Antibacterial Glucose-based Composite Nanoparticle and Processing Method and Use thereof

Abstract

The present disclosure discloses an antibacterial glucose-based composite nanoparticle and a processing method and use thereof, and belongs to the technical field of processing of modern food. According to the present disclosure, the antibacterial composite nanoparticle is prepared by using a particle surface positioning modification technology and a physical field charge transfer technology with a natural glucose-based nanoparticle as a raw material. The obtained antibacterial composite nanoparticle has a particle size of 50-1,000 nm, a surface zeta potential of 0 to −10 mV and a broad-spectrum antibacterial rate of greater than 98%. The shelf life of food can be effectively prolonged to prevent spoilage of products. The antibacterial composite nanoparticle can be used in food, textiles, daily chemicals, medicine and many other fields, and has a wide application prospect.

Claims

1. A processing method of an antibacterial glucose-based composite nanoparticle, comprising the following steps: (1) dispersing a natural glucose-based nanoparticle in water, and adding a microbial GH13 family glucoside hydrolase that is 50-200 U/g of the natural glucose-based nanoparticle for a catalytic reaction; (2) after the reaction is completed, adding an organic acid anhydride esterification agent and an etherification agent, adjusting the pH to 7-13 and perform a reaction in a microwave environment; and (3) after the reaction is completed, adding a preservative of 0.01-1% by mass of the natural glucose-based nanoparticle and perform a reaction in an ultrasonic environment, and then conducting precipitation and drying; wherein, the preservative comprises one or more selected from the group consisting of nisin, lysozyme and chitin.

2. The method according to claim 1, wherein, the natural glucose-based nanoparticle has a molecular weight of 10.sup.6-10.sup.8 g/mol and a dispersed molecular density of 1,000-2,000 g.Math.mol.sup.−1.Math.nm.sup.−3.

3. The method according to claim 1, wherein, in step (1), the natural glucose-based nanoparticle in the water has a mass concentration of 10-40%.

4. The method according to claim 1, wherein, in step (1), the catalytic reaction is carried out at a constant temperature of 30-70° C. and a pH of 3.5-7.0 for 0.5-12 h.

5. The method according to claim 1, wherein, in step (2), the organic acid anhydride esterification agent is added in an amount of 0.5-3% of the mass of the natural glucose-based nanoparticle.

6. The method according to claim 1, wherein, in step (2), the etherification agent is added in an amount of 1-10% of the mass of the natural glucose-based nanoparticle.

7. The method according to claim 1, wherein, in step (3), an ultrasonic frequency is 20-100 kHz; and in step (3), the reaction is carried out at 20-50° C. for 0.1-5 h to realize charge transfer.

8. An antibacterial glucose-based composite nanoparticle prepared by using the method according to claim 1.

9. Use of the antibacterial glucose-based composite nanoparticle according to claim 8 in active food packaging, cosmetics, textiles, hydrogels and adhesives.

Description

BRIEF DESCRIPTION OF FIGURES

[0025] FIG. 1 is an electron microscope photograph (bar 100 nm) of an antibacterial glucose-based composite nanoparticle obtained in Example 1.

DETAILED DESCRIPTION

[0026] A measurement method of a broad-spectrum antibacterial rate is as follows.

[0027] Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Listeria monocytogenes and other food-borne spoilage bacteria are subjected to streak culture on a nutrient agar culture medium at 37° C. for 12 h. A single colony is picked, cultured in a nutrient broth culture medium at 37° C. for 12 h, and then subjected to plate counting. A certain amount of a bacterial liquid is sucked into 100 mL of a nutrient broth culture medium (with a finally number of 107 CFU/mL). Then, an appropriate amount of an antibacterial glucose-based composite nanoparticle is added to obtain a mixture. Next, the mixture is cultured in a constant-temperature incubator at 37° C. Samples are measured at 0 h, 4 h, 6 h, 8 h, 10 h, 12 h and 24 h to obtain an OD600 value. The sample cultured for 12 h is subjected to plate counting and then measured to obtain an antibacterial rate. Three parallel tests are carried out on each sample, and a calculation formula is as follows:

antibacterial rate (%)=(OD600.sub.blank-OD600.sub.sample)/OD600.sub.blank,

[0028] where, the OD600.sub.blank refers to an OD600 value when the antibacterial glucose-based composite nanoparticle is not added, and the OD600.sub.sample refers to an OD600 value when the antibacterial glucose-based composite nanoparticle is added.

[0029] A measurement method of a surface zeta potential is as follows.

[0030] A to-be-tested antibacterial glucose-based composite nanoparticle is prepared into a 0.1% (w/v) solution, and then measured by using a Malvern Nano ZS tester at 25° C. to obtain a surface zeta potential.

[0031] A natural glucose-based nanoparticle may be obtained by extracting some tissues from cereal grains, algae and animals in a growing period by using an existing technology, or extracting a microorganism from bacteria after activated culture and fermentation. Specifically, the antibacterial glucose-based composite nanoparticle may be prepared with reference to the following literature: Structure and digestibility of endosperm water-soluble a-glucans from different sugary maize mutants, Food Chemistry 143 (2014) 156-162.

Example 1

[0032] A glucose-based nanoparticle (with a molecular weight of 2.3*10.sup.7 g/mol and a dispersed molecular density of 1,230 g/(mol.Math.nm.sup.3)) derived from oysters was weighed and prepared into a homogeneous aqueous solution with a mass concentration of 40%. A microbial GH13 family amyloglucosidase that was 200 U/g of the substrate was added. Parameters of a reaction system were adjusted as follows: the temperature was 50° C., the pH was 7.0, and constant-temperature catalysis was conducted for 0.5 h. Succinic anhydride was added in an amount of 0.5% of a mass of the substrate, oxirene was added in an amount of 3% of the mass of the substrate, and the pH of a reaction system was adjusted to 12. Then, a microwave-assisted processing technology was used for adjusting a microwave power to 800 W to carry out a reaction at 50° C. for 6 h. Next, chitin was added in an amount of 0.01% of the mass of the substrate, and a physical field charge transfer technology was used for adjusting an ultrasonic frequency to 100 kHz to carry out a reaction at 20° C. for 0.5 h. Finally, precipitation and drying were conducted to obtain a target product.

[0033] The obtained target product had an average particle size of 110 nm, a surface zeta potential of −5.2 mV and a broad-spectrum antibacterial rate of 98.7%.

Example 2

[0034] A glucose-based nanoparticle (with a molecular weight of 7.3*10.sup.6 g/mol and a dispersed molecular density of 1,510 g/(mol.Math.nm.sup.3)) derived from rice was weighed and prepared into a homogeneous aqueous solution with a mass concentration of 10%. A microbial GH13 family maltosidase that was 50 U/g of the substrate was added. Parameters of a reaction system were adjusted as follows: the temperature was 30° C., the pH was 6.0, and constant-temperature catalysis was conducted for 8 h. Acetic anhydride was added in an amount of 3% of a mass of the substrate, oxirene was added in an amount of 1% of the mass of the substrate, and the pH of a reaction system was adjusted to 10. Then, a microwave-assisted processing technology was used for adjusting a microwave power to 400 W to carry out a reaction at 30° C. for 10 h. Next, nisin was added in an amount of 0.5% of the mass of the substrate, and a physical field charge transfer technology was used for adjusting an ultrasonic frequency to 50 kHz to carry out a reaction at 50° C. for 2 h. Finally, precipitation and drying were conducted to obtain a target product.

[0035] The obtained target product had an average particle size of 170 nm, a surface zeta potential of −7.5 mV and a broad-spectrum antibacterial rate of 99.4%.

Example 3

[0036] A glucose-based nanoparticle (with a molecular weight of 1.8*10.sup.6 g/mol and a dispersed molecular density of 1,080 g/(mol.Math.nm.sup.3)) derived from Kluyveromyces marxianus was weighed and prepared into a homogeneous aqueous solution with a mass concentration of 20%. A microbial GH13 family maltosidase that was 100 U/g of the substrate was added. Parameters of a reaction system were adjusted as follows: the temperature was 60° C., the pH was 5.0, and constant-temperature catalysis was conducted for 2 h. Maleic anhydride was added in an amount of 1% of a mass of the substrate, ethyl chloride was added in an amount of 5% of the mass of the substrate, and the pH of a reaction system was adjusted to 8. Then, a microwave-assisted processing technology was used for adjusting a microwave power to 500 W to carry out a reaction at 35° C. for 3 h. Next, lysozyme was added in an amount of 1% of the mass of the substrate, and a physical field charge transfer technology was used for adjusting an ultrasonic frequency to 80 kHz to carry out a reaction at 30° C. for 1 h. Finally, precipitation and drying were conducted to obtain a target product.

[0037] The obtained target product had an average particle size of 290 nm, a surface zeta potential of −1.2 mV and a broad-spectrum antibacterial rate of 99.3%.

Example 4 Optimization of Use Amount of Enzyme

[0038] With reference to Example 1, corresponding composite particles were separately prepared by changing the use amount of a microbial GH13 family glucoside hydrolase into 30 U/g and 300 U/g when other conditions were unchanged. Properties of the composite particles were measured, and results were shown in Table 1.

TABLE-US-00001 TABLE 1 Results of properties of composite particles prepared with different use amounts of an enzyme Use amount of enzyme Surface zeta potential Antibacterial rate (U/g) (mV) (%) 9 −12.8 63.4 30 −11.2 75.2 300 −10.5 80.2

[0039] According to the results, it was shown that when the enzyme was used in a too high amount or too low amount, the obtained composite particles had a surface charge of less than −10 mV and an antibacterial rate of less than 90%.

Comparative Example 1

[0040] A glucose-based nanoparticle (with a molecular weight of 2.3*10.sup.7 g/mol and a dispersed molecular density of 1,230 g/(mol.Math.nm.sup.3)) derived from oysters was weighed and prepared into a homogeneous aqueous solution with a mass concentration of 40%. A microbial GH13 family amyloglucosidase that was 200 U/g of the substrate was added. Parameters of a reaction system were adjusted as follows: the temperature was 50° C., the pH was 7.0, and constant-temperature catalysis was conducted for 0.5 h. Succinic anhydride was added in an amount of 0.5% of a mass of the substrate, oxirene was added in an amount of 3% of the mass of the substrate, and the pH of a reaction system was adjusted to 12. Then, a microwave-assisted processing technology was used for adjusting a microwave power to 800 W to carry out a reaction at 50° C. for 6 h. Finally, precipitation and drying were conducted to obtain a target product.

[0041] The obtained target product had a surface zeta potential of −32.5 mV and a broad-spectrum antibacterial rate of 0%. It could be seen that the pure glucose-based nanoparticle had antibacterial activity of 0. In addition, by simply using a same amount of chitin to conduct an antibacterial experiment, it was found that the nanoparticle had a broad-spectrum antibacterial rate of 89.4%.

Comparative Example 2

[0042] A glucose-based nanoparticle (with a molecular weight of 2.3*10.sup.7 g/mol and a dispersed molecular density of 1,230 g/(mol.Math.nm.sup.3)) derived from oysters was weighed and prepared into a homogeneous aqueous solution with a mass concentration of 40%. A microbial GH13 family amyloglucosidase that was 200 U/g of the substrate was added. Parameters of a reaction system were adjusted as follows: the temperature was 50° C., the pH was 7.0, and constant-temperature catalysis was conducted for 0.5 h. Succinic anhydride was added in an amount of 0.5% of a mass of the substrate, oxirene was added in an amount of 3% of the mass of the substrate, and the pH of a reaction system was adjusted to 12. Then, a microwave-assisted processing technology was used for adjusting a microwave power to 800 W to carry out a reaction at 50° C. for 6 h. Next, chitin was added in an amount of 0.01% of the mass of the substrate to carry out a reaction by direct stirring at 20° C. for 0.5 h without an ultrasonic charge transfer process. Finally, precipitation and drying were conducted to obtain a target product.

[0043] The obtained target product had an average particle size of 625 nm, a surface zeta potential of −9.2 mV and a broad-spectrum antibacterial rate of 91.7%.

Comparative Example 3

[0044] With reference to Example 1, an organic acid anhydride was simply used for modification, 3% of oxirene was not added, and other conditions were unchanged.

[0045] A glucose-based nanoparticle (with a molecular weight of 2.3*10.sup.7 g/mol and a dispersed molecular density of 1,230 g/(mol.Math.nm.sup.3)) derived from oysters was weighed and prepared into a homogeneous aqueous solution with a mass concentration of 40%. A microbial GH13 family amyloglucosidase that was 200 U/g of the substrate was added. Parameters of a reaction system were adjusted as follows: the temperature was 50° C., the pH was 7.0, and constant-temperature catalysis was conducted for 0.5 h. Succinic anhydride was added in an amount of 0.5% of a mass of the substrate, and the pH of a reaction system was adjusted to 12. Then, a microwave-assisted processing technology was used for adjusting a microwave power to 800 W to carry out a reaction at 50° C. for 6 h. Next, chitin was added in an amount of 0.01% of the mass of the substrate, and a physical field charge transfer technology was used for adjusting an ultrasonic frequency to 100 kHz to carry out a reaction at 20° C. for 0.5 h. Finally, precipitation and drying were conducted to obtain a target product. The obtained target product had a broad-spectrum antibacterial rate of 83%.