KR101317468B1 - Edible packing film for preserving fruit or vegetable for long time and a production method thereof - Google Patents

Abstract

The present invention relates to an edible packaging film for long-term storage of fruits or vegetables and a method of manufacturing the same. The edible film for maintaining the functional freshness of the fruit or vegetable according to the present invention is very excellent in tensile strength, elongation and moisture permeability, and the fruit or vegetable packaged with the film is excellent in inhibiting the growth of microorganisms during storage. The microbiological stability of vegetables can be ensured, and the quality of fruits or vegetables, including strawberries, can be maintained during storage, and thus can be usefully used for packaging fruits or vegetables having a long storage period.

Description

Edible packing film for preserving fruit or vegetable for long time and a production method

The present invention relates to an edible packaging film for long-term storage of fruits or vegetables and a method of manufacturing the same.

Recently, as environmental problems arise, interest in environmentally friendly food packaging materials using biodegradable polymer materials as plastic films is increasing. In particular, the edible film is easily decomposed and edible than a plastic composite film made of a conventional polymer material, and thus has an advantage of reducing environmental pollution problems caused by conventional plastic food packaging materials. In addition, the edible film functions to coat the food surface or to be used inside the food to protect the food from external shocks and increase the shelf life of the food and at the same time prevent the movement of moisture, gases and solutes. Furthermore, the edible film not only decomposes more easily than conventional polymer materials, but also adds components such as flavors, pigments, and sweeteners to the packaging material to impart organoleptic properties to the contents, and individually for practical reasons such as strawberries. It has the advantage of individually packaging products that cannot be packaged. Interesting among these edible films are protein films based on gelatin, corn zein, wheat gluten, soy protein, collagen and casein. Of these, relatively inexpensive grain proteins are widely used in edible films (Yang Sung-bum et al., KOREAN J. FOOD SCI. TECHNOL., 1997, 29 (3), 452-459).

Berries, such as fennel and snowflake, produced in Korea, are increasing in exports to Japan and Southeast Asia, and are usually harvested when the color of the skin is about 60-70%. It takes into account the expected shelf life and the maturity at which the coloring takes place before being transported to the exporting country and delivered to the consumer. However, strawberries are susceptible to decay due to contamination by harmful microbial growth during harvesting, storage and flow after harvesting, and due to physical damage and swallowing of tissues, the degree of surface receding, active respiration and excessive proliferation It is difficult to maintain short shelf life and freshness due to deterioration of appearance quality such as weight loss, softening of fruit, discoloration and discoloration due to overheating. Therefore, there is a great deal of difficulty and expense in keeping strawberries fresh after harvest until they are consumed by the consumer. In particular, the export berries are urgently needed to develop management technology to increase the quality and shelf life of strawberries, which are generally distributed and sold in Korea due to transport and transportation to the exporting country. There is a need to develop a storage technology that can last for more than five days. Therefore, researches on MA storage, heat treatment, and chemical treatment have been conducted to improve storage properties in addition to low temperature storage for maintaining freshness of strawberries (Kim, et al., Korean J. food preserv., 2010, 17 (2), 196- 201).

Conventionally known packaging technology is disclosed in Republic of Korea Patent No. 20-325130 discloses a functional leading maintenance packaging film for long-term storage of vegetables and fruits by mixing antimicrobial compounds and anti-application compounds in polyethylene resin. In addition, Korean Patent Laid-Open Publication No. 1999-078592 discloses a functional packaging film having both antimicrobial activity, respiratory control, and further biodegradability in a polymer material. However, the film still has a problem of causing environmental pollution as a polymer film, a plastic film capable of maintaining a fresh lead in the long-term storage of fruits or vegetables using chaejong protein has not been developed.

Accordingly, the inventors of the present invention to solve the above problems, and to develop a edible film packaging material of fruits or vegetables that are difficult to store for a long time, such as strawberries, to produce an edible packaging film containing vegetable protein, including a strawberry After pretreatment to the fruit or vegetable, the present invention was completed by confirming that the freshness of the fruit or vegetable is maintained by packaging with an edible packaging film made of the vegetable protein.

It is an object of the present invention to provide an edible packaging film for long term storage of fruits or vegetables.

It is another object of the present invention to provide a method for producing an edible packaging film for long term storage of fruits or vegetables.

Another object of the present invention to provide a packaging method for long-term storage of fruits or vegetables using the decorative packaging film.

To achieve the above object,

The present invention provides an edible packaging film for long-term storage of fruits or vegetables comprising vegetable protein extracted from any one selected from the group consisting of rapeseed gourd, rice bran, barley and red algae.

In addition, the present invention comprises the steps of preparing a film solution by dissolving vegetable protein, plasticizer and sugar in distilled water (step 1); And

After heating the film solution prepared in step 1, and then divided into modules to a thickness of 50-60 ㎛ dried to prepare a decorative packaging film (step 2) decorating for long-term storage of the fruit or vegetable It provides a method for producing a sex packaging film.

Further, pretreatment washing the fruits or vegetables using fumaric acid, chlorine dioxide, organic acids or mixtures thereof as washing liquid (step 1); And

It provides a packaging method for long-term storage of fruit or vegetables comprising the step (step 2) of packaging the fruit or vegetable is removed from the water in step 1 with the decorative film and sealed with a heat adhesive.

The edible film for maintaining the functional freshness of the fruit or vegetable according to the present invention is very excellent in tensile strength, elongation and moisture permeability, and the fruit or vegetable packaged with the film is excellent in inhibiting the growth of microorganisms during storage. The microbial stability of the vegetables can be secured, and the fruit or vegetable quality, including strawberries, can be maintained during storage, which can be useful for packaging fruits or vegetables having a long shelf life. Furthermore, there is an advantage that the production cost can be lowered during film production by using chaejongchae squeezed oil remaining from the rapeseed used in the present invention.

1 is a view showing a strawberry packed with an edible film according to the present invention.

Hereinafter, the present invention will be described in detail.

The present invention provides an edible packaging film for long-term storage of fruits or vegetables comprising vegetable protein extracted from any one selected from the group consisting of rapeseed gourd, rice bran, barley and red algae.

Preferably, the vegetable protein may be a water-soluble protein extracted from chaejongbak.

The decorative packaging film according to the present invention can be used to package strawberries in fruits or vegetables.

In addition,

Dissolving the plant protein, plasticizer and sugar in distilled water to prepare a film solution (step 1); And

After heating the film solution prepared in step 1, and then divided into modules to a thickness of 50-60 ㎛ dried to prepare a decorative packaging film (step 2) decorating for long-term storage of the fruit or vegetable It provides a method for producing a sex packaging film.

The vegetable protein of step 1 may be one extracted from any one selected from the group consisting of rapeseed gourd, rice bran gourd, loaves and red algae, and preferably, the vegetable protein extracted from rapeseed gourd may be used.

The vegetable protein may be extracted by mixing any one selected from the group consisting of rapeseed gourd, rice bran gourd, loaves and red algae with distilled water, pulverizing and stirring at room temperature.

The vegetable protein of step 1 of the present invention may be used at 3-5% by weight based on the total weight, preferably 4.0-4.5% by weight based on the total weight.

If it is outside the above range, there is a problem that the film is not formed because the amount of protein that is the base material of the edible film is less than 3% by weight, and when the amount is greater than 5% by weight the film is formed When the film is formed because the protein is not evenly dispersed in the solution there is a problem that the physical properties of the film is not constant.

In addition, the plasticizer of step 1 according to the present invention may be used sorbitol, mannitol, xylitol, glycerol or a mixture thereof, preferably sorbitol.

At this time, the plasticizer of step 1 may be added at 1.5-2.5% by weight based on the total weight.

If it is out of the range, if less than 1.5% by weight of the amount of plasticizer to help the formation of the film is too small, there is a problem that the film is not formed, if it exceeds 2.5% by weight the problem of decreasing the tensile strength of the film have.

Furthermore, the sugar of step 1 may be added at 0.4-0.6% by weight based on the total weight.

If it is out of the above range, if less than 0.4% by weight of a small amount of sugar, which is one kind of plasticizer, there is a problem that the film is not formed, if the weight of more than 0.6% by weight due to the characteristics of the sugar as the sugar increases There is a problem in that the formation of the film is not properly broken.

Step 2 is a step of preparing a decorative packaging film by heating the film solution prepared in step 1 after dispensing in a module to a thickness of 50-60 ㎛, the film solution prepared in step 1 is 85 It may be prepared by heating at −95 ° C. for 0.5-1 hour.

At this time, when the temperature for heating the film solution is out of the above range, when the temperature is less than 85 ℃, the material in the film-forming solution is not heated enough to not dissolve and evenly dispersed in the film-forming solution to dispense the film to the module and dried When there is a problem that the film is not formed properly, when the temperature is greater than 95 ℃ there is a problem that the components of the film-forming materials are modified due to the high temperature.

In addition, when the thickness of the film solution dispensed to the module is out of the above range, if the thickness is less than 50 ㎛, the film is not formed well due to the too thin thickness, there is a problem that the film is torn well, if the thickness is more than 60 ㎛ There is a problem that the physical properties of the film is reduced.

Specifically, 4% by weight of chaejongbak protein, 2% by weight of sorbitol as a plastic material, 0.5% by weight of sugar, 93.5% by weight of distilled water and heat-treated at 80-90 ℃ for 30 minutes to prepare a film solution, the film produced The solution may be dispensed into modules at a constant thickness of 50-60 μm and dried at room temperature to produce an edible film.

Tensile strength of the edible film prepared by the above method was found to be 6 times higher than that of the conventional soybean separation protein film, and the elongation was 8 times higher than that of the control group (Experimental Example 1). As a control, it was confirmed to be two times lower than the soybean protein film conventionally used (Experimental Example 2). Therefore, the edible film according to the present invention can be usefully used as an edible film for long-term storage of fruits or vegetables because it is very excellent in tensile strength, elongation and moisture permeability.

Further,

Pretreatment washing the fruit or vegetable using fumaric acid, chlorine dioxide, organic acid or mixtures thereof as washing liquid (step 1); And

It provides a packaging method for long-term storage of the fruit or vegetable comprising the step (step 2) of packaging the fruit or vegetable from which the water is removed in step 1 with the decorative film of the present invention and sealed with a heat adhesive.

Specifically, the washing solution of step 1 is preferably fumaric acid, it is preferable to use a dilution of the fumaric acid to 4-6%.

At this time, the fruit of step 1 is preferably strawberry.

The edible film of step 2 may be prepared according to the following steps:

Preparing a film solution by mixing vegetable protein, plasticizer, sugar, and distilled water (step 1); And

Dispersing the film solution prepared in step 1 to a module to prepare a decorative film (step 2) comprising the step of drying the decorative film.

Specifically, the packaging method of the fruit or vegetable according to the present invention, soaking the fruit or vegetable in water containing 4-6% of fumaric acid sufficiently soaked for 5-10 minutes, washed fruit or After the vegetables are passed through a cold air shower device in which cold air comes out, the water can be removed, and then packaged with a functional freshness-maintaining edible film prepared by the above method at a constant weight, and the edible film can be sealed with a heat adhesive.

The fruit or vegetable packaged by the above method has an excellent rate of increase in the total number of aerobic bacteria, yeast and mold compared to the control group (Experimental Example 3), and the packaging technology of the fruit or vegetable using the functional freshness-maintaining edible film according to the present invention. It is excellent in inhibiting the growth of microorganisms during storage, and can secure the microbiological stability of fruits or vegetables, so it is possible to increase the shelf life certainly and can be usefully used for packaging fruits or vegetables with a long storage period.

In particular, the strawberry packaged by the above method is not only excellent in the increase rate of the total aerobic bacteria, yeast and mold number compared to the control group (Experimental Example 3), but also the sensory test results, appearance, texture, flavor, overall preference of the strawberry during storage The sensory evaluation in all treatment groups showed a tendency to decrease with increasing storage period, but the strawberry packaged by the packaging technology using chaejong film edible film according to the present invention, excellent in all aspects compared to the control during storage It was confirmed that it appears (Experimental Example 4) Strawberry packaged using the edible film according to the present invention can be usefully used for packaging for long-term storage of strawberries because the quality of the strawberry is maintained during storage.

Hereinafter, the present invention will be described in detail with reference to Examples and Experimental Examples.

However, the following examples are illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

< Manufacturing example  1> Edibility  Basic material extraction of film

The following experiment was carried out to extract the chaejong protein, which is the basic material for preparing the edible film.

100 g of chaejongbak and 500 mL of distilled water were mixed at a ratio of 1: 5 (w / w), and then treated with an ultrasonic mill for 10 minutes, and then stirred at room temperature for 2 hours to extract a water-soluble jongjong protein. After stirring, centrifugation was carried out at 5000 rpm for 15 minutes to remove impurities, and the supernatant was taken and lyophilized to obtain 9 g of chaebol protein.

< Example  1> Edibility  Manufacture of film

Step 1: Preparation of Film Solution

4 g (4% (w / w)) of the chaebol protein obtained in Preparation Example 1, 2 g (2% (w / w)) of sorbitol as a plastic material, 0.5 g (0.5% (w / w)) of sugar 100 ml of distilled water, mixed and heat-treated at 90 ℃ for 30 minutes to prepare a film solution.

Step 2: Preparation of the Film

The film solution prepared in step 1 was dispensed in a module with a constant thickness of 50-60 μm and dried at room temperature to prepare an edible film.

< Experimental Example  1> Edibility  Measurement of film properties

In order to measure the physical properties of the chaejongbak edible film prepared in Example 1 was measured the tensile strength and elongation. As a control film, a conventionally known soybean separation protein film was used.

After cutting the edible film for 24 hours in a thermo-hygrostat adjusted to a temperature of 25 and a relative humidity of 50% to adjust the moisture content of the film, Instron (Model 1101) according to ASTM D882-90 standard test method , Instron Engineering Corp ,. USA) was used to measure the tensile strength and elongation of the film. At this time, the difference between the initial grip (grip) for the Instron measurement was adjusted to 50 mm, crosshead speed to 500 mm / min. Tensile strength and elongation were calculated using the following equations (1) and (2). The results are shown in Table 1 below.

At this time,

A = average cross-sectional area of the film

F = the greatest force acted until the film is cut

ΔL = distance between grips moved until the film is cut

L = distance between the grips

Tensile Strength (MPa) Elongation (%) Example 1 20.71 53.38 Control group 3.25 6.1

As shown in Table 1, the tensile strength of the chaejongbak edible film according to the present invention was found to be 6 times higher than the conventional soybean separation protein film used as a control, it was confirmed that the elongation is 9 times higher than the control group. .

Therefore, the chaejongbak edible film according to the present invention is very excellent in tensile strength and elongation rate can be usefully used as an edible film for long-term storage of fruits or vegetables.

< Experimental Example  2> Edibility  Film Moisture permeability  Measure

In order to measure the moisture permeability of the chaejongbak edible film prepared in Example 1 was performed the following experiment. As a control film, a conventionally known soybean separation protein film was used.

The moisture permeability was measured in the same manner as in the tensile strength measurement, and the edible film cut was left for 24 hours in a constant temperature and humidity chamber of 25 controlled to 50% relative humidity to adjust the moisture content of the film, followed by ASTM E96-90 standard test method. According to the cup method (cup method) to measure the moisture permeability, the moisture permeability was calculated.

Moisture permeability and water vapor permeability were calculated using the following equations (3) and (4). The results are shown in Table 2 below.

Slope = cup weight over time

Film area = area of film where moisture transfer is taking place

L = average thickness of the film

Δp = difference in the partial pressure of water vapor inside and outside the cup

Moisture permeability (ng m / m ² sPa) Example 1 2.64 Control group 6.91

As shown in Table 2, the moisture permeability of the chaejongbak edible film according to the present invention was confirmed to have an effect of more than two times lower than the soybean separation protein film conventionally used as a control.

Therefore, the chaejongbak edible film according to the present invention is excellent in moisture permeability can be usefully used as an edible film for long-term storage of fruits or vegetables.

< Example  2> Edibility  Strawberry Packaging With Film

Step 1: wash the strawberries

Fumaric acid at a concentration of 0.5% was prepared in order to pre-clean the strawberries before packaging the strawberries using the edible film prepared in Example 1. After soaking the strawberry in fumaric acid for 5 minutes to reduce the harmful microorganisms present on the surface of the strawberry, the washed strawberry was drained through a cold air shower device with cold air.

Step 2: Strawberry Packaging

The dried strawberry in step 1 was packaged with the edible film prepared in Example 1 at a weight of 250-300 g and the edible film was sealed with a heat adhesive.

< Experimental Example  3> Determination of aerobic bacteria count of stored strawberries

The following experiment was performed to analyze the quality change of the packaged strawberry in Preparation Example 2. As a control, strawberries were packaged in a PET box without pretreatment and used.

The strawberry sample packaged in Preparation Example 2 was stored for 14 days, and then, 3, 7, 10, 12, and 14 days were collected with strawberry sterilized mass (scalpel) and placed in a sterile bag for 3 minutes. 2, AES Laboratoire, France). Homogenized samples were filtered using sterile gauze, 10-fold serial dilution with 0.1% sterile peptone water, then aliquoted into each medium and repeated three times per sample. Total aerobic bacteria were incubated for 37 to 3 days using plate count agar (PCA, Difco Co.), and yeast and mold were cultured for 25 to 5 days using potato agar medium (PDA, Difco Co.). Thereafter, colonies formed were counted. The number of microorganisms detected is expressed in colony forming units (CFU) per gram of sample. The results are shown in Tables 3 and 4 below.

Total aerobic Number of bacteria Storage period (days) Example 2
(Log CFU / g) Control group
(Log CFU / g) 0 1.30 2.86 3 1.36 3.08 7 1.50 3.19 10 1.67 3.2 12 1.79 3.57 14 1.89 3.69

Yeast and Mold Can Storage period (days) Example 2
(Log CFU / g) Control group
(Log CFU / g) 0 1.00 2.59 3 1.56 2.80 7 1.63 2.93 10 1.67 3.10 12 1.86 3.26 14 1.99 3.72

As shown in Tables 3 and 4 above, in the case of strawberries pretreated with fumaric acid and packaged using the chaebol edible film prepared in Example 1 (Example 2), the total aerobic bacterial count was 1.30 Log CFU for 14 days. / g increased from 1.89 Log CFU / g to 0.59 Log CFU / g, while the aerobic number of the untreated control group increased from 2.89 Log CFU / g to 3.69 Log CFU / g to 0.8 Log CFU / g, with initial aerobic bacteria Comparing the number of aerobic bacteria during storage for 14 days with the control group was confirmed that the number of aerobic bacteria than the strawberry of Example 2 was shown that the strawberry of Example 2 according to the present invention is more than 10 times excellent in inhibiting aerobic bacteria.

In addition, in Example 2 according to the present invention, the number of yeasts and molds increased 0.99 Log CFU / g from 1.00 Log CFU / g to 1.99 Log CFU / g, whereas the number of yeasts and molds of the control group was 2.59 Log CFU / It was confirmed that the strawberry of Example 2 according to the present invention increased about 1.13 Log CFU / g from 3.72 Log CFU / g to about 10 times superior to yeast and mold.

Therefore, the packaging technology of strawberries using chaejongbak edible film according to the present invention is excellent in inhibiting the growth of microorganisms during storage, so it is possible to ensure the microbiological stability of fruits or vegetables, including strawberries to increase the storage period certainly It can be useful for packaging fruits or vegetables, including strawberries for long exports.

< Experimental Example  4> Sensory test

Sensitivity to the appearance, texture, flavor and overall acceptability of the sample by 10 panelists trained to analyze the quality change during storage of the packaged strawberries in Example 2 The test was performed. At this time, the rating for each sample was 9-point symbol scale method (9-8 points: very good, 7-6: good, 5-4: normal, 3-2: bad, 1: very bad) according to the selected criteria. Evaluated. The results are shown in Table 5 below.

storage duration
(Work)
Appearance

Texture
incense
Overall preference Example 2 Control group Example 2 Control group Example 2 Control group Example 2 Control group
0
9.00

9.00
9.00
9.00
9.00
9.00
9.00
9.00
3
8.56

8.25
8.38
8.00
8.63
8.63
8.50
8.13
7
7.75

7.00
7.75
7.13
7.75
7.63
7.88
7.00
10
7.00

6.25
6.75
6.13
7.38
7.25
7.00
6.31
12
5.63

4.88
6.00
5.25
6.94
6.75
5.69
4.94
14
4.75

3.94
5.13
4.38
5.88
5.50
4.81
3.94

As shown in Table 5, as a result of sensory evaluation of strawberries during storage, appearance, texture, flavor, and overall preference showed that the sensory evaluation was lowered in all treatment groups with increasing storage period, but according to the present invention Strawberries packaged by the packaging technology using the edible film was found to appear better in all aspects than the control during storage.

Therefore, the packaging technology of the strawberry using the chaejongbak edible film according to the present invention can be usefully used for fruit or vegetable packaging, including strawberries for long exports because the quality of the strawberry is maintained during storage.

Claims (15)

Edible packaging film for long-term storage of fruits or vegetables containing a vegetable protein extracted from any one selected from the group consisting of chaejongbak, rice bran, barley, and red algae.
The edible packaging film of claim 1, wherein the vegetable protein is rapeseed.
The edible packaging film of claim 1, wherein the fruit is a strawberry.
Dissolving the plant protein, plasticizer and sugar in distilled water to prepare a film solution (step 1); And
Long-term storage of the fruit or vegetable of claim 1 prepared by the step (step 2) of preparing a decorative packaging film by heating the film solution prepared in step 1 to a thickness of 50-60 ㎛ after drying the module Method for producing a decorative packaging film for use.
The method of claim 4, wherein the vegetable protein of step 1 is extracted from any one selected from the group consisting of rapeseed gourds, rice bran gourds, loaves and red algae.
The method of claim 5, wherein the vegetable protein of step 1 is extracted from rapeseed gourd.
The method of claim 4, wherein the vegetable protein is a water-soluble protein which is extracted by mixing any one selected from the group consisting of rapeseed gourd, rice bran gourd, loaves and red algae with distilled water, pulverized and stirred at room temperature. Method for producing a decorative packaging film.
The method of claim 4, wherein the protein extracted from the plant of step 1 is added in an amount of 3-5% by weight based on the total weight.
The method of claim 4, wherein the plasticizer of step 1 is sorbitol, mannitol, xylitol, glycerol or a mixture thereof.
10. The method of claim 9, wherein the plasticizer of step 1 is sorbitol.
The method according to claim 4, wherein the plasticizer of step 1 is added at 1.5-2.5 wt% based on the total weight.
The method of claim 4, wherein the sugar of step 1 is added in an amount of 0.4-0.6% by weight based on the total weight.
The method of claim 4, wherein the heating of step 2 is carried out at 85-95 ° C for 0.5-1 hour.
Pretreatment washing the fruit or vegetable using fumaric acid, chlorine dioxide, organic acid or mixtures thereof as washing liquid (step 1); And
Packaging method for long-term storage of fruits or vegetables comprising the step (step 2) of packing the fruit or vegetable, the water is removed in step 1 with the edible film of claim 1 and sealed with a heat adhesive.
15. The method of claim 14, wherein the fruit of step 1 is a strawberry.

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