A spontaneous modified atmosphere packaging for preserving strawberries

Abstract

The utility model discloses a spontaneous type modified atmosphere packaging for strawberry fresh -keeping, including the packing box of no lid and the food packaging bag of covering in packing box outside, packing box long 16~20cm, wide 11~15cm, high 3~5cm, and the both ends of food packaging bag are sealed, and at least one opening is arranged on the surface, and the total area of opening is 3~5cm 2 , and the opening is covered by PDMS film. The utility model overcomes the problems of poor fresh -keeping effect of the prior art strawberry packaging and the problems of complex operation and high cost of active type modified atmosphere packaging.

Description

Technical Field

[0001] This utility model belongs to the field of ready-to-eat fruit and vegetable preservation technology, specifically relating to a self-generating modified atmosphere packaging for strawberry preservation. Background Technology

[0002] Strawberries are mainly supplied during the winter and spring off-season, playing a vital role in filling market gaps and ensuring people's health and nutrition. However, the rapid deterioration of strawberry quality after harvest has been a long-standing technical challenge in strawberry preservation. There are many reasons for this post-harvest quality deterioration, primarily including senescence and spoilage, and pathogen infection. Strawberries are non-climacteric fruits, exhibiting a high respiration rate after harvest. Senescence produces free radicals that damage cell membrane permeability, increasing the activity of cellulase and pectinase, which in turn decompose cell walls, leading to rapid softening, rapid loss of flavor and nutrients, and loss of commercial value. Furthermore, strawberries have a high water content, thin skin, and thick flesh, making them highly susceptible to Rhizopus stolonifera (…). Rhizopus stolonifer ) and Botrytis cinerea ( Botrytis cinerea Infection by fungal pathogens such as _____ leads to rotting. Statistics show that over 90% of strawberry consumption in my country is for fresh consumption, with less than 10% used for processing into strawberry jam, strawberry wine, strawberry juice, and frozen strawberry products. Therefore, post-harvest logistics and preservation technology for fresh strawberries is extremely important.

[0003] Strawberries are typically transported and stored in cardboard boxes or plastic packaging with ventilation holes for short-term post-harvest transport and preservation. For medium- to long-term preservation, modified atmosphere packaging (MAP) technology can be used. This technology mainly works by altering the composition of gases in the environment, usually by adjusting the ratio of oxygen (O2), carbon dioxide (CO2), and nitrogen (N2), to inhibit the growth and reproduction of microorganisms, as well as the respiration of fruits and vegetables and ethylene synthesis, thereby delaying their aging and spoilage process.

[0004] Modified atmosphere packaging (MAP) falls into two main categories: active MAP and passive MAP. The former typically involves artificially filling the packaging with a specific ratio of mixed gases to quickly establish ideal gaseous conditions. The latter relies on the spontaneous regulation of CO2 and low O2 ratios within the sealed packaging by the respiration of the fruit and vegetables, creating a suitable microenvironment. Traditional MAP used for strawberries after harvest is primarily active MAP, which involves filling the packaging with CO2 and N2 in a certain ratio to achieve a low O2 and high CO2 gaseous environment. This, combined with the strawberry's own respiration, inhibits the fruit's respiratory metabolism and the proliferation of pathogens, delaying quality deterioration during the transport and marketization process. However, active MAP requires specialized equipment (such as gas mixing devices and high-precision gas filling machines) and strict process control, resulting in high initial investment and operating costs, making it difficult for small and medium-sized production enterprises to adopt.

[0005] Self-modified atmosphere packaging (SMAP) is a simple, harmless, and efficient technology for preserving fruits and vegetables. Based on the physiological characteristics and respiration of fruits and vegetables, it utilizes the permeability of the modified atmosphere packaging film to spontaneously regulate the concentration of CO2 and O2 within the packaging, creating a suitable gaseous microenvironment for the fruits and vegetables and maintaining their quality. However, currently, there is no scientifically complete and comprehensive technical method or supporting product for SMAP that relies entirely on the respiration of strawberry fruit for post-harvest preservation. The packaging form, materials, and size ratios for SMAP used in strawberry preservation require further investigation. Utility Model Content

[0006] Based on the above technical problems, the purpose of this utility model is to provide a self-contained modified atmosphere packaging method for post-harvest preservation of strawberries that has good preservation effect, is simple to operate, safe and non-toxic, and low cost. To achieve the above objective, this utility model provides the following technical solution:

[0007] A self-contained modified atmosphere packaging system for strawberry preservation includes an open-top box and a food packaging bag fitted over the box. The box is 16-20 cm long, 11-15 cm wide, and 3-5 cm high. The food packaging bag is sealed at both ends, but has at least one opening on its surface, with a total area of ​​3-5 cm². 2 The opening is covered by a PDMS (polydimethylsiloxane) film.

[0008] Further optimization resulted in a packaging box measuring 18cm in length, 13cm in width, and 4cm in height, with a total opening area of ​​4cm². 2 .

[0009] Furthermore, the opening is provided in two or more forms.

[0010] Furthermore, each opening has the same area.

[0011] Furthermore, the opening is located on the side of the food packaging bag corresponding to the upper part of the packaging box.

[0012] Furthermore, the food packaging bag has a length of 28-32 cm and a width of 26-30 cm.

[0013] Furthermore, the packaging box is a PET box, and the food packaging bag is a plastic food storage bag.

[0014] Compared to existing post-harvest packaging for strawberries, this invention has at least the following advantages:

[0015] (1) This utility model utilizes the capacity of the most common strawberry packaging box size on the market (16~19cm, width 12~15cm, height 3~5cm) to achieve a stable high CO2 (about 10%) / low O2 (about 2.5%) gas environment inside the packaging at room temperature using PDMS film and the high respiration rate of strawberries after harvest. This replaces the traditional modified atmosphere packaging of strawberries, which requires the use of special equipment to replace the gas environment inside the packaging. This packaging does not require the purchase of special equipment or gas conditioning agents, is simple to operate, and reduces industry costs.

[0016] (2) This invention utilizes only PDMS film and the high respiration rate of strawberries after harvest to achieve a low O2 / high CO2 gas environment inside the packaging at room temperature, which effectively inhibits the respiration of strawberries after harvest and the reproduction of pathogens, delays the aging and quality deterioration of strawberry fruits, controls the occurrence of post-harvest rot, and avoids the potential harm to the human body from other chemical preservatives.

[0017] (3) By inhibiting the respiration of strawberry fruit at room temperature, this utility model effectively reduces the post-harvest weight loss of the fruit, and maintains the color and crispness of the fruit. After 5 days at room temperature, the weight loss of strawberry fruit is 14.9% of that of the control group, the color is 1.04 times that of the control group, and the crispness is 1.12 times that of the control group.

[0018] (4) This invention effectively inhibits the occurrence of postharvest rot of strawberries at room temperature. The strawberry disease index was only 0.14 after 5 days at room temperature, while the control group reached 0.46.

[0019] (5) The PDMS membrane used in this invention has good biocompatibility and is harmless to the human body. In addition, the PDMS membrane is also elastic and can be recycled together with open packaging boxes and food packaging bags, which is safe and environmentally friendly. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the self-generating modified atmosphere packaging for post-harvest preservation of strawberry fruit according to this utility model.

[0021] Figure 2 This is a schematic diagram showing the changes in CO2 and O2 concentrations inside the packaging 5 days after the sampling of the Example and Comparative Example 1.

[0022] Figure 3 This is a schematic diagram comparing the appearance quality of strawberry fruits 5 days after harvest, as shown in the examples and Comparative Example 1.

[0023] Figure 4 This is a schematic diagram comparing the strawberry decay index 5 days after harvest for both the example and Comparative Example 1.

[0024] Figure 5 This is a schematic diagram illustrating the change in strawberry rot rate 5 days after harvest for both the example and Comparative Example 1.

[0025] Figure 6 This is a schematic diagram illustrating the changes in strawberry weight loss rate 5 days after harvest, as shown in the examples and Comparative Example 1.

[0026] Figure 7 This is a schematic diagram showing the comparison of strawberry fruit brightness 5 days after harvest, as shown in the examples and Comparative Example 1.

[0027] Figure 8 This is a schematic diagram comparing the crispness of strawberry fruits 5 days after harvest, as shown in the examples and Comparative Example 1.

[0028] In the picture, 1. food packaging bag; 2. opening; 3. PDMS film; 4. packaging box; 5. sealing line. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0030] Example 1

[0031] like Figure 1 As shown, a self-contained modified atmosphere packaging for strawberry preservation includes an open-top packaging box 4 and a food packaging bag 1 fitted over the packaging box 4. In this embodiment, the packaging box 4 is 18cm long, 13cm wide, and 4cm high, and the food packaging bag 1 is sealed at both ends (sealing line 5 as shown). Figure 1 As shown), the surface of the food packaging bag 1 has two 2 cm² areas. 2 Opening 2 has a total area of ​​4 cm². 2 The opening 2 is covered by a PDMS film 3. The two openings 2 are positioned on the side of the food packaging bag 1 corresponding to the upper part of the packaging box 4, and the center distance of the two openings 2 from the center of the food packaging bag 1 is equal. In this embodiment, the food packaging bag is 30 cm long and 28 cm wide.

[0032] In this embodiment, the lidless packaging box 4 is made of PFT material, and the food packaging bag 1 can be a preservation bag. In this embodiment, the food packaging bag 1 is a roll-type sheet bag with a length that can be freely cut, a width of 28 cm, a thickness of 19 mils on both sides, and a material of PE+PA seven-layer co-extrusion. The sealing line 5 of the sealing machine has a width of 3 mm.

[0033] In this embodiment, the PDMS membrane is of type KYN-50 μm, and the CO2 permeability is 1.921·10⁻⁶. 6 cm 3 / 24 h·0.1MPa, O2 transmittance is 4.103·10 5 cm 3 / 24 h·0.1 MPa; In this embodiment, when making the food packaging bag 1: a 30 cm long food packaging bag (fixed width 28 cm) is cut, and two symmetrical openings of 1 cm × 2 cm are cut from the center of one side. Two 1.5 cm × 2.5 cm PDMS films are cut and attached to the two 1 cm × 2 cm openings in the center of the packaging bag, completely covering the two openings. The PDMS film itself is adhesive, and after being covered on the food packaging bag, it will stick to the food packaging bag. It will be more stable after being pressed slightly by hand.

[0034] In application, strawberries of uniform size, without mechanical damage, disease, and maturity are selected within one hour after harvest and packaged into the aforementioned packaging box 4. Each box of strawberries is placed into a pre-opened food packaging bag 1 with PDMS film attached, sealed with a plastic sealer, and stored at room temperature, and is recorded as a self-contained modified atmosphere group.

[0035] Comparative Example 1

[0036] The packaging used in this comparative example differs from the self-contained modified atmosphere packaging of Example 1 in that it simulates the form of short-term strawberry transportation packaging on the market, without covering the opening 2 with PDMS film 3. Other structures and dimensions are the same as in Example 1.

[0037] In this application, strawberries of uniform size, without mechanical damage, disease, and maturity were selected within one hour of harvest and evenly packaged into boxes. Each box of strawberries was placed in an open food packaging bag without PDMS film, sealed with a plastic sealer, and stored at room temperature; this was designated as the control group.

[0038] In Example 1 and the control group, the gas environment inside the packaging was measured every 6 hours, and the decay index, decay rate, weight loss rate, fruit brightness, and fruit crispness were measured on days 3 and 5. The results are as follows: Figures 2-8 As shown, this invention's self-contained modified atmosphere packaging utilizes the strong respiration of strawberries after harvest to achieve a stable high CO2 (approximately 10%) / low O2 (approximately 2.5%) gaseous environment within the packaging. This significantly inhibits post-harvest pathogen infection and reduces post-harvest spoilage during room temperature storage. Simultaneously, by suppressing respiration during strawberry storage at room temperature, this invention effectively reduces post-harvest weight loss, delays the decline in color and crispness during post-harvest storage, and effectively extends the post-harvest transportation time and shelf life of strawberries.

[0039] Comparative Example 2

[0040] This comparative example, based on Example 1, increased the opening area, but the CO2 content inside the packaging still failed to meet the expected target. When the total opening area was increased to 10 cm², the CO2 content remained the same. 2At that time, the CO2 content inside the packaging remained stable at around 5.5%.

[0041] Comparative Example 3

[0042] This comparative example reduces the opening area compared to Example 1. Reducing the opening area causes the CO2 content inside the packaging to exceed 15%, and excessively high carbon dioxide levels can actually accelerate post-harvest aging and spoilage of the fruit. When the total opening area is reduced to 2 cm²... 2 At that time, the CO2 content inside the packaging was eventually maintained at around 20%.

[0043] Example 2

[0044] The difference between this embodiment and embodiment 1 is that there is only one opening 2, located in the center of the food packaging 1, with an area of ​​4 cm². 2 .

[0045] The above are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the scope of protection of the present utility model.

Claims

1. A self-contained modified atmosphere packaging for strawberry preservation, comprising an open-top packaging box (4) and a food packaging bag (1) fitted over the packaging box (4), characterized in that: The packaging box (4) is 16-20cm long, 11-15cm wide, and 3-5cm high. The food packaging bag (1) is sealed at both ends, and has at least one opening (2) on its surface. The total area of ​​the opening (2) is 3-5cm². 2 The opening (2) is covered by a PDMS film (3).

2. The self-contained modified atmosphere packaging for strawberry preservation according to claim 1, characterized in that: The packaging box (4) is 18cm long, 13cm wide, and 4cm high, and the total area of ​​the opening (2) is 4cm². 2 .

3. The self-contained modified atmosphere packaging for strawberry preservation according to claim 1, characterized in that: The opening (2) is provided in two or more places.

4. The self-contained modified atmosphere packaging for strawberry preservation according to claim 3, characterized in that: Each opening (2) has the same area.

5. The self-contained modified atmosphere packaging for strawberry preservation according to claim 1, characterized in that: The opening (2) is located on the side of the food packaging bag (1) corresponding to the upper part of the packaging box (4).

6. The self-contained modified atmosphere packaging for strawberry preservation according to claim 1, characterized in that: The food packaging bag (1) has a length of 28~32 cm and a width of 26~30 cm.

7. The self-contained modified atmosphere packaging for strawberry preservation according to claim 1, characterized in that: The packaging box (4) is a PET box, and the food packaging bag (1) is a plastic preservation bag.

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