Preparation Of Antibacterial Chitosan/Sodium Alginate Nanoparticles And Application In The Starch Film

Tea polyphenols(TP) and potassium sorbate(PS) are very widely application of antimicrobial agents in foods, harmless to human body. But they are easily oxidized by air and degrade if they are used directly, which will lose antibacterial activity. Therefore, their application are limited in various fields. In this research, using chitosan(CS), sodium alginate(SA) as capsule materials in order to prevent the oxidation of the tea polyphenols and potassium sorbate. Drug-loading nanoparticles were prepared by the inverse emulsion crossing method. It not only could increase the stability of tea polyphenols and potassium sorbate and became more widely used, but also could achieve slow release and prolonged the time of antibacterial. Therefore, the research of the drug-loading nanoparticles has a good application prospect by the method of inverse emulsion crossing in medicine, the food industry and other fields.In this paper, tea polyphenols chitosan/sodium alginate nanoparticles and potassium sorbate chitosan/sodium alginate nanoparticles were prepared by incubation absorption and entrapping respectively. And the structure, surface morphology of blank nanoparticles and drug-loading nanoparticles were characterize by the FTIR, DSC, TGA, etc.Preparation conditions of chitosan/sodium alginate nanoparticles(CS/SA NPs) using inverse emulsion crossing method were investigated by the orthogonal experiment with particle size as criterion. The effect of the reaction conditions on particle size were investigated. The result showed that the optimal preparation conditions were as follows: sodium alginate solution is 1.5%(w/v), emulsifier concentration Tween 80 and Span 80 are 5%(v/v) and 9%(v/v) of the oil phase, respectively, calcium chloride solution concentration is 1.5%(w/v) and chitosan solution concentration is 1.0%(w/v). Nanoparticles have ideal spherical in shape, smooth surface, uniform particle size distribution, stability and the average particle size is 171.1nm, the Zeta potential of nanoparticles is about +41.4mV.Tea polyphenols and potassium sorbate were loaded on the basis of the CS/SA NPs by the adsorption drug-loading method, and it made the following research: tea polyphenol chitosan/sodium alginate nanoparticles(TP-CS/SA NPs) were prepared via incubation absorption method. The effect on loading effciency and entrapment effciency of a series of factors was studied, including the adsorption time, adsorption temperature and tea polyphenols solution concentration. It was concluded that the optimal formula: tea polyphenols solution concentration is 2mg/ml, tea polyphenols with CS/SA NPs adsorption temperature is 25℃, adsorption time is 120 min. In the end loading effciency and entrapment effciency reach 73.1%, 54.3%. Tea polyphenol of drug-loading nanoparticles are released soon within the initial 5h through the in vitro release study, reach 58.3%, while 5h after release curve is stable. The tea polyphenols release of TP-CS/SA NPs fits Fickian diffusion and substrate swelling model; Potassium sorbate chitosan/sodium alginate nanoparticles(PS-CS/SA NPs) were prepared via incubation absorption method. The effect on loading effciency and entrapment effciency of a series of factors was studied, including the adsorption time, adsorption temperature and potassium sorbate concentration. It was concluded that the optimal formula: potassium sorbate solution of 0.4mg/ml, adsorption time of 120 min, potassium sorbate with CS/SA NPs adsorption temperature of 25℃. In the end loading effciency and entrapment effciency reach 19.0%, 58.7%. Potassium sorbate of drug-loading nanoparticles are released soon within the initial 5h through the in vitro release study, reach 83%, while 5h after release curve is stable. The potassium sorbate release of PS-CS/SA NPs fits Fickian diffusion and substrate swelling model.In this paper, tea polyphenols chitosan/sodium alginate nanoparticles(CS/TP/SA NPs) was prepared by entrapping method, and taking the loading effciency as an evaluation index. Preparation conditions of CS/TP/SA NPs were investigated by the orthogonal experiment. The optimal preparation conditions were as follows: sodium alginate solution of 1.0%(w/v), chitosan solution of 0.5%(w/v), calcium chloride solution of 1.5%(w/v), tea polyphenols quality and sodium alginate solution volume ratio of 12: 1. CS/TP/SA NPs are prepared under the optimal condition, encapsulation efficiency and loading efficiency are 46.0% and 6.1%, respectively. The loading efficiency and encapsulation efficiency of CS/TP/SA NPs studies are performed in terms of chitosan solution mass concentration, tea polyphenols quality and sodium alginate solution volume ratio, sodium alginate solution mass concentration, calcium chloride solution mass concentration. The tea polyphenol release of CS/TP/SA NPs fits Fickian diffusion model through in the vitro release study, tea polyphenol of drug-loading nanoparticles are released soon within the initial 4h, reach 76.8%, while 4h after tea polyphenol is release slowly, release curve is stable.The CS/TP/SA NPs microemulsion was added to the starch in the matrix. And edible antimicrobial film starch was prepared by coating, and the preparation of antibacterial membrane against gram-negative bacteria Echerichia coli and gram positive bacteria Saphylococcus aureus were evaluated. The results showed that the preparation of starch membrane against Echerichia coli and Saphylococcus aureus have good antimicrobial properties. Saphylococcus aureus antibacterial effect is better than Echerichia coli.