore, it is a challenge to develop new cellulose materials based on certain antibacterial activity and good film stability.

CN105218837 A method for preparing amorphous cellulose particles in an aqueous solvent system, comprising dissolving natural cellulose in water and/or organic solvent dispersions below 0°C to obtain a cellulose solution with a concentration of 0.5wt%-10wt%, in the dispersion of cellulose solution in water and/or organic solvent, to obtain the mixed solution of cellulose dispersion, remove the inorganic salt and/or organic solvent, and then remove impurities and dry to obtain amorphous Cellulose particles.

Contents of the invention

The purpose of the present invention is to aim at the above-mentioned present situation, aim to provide a kind of simple, process green, the prepared material has good film-forming property, stability and good bacteriostasis performance antibacterial fresh-keeping coating film based on natural polysaccharide particles The preparation method of the agent.

The way to achieve the purpose of the present invention is, a kind of preparation method of antibacterial and fresh-keeping coating agent based on natural polysaccharide particles, the specific steps of preparation are as follows:

1) Weigh 5g-8g of natural polysaccharide particles and disperse them in 100mL-600ml of water to obtain a natural polysaccharide particle solution;

The natural polysaccharide particles are either amorphous cellulose particles, or one of microcrystalline cellulose, microcrystalline starch, cellulose nanofibers, and cellulose nanocrystals;

2) Add 1.32g-8.94g oxidizing agent to the natural polysaccharide particle solution obtained in step 1) and react at room temperature for 6h, or at 37°C-40°C in the dark for 6h-8h, and selectively remove the hydroxyl groups on the surface of the natural polysaccharide particle Oxidation to obtain oxidized natural polysaccharide particle solution;

The oxidizing agent is sodium periodate, potassium periodate or periodic acid;

3) Add 5g-6g of compound nisin with bacteriostatic activity to the obtained natural polysaccharide particle solution in step 2) and react at room temperature for 6-8 hours, then remove the dialysis in the reaction system by dialysis with a cut-off of 3000 Salt, get antibacterial and fresh-keeping coating agent.

Compared with prior art, the present invention has following advantage:

1. The selected raw materials are natural polysaccharide particles, and the natural polysaccharide materials are safe;

2. The obtained antibacterial and fresh-keeping coating agent has good antibacterial activity;

3. The obtained antibacterial and fresh-keeping coating agent is easy to form a film after drying in water, and has good stability;

4. The reaction process is simple, and the prepared antibacterial and fresh-keeping coating agent has no harm to human body, is safe and nontoxic.

Description of drawings

Fig. 1 is the optical fiber photograph of the cellulose colloid particle antibacterial agent of embodiment 7 gained,

Fig. 2 is the optical fiber photograph of the cellulose colloid particle antibacterial agent of embodiment 8 gained,

Fig. 3 is the optical fiber photograph of the cellulose colloid particle antibacterial agent of embodiment 9 gained,

Fig. 4 is the optical fiber photograph of the cellulose colloid particle antibacterial agent that embodiment 11 gains.

detailed description

The present invention disperses natural polysaccharide particles in water to obtain natural polysaccharide particle solution. The natural polysaccharide particles are either amorphous cellulose particles, or one of microcrystalline cellulose, microcrystalline starch, cellulose nanofibers, and cellulose nanocrystals.

The method disclosed in CN105218837 is used for the amorphous cellulose particles, which is to dissolve the linters in 7wt%/12wt% NaOH/urea in advance to obtain a cellulose solution with a concentration of 0.5wt%, and then dissolve the cellulose solution at -12 Refrigerate at ℃ for 5 minutes, take it out, and dissolve it by mechanical stirring at room temperature to obtain a transparent and viscous solution, add it dropwise to absolute ethanol with the same volume as the cellulose solution under the condition of mechanical stirring, and then remove the ethanol by vacuum distillation. The obtained amorphous cellulose aqueous dispersion particles are removed by washing to remove inorganic substances.

The size of the used microcrystalline starch and microcrystalline cellulose is 10-200 microns, and the size of the cellulose nanofiber and the cellulose nanocrystal is nanoscale. Preferably, the size of the cellulose nanofibers and cellulose nanocrystals is 100 nm.

In the present invention, 5g of microcrystalline cellulose, microcrystalline starch, cellulose nanofibers, and cellulose nanocrystals are dispersed in 100mL of water, and 1.32g-7.92g of sodium periodate is added to react at room temperature or at 37°C for 6h Finally, at this time, all sodium periodate participated in the oxidation reaction of starch, and then 5g-6g nisin, a compound with antibacterial activity, was added and reacted at room temperature for 6 hours.

In the present invention, 5g-8g amorphous cellulose particles are dispersed in 200mL-600mL water, 2.64g-8.94g sodium periodate is added and reacted in the dark at 37°C-40°C for 6h-8h, at this time, all sodium periodate Participated in the oxidation reaction of starch, then added 5g-7g of compound nisin with antibacterial activity, and reacted at room temperature for 6 hours.

After nisin was added for reaction, the salt in the reaction system was removed by dialysis through a dialysis bag with a cut-off of 3000 to obtain a bacteriostatic and fresh-keeping coating agent.

The antibacterial and fresh-keeping film coating agent prepared by the invention is easy to dry and form a film naturally when sprayed on the surface of dairy products, and has stable performance after film formation, and can improve the aroma and flavor of food due to the unique structure of natural polysaccharide particles.

The present invention is described in detail below with specific examples.

Example 1. Weigh 5g of microcrystalline starch and disperse it in 100mL of water, add 1.32g of sodium periodate to the natural polysaccharide particle solution and react at room temperature for 6 hours, add 5g of nisin and react at room temperature for 6 hours, then pass the cut-off The 3000 dialysis bag was dialyzed to remove the salt in the reaction system to obtain the antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The evaluation of the antibacterial activity of the product of this example on fresh meat products refers to the national standard (GB4789.2-2010, GB 5009.44-2003), which can significantly increase the storage days, and can extend the shelf life by 8 days compared with meat products not dipped in antibacterial agents Expect.

Example 2. Weigh 5g microcrystalline starch and disperse it in 100mL water, add 2.64g sodium periodate to the natural polysaccharide particle solution and react at 37°C for 6h, add 2.64g sodium periodate and react at 37°C for 6h, then Slowly add 5 g of nisin into the above system dropwise, react at room temperature for 6 hours, and then dialyze through a dialysis bag with a cutoff of 3000 to remove the salt in the reaction system to obtain an antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The antibacterial activity evaluation of the cellulose colloid particle bacteriostatic agent obtained in this example to fresh meat products refers to the national standard (GB4789.2-2010, GB 5009.44-2003), which can obviously increase the storage days. The meat products can extend the shelf life of 12 days.

Example 3. Weigh 5g of microcrystalline cellulose and disperse it in 200mL of water, add 7.92g of sodium periodate to the natural polysaccharide particle solution and react at 37°C for 6 hours, add 6g of nisin and react at room temperature for 6 hours, then pass the interception Amount of 3000 dialysis bags dialyzed to remove the salt in the reaction system, to obtain antibacterial fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The antibacterial activity evaluation of the cellulose colloid particle bacteriostatic agent obtained in this example to fresh meat products refers to the national standard (GB4789.2-2010, GB 5009.44-2003), which can significantly increase the storage days, compared with the bacteriostatic agent not dipped The meat products can extend the shelf life of 15 days.

Example 4 is the same as Example 1, except that 5 g of cellulose nanofibers are weighed and dispersed in 100 mL of water.

Example 5 is the same as Example 1, except that 5 g of cellulose nanocrystals are weighed and dispersed in 100 mL of water.

Example 6, the cotton linters were pre-dissolved in 7wt%/12wt% NaOH/urea to obtain a cellulose solution with a concentration of 0.5wt%, and then the cellulose solution was frozen in a -12°C refrigerator for 5min, taken out, and kept at room temperature Dissolved by mechanical stirring to obtain a transparent viscous solution, which was added dropwise to absolute ethanol with the same volume as the cellulose solution under mechanical stirring, then the ethanol was removed by distillation under reduced pressure, and the amorphous was obtained by washing to remove inorganic substances Aqueous cellulose dispersion particles.

Weigh 5g of microcrystalline cellulose and disperse it in 200mL of water, add 2.64g of sodium periodate to the natural polysaccharide particle solution and react in the dark at 37°C for 6 hours, add 5g of nisin and react at room temperature for 6 hours, and then pass the cut-off of 3000 dialysis bags were dialyzed to remove the salt in the reaction system to obtain antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The antibacterial activity evaluation of the cellulose colloid particle bacteriostatic agent obtained in this example to fresh meat products refers to the national standard (GB4789.2-2010, GB 5009.44-2003), which can obviously increase the storage days. The meat products can extend the shelf life of 10 days.

Embodiment 7, with embodiment 6, the difference is,

Weigh 5g of microcrystalline cellulose and disperse it in 200mL of water, add 5.28g of sodium periodate to the natural polysaccharide particle solution and react in the dark at 40°C for 6 hours, add 5g of nisin and react at room temperature for 6 hours, and then pass the cut-off of 3000 dialysis bags were dialyzed to remove the salt in the reaction system to obtain antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The evaluation of the antibacterial activity of the product of this example on fresh meat products refers to the national standard (GB4789.2-2010, GB5009.44-2003), which can significantly increase the storage days, and can be extended by 13 days compared with meat products that have not been dipped in antibacterial agents shelf life.

The photo of the optical fiber of the cellulose colloid particle bacteriostatic agent obtained in the present embodiment is shown in Fig. 1 .

Embodiment 8, with embodiment 6, the difference is,

Weigh 5g of microcrystalline cellulose and disperse it in 400mL of water, add 6.6g of sodium periodate to the natural polysaccharide particle solution and react in the dark at 37°C for 8 hours, add 7g of nisin and react at room temperature for 6 hours, and then pass the cut-off of 3000 dialysis bags were dialyzed to remove the salt in the reaction system to obtain antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The evaluation of the antibacterial activity of the product of this example on fresh meat products refers to the national standard (GB4789.2-2010, GB5009.44-2003), which can significantly increase the storage days, and can be extended by 15 days relative to meat products that have not been dipped in antibacterial agents shelf life.

The photo of the optical fiber of the cellulose colloid particle bacteriostatic agent obtained in the present embodiment is shown in Fig. 2 .

Embodiment 9, with embodiment 6, the difference is,

Weigh 6g of microcrystalline cellulose and disperse it in 400mL of water, add 7.62g of sodium periodate to the natural polysaccharide particle solution and react in the dark at 37°C for 6 hours, add 7g of nisin and react at room temperature for 6 hours, and then pass the cut-off of 3000 dialysis bags were dialyzed to remove the salt in the reaction system to obtain antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The evaluation of the antibacterial activity of the product of this example on fresh meat products refers to the national standard (GB4789.2-2010, GB5009.44-2003), which can significantly increase the storage days, and can be extended by 14 days relative to meat products that have not been dipped in antibacterial agents shelf life.

The photo of the optical fiber of the cellulose colloid particle bacteriostatic agent obtained in the present embodiment is shown in Fig. 3 .

Embodiment 10, with embodiment 6, the difference is,

Weigh 8g of microcrystalline cellulose and disperse it in 600mL of water, add 8.94g of sodium periodate to the natural polysaccharide particle solution and react in the dark at 37°C for 8 hours, add 7g of nisin and react at room temperature for 6 hours, and then pass the cut-off of 3000 dialysis bags were dialyzed to remove the salt in the reaction system to obtain antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The evaluation of the antibacterial activity of the product of this example on fresh meat products refers to the national standard (GB4789.2-2010, GB5009.44-2003), which can significantly increase the storage days, and can be extended by 15 days relative to meat products that have not been dipped in antibacterial agents shelf life.

Embodiment 11, with embodiment 6, the difference is,

Weigh 8g of microcrystalline cellulose and disperse it in 600mL of water, add 8.94g of sodium periodate to the natural polysaccharide particle solution and react in the dark at 40°C for 8 hours, add 8g of nisin and react at room temperature for 6 hours, and then pass the cut-off of 3000 dialysis bags were dialyzed to remove the salt in the reaction system to obtain antibacterial and fresh-keeping coating agent. Spray the antibacterial and fresh-keeping coating agent directly and evenly on the surface of meat products, and dry to form a film. The evaluation of the antibacterial activity of the product of this example on fresh meat products refers to the national standard (GB4789.2-2010, GB5009.44-2003), which can significantly increase the storage days, and can be extended by 18 days compared with meat products that have not been dipped in antibacterial agents. shelf life.

The photo of the optical fiber of the cellulose colloid particle bacteriostatic agent obtained in the present embodiment is shown in Fig. 4 .

Claims (6)

1. a kind of preparation method of the bacteriostasis, preservation plastics based on natural polysaccharide particle, it is characterised in that：The specific step for preparing It is rapid as follows：

1) 5g-8g natural polysaccharide particles are weighed to be scattered in 100mL-600ml water, natural polysaccharide particle solution is obtained；

The natural polysaccharide particle is unformed cellulose grain, or is microcrystalline cellulose, Microcrystalline Starch, cellulose Nanowire One kind in dimension, Cellulose nanocrystal；

2) to step 1) add 1.32g-8.94g oxidants to react 6h at room temperature in gained natural polysaccharide particle solution, or Lucifuge reaction 6h-8h, natural after the hydroxyl selective oxidation on natural polysaccharide particle surface is aoxidized at 37 DEG C -40 DEG C Polysaccharide particle solution；

The oxidant is sodium metaperiodate, potassium metaperiodate or periodic acid；

3) to step 2) add in gained natural polysaccharide particle solution the 5g-6g there is the compound nisin of bacteriostatic activity At room temperature reaction 6-8 hours, the salt removed in reaction system of then being dialysed by the bag filter that interception is 3000 obtained antibacterial guarantor Fresh plastics.

2. the preparation method of a kind of bacteriostasis, preservation plastics based on natural polysaccharide particle according to claim 1, it is special Levy and be：One kind in 5g microcrystalline celluloses, Microcrystalline Starch, cellulose nano-fibrous, Cellulose nanocrystal is scattered in 100mL In water, after adding 1.32g-7.92g sodium metaperiodates to react 6h in room temperature or at 37 DEG C, then add the chemical combination with bacteriostatic activity Thing 5g-6g nisins, in room temperature reaction 6 hours.

3. the preparation method of a kind of bacteriostasis, preservation plastics based on natural polysaccharide particle according to claim 1, it is special Levy and be：The unformed cellulose grains of 5g-8g are scattered in 200mL-600mL water, add 2.64g-8.94g sodium metaperiodates to exist Lucifuge reaction 6h-8h at 37 DEG C -40 DEG C, now, sodium metaperiodate all take part in the oxidation reaction of starch, then add 5g-7g tools There is the compound nisin of bacteriostatic activity, in room temperature reaction 6 hours.

4. the preparation method of a kind of bacteriostasis, preservation plastics based on natural polysaccharide particle according to claim 1, it is special Levy and be：Step 1) in unformed cellulose grain be the NaOH/ urea that cotton linter is previously dissolved in 7wt%/12wt%, obtain It is the cellulose solution of 0.5wt% to concentration, then by cellulose solution in -12 DEG C of refrigerator freezing 5min, takes out, leads at room temperature Mechanical agitation dissolving is crossed, the solution of clear viscous is obtained, cellulose solution volume is dropped under conditions of mechanical agitation identical Absolute ethyl alcohol in, ethanol is then removed by vacuum distillation, as wash remove inorganic matter obtained by unformed cellulose water Dispersion granule.

5. the preparation method of a kind of bacteriostasis, preservation plastics based on natural polysaccharide particle according to claim 1, it is special Levy and be：Step 1) in Microcrystalline Starch used, the size of microcrystalline cellulose in 10-200 microns, cellulose nano-fibrous and fiber The nanocrystalline size of element is nanoscale.

6. the preparation method of a kind of bacteriostasis, preservation plastics based on natural polysaccharide particle according to claim 1 or 3, its It is characterised by：Cellulose nano-fibrous, Cellulose nanocrystal size is 100nm.