Preparation method and application of ion modified polysaccharide edible film

Abstract

The invention relates to a preparation method and application of an ion modified polysaccharide edible film. The preparation method mainly comprises a process route of chitosan content and edible film coating liquid preparation. The method comprises the following steps: pretreating chitosan, and uniformly dispersing the chitosan in a solvent to form a polysaccharide solution; after a specific Mg ion compound is dissolved, a polysaccharide solution is slowly added according to a certain proportion, Mg ions and polysaccharide chains are promoted to generate chemical bonding or electrostatic interaction under the constant-temperature stirring condition, the ion modification process is achieved, and the modification effect is optimized by precisely regulating and controlling the reaction temperature, time and ion concentration. The film has enhanced mechanical properties, gas barrier properties and antibacterial activity, can effectively prolong the shelf life of food in the field of food packaging, reduces the influence of packaging wastes on the environment, opens up a new way for green food packaging materials, and has wide application prospects in the food industry.

Description

Technical Field

[0001] The invention belongs to the technical field of food preservation and processing, and specifically relates to a preparation method and application of an ion-modified polysaccharide edible film. Background Art

[0002] Polysaccharide edible film is a new type of food packaging material, which is biodegradable and edible. It is mainly composed of natural polysaccharide materials such as starch, protein, cellulose, etc., and is prepared through processing technology. In the field of food packaging, it can replace traditional plastic films, reduce pollution to the environment, and can be digested and absorbed by the human body without causing harm to health. In the research in the field of polysaccharide edible films, the application of additives, such as antioxidants, preservatives, thickeners, etc., is involved to improve the stability of edible films, prevent food spoilage and extend the shelf life of food. However, the application of polysaccharide edible films alone not only limits the stability of the film, but also the addition of some substances will increase the preservation performance of the film, such as improving the color, aroma, chewiness, texture and other sensory properties of food, improving antibacterial properties, prolonging the rancidity time and thus extending the shelf life. There are more studies on polysaccharide films at home and abroad, and fewer studies on added ion modifications, especially the addition of Mg. 2+ There are almost no related studies. In this experiment, food-grade Mg ions were added, and the membrane properties were measured by measuring the particle size of the composite membrane, Fourier transform infrared, and differential calorimetry. The results showed that the membrane structure was more stable after adding Mg ions, and the color, texture, index lipid peroxidation (TBARS) value, volatile basic nitrogen (TVB-N) value, TBRS, sensory characteristics, and total colony count of the coating group at different days of storage were better than those of the control group. Summary of the invention

[0003] The invention discloses a method for preparing an ion-modified polysaccharide edible film. A specific polysaccharide raw material is selected, dissolved in a suitable solvent system, and fully dissolved under specific temperature and stirring conditions to form a uniform polysaccharide solution. A Mg ion solution with specific functions is slowly dripped into the polysaccharide solution, and the Mg ions interact with the active groups on the polysaccharide molecular chain to perform an ion modification reaction. The reaction process strictly controls the reaction time, pH value and other conditions to ensure the uniformity and stability of the modification effect. Finally, an ion-modified polysaccharide edible film with multiple excellent properties such as good mechanical properties, barrier properties and antibacterial properties is obtained. The edible film can be widely used in the fields of food preservation, packaging, etc., providing a green, environmentally friendly and excellent performance packaging material solution for the food industry, while expanding the application potential of polysaccharides in the field of edible materials, with significant economic and social benefits. The present invention mainly aims to solve an edible coating technology that can improve the quality of food during storage and extend the shelf life. The method comprises the following steps: (1) weighing 2-2.5 g of chitosan (CS) and dissolving it in 100 ml of sterile water, adding 1-1.5% acetic acid and 1-1.5% glycerol, and adding 0.1-0.15% tea polyphenols, and dissolving the mixture by magnetic stirring for 12 hours to prepare a chitosan coating solution;

[0004] (2) adding 0.75-0.80% concentration of MgCl2;

[0005] (3) Adjust the pH range of the mixture to 5-6.5.

[0006] Add Mg 2+ The particle size of the polysaccharide edible film ranges from 600 to 650 nm, the potential is 45 to 49, and the PDI is 0.5 to 0.6. The coating liquid belongs to a highly stable system. The lipid peroxidation (TBARS) value and the volatile basic nitrogen (TVB-N) value of the coating liquid group are lower than those of the control group at 0, 3, 5, 7, 9, and 12 days of storage; the hardness and elasticity of the coating liquid group in the texture characteristics are increased by 10% to 15% at 0, 3, 5, 7, 9, and 12 days of storage; the sensory characteristics of the coating liquid group at 0, 3, 5, 7, 9, and 12 days of storage are 20% to 15% higher than those of the control group. The total number of colonies in the coating liquid group is reduced by 15% to 20% at 0, 3, 5, 7, 9, and 12 days of storage compared with the control group, and the shelf life is delayed by 3 to 5 days. DETAILED DESCRIPTION

[0007] In order to make the purpose, features and advantages of the present invention more obvious and understandable, the embodiments of the present invention are clearly and completely described below in conjunction with specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, such as embodiments that only change the purpose without changing the basic principles involved in the claims, belong to the scope of protection of the present invention.

[0008] Embodiment 1:

[0009] (1) Weigh 2 g of chitosan (CS) and dissolve it in 100 ml of sterile water, add 1% acetic acid and 1% glycerol, and add 0.1% tea polyphenols. The mixture is dissolved by magnetic stirring for 12 h to prepare a chitosan coating solution;

[0010] (2) adding 0.75% concentration of MgCl2;

[0011] (3) Adjust the pH range of the mixture to 5-6.5.

[0012] The component combination features not described in detail in the specification belong to the content that is easily thought of by the known technology or easily determined and undisputed when implementing the present invention. The above scheme is only a description of several preferred implementation methods of the present application, but the protection scope of the present application is not limited to this. Any person familiar with the technology can easily implement within the scope of the description of the present application without changing the changes or substitutions involved in the basic principles of the claims, which should be covered within the protection scope of the present application, that is, the protection scope of the present application should be based on the protection scope of the claims.

[0013] Embodiment 2:

[0014] (1) Weigh 2 g of chitosan (CS) and dissolve it in 100 ml of sterile water, add 1% acetic acid and 1% glycerol, and add 0.1% tea polyphenols. The mixture is dissolved by magnetic stirring for 12 h to prepare a chitosan coating solution;

[0015] (2) adding 0.78% concentration of MgCl2;

[0016] (3) Adjust the pH range of the mixture to 5-6.0.

[0017] Embodiment 3:

[0018] (1) Weigh 2.5 g of chitosan (CS) and dissolve it in 100 ml of sterile water, add 1.5% acetic acid and 1.5% glycerol, and add 0.1% tea polyphenols. The mixture is dissolved by magnetic stirring for 12 h to prepare a chitosan coating solution;

[0019] (2) adding 0.8% concentration of MgCl2;

[0020] (3) Adjust the pH range of the mixture to 5-6.3.

Claims

1. A method for preparing an ion-modified polysaccharide edible film, characterized in that: (1) Weigh 2-2.5 g of chitosan (CS) and dissolve it in 100 ml of sterile water, add 1%-1.5% acetic acid and 1%-1.5% glycerol, and add 0.1%-0.15% tea polyphenols. The mixture is dissolved by magnetic stirring for 12 hours to prepare a chitosan coating solution; (2) adding 0.75%-0.80% concentration of MgCl2; (3) Adjust the pH range of the mixture to 5-6.

5.

2. An ion-modified polysaccharide edible film, characterized in that: The method for preparing an ion-modified polysaccharide edible film according to claim 1 is used.

3. The use of an ion-modified polysaccharide edible film according to claim 2, characterized in that: Add Mg 2+ The particle size range of the polysaccharide edible film is 600-650nm, the potential is 45-49, the PDI is 0.5-0.6, the coating liquid belongs to a highly stable system, the oxidative rancidity index lipid peroxidation (TBARS) value and the volatile basic nitrogen (TVB-N) value of the coating liquid group are lower than those of the control group at 0, 3, 5, 7, 9 and 12 days of storage; the hardness and elasticity of the texture characteristics of the coating liquid group are increased by 10%-15% at 0, 3, 5, 7, 9 and 12 days of storage; the sensory characteristics evaluation of the coating liquid group at 0, 3, 5, 7, 9 and 12 days of storage is improved by 20%-15% compared with the control group; the total colony count of the coating liquid group is reduced by 15%-20% at 0, 3, 5, 7, 9 and 12 days of storage compared with the control group, and the shelf life is delayed by 3-5 days.