CN113736119B

CN113736119B - Preparation method and application of biodegradable antioxidant fruit and vegetable preservative film

Info

Publication number: CN113736119B
Application number: CN202111230588.6A
Authority: CN
Inventors: 张彩丽; 杨璠; 翁云宣; 赵敏
Original assignee: Beijing Technology and Business University
Current assignee: Beijing Technology and Business University
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2022-04-15
Anticipated expiration: 2041-10-22
Also published as: CN113736119A

Abstract

The invention discloses a preparation method and application of a biodegradable antioxidant fruit and vegetable preservative film, belonging to the field of biodegradable food film processing. The preparation method of the fruit and vegetable preservative film comprises the following steps: mixing starch, glycerol, organic modified montmorillonite and quercetin to obtain modified powder, mixing the modified powder and PBAT for granulation to obtain composite granules, and then performing blow molding to obtain the biodegradable antioxidant fruit and vegetable preservative film. The fruit and vegetable preservative film prepared by the method takes PBAT and starch as base materials, all the raw materials are biodegradable materials, and the waste materials can be treated in modes of composting, soil landfill and the like, so that the fruit and vegetable preservative film is green and environment-friendly, accords with the concept of sustainable development, and has the advantages of strong mechanical property, high barrier property, good oxidation resistance, good preservation performance, greenness, environmental protection and no toxicity.

Description

Preparation method and application of biodegradable antioxidant fruit and vegetable preservative film

Technical Field

The invention relates to a preparation method and application of a biodegradable antioxidant fruit and vegetable preservative film, belonging to the field of biodegradable food film processing.

Background

The harvested fruits and vegetables still have vigorous physiological activities, the temperature of the storage environment of the fruits and vegetables is increased along with respiration, so that the surfaces of the fruits and vegetables are wilted, the quality of the fruits and vegetables is reduced, and the fresh fruits and vegetables are further promoted to ripen and age along with the ripened ethylene of the fruits and vegetables.

The fruit and vegetable preservative film is a functional film, the oxygen concentration is reduced to the maximum extent mainly by means of the air permeability of the film, the respiration consumption is inhibited, the fruit and vegetable aging is delayed, the traditional functional preservative film can play a role in packaging, but the preservative requirements of the modern market can not be met obviously, in the existing research, in order to achieve the purpose of better preservation, substances capable of absorbing or inhibiting various gases generated by fruits and vegetables are usually added in the preparation process of the preservative film to prevent the ripening and aging effects, such as travertine, zeolite, quartz stone, a moisture absorbent calcium chloride and the like, but the mechanical performance of the preservative film can be reduced by adding granular substances; in addition, in order to prevent food oxidation and microbial contamination, some antibacterial agents and antioxidants are added into the film, however, conventionally used synthetic antioxidants (such as tert-butyl hydroquinone, butyl hydroxy toluene, butyl hydroxy anisol and propyl gallate) and antibacterial agents (such as sorbic acid, benzoic acid and sodium benzoate) have toxicity, carcinogenicity and mutagenicity, and the film can penetrate into the fruits and vegetables after being coated on the surface layers of the fruits and vegetables for a long time, so that certain influence is caused on the health of human bodies; with the enhancement of environmental awareness, research has led to the development of degradable fruit and vegetable films, wherein starch (St) is a renewable and completely biodegradable product, which is rich in source, low in cost, but low in elongation at break, so that in the prior art, starch and thermoplastic degradable plastic (especially, a copolymer of butylene adipate and butylene terephthalate, PBAT) are usually compounded to prepare a starch/PBAT composite material by utilizing the characteristics of good ductility and elongation at break of PBAT, good film forming property and the like.

In conclusion, in order to meet the needs of social and economic development, the novel packaging film which is safe and environment-friendly is significant.

Disclosure of Invention

In order to solve the technical problems, the invention provides a preparation method and application of a biodegradable antioxidant fruit and vegetable preservative film.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a preparation method of a biodegradable antioxidant fruit and vegetable preservative film, which comprises the following steps: mixing starch (St), glycerol, Organic Modified Montmorillonite (OMMT) and Quercetin (QUE) for 5min according to a certain proportion to obtain modified powder, mixing the modified powder and PBAT for granulation to obtain composite granules, and then performing blow molding to obtain the biodegradable antioxidant fruit and vegetable preservative film.

Further, the modified powder raw materials comprise, by mass, 100 parts of starch (St), 35 parts of glycerol, 5-20 parts of Organic Modified Montmorillonite (OMMT) and 0.1-1 part of Quercetin (QUE).

Further, the mass ratio of the modified powder to the PBAT is 4: 6.

Further, the temperature of the mixing granulation was 100-140 ℃ and the temperatures from the feeding zone to the head zone by the twin-screw extruder were 110, 120, 130, 140, 120 and 100 ℃ respectively.

Further, the temperature of the blow molding is 110-.

The invention also provides the biodegradable antioxidant fruit and vegetable preservative film prepared by the preparation method.

The invention also provides application of the biodegradable antioxidant fruit and vegetable preservative film in fruit and vegetable packaging.

The invention discloses the following technical effects:

1) the glycerol belongs to a natural organic matter derived from renewable resources, contains 3 hydroxyl groups, has strong hydrogen bonding effect with hydroxyl on the surface of the starch, and enables the starch to have thermoplastic processing performance after being added.

2) Quercetin (QUE) is widely present in fruits and vegetables, is a natural flavonoid, has no toxic action on human bodies, is cheap and easily available, and is insoluble in water, so that the slow release effect of the quercetin in the packaging process can be enhanced by containing hydrophilic glycerol, so that the antibacterial and antioxidant properties of the preservative film are enhanced, and the shelf life of fruits and vegetables is effectively prolonged.

3) The Organic Modified Montmorillonite (OMMT) is an inorganic sheet material, and the structural units of the material mainly comprise Si-O tetrahedrons arranged in a two-dimensional orientation mode and Al-O-OH octahedrons arranged in a two-dimensional orientation mode, so that the material plays a role in enhancing the preservative film in the two-dimensional direction, the mechanical property of the preservative film can be effectively enhanced only by adding a small amount of organic modified montmorillonite in the preparation process of the preservative film, meanwhile, the path of gas passing through the film can be prolonged, and the barrier property of the film is improved.

4) In the preparation process, the hydrogen bonds are fully formed between the glycerol and the starch by stronger shearing force and controlling and keeping a certain temperature, so that the proportion of the hydrogen bonds between the starch molecules and the hydrogen bonds in the starch molecules is reduced, and the starch obtains the optimal plasticizing effect. The forming method adopted by the invention can uniformly mix the materials, is easy to blow films, can realize batch production and has high production efficiency.

5) The matrix materials of the fruit and vegetable preservative film are PBAT and starch, all production raw materials of the preservative film are biodegradable materials, and the preservative film can be treated in composting, soil landfill and other modes after being discarded, is green and environment-friendly, accords with the concept of sustainable development, has simple preparation process, easily obtained raw materials, is harmless to human bodies, and has positive significance for the development of biodegradable films to high performance, multiple functions, easy forming and processing and low cost.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is an X-ray diffraction pattern of the fruit and vegetable preservative films prepared in examples 1-4 and comparative examples 1-2 and raw material OMMT;

FIG. 2 is a comparison of the visual characterization of mangoes in different packaging states;

FIG. 3 is a comparison of visual representations of bananas in different packaging states.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The starch (St), glycerol, Organic Modified Montmorillonite (OMMT) and Quercetin (QUE) are all purchased.

The technical solution of the present invention is further illustrated by the following examples.

Example 1

Weighing 100 parts of starch (St), 35 parts of glycerol, 5 parts of Organic Modified Montmorillonite (OMMT) and 1 part of Quercetin (QUE) according to parts by weight, and mixing in a high-speed mixer for 5min to obtain modified powder; mixing the modified powder and PBAT according to a mass ratio of 4:6, and then carrying out twin-screw melt extrusion granulation, wherein the temperatures from the feeding area to the head area by using a twin-screw extruder are respectively 110, 120, 130, 140, 120 and 100 ℃. Then extruding and blow molding at 140 ℃ by using a film blowing machine to obtain the biodegradable antioxidant fruit and vegetable preservative film which is marked as OMMT-5%.

Example 2

Weighing 100 parts of starch (St), 35 parts of glycerol, 10 parts of Organic Modified Montmorillonite (OMMT) and 1 part of Quercetin (QUE) according to parts by weight, and mixing in a high-speed mixer for 5min to obtain modified powder; mixing the modified powder and PBAT according to a mass ratio of 4:6, and then carrying out double-screw melt extrusion granulation, wherein the temperature of each section of the double-screw extruder is 140 ℃. Then extruding and blow molding at 110 ℃ by using a film blowing machine to obtain the biodegradable antioxidant fruit and vegetable preservative film which is marked as OMMT-10%.

Example 3

Weighing 100 parts of starch (St), 35 parts of glycerol, 15 parts of Organic Modified Montmorillonite (OMMT) and 1 part of Quercetin (QUE) according to parts by weight, and mixing in a high-speed mixer for 5min to obtain modified powder; mixing the modified powder and PBAT according to a mass ratio of 4:6, mixing the materials according to the proportion, and then carrying out double-screw melt extrusion granulation, wherein the temperature of each section of a double-screw extruder is 120 ℃. Then extruding and blow molding at 120 ℃ by using a film blowing machine to obtain the biodegradable antioxidant fruit and vegetable preservative film which is marked as OMMT-15%.

Example 4

Weighing 100 parts of starch (St), 35 parts of glycerol, 20 parts of Organic Modified Montmorillonite (OMMT) and 1 part of Quercetin (QUE) according to parts by weight, and mixing in a high-speed mixer for 5min to obtain modified powder; mixing the modified powder and PBAT according to a mass ratio of 4:6, mixing the materials according to the proportion of 6, and then carrying out double-screw melt extrusion granulation, wherein the temperature of each section of a double-screw extruder is 130 ℃. Then extruding and blow molding at 140 ℃ by using a film blowing machine to obtain the biodegradable antioxidant fruit and vegetable preservative film which is marked as OMMT-20%.

Example 5

Weighing 100 parts of starch (St), 35 parts of glycerol, 15 parts of Organic Modified Montmorillonite (OMMT) and 0.1 part of Quercetin (QUE) according to parts by weight, and mixing in a high-speed mixer for 5min to obtain modified powder; mixing the modified powder and PBAT according to a mass ratio of 4:6, mixing the materials according to the proportion, and then carrying out double-screw melt extrusion granulation, wherein the temperature of each section of a double-screw extruder is 100 ℃. Then extruding and blow molding at 120 ℃ by using a film blowing machine to obtain the biodegradable antioxidant fruit and vegetable preservative film.

Comparative example 1

The difference is that the antioxidant fruit and vegetable preservative film prepared by the comparative example is marked as starch/PBAT without adding Organic Modified Montmorillonite (OMMT) and Quercetin (QUE).

Comparative example 2

The difference is that the antioxidant fruit and vegetable preservative film prepared by the comparative example is marked as starch/PBAT/QUE without adding Organic Modified Montmorillonite (OMMT).

Comparative example 3

The only difference from example 1 is that Quercetin (QUE) was not added.

Comparative example 4

The difference from example 1 is only that the modified powder and PBAT are mixed in a mass ratio of 5: and 5, mixing.

Comparative example 5

The only difference from example 1 is that no glycerol is added. The preservative film can not be processed into a film without adding glycerin, and the starch has no processability, so that the preservative film for fruits and vegetables can not be obtained.

Comparative example 6

Pure PBAT films.

The X-ray diffraction patterns obtained by irradiating the fruit and vegetable preservative films prepared in examples 1-4 and comparative examples 1-2 and the raw material OMMT with X-rays are shown in figure 1, and it can be seen from figure 1 that when montmorillonite accounts for 20 parts of the powder content in example 4, a peak appears at 4.89 degrees 2 theta. The stripping of the montmorillonite is incomplete, and part of the non-stripped montmorillonite is gathered in the matrix membrane material, so the addition amount of the montmorillonite in the embodiment is not more than 20 parts. In addition, in comparative example 4, when the modified powder and PBAT were mixed in a mass ratio of 5: 5 when the components are mixed, the prepared film has poor mechanical property and cannot well meet the actual use requirement. The addition amount of the quercetin is controlled to be 0.1-1 part, and when the addition amount is less than 0.1 part, the antioxidant fresh-keeping effect of the composite film is poor; above 1 part, the cost of the composite membrane will increase, and under the condition of satisfying the use requirement, it is not recommended to continuously increase the part of quercetin.

Performance testing

The mechanical performance test of the fruit and vegetable preservative films prepared in the examples 1-5 and the comparative examples 1-6 is carried out according to GB/T10004-2008, and the test results are shown in Table 1.

Table 1 results of mechanical property test of fruit and vegetable preservative film prepared in examples and comparative examples

O content of the fruit and vegetable wrap films prepared in examples 1 to 5 and comparative examples 1 to 7 was measured by a VAC-V2 pressure differential gas permeameter₂、N₂And CO₂The results of the transmittance are shown in Table 2.

TABLE 2O of fruit and vegetable preservative films prepared in examples and comparative examples₂、N₂And CO₂Transmission coefficient

As can be seen from tables 1 and 2, the OMMT and QUE added starch/PBAT films prepared by the examples of the invention have excellent mechanical properties, barrier properties, freshness retaining properties and processability. Which has comparable mechanical properties to pure PBAT films. Compared with pure starch/PBAT films, the starch/PBAT film added with OMMT and QUE has higher barrier property and fresh-keeping property, the raw materials used by the film prepared by the invention can be biodegraded, and the film has the characteristics of environmental protection and no toxicity, and has positive significance for the development of biodegradable films to high performance, multiple functions, easy forming and processing and low cost.

Mango and banana were packaged and kept fresh with different wrap films (PE film, wrap film PBAT/starch prepared in comparative example 1, wrap film OMMT-5% prepared in example 1 and wrap film OMMT-20% prepared in example 4), and no package was set as a control, the visual characterization contrast graphs for 0, 3 and 6 days are shown in fig. 2 and 3, the unpackaged fruits showed significant black spots around 3 days, and the discoloration was severe after 6 days. The preservative films prepared by the embodiments 1 and 4 of the invention have the effect of obviously prolonging the preservation period of fruits, and the effect is superior to that of the traditional PE preservative film. The preservative film has the advantages that the preservative film has a respiration regulation effect, and the respiration of fruits and vegetables is reduced, so that the effect of effectively prolonging the service life of the fruits is achieved.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims

1. A preparation method of a biodegradable antioxidant fruit and vegetable preservative film is characterized by comprising the following steps: mixing starch, glycerol, organic modified montmorillonite and quercetin to obtain modified powder, mixing the modified powder and PBAT for granulation to obtain composite granules, and then performing blow molding to obtain the biodegradable antioxidant fruit and vegetable preservative film;

the modified powder raw materials comprise, by mass, 100 parts of starch, 30-40 parts of glycerol, 5-20 parts of organically modified montmorillonite and 0.1-1 part of quercetin;

the mass ratio of the modified powder to the PBAT is 4: 6.

2. The method as claimed in claim 1, wherein the temperature of the mixing granulation is 100-140 ℃.

3. The method as claimed in claim 1, wherein the blow molding temperature is 110-140 ℃.

4. A biodegradable antioxidant fruit and vegetable preservative film prepared by the preparation method of any one of claims 1 to 3.

5. The biodegradable antioxidant fruit and vegetable preservative film as claimed in claim 4, which is applied to fruit and vegetable packaging.