A microporous atmosphere preservation method suitable for bayberry and strawberry

Abstract

The invention discloses a microporous atmosphere preservation method suitable for bayberry and strawberry, and relates to the technical field of food preservation. The invention first fumigates bayberry or strawberry with a treatment agent containing L-cysteine, isovitamin sodium salt and tea polyphenols, then precools the fruit, and then performs microporous atmosphere preservation treatment under a specific atmosphere after ozone treatment. The invention effectively solves the problem of anaerobic respiration of bayberry and strawberry in the late storage process, slows down the quality deterioration, and thus prolongs the shelf life.

Description

Technical Field

[0001] The invention relates to the technical field of food preservation, in particular to a microporous atmosphere-controlled preservation method suitable for waxberry and strawberry. Background Art

[0002] Strawberries and bayberries are berries with soft, juicy and aromatic fruits. They are rich in phenols and other natural antioxidant active ingredients, and have high nutritional value and therapeutic effects. However, the fruit tissues of strawberries and bayberries are delicate and easily damaged by mechanical damage during harvesting, storage and transportation. After harvesting, the metabolic balance of reactive oxygen species (ROS) is disrupted, and ROS accumulates rapidly. Therefore, the fruits are prone to rot and deterioration, and can only be stored for 1 to 3 days at room temperature.

[0003] At present, common preservation technologies for fruits and vegetables after harvest include heat treatment, modified atmosphere preservation, radiation preservation, coating preservation, ultrasonic preservation and other preservation methods. Among them, modified atmosphere packaging (MAP) is widely used in the preservation of fruits such as bayberry, blueberry and grapes. However, since the diffusion rate of CO2 in the film used in MAP is 2-8 times faster than that of O2, this characteristic is not suitable for fruits and vegetables with high respiratory rates. In low O2 and high CO2 environments, anaerobic and unpleasant odors are easily generated. Based on the above technical problems, perforated modified atmosphere packaging (P-MAP) is used in the preservation of fruits and vegetables. Rodriguez et al. packaged blueberries with LDPE with a pore size of 3 mm and a pore number of 2. On the 7th day, a stable atmosphere was passively generated in the package through respiration, which effectively reduced the decay of blueberries. Liguori et al. found that the atmosphere filled with a ratio of 20% CO2 + 80% N2 and packaged with a microporous polypropylene film with a pore size of 100 μm and a pore number of 1 could maintain the initial atmosphere in a dynamic balance, which had the best effect on the preservation of grapes. However, the research on microporous modified atmosphere packaging technology is still immature, and the use of microporous membrane modified atmosphere packaging technology to preserve berries still needs further research. Summary of the invention

[0004] The purpose of the present invention is to provide a microporous atmosphere preservation method suitable for bayberry and strawberry, so as to solve the problems existing in the above-mentioned prior art and achieve excellent storage effect on berry strawberry and bayberry.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a microporous atmosphere preservation method applicable to bayberry and strawberry, comprising the following steps:

[0007] (1) Fumigating bayberry or strawberry with a treatment agent;

[0008] (2) precooling the bayberry or strawberry treated in step (1) to a fruit center temperature of 4° C.;

[0009] (3) treating the bayberry or strawberry precooled in step (2) with ozone gas;

[0010] (4) placing the bayberry or strawberry treated in step (3) in an atmosphere of 4±1°C and 8.5-11% O2+9-10% CO2+79-82% N2 using a microporous modified atmosphere packaging film for modified atmosphere preservation;

[0011] The treatment agent consists of L-cysteine, isovitamin sodium salt, tea polyphenols and water, wherein the concentration of L-cysteine ​​is 0.3-0.5 μL / L, the concentration of isovitamin sodium salt is 0.5-0.8 μL / L, and the concentration of tea polyphenols is 0.4-0.7 μL / L.

[0012] Furthermore, the fumigation temperature is 10-15°C and the time is 5-6h.

[0013] Furthermore, during the precooling process, the humidity of the precooling environment is 85-90% and the temperature is 0-4°C.

[0014] Furthermore, the ozone concentration in the ozone gas treatment process is 17-45 mg / m 3 , the processing time is 30min.

[0015] Furthermore, the microporous modified atmosphere packaging film is a PET / PP polymer film, the micropore diameter corresponding to strawberries is 105 μm, and the number of pores is 3 / 243.39 cm 2 The corresponding micropore diameter of bayberry is 90 μm, and the number of pores is 3 / 243.39 cm 2 .

[0016] Furthermore, when the treatment object is waxberry, the ambient gas in step (4) is 10.5% O2+9.8% CO2+79.7% N2.

[0017] Furthermore, when the treatment object is strawberry, the ambient gas in step (4) is 9% O2+9% CO2+82% N2.

[0018] The present invention combines ozone treatment and microporous atmosphere preservation technology, and before ozone treatment, a treatment agent is used to fumigate the fruit according to the characteristics of bayberry and strawberry, and then a pre-cooling treatment is performed, thereby ensuring the storage and preservation effect of bayberry and strawberry to a great extent.

[0019] The controlled atmosphere environment and micropore parameters of the present invention can meet the storage requirements of bayberry and strawberry, but the controlled atmosphere environment requirements of the controlled atmosphere preservation process of bayberry and strawberry after fumigation and precooling are slightly different. The controlled atmosphere environment of 10.5% O2+9.8% CO2+79.7% N2 can ensure the best storage effect of bayberry, and the controlled atmosphere environment of 9% O2+9% CO2+82% N2 can ensure the best storage effect of strawberry.

[0020] The present invention discloses the following technical effects:

[0021] The processing method of the present invention can achieve excellent storage and preservation effects of bayberry and strawberry, solves the problem of anaerobic respiration occurring in the late storage period when bayberry and strawberry are packaged in modified atmosphere packaging, slows down the quality deterioration, and thus prolongs the shelf life. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0024] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0025] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0026] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0027] Unless otherwise specified, the "parts" described in the present invention are all based on mass parts.

[0028] The bayberry used in the embodiment of the present invention is the big floating bayberry, and the strawberry used is the "Hongyan" strawberry. When picking, any diseased fruits are excluded, and fruits without mechanical damage are selected.

[0029] Example 1

[0030] A microporous atmosphere-controlled fresh-keeping method for bayberry:

[0031] (1) The bayberry was fumigated with a treatment agent for 5 hours at a fumigation temperature of 12°C; wherein the concentration of L-cysteine ​​in the treatment agent was 0.3 μL / L, the concentration of isovitamin sodium salt was 0.8 μL / L, and the concentration of tea polyphenols was 0.4 μL / L.

[0032] (2) precooling the bayberry treated in step (1) to a fruit center temperature of 4° C., the precooling environment humidity being 88% and the temperature being 0° C.;

[0033] (3) The pre-cooled bayberry was treated with ozone gas (OG) at a concentration of 32 mg / m 3 , the processing time is 30min;

[0034] (4) A modified atmosphere packaging box (183 mm × 133 mm × 80 mm) made of polypropylene (PP) was used. Each box was filled with (100 ± 1) g of bayberry and then filled with 10.5% O2 + 9.8% CO2 + 79.7% N2. The box was then sealed with a PET / PP polymer film (243.39 cm 2 ) for heat sealing, and the packaged bayberry is stored in an environment of (4±1)°C and a relative humidity of 90% to 95%; the pore size of the PET / PP polymer film is 90 μm, and the number of pores is 3 / 243.39 cm 2 .

[0035] Example 2

[0036] A microporous atmosphere-controlled fresh-keeping method for bayberry:

[0037] (1) The bayberry was fumigated with a treatment agent for 6 hours at a fumigation temperature of 15°C; wherein the concentration of L-cysteine ​​in the treatment agent was 0.5 μL / L, the concentration of isovitamin sodium salt was 0.5 μL / L, and the concentration of tea polyphenols was 0.4 μL / L.

[0038] (2) precooling the bayberry treated in step (1) to a fruit center temperature of 4° C., in a precooling environment with a humidity of 85% and a temperature of 2° C.;

[0039] (3) The pre-cooled bayberry was treated with ozone gas (OG) at a concentration of 45 mg / m3 , the processing time is 30min;

[0040] (4) A modified atmosphere packaging box (183 mm × 133 mm × 80 mm) made of polypropylene (PP) was used. Each box was filled with (100 ± 1) g of bayberry and then filled with 9% O2 + 10% CO2 + 81% N2. The box was then sealed with a PET / PP polymer film (243.39 cm 2 ) for heat sealing, and the packaged bayberry is stored in an environment of (4±1)°C and a relative humidity of 90% to 95%; the micropore diameter of the modified atmosphere packaging film (PET / PP polymer film) is 90 μm, and the number of pores is 3 / 243.39 cm 2 .

[0041] Example 3

[0042] A microporous atmosphere-controlled fresh-keeping method for bayberry:

[0043] (1) The bayberry was fumigated with a treatment agent for 5.5 hours at a fumigation temperature of 14°C; wherein the concentration of L-cysteine ​​in the treatment agent was 0.4 μL / L, the concentration of isovitamin sodium salt was 0.6 μL / L, and the concentration of tea polyphenols was 0.5 μL / L.

[0044] (2) precooling the bayberry treated in step (1) to a fruit center temperature of 4° C., in a precooling environment with a humidity of 90% and a temperature of 1° C.;

[0045] (3) The pre-cooled bayberry was treated with ozone gas (OG) at a concentration of 17 mg / m 3 , the processing time is 30min;

[0046] (4) A modified atmosphere packaging box (183 mm × 133 mm × 80 mm) made of polypropylene (PP) was used. Each box was filled with (100 ± 1) g of bayberry and then filled with 10% O2 + 10% CO2 + 80% N2. The box was then sealed with a PET / PP polymer film (243.39 cm 2 ) for heat sealing, and the packaged bayberry is stored in an environment of (4±1)°C and a relative humidity of 90% to 95%; the micropore diameter of the modified atmosphere packaging film (PET / PP polymer film) is 90 μm, and the number of pores is 3 / 243.39 cm 2 .

[0047] Example 4

[0048] A microporous atmosphere preservation method for strawberries:

[0049] (1) The strawberries were fumigated with a treatment agent for 5 h at a fumigation temperature of 15°C; wherein the concentration of L-cysteine ​​in the treatment agent was 0.3 μL / L, the concentration of isovitamin sodium salt was 0.6 μL / L, and the concentration of tea polyphenols was 0.5 μL / L.

[0050] (2) precooling the strawberries treated in step (1) to a fruit center temperature of 4° C. in a precooling environment with a humidity of 85% and a temperature of 1° C.;

[0051] (3) The pre-cooled strawberries were treated with ozone gas (OG) at a concentration of 30 mg / m 3 , the processing time is 30min;

[0052] (4) A polypropylene (PP) modified atmosphere packaging box (183 mm × 133 mm × 80 mm) was used. Each box was filled with (100 ± 1) g of strawberries and filled with 9% O2 + 9% CO2 + 82% N2. The box was then sealed with a PET / PP polymer film (243.39 cm 2 ) for heat sealing, and the packaged strawberries are stored in an environment of (4±1)°C and a relative humidity of 90% to 95%; the micropore diameter of the modified atmosphere packaging film (PET / PP polymer film) is 105 μm, and the number of pores is 3 / 243.39 cm 2 .

[0053] Example 5

[0054] A microporous atmosphere preservation method for strawberries:

[0055] (1) The strawberries were fumigated with a treatment agent for 6 h at a fumigation temperature of 10°C; wherein the concentration of L-cysteine ​​in the treatment agent was 0.5 μL / L, the concentration of isovitamin sodium salt was 0.8 μL / L, and the concentration of tea polyphenols was 0.7 μL / L.

[0056] (2) precooling the strawberries treated in step (1) to a fruit center temperature of 4° C., in a precooling environment with a humidity of 85% and a temperature of 2° C.;

[0057] (3) The pre-cooled strawberries were treated with ozone gas (OG) at a concentration of 25 mg / m 3 , the processing time is 30min;

[0058] (4) A modified atmosphere packaging box (183 mm × 133 mm × 80 mm) made of polypropylene (PP) was used. Each box was filled with (100 ± 1) g of strawberries and then filled with 9.5% O2 + 10% CO2 + 80.5% N2. The box was then sealed with a PET / PP polymer film (243.39 cm 2 ) for heat sealing, and the packaged strawberries are stored in an environment of (4±1)°C and a relative humidity of 90% to 95%; the micropore diameter of the modified atmosphere packaging film (PET / PP polymer film) is 105 μm, and the number of pores is 3 / 243.39 cm 2 .

[0059] Example 6

[0060] A microporous atmosphere preservation method for strawberries:

[0061] (1) The strawberries were fumigated with a treatment agent for 5.5 h at a fumigation temperature of 10°C; wherein the concentration of L-cysteine ​​in the treatment agent was 0.4 μL / L, the concentration of isovitamin sodium salt was 0.6 μL / L, and the concentration of tea polyphenols was 0.5 μL / L.

[0062] (2) precooling the strawberries treated in step (1) to a fruit center temperature of 4° C. in a precooling environment with a humidity of 90% and a temperature of 1° C.;

[0063] (3) The pre-cooled strawberries were treated with ozone gas (OG) at a concentration of 30 mg / m 3 , the processing time is 30min;

[0064] (4) A modified atmosphere packaging box (183 mm × 133 mm × 80 mm) made of polypropylene (PP) was used. Each box was filled with (100 ± 1) g of strawberries and then filled with 10% O2 + 9% CO2 + 81% N2. The box was then sealed with a PET / PP polymer film (243.39 cm 2 ) for heat sealing, and the packaged strawberries are stored in an environment of (4±1)°C and a relative humidity of 90% to 95%; the micropore diameter of the modified atmosphere packaging film (PET / PP polymer film) is 105 μm, and the number of pores is 3 / 243.39 cm 2 .

[0065] Comparative Example 1

[0066] The only difference from Example 1 is that 7% O2+7% CO2+86% N2 is used for controlled atmosphere preservation.

[0067] Comparative Example 2

[0068] The only difference from Example 4 is that 8% O2+8% CO2+84% N2 is used for controlled atmosphere preservation.

[0069] Comparative Example 3

[0070] The only difference from Example 1 is that the fumigation treatment in step (1) is not performed.

[0071] Comparative Example 4

[0072] The only difference from Example 4 is that the fumigation treatment in step (1) is not performed.

[0073] Effect verification example:

[0074] After 7 days of storage, the fruit decay index, firmness reduction rate, and weight loss rate data are shown in Table 1:

[0075] Table 1

[0076] Decay index / % Hardness reduction rate / % Weight loss rate / % Example 1 1.62 5.01 4.15 Example 2 1.65 5.13 4.23 Example 3 1.66 5.29 4.29 Example 4 1.74 5.34 4.33 Example 5 1.79 5.39 4.38 Example 6 1.81 5.42 4.45 Comparative Example 1 2.38 6.67 6.42 Comparative Example 2 2.59 6.74 6.57 Comparative Example 3 2.56 6.98 6.69 Comparative Example 4 2.97 7.02 6.88

[0077] Among them: In the determination of fruit decay index, it will be divided into 4 levels according to the decay area: Level 0: no decay; Level 1: the decay area is less than 1 / 4; Level 2: the decay area accounts for 1 / 4 to 1 / 2; Level 3: the decay area is greater than 1 / 2; the decay index is calculated according to the following formula:

[0078]

[0079] The weight loss rate was calculated using the differential weight method and expressed as the percentage of weight loss relative to the initial body weight:

[0080]

[0081] Where: W0 is the initial mass of the sample / g; W i It is the mass of sample in each measurement / g.

[0082] It can be seen that bayberry and strawberry require a suitable controlled atmosphere for preservation. When the gas environment is adjusted, the storage and preservation effect is greatly affected. At the same time, the fumigation process greatly guarantees the storage and preservation effect of bayberry and strawberry.

[0083] It was determined that after being treated with the microporous atmosphere preservation technology of the present invention, the contents of total phenols, anthocyanins and flavonoids in bayberry were as follows:

[0084] Table 2

[0085] Total phenols / (U / g) Anthocyanin / (U / g) Flavonoids / (U / g) Example 1 0.78 4.48 0.98 Example 2 0.76 4.47 0.97 Example 3 0.77 4.45 0.93

[0086] It has been determined that after being treated with the microporous atmosphere-controlled fresh-keeping technology of the present invention, the soluble solid content, sugar-acid ratio and vitamin C content retention rate of the strawberries are as follows:

[0087] Table 3

[0088]

[0089] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A microporous atmosphere preservation method suitable for bayberry and strawberry, characterized in that: The following steps are involved: (1) Fumigating bayberry or strawberry with a treatment agent; (2) precooling the bayberry or strawberry treated in step (1) to a fruit center temperature of 4° C.; (3) treating the bayberry or strawberry precooled in step (2) with ozone gas; (4) placing the bayberry or strawberry treated in step (3) in an environment of 4±1°C, 8.5-11% O2+9-10% CO2+79-82% N2, using a microporous modified atmosphere packaging film for modified atmosphere preservation; The treatment agent is composed of L-cysteine, isovitamin sodium salt, tea polyphenols and water, wherein: the concentration of L-cysteine ​​is 0.3-0.5 μL / L, the concentration of isovitamin sodium salt is 0.5-0.8 μL / L, and the concentration of tea polyphenols is 0.4-0.7 μL / L; The microporous modified atmosphere packaging film is a PET / PP polymer film, the micropore diameter corresponding to strawberries is 105 μm, and the number of pores is 3 / 243.39 cm 2 The corresponding micropore diameter of Bayberry is 90 μm, and the number of pores is 3 / 243.39 cm 2 .

2. The microporous atmosphere preservation method according to claim 1, characterized in that: The fumigation temperature is 10-15°C and the time is 5-6h.

3. The microporous atmosphere preservation method according to claim 1, characterized in that: During the precooling process, the precooling environment humidity is 85-90% and the temperature is 0-4°C.

4. The microporous atmosphere preservation method according to claim 1, characterized in that: The ozone concentration in the ozone gas treatment process is 17-45 mg / m 3 , the processing time is 30 min.

5. The microporous atmosphere preservation method according to claim 1, characterized in that: When the treatment object is bayberry, the ambient gas in step (4) is 10.5% O2+9.8% CO2+79.7% N2.

6. The microporous atmosphere preservation method according to claim 1, characterized in that: When the treatment object is strawberry, the ambient gas in step (4) is 9% O2+9% CO2+82% N2.

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