CN104693811B - A kind of functional gelatin food packaging film and preparation method thereof - Google Patents

Abstract

The invention provides a functional gelatin food packaging film and a preparation method thereof, and belongs to the field of food packaging. The method includes the steps that firstly, carboxylation beta-cyclodextrin is prepared through a hydrogen peroxide oxidation method, natural active matter dissolved in an ethanol solution is dripped into the carboxylation beta-cyclodextrin dissolved in the ethanol solution, the carboxylation beta-cyclodextrin stands still after ultrasonic operation, extracted, filtered, washed, frozen and dried, and then embedding carboxylation beta-cyclodextrin for embedding the natural active matter is obtained. The embedding carboxylation beta-cyclodextrin and a gelatin solution are blended, evenly stirred, taken out after being frozen, and completely dissolved, glycerinum and dialdehyde carboxymethylcellulose are sequentially added for reactions conducted for 10-40 minutes respectively, the materials are poured into a die after de-aeration and dried, and then the functional gelatin food packaging film is obtained. The prepared functional gelatin food packaging film has the advantages of resisting bacteria and oxidation and being good in mechanical performance and heat stability; products are safe, capable of achieving the healthcare effect and free of poisonous and side effects. The film can be degraded and beneficial to environmental protection, and has potential market application prospects.

Description

A kind of functional gelatin food packaging film and preparation method thereof

technical field

The invention relates to the field of food packaging. Specifically, it relates to a functional gelatin food packaging film with antibacterial, antioxidative, good mechanical properties and thermal stability and a preparation method thereof.

Background technique

Resources, environment and population are the three main factors restricting the sustainable development of our country in the 21st century. Environmental protection and resource conservation have become the basic strategies for sustainable development in countries all over the world. However, my country has a large population and rapid economic growth, and the demand for food packaging films has increased rapidly, posing a huge challenge to the environment and resources. Therefore, the research and development of food packaging products using natural biological materials as raw materials has gradually become a research hotspot in the field of packaging. Natural food packaging film is a kind of dense film formed by using biological macromolecules as the main matrix, supplemented by plasticizers, and interacting between film-forming molecules through certain processing procedures. It mainly prevents the migration of gas, water vapor, solute and aromatic components to avoid changes in flavor and texture of packaged food during storage and transportation, so as to ensure the quality of food and extend the shelf life. In recent years, common food packaging films include glutinous rice paper for candy packaging, corn baking packaging cups for ice cream, tofu skin for meat and vegetables, and sausage casings for meat fillings. It can be seen that packaging film has a wide range of uses in life and has potential market application prospects.

Due to the advantages of good biocompatibility and degradability, protein packaging films have gradually been widely recognized in recent years. Among the many protein packaging films, gelatin film is the most eye-catching. Gelatin is a protein that converts the triple helix structure of collagen into random chains. It is mainly obtained by hydrolyzing collagen in connective tissues such as skin and bone of higher animals. It is rich in essential amino acids for the human body and has high nutritional value. The hot water solubility of gelatin and the reversibility of sol and gel are unmatched by other film-forming colloids. In addition, gelatin has a wide range of sources, is easy to prepare, and is cheap, providing the necessary conditions for the wide application of gelatin. However, the scope of application of pure gelatin film is limited by its single activity. Therefore, the study of activated gelatin is of great significance.

Most natural active substances are sensitive to air, sunlight and temperature, easy to oxidize and deteriorate, volatile, and have low solubility in water. For example, tea tree oil is unstable and volatile, and has a strong pungent smell. Or under the action of oxygen, p-cumene with skin irritation is generated, and its properties change; ferulic acid is a polyphenol derivative with antioxidant properties, which has obvious anti-oxidation, free radical scavenging, anti-infection However, after exposure to air, ultraviolet rays and heat, it is easily oxidized, resulting in functional and sensory changes, affecting its use. Therefore, the application of such active substances is severely limited.

β-cyclodextrin is composed of 7 D-type glucopyranose linked by α-1,4-glycosidic bonds. The monomers are bound together in a ring form to form a hydrophilic surface on the outside, and a hydrophilic surface on the inside. It is a closed cylindrical structure with a chiral hydrophobic cavity of a certain size. However, the defect that β-cyclodextrin is slightly soluble in water limits its application range. Therefore, β-cyclodextrin is oxidized by hydrogen peroxide to make carboxylated β-cyclodextrin, thereby improving its water solubility. Utilizing the hydrophobic characteristics of the inner cavity of carboxylated β-cyclodextrin, natural active substances are included in it to form host-guest inclusion complexes. After the clathrate is formed, the natural active substance can be protected from the influence of external light, oxygen, heat and other environments, improving its stability and reducing the total amount of volatilization, so as to achieve the effect of slow release; through carboxylation of β-cyclodextrin The hydrophobic inner cavity encloses the natural active, while the outer hydrophilic surface indirectly increases the solubility of the natural active. Therefore, the use of carboxylated β-cyclodextrins provides a good way to expand the application of natural active substances.

The present invention utilizes carboxylated β-cyclodextrin and natural active substances to prepare clathrate; blends clathrate with gelatin solution to prepare functional gelatin food packaging film matrix solution; defoams the matrix solution and pours it into a mold , at 20-60 ^o C, dry for 1-5 days, and finally make a functional gelatin food packaging film. The food packaging film prepared by the invention has the characteristics of antibacterial, anti-oxidation and improving immunity; it also has special aromatic smell and can improve the nutritional value of food. So far, there is no relevant literature or invention related reports on this research.

Contents of the invention

In order to improve the water solubility of β-cyclodextrin and exert the effect of natural active substances, the present invention uses carboxylated β-cyclodextrin to embed natural active substances, thereby improving the stability and solubility of natural active substances, and gelatin through a A series of processes to make functional gelatin food packaging film.

The present invention is realized through the following technical solutions. Unless otherwise specified, the parts involved are all parts by weight, and the percentages are all percentages by weight.

The invention provides a functional gelatin food packaging film, the preparation method of which is as follows:

(1) While stirring, spray hydrogen peroxide into β-cyclodextrin, and dropwise add copper sulfate solution with a mass fraction of 0.01-1%, react at 40 ^o C for 3-10 minutes, and then place it at 70 ^o C React for 5-30 minutes, then dissolve the reactant in boiling water at 100 ^o C and react for 30 minutes. After the solution drops to room temperature, centrifuge and precipitate the supernatant with absolute ethanol, and wash with 10-40% ethanol solution After precipitation, freeze-dry the precipitate to obtain carboxylated β-cyclodextrin;

(2) At 30~60 ^o C, stir and dissolve carboxylated β-cyclodextrin in 10~50% ethanol solution, and at the same time, stir and dissolve natural active substances in 0~30% ethanol solution, and add dropwise into the above carboxylated β-cyclodextrin solution, ultrasonicated at 10-30 ^o C for 2-6 hours, then stood at 4 ^o C for 12 hours, then suction filtered and washed 3 times with 10-40% ethanol solution, Freeze-dry the filter cake to obtain embedded carboxylated β-cyclodextrin embedded with natural active substances;

(3) Blend and stir the embedded carboxylated β-cyclodextrin and gelatin solution evenly, freeze at -20 ^o C for 12~72 hours, take it out and dissolve completely at 30~50 ^o C, add gelatin dry weight 5~ After reacting 30% glycerin for 10-40 minutes, add dialdehyde carboxymethyl cellulose with 0.1-10% dry weight of gelatin and react for 10-40 minutes to obtain a functional gelatin food packaging film matrix solution;

(4) After defoaming the above matrix solution, pour it into a mold, and dry it in flowing air with a humidity of 10-50% at 20-60 ^o C for 1-5 days to obtain a functional gelatin food packaging film.

The natural active substances described in the above technical case are grape seed extract, rosemary extract, β-carotene, lycopene, shikonin, ferulic acid, tea polyphenols, propolis flavonol, menthol , black pepper resin, tea tree oil, bergamot oil, ginger oil, horseradish oil, turmeric oil, shallot oil, chamomile oil, fennel oil, onion oil and garlic oil, any one or a mixture of several.

In the above technical case, the mass ratio of hydrogen peroxide to β-cyclodextrin is 1:(5~500).

In the above technical case, the ratio of the natural active substance to the carboxylated β-cyclodextrin is 1:(1~500) by dry weight.

In the above technical case, the ratio of the embedded carboxylated β-cyclodextrin to gelatin is 1:(1~1000) by dry weight.

Compared with the prior art, the present invention has various positive effects and advantages, which can be summarized as follows:

(1) The functional gelatin food packaging film provided by the present invention, its basic raw material is a natural material, has no toxic and side effects, and is an edible packaging film;

(2) The functional gelatin food packaging film provided by the present invention uses β-cyclodextrin oxidized with hydrogen peroxide to obtain carboxylated β-cyclodextrin, which can improve the water solubility of β-cyclodextrin and broaden its application scope;

(3) The functional gelatin food packaging film provided by the present invention, through the embedding effect of carboxylated β-cyclodextrin, not only can protect the natural active substances from the interference of the external environment, but also improve its physical and chemical stability, and fully exert its application. Some properties can also improve the solubility of natural active substances and expand their application range;

(4) The functional gelatin food packaging film provided by the present invention can play a controlled release effect on the embedded natural active substance, so that it can be released slowly for a long time and achieve a long-term effect;

(5) The functional gelatin food packaging film provided by the present invention uses gelatin as the main raw material to compound carboxylated β-cyclodextrin and natural active substances, and adds glycerin and dialdehyde carboxymethyl cellulose to obtain a food packaging film with good Excellent thermal stability, barrier and mechanical properties;

(6) In the functional gelatin food packaging film provided by the present invention, the natural active substance embedded in carboxylated β-cyclodextrin has the effects of antibacterial, anti-oxidation and health care, and the packaging film can reduce the growth of food bacteria and avoid food contamination. Secondary pollution, prolonging the shelf life of food;

(7) The functional gelatin food packaging film provided by the present invention has good biocompatibility and degradability, can well replace petroleum-based plastic films, and the waste will not cause environmental pollution;

(8) The functional gelatin food packaging film provided by the present invention has a wide range of raw material sources, low cost, simple and easy film manufacturing process, potential economic benefits, and is conducive to wide application.

Specific implementation method

Three embodiments of the present invention are given below, and the present invention will be described in detail through the embodiments. It is necessary to point out here that embodiment is only used to further illustrate the present invention, can not be interpreted as the limitation of protection scope of the present invention, those skilled in the art can make some non-essential improvements according to the content of the present invention above and adjust.

In the following examples, unless otherwise specified, the parts involved are all parts by weight, and the percentages are all percentages by weight.

Example 1

While stirring, spray 4 parts of hydrogen peroxide into 80 parts of β-cyclodextrin, and drop 1 part of copper sulfate solution with a mass fraction of 0.02%, react at 40 ^o C for 5 minutes, and then react at 70 ^o C 15 minutes, then dissolve the reactant in boiling water at 100 ^o C and react for 30 minutes. After the solution drops to room temperature, centrifuge and precipitate the supernatant with absolute ethanol, wash the precipitate with 30% ethanol solution, and freeze the precipitate Dry to obtain carboxylated β-cyclodextrin; at 35 ^o C, dissolve 50 parts of carboxylated β-cyclodextrin in 20% ethanol solution while stirring and dissolving 25 parts of natural active substances in 15% ethanol solution Stir to dissolve in the medium, and add dropwise to the above carboxylated β-cyclodextrin solution, at 15 ^o C, after ultrasonication for 3 hours, stand at 4 ^o C for 12 hours, filter with suction and wash 3 times with 20% ethanol solution, Freeze-drying to obtain embedded carboxylated β-cyclodextrin embedding natural active substances; 10 parts of embedded carboxylated β-cyclodextrin and 1000 parts of gelatin solution with a mass fraction of 1% were blended and stirred evenly, Freeze at -20 ^o C for 36 hours, take it out and dissolve completely at 40 ^o C, add glycerin with 15% dry weight of gelatin to react for 30 minutes, then add dialdehyde carboxymethyl cellulose with 5% dry weight gelatin to react for 30 minutes , to obtain a matrix solution of functional gelatin food packaging film; pour the above matrix solution into a mold after defoaming, and dry in flowing air with a humidity of 30% at 50 ^o C for 3 days to obtain a functional gelatin food packaging film.

Example 2

While stirring, spray 1 part of hydrogen peroxide into 50 parts of β-cyclodextrin, and dropwise add 1 part of copper sulfate solution with a mass fraction of 0.3%, react at 40 ^o C for 8 minutes, and then react at 70 ^o C 30 minutes, then dissolve the reactant in boiling water at 100 ^o C and react for 30 minutes. After the solution drops to room temperature, centrifuge and precipitate the supernatant with absolute ethanol, wash the precipitate with 20% ethanol solution, and freeze the precipitate Dry to obtain carboxylated β-cyclodextrin; at 45 ^o C, dissolve 10 parts of carboxylated β-cyclodextrin in 10% ethanol solution while stirring and dissolving 1 part of natural active substance in 30% ethanol solution Stir to dissolve in the medium, and add dropwise to the above carboxylated β-cyclodextrin solution, at 10 ^o C, after ultrasonication for 2 hours, stand at 4 ^o C for 12 hours, then suction filter and wash 3 times with 10% ethanol solution , freeze-dried to obtain embedded carboxylated β-cyclodextrin embedding natural active substances; 5 parts of embedded carboxylated β-cyclodextrin and 2000 parts of gelatin solution with a mass fraction of 5% were blended and stirred evenly , freeze at -20 ^o C for 24 hours, take it out and dissolve it completely at 30 ^o C, add glycerin with 20% dry weight of gelatin to react for 10 minutes, then add dialdehyde carboxymethyl cellulose with 10% dry weight gelatin to react for 20 Minutes to obtain a functional gelatin food packaging film matrix solution; pour the above matrix solution into a mold after defoaming, and dry in flowing air with a humidity of 40% at 60 ^o C for 3 days to obtain a functional gelatin food packaging film.

Example 3

While stirring, spray 5 parts of hydrogen peroxide into 120 parts of β-cyclodextrin, and drop 1 part of copper sulfate solution with a mass fraction of 0.5%, react at 40 ^o C for 5 minutes, and then react at 70 ^o C 30 minutes, then dissolve the reactant in boiling water at 100 ^o C and react for 30 minutes. After the solution drops to room temperature, centrifuge and precipitate the supernatant with absolute ethanol, wash the precipitate with 30% ethanol solution, and freeze the precipitate Dry to obtain carboxylated β-cyclodextrin; at 35 ^o C, dissolve 25 parts of carboxylated β-cyclodextrin in 35% ethanol solution while stirring and dissolving 0.5 part of natural active substance in 25% ethanol solution Stir to dissolve in the medium, and add dropwise to the above carboxylated β-cyclodextrin solution, at 20 ^o C, after ultrasonication for 4 hours, stand at 4 ^o C for 12 hours, then suction filter and wash 3 times with 25% ethanol solution , freeze-dried to obtain embedded carboxylated β-cyclodextrin embedding natural active substances; 0.2 parts of embedded carboxylated β-cyclodextrin and 1000 parts of gelatin solution with a mass fraction of 2% were blended and stirred evenly , freeze at -20 ^o C for 48 hours, take it out and dissolve it completely at 45 ^o C, add glycerin with 15% dry weight of gelatin to react for 30 minutes, then add dialdehyde carboxymethyl cellulose with 3% dry weight gelatin to react for 15 Minutes to obtain a functional gelatin food packaging film matrix solution; pour the above matrix solution into a mold after defoaming, and dry in flowing air with a humidity of 25% at 40 ^o C for 3 days to obtain a functional gelatin food packaging film.

Claims (5)

1. A functional gelatin food packaging film, characterized in that the preparation method is as follows: (1) While stirring, spray hydrogen peroxide into β-cyclodextrin, and dropwise add copper sulfate solution with a mass fraction of 0.01-1%, react at 40 ^o C for 3-10 minutes, and then place it at 70 ^o C React for 5-30 minutes, then dissolve the reactant in boiling water at 100 ^o C and react for 30 minutes. After the solution drops to room temperature, centrifuge and precipitate the supernatant with absolute ethanol, and wash with 10-40% ethanol solution After precipitation, freeze-dry the precipitate to obtain carboxylated β-cyclodextrin; (2) At 30~60 ^o C, stir and dissolve carboxylated β-cyclodextrin in 10~50% ethanol solution, and at the same time, stir and dissolve natural active substances in 0~30% ethanol solution, and add dropwise into the above carboxylated β-cyclodextrin solution, ultrasonicated at 10-30 ^o C for 2-6 hours, then stood at 4 ^o C for 12 hours, then suction filtered and washed 3 times with 10-40% ethanol solution, Freeze-dry the filter cake to obtain embedded carboxylated β-cyclodextrin embedded with natural active substances; (3) Blend and stir the embedded carboxylated β-cyclodextrin and gelatin solution evenly, freeze at -20 ^o C for 12~72 hours, take it out and dissolve completely at 30~50 ^o C, add gelatin dry weight 5~ After reacting 30% glycerin for 10-40 minutes, add dialdehyde carboxymethyl cellulose with 0.1-10% dry weight of gelatin and react for 10-40 minutes to obtain a functional gelatin food packaging film matrix solution; (4) After defoaming the above matrix solution, pour it into a mold, and dry it in flowing air with a humidity of 10-50% at 20-60 ^o C for 1-5 days to obtain a functional gelatin food packaging film. 2. The functional gelatin food packaging film according to claim 1, characterized in that said natural active substances are grape seed extract, rosemary extract, β-carotene, lycopene, shikonin, a Ferulic Acid, Tea Polyphenols, Propolis Flavonols, Menthol, Black Pepper Resin, Tea Tree Oil, Bergamot Oil, Ginger Oil, Horseradish Oil, Turmeric Oil, Chive Oil, Chamomile Oil, Fennel Oil, Onion Oil and Garlic Oil any one or a mixture of several. 3. The functional gelatin food packaging film according to claim 1, characterized in that the mass ratio of hydrogen peroxide and β-cyclodextrin is 1:(5～500). 4. The functional gelatin food packaging film according to claim 1, characterized in that the ratio of natural active substance and carboxylated β-cyclodextrin is 1:(1～500) by dry weight. 5. The functional gelatin food packaging film according to claim 1, characterized in that the ratio of embedded carboxylated β-cyclodextrin to gelatin is 1:(1～1000) by dry weight.