Packaging body and packing method

Abstract

To provide a packaging body and a packing method improved in freshness keeping effect of cut vegetable.SOLUTION: A packaging body is formed by hermetically packaging cut vegetable in a packaging container formed of a resin film, and (a) when a ratio of an air volume (cm3) in the packaging container to a cut vegetable volume (cm3) in a hermetically packaged state is defined to be HS1, and when a ratio of the air volume (cm3) in the packaging container to the cut vegetable volume (cm3) at 10°C and 72 hours later is defined to be HS2, HS2 / HS1 is 1-1.5, and (b) an oxygen concentration in the packaging container 72 hours after tight packaging is 0.1-20%, and in the hermetically packaged state, 90 mass% or more of cut cabbage is included to the total mass of the cut vegetable.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a package and a packaging method.

Background Art

[0002] Conventionally, as a method for maintaining the freshness of harvested cut vegetables, a method of appropriately suppressing the respiration of cut vegetables to maintain freshness is known. A packaging material used for maintaining the freshness of such cut vegetables is known as MA (Modified Atmosphere) packaging.

[0003] For example, Patent Document 1 discloses a method of maintaining freshness by setting the odor intensity in an odor monitor in terms of NH 3 conversion in a packaging container storing fruits and vegetables including shredded cabbage to 600 or less. According to Patent Document 1, by suppressing the odor intensity (S) in the odor monitor in terms of NH 3 conversion corresponding to the concentration of methyl sulfide, which is a cause of off-odor, to a certain value or less, it is possible to suppress off-odor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the technique disclosed in Patent Document 1 focuses on the off-odor generated from shredded cabbage, and there is still room for improvement in the freshness maintaining effect. Generally, a package in which cut vegetables such as shredded cabbage are hermetically packaged has a certain amount of headspace from the viewpoints of cushioning property, appearance, packaging convenience, etc. Therefore, in order to further improve the freshness retention effect of cut vegetables, the present inventors newly focused on the headspace and conducted intensive studies. As a result, it was found that as time passes, the headspace increases and an off-odor tends to occur due to respiratory disorders of the cut vegetables. Therefore, as a result of further studies, it was found that by controlling both the change amount of the headspace and the oxygen concentration in the package, the freshness retention effect of cut vegetables can be effectively improved, and the present invention was completed.

Means for Solving the Problems

[0006] According to the present invention, a package obtained by hermetically packaging cut vegetables in a packaging container made of a resin film, (a) When the ratio of the air volume (cm 3 ) in the packaging container to the volume of the cut vegetables (cm 3 ) at the time of the hermetic packaging is defined as HS1, and the ratio of the air volume (cm 3 ) in the packaging container to the volume of the cut vegetables (cm 3 ) 72 hours after the hermetic packaging at 10°C is defined as HS2, HS2 / HS1 is 1 to 1.5, (b) The oxygen concentration in the packaging container 72 hours after the hermetic packaging is 0.1 to 20%, A package is provided which contains 90% by mass or more of cut cabbage with respect to the total mass of the cut vegetables at the time of the hermetic packaging.

[0007] Also, according to the present invention, A packaging method for hermetically packaging cut vegetables in a packaging container made of a resin film, (a) When the ratio of the air volume (cm 3 ) in the packaging container to the volume of the cut vegetables (cm 3 ) at the time of the hermetic packaging is defined as HS1, and the ratio of the air volume (cm 3 ) in the packaging container to the volume of the cut vegetables (cm3 ) When the ratio of is HS2, HS2 / HS1 is 1 to 1.5, (b) The oxygen concentration in the packaging container 72 hours after the sealed packaging is 0.1 to 20%, A packaging method is provided in which, at the time of the sealed packaging, cut cabbage is contained in an amount of 90% by mass or more based on the total mass of the cut vegetables.

Effect of the Invention

[0008] According to the present invention, there are provided a package and a packaging method capable of improving the freshness retention effect of cut vegetables.

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail.

[0010] In this specification, the term "substantially" means including a range considering manufacturing tolerances, assembly variations, etc., unless otherwise explicitly stated. In this specification, the notation "X to Y" in the description of a numerical range represents X or more and Y or less, unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".

[0011] <Package> The package of the present embodiment is formed by sealing cut vegetables in a packaging container made of a resin film, and satisfies the following (a) and (b). Further, at the time of the sealed packaging, cut cabbage is contained in an amount of 90% by mass or more based on the total mass of the cut vegetables. Thereby, the freshness retention effect of cut vegetables can be improved and the generation of off-odor can be suppressed. (a) The ratio of the volume of air in the packaging container (cm 3 ) to the volume of the cut vegetables (cm 3 ) at the time of the sealed packaging is defined as HS1, and the ratio of the volume of air in the packaging container (cm 3 ) to the volume of the cut vegetables (cm 3 ) 72 hours after the sealed packaging at 10°C is defined as HS2. When HS2 / HS1 is 1 to 1.5, (b) The oxygen concentration in the packaging container 72 hours after the sealed packaging is 0.1 to 20%.

[0012] Here, conventionally, the cut vegetable package was intended to maintain the freshness of cut vegetables by suppressing the respiration of cut vegetables. On the other hand, if the respiration of cut vegetables is suppressed too much, the respiration of cut vegetables tends to switch to anaerobic respiration, and an unpleasant odor is likely to occur from the cut vegetables. That is, since oxygen in the package is consumed by the respiration of cut vegetables, over time, the oxygen concentration in the package gradually decreases, and due to respiratory disorders such as anaerobic respiration of cut vegetables, a part of the cut vegetables begins to rot and decompose, resulting in the generation of an unpleasant odor such as ethanol gas. As a result, gases that cause unpleasant odors accumulate in the package, and while the air volume (cm 3 ) in the packaging container, so-called headspace, increases, the volume slightly decreases due to the decomposition of a part of the cut vegetables, and it is considered that the ratio of the headspace volume to the cut vegetable volume (headspace ratio) increases. Therefore, the inventors of the present invention focused on the change in the headspace ratio of such a package and conducted studies. As a result, they newly found that it is effective to control both the oxygen concentration in the package and the change amount of the headspace ratio after 72 hours.

[0013] In this embodiment, the headspace refers to the air volume (cm 3 ) excluding the cut vegetable volume (cm 3 ) in the package, that is, the intended space volume. Also, the measurement of the headspace is performed as follows. First, a package in which cut vegetables are put into a packaging container and sealed is placed in a water tank filled with water, and the volume of the package is obtained from the volume of the overflowed water. On the other hand, the weight of the cut vegetables is measured, the volume is calculated as the specific gravity 1 of the cut vegetables, and the volume of the cut vegetables is subtracted from the volume of the package obtained above to obtain the headspace (cm 3 ) of the package.

[0014] In this embodiment, HS1 is the cut vegetable volume (cm3 ) represents the ratio of the air volume (cm 3 ) in the packaging container to the cut vegetable volume after 10°C for 72 hours from the sealed package (cm 3 ) represents the ratio of the air volume (cm 3 ) in the packaging container to the cut vegetable volume (cm (a) In this embodiment, HS2 / HS1 is from 1 to 1.5, preferably from 1.0 to 1.4, and more preferably from 1.0 to 1.3. By setting HS2 / HS1 of this embodiment within the above numerical range, the variation in the headspace ratio can be reduced, the respiration of cut vegetables can be moderately suppressed, and the freshness retention effect can be improved.

[0015] (b) Further, in this embodiment, the oxygen concentration in the packaging container 72 hours after the sealed package is 0.1 to 20%, preferably 0.15 to 15%, and more preferably 0.2 to 10%. By setting the oxygen concentration 72 hours after in this embodiment to be equal to or higher than the above lower limit value, the respiration of cut vegetables can be maintained, and the generation of off-odor due to respiratory disorders can be suppressed. On the other hand, by setting the oxygen concentration 72 hours after in this embodiment to be equal to or lower than the above upper limit value, the freshness of cut vegetables can be more easily maintained for a longer period by suppressing the respiration of cut vegetables. Although the details of obtaining the freshness retention effect of cut vegetables by controlling the oxygen concentration 72 hours after the sealed package are not clear, it is considered important to control the balance between restricting the respiration of cut vegetables and gradually shifting to a respiratory arrest state, and the oxygen permeation amount from the outside air entering the inside of the package.

[0016] Also, in the package of this embodiment, the oxygen concentration in the packaging container 24 hours after the sealed package is 5 to 20%, preferably 10 to 18%. By setting the oxygen concentration 24 hours after in this embodiment to be equal to or higher than the above lower limit value, the respiration of cut vegetables can be maintained, and the generation of off-odor due to respiratory disorders can be suppressed. On the other hand, by setting the oxygen concentration 24 hours after in this embodiment to be equal to or lower than the above upper limit value, the freshness of cut vegetables can be more easily maintained by suppressing the respiration of cut vegetables.

[0017] In addition, in this embodiment, the oxygen concentration in the packaging container 96 hours after the sealed packaging is 0.1 to 18%, preferably 0.4 to 15%, and more preferably 0.5 to 12%. By setting the oxygen concentration 96 hours after in this embodiment to be not less than the above lower limit value, the minimum respiratory state of the cut vegetables can be maintained, and the generation of off-odor due to respiratory disorder can be suppressed. On the other hand, by setting the oxygen concentration 96 hours after in this embodiment to be not more than the above upper limit value, it becomes easier to maintain the freshness of the cut vegetables for a longer period by suppressing the respiration of the cut vegetables.

[0018] In addition, in this embodiment, it is preferable that the oxygen concentration in the packaging container 96 hours after the sealed packaging is higher than the oxygen concentration in the packaging container 72 hours after the sealed packaging. Thereby, the respiration of the cut vegetables is maintained, and the freshness retention period can be extended. The ratio of the oxygen concentration (%) in the packaging container 96 hours after the sealed packaging to the oxygen concentration (%) in the packaging container 72 hours after the sealed packaging is preferably 1 to 4.

[0019] The package of this embodiment can more stably improve the freshness retention effect by satisfying the following conditions. (c) In this embodiment, HS1 is not particularly limited, but from the viewpoints of the appearance, cushioning property, filling property, etc. of the package for general consumers, it is preferably 2.5 to 4.0. (d) In this embodiment, it is desired that HS2 has little variation with respect to HS1, but from the viewpoints of the appearance, cushioning property, filling property, etc. of the package for general consumers, it is preferably 2.5 to 4.0.

[0020] In the package of this embodiment, the above HS1, HS2, and the oxygen concentration in the package can be adjusted by the oxygen transmission rate of the resin film, the presence or absence and size of the through holes, the packaging amount of the cut vegetables, the environmental temperature, etc. For example, when the packaging amount of the cut vegetables is small and the headspace is large, the respiration of the cut vegetables is less suppressed, so it becomes easier to reduce the change amount of the headspace.

[0021] The package of this embodiment is obtained by accommodating cut vegetables in a packaging container made of a resin film and then performing a sealed packaging. As a method of sealed packaging, when the packaging container is in a bag shape, as a method of closing its opening, there is no particular limitation as long as the packaged cut vegetables do not fall off from the packaging container and the oxygen concentration can be kept constant. For example, sealing methods such as heat sealing, caulking methods such as bag sealing, rubber bands, adhesive tapes, and clips can be mentioned. Among them, from the viewpoint of appropriately maintaining the headspace and suppressing the inflow and outflow of gas in the package, heat sealing is preferable. Also, a zipper may be attached to the opening. Two or more of these sealing methods and caulking methods may be combined.

[0022] The amount of cut vegetables accommodated in the packaging container may vary depending on the size of the container, the type of cut vegetables, the use of the package, etc. In the case of cut vegetables for general consumers, for example, from the viewpoints of being easily consumable immediately after opening and having suitable carry-home and handling properties, it is preferably 50 to 1000 g, more preferably 100 to 800 g.

[0023] [Cut Vegetables] From the viewpoint of obtaining an effective freshness retention effect, the package of this embodiment contains 90% by mass or more of cut cabbage with respect to the total mass of the cut vegetables at the time of sealed packaging, and it may be 100% by mass. The ratio of cut cabbage can be appropriately set in consideration of seasons, purposes, appearance, etc. In this embodiment, cut vegetables mean non-heated vegetables that are cut by a known method in consideration of the edible parts of vegetables cultivated by soil cultivation or hydroponics, such as roots, epidermis, cores, edges, seeds, and flowers being removed, and the edible parts of the vegetables being easy to eat and cook easily.

[0024] The vegetables other than cabbage are not particularly limited. For example, large leaf, spinach, komatsuna, mizuna, mibuna, asparagus, kuushinsai, lettuces (lettuce, leaf lettuce, cos lettuce, sunny lettuce, salad turnip, sanchu, etc.), thyme, sage, parsley, Italian parsley, rosemary, oregano, lemon balm, chive, lavender, salad burnet, ramsons, rocket, dandelion, nasturtium, basil, arugula, cress, moringa, celery, kale, leek, Chinese cabbage, shungiku, butterbur, banana, chingensai, honeywort, celery, mizuna cabbage, broccoli, cauliflower, myoga, daikon radish, carrot, burdock, radish, turnip, sweet potato, potato, long potato, yam, taro, Chinese arrowroot, yamato potato, pepper, paprika, shishitou, cucumber, eggplant, tomato, cherry tomato, pumpkin, bitter gourd, okra, sweet corn, chicory, trevis, endive, tatsoi, onion, garlic chives, edamame, green bean, snap bean, broad bean, mushroom and the like can be mentioned. These may be mixed one kind or two or more kinds and packaged. Among them, from the viewpoint of good compatibility with cabbage and good appearance and freshness retention, vegetables mainly eaten without heating are preferred, and lettuces (lettuce, leaf lettuce, cos lettuce, sunny lettuce, salad turnip, sanchu, etc.), carrots, daikon radishes, kale, celery, spinach, komatsuna, mizuna, cucumbers, onions, peppers, paprika, endives, trevis, etc. are more preferred.

[0025] [Packaging container] The packaging container of the present embodiment is composed of a resin film described later. Examples of the form of the packaging container include known forms such as a bag shape, a sheet shape, a self-standing container, or its lid portion. Among them, from the viewpoint of stably exhibiting the freshness retention effect, a bag shape (packaging bag) is preferable. In the case of a bag shape, the size can be about 100 mm × 100 mm to 250 mm × 350 mm for the packaging of cut vegetables for general consumers. Further, in the case of a bag shape, it may or may not have a gusset. Known methods can be used for the manufacturing method of the packaging container. Also, in the case of making it bag-shaped, for bag-making, fusion sealing or wet sealing may be used. Fusion sealing looks better and has stronger seal strength.

[0026] [Resin film] (Raw material) From the viewpoint that cut vegetables can be visually recognized from the outside, the resin film is preferably transparent or translucent, and more preferably transparent. Also, it may be one with printing for the purpose of identifying cut vegetables or the like.

[0027] The synthetic resin constituting the resin film is not particularly limited as long as it can be used for packaging cut vegetables, and known ones can be used. For example, various polyethylenes and ethylene copolymers, polypropylene, polyamide resin, polyvinyl chloride, polystyrene, acrylic resin, polyester resins such as polyethylene terephthalate and polylactic acid, etc. can be mentioned. These may be homopolymers, may be copolymers of two or more types, or may contain two or more types of these homopolymers and copolymers.

[0028] Specific examples of the above various polyethylenes and ethylene copolymers include copolymers such as ethylene-vinyl alcohol copolymer, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, metallocene-linear low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-propylene copolymer, ethylene-α-olefin copolymer, or ionomers, etc. These may contain one or more types, or may be a mixture of these and other resins.

[0029] Examples of the polyamide resin include nylon. Nylon includes nylon 6, nylon 11, nylon 12, nylon 66, nylon 6·10, nylon 6·12, nylon 6·T, nylon 6·I, nylon 9T, nylon M5T, polymetaxylylene adipamide (MXD nylon), etc., which can be used alone or in combination of two or more. Among these, nylon 6, nylon 11, nylon 12 and combinations of two or more of them are preferred, and nylon 6 and combinations of two or more of them are more preferred.

[0030] Linear low density polyethylene (L-LDPE) is usually a copolymer of ethylene and a small amount of α-olefin. The type of α-olefin is not particularly limited. Typical α-olefins include α-olefins having 3 to 10 carbon atoms such as 1-butene, 1-hexene, 4-methylpentene-1, 1-octene, etc.

[0031] For example, when the cut vegetables to be packaged are heavy, it is preferable to use a multilayer film obtained by dry lamination, extrusion lamination, or coextrusion of polyethylene with films such as unstretched polypropylene, stretched polypropylene, unstretched nylon, stretched nylon, and stretched polyester. In addition, the resin film may be subjected to stretching treatment, annealing, etc., and further, a film provided with a sealant layer may be used. Among them, by performing stretching treatment, the rigidity, pinhole resistance, water vapor / oxygen barrier property, and appearance of the resin film can be improved. For example, stretched nylon, stretched polylactic acid, and stretched polystyrene are preferable.

[0032] The resin film may contain additives such as an anti-fogging agent, an anti-blocking agent, a heat stabilizer, a lubricant, an impact modifier, a processing aid, an antistatic agent, an ultraviolet absorber, an antioxidant, a weathering deterioration inhibitor, a filler, and a pigment, as long as the performance of the resin film is not impaired.

[0033] Specific examples of the above-mentioned anti-fogging agent include glycerin laurate, diglycerin laurate, decaglycerin laurate, glycerin monostearate, sorbitan stearate, and the like.

[0034] Examples of the above-mentioned anti-blocking agent include fine particulate inorganic compounds such as silica, alumina, aluminosilicate, and diatomaceous earth; fine particulate organic compounds such as polyethylene, crosslinked polyethylene, polymethyl methacrylate, and crosslinked polymethyl methacrylate. Among them, from the viewpoint of maintaining the freshness retention effect, fine particulate inorganic compounds are preferred, and silica is more preferred.

[0035] The method for obtaining the resin film is not particularly limited. Examples of the method for obtaining the resin film include known methods such as extrusion, inflation, and calendering.

[0036] The resin film may be a single layer or a multilayer of two or more layers.

[0037] (Multilayer film) By making the resin film multilayer, the desired functionality can be enhanced. For example, by adding functions such as slipperiness to the surface layer of the resin film, the handling property and heat sealability of the resin film can be improved, and a packaging container excellent in the balance between stretchability and rigidity can be stably obtained. Further, for example, by making the resin film into a two-layer or three-layer structure and using a layer containing an anti-blocking agent as at least one of the surface layers, slipperiness can be obtained. When the resin film is multilayer, the resins serving as the base for each layer may be the same as or different from each other. From the viewpoint of obtaining good adhesion between layers, it is preferable that the same resin is used for each layer.

[0038] When the resin film is multilayered, the thicknesses of the respective layers may be the same as each other or different. For example, in the case of a three-layer structure, the thickness of the intermediate layer may be the highest and the thickness of the surface layer may be low. The surface layer is preferably 10 to 20%, more preferably 12 to 17% of the total thickness of the resin film.

[0039] As a method for obtaining a multilayer film, known methods such as dry lamination, extrusion lamination, coextrusion, and coating can be appropriately used. From the viewpoint of improving the adhesion between layers and controlling the layer thickness, coextrusion is preferable.

[0040] (Oxygen transmission rate) The oxygen transmission rate of the resin film at 23°C and 60% RH is preferably 200 cc / m 2 ·day·atm or more, more preferably 1500 cc / m 2 ·day·atm or more, still more preferably 1800 cc / m 2 ·day·atm or more. On the other hand, the oxygen transmission rate of the resin film at 23°C and 60% RH is preferably 62500 cc / m 2 ·day·atm or less, more preferably 15000 cc / m 2 ·day·atm or less, still more preferably 10000 cc / m 2 ·day·atm or less. Further, when more importance is attached to airtightness, the range of 1500 to 2000 cc / m 2 ·day·atm is preferable, and the range of 1600 to 1980 cc / m 2 ·day·atm, or the range of 1800 to 1950 cc / m 2 ·day·atm is more preferable. Also, when importance is attached to the selectivity of cut vegetables in the package, the range of 3000 to 5000 cc / m 2 ·day·atm is preferable, and the range of 3500 to 4500 cc / m 2 ·day·atm, or the range of 3800 to 4300 cc / m 2·The range of ·day·atm is more preferable.

[0041] The oxygen permeation amount can be calculated from the oxygen concentration gradient by measuring the oxygen concentration in the packaging container for each of, for example, the packaging container immediately after being filled with nitrogen and the packaging container after being left for a certain period of time after being filled with nitrogen.

[0042] Also, in the present invention, the oxygen permeation amount of the resin film can be adjusted by controlling the selection of the material of the resin film, the film manufacturing method, the film layer structure, the presence or absence of through-holes, the average diameter of the through-holes, and the like.

[0043] (Thickness) The thickness of the resin film is preferably 5 to 300 μm, more preferably 10 to 200 μm, still more preferably 20 to 100 μm, and even more preferably 20 to 70 μm. By setting the thickness of the resin film to be equal to or greater than the above lower limit value, while enhancing the strength of the packaging container and suppressing deformation due to external stress, a freshness retention effect can be stably obtained. By setting the thickness of the resin film to be equal to or greater than the above upper limit value, the flexibility (pliability) of the packaging container can be maintained, and the headspace can be varied according to the amount of gas in the package.

[0044] (Through-hole) The resin film may have through-holes formed therein. Thereby, the oxygen permeability of the package can be easily adjusted. Thereby, while effectively maintaining the freshness of cut vegetables, the occurrence of discoloration and off-odor can be suppressed.

[0045] The planar shape of the through-hole may be, for example, circular, polygonal, or a slit. The circular shape is not limited to a perfect circle and includes a substantially circular shape. Also, in addition to the circular shape, a semi-circular shape or a crescent shape may be used. The polygon may be any shape surrounded by three or more line segments such as a triangle, a quadrilateral, and a pentagon. The slit is a cut or gap penetrating the resin film and may be a straight line, a curve, an L-shape, an X-shape, etc., and its length and the like are not particularly limited.

[0046] The average diameter of the through-holes is preferably 10 μm to 200 μm, more preferably 20 to 100 μm, even more preferably 40 to 80 μm, and still more preferably 50 to 70 μm. By setting it to be not less than the above lower limit value, the oxygen permeability of the package is improved, and the generation of abnormal odors is easily suppressed. On the other hand, by setting it to be not more than the above upper limit value, the MA effect can be maintained while preventing the intrusion of foreign matters, and the freshness of the cut vegetables can be easily maintained. Note that the average diameter of the through-holes is calculated assuming that the through-holes are perfect circles from the opening area of the through-holes.

[0047] When the resin film has a plurality of through-holes, from the viewpoint of ease of production, it is preferable that the diameters of all the through-holes fall within the above numerical range, but the diameters of some of the through-holes may be outside the range of 10 to 200 μm.

[0048] The hole density is appropriately set according to the oxygen permeability of the package, the headspace ratio, etc., but per package, it is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5.

[0049] The method for forming the above through-holes is not particularly limited, and known methods can be adopted. Examples of such known methods include a laser processing method, a needle processing method including a hot needle, and a method using a mold such as a roll cutter.

[0050] <Packaging method> The packaging method of hermetically packaging cut vegetables in a packaging container made of the resin film of the present embodiment satisfies the following (a) and (b), and at the time of the hermetic packaging, it contains 90% by mass or more of cut cabbage with respect to the total mass of the cut vegetables. (a) The ratio of the volume of air in the packaging container (cm 3 ) to the volume of the cut vegetables (cm 3 ) at the time of the hermetic packaging is defined as HS1, and the volume of the cut vegetables (cm 3The ratio of the air volume (cm 3 ) in the packaging container to is defined as HS2. When HS2 / HS1 is in the range of 1 to 1.5, (b) The oxygen concentration in the packaging container 72 hours after the sealed packaging is 0.1 to 20%. This can maintain the freshness of the cut vegetables and suppress the generation of off - odors of the cut vegetables. Note that the above conditions (a) and (b) are the same as those described for the above - mentioned package.

[0051] In the packaging method of this embodiment, it is preferable to store the package at an environmental temperature of 10°C or less. The environmental temperature refers to, for example, the temperature setting of the refrigerator or freezer where the package is stored, the set temperature of the temperature control of the showcase where the package is displayed at the storefront, etc. It does not intend to strictly measure the temperature around the package. Also, it is sufficient that the average environmental temperature is 10°C or less. Due to inevitable situations such as transportation of the package and opening and closing of the door, it may temporarily reach around 10°C.

[0052] In the packaging method of this embodiment, it is preferable to seal - package the cut vegetables together with the atmosphere in the packaging container. This can simply and stably obtain a package with an improved freshness - maintaining effect. In other words, it is preferable not to use the packaging container as a vacuum pack or perform replacement with a gas set to a predetermined composition.

[0053] As described above, the embodiments of the present invention have been described, but these are examples of the present invention, and various configurations other than the above can be adopted. Also, the present invention is not limited to the above - described embodiments, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention.

Examples

[0054] Hereinafter, the present invention will be described in detail based on examples and comparative examples. Just to be clear, the present invention is not limited to the examples.

[0055] [Example 1] · Preparation of Packaging Bag As the resin film, an anti-fog biaxially stretched polypropylene film manufactured by Gunze Co., Ltd., trade name "Silphan MV2" (thickness 25 μm) was prepared. The resin film was irradiated with a pulsed laser to provide holes (through-holes) with a diameter of 70 μm. The density of the holes was appropriately adjusted so that the value would be 2 holes / package (1 piece). Two pieces of the obtained resin film cut into a rectangle of a predetermined size were prepared, overlapped, and three sides of the rectangle were heat-sealed to create a bag-shaped packaging container (packaging bag) of the size shown in Table 1. For heat-sealing, P-300 manufactured by Fuji Impulse Co., Ltd. was used.

[0056] · Preparation of Package Fresh cabbages were prepared and cut into 1 mm widths using a slicer. The length of the cabbages was about 50 mm to 150 mm in order to correspond to the cabbage leaves. 130 g of the cut cabbages were sealed in the prepared packaging bag, and the opening was closed by heat-sealing to create a sealed package. At this time, in order to adjust the headspace ratio (HS1; the ratio of the air volume (cm 3 ) in the packaging container to the volume of the cut vegetable body (cm 3 ) at the time of sealed packaging) to 3, it was sealed so as to appropriately leave air (atmosphere) in the package. This was immediately stored at an environmental temperature of 10 °C (refrigerator, set temperature 10 °C).

[0057] · Measurement (1) The ratio (HS) of the air volume (cm 3 ) in the packaging bag to the volume of the cut cabbages (cm 3 ) at the time of sealed packaging (0 hours), 24 hours later, 72 hours later, and 96 hours later was calculated respectively. The measurement of the headspace (HS) was performed as follows. First, the package in which the cut cabbages were put into the packaging container and sealed was placed in a water tank filled with water, and the volume of the package was obtained from the volume of the overflowed water. On the other hand, the weight of the cut cabbages was measured, the volume was calculated as the specific gravity 1 of the cut cabbages, and the volume of the cut cabbages was subtracted from the volume of the package obtained above to obtain the headspace (cm of the package.3 ) was determined. (2) At the time of such sealed packaging (0 hours), 24 hours later, 72 hours later, and 96 hours later, the oxygen concentration in each packaging container was measured. The oxygen concentration was measured by the measurement method shown below. The results are shown in Table 1.

[0058] [Example 2] · Preparation of packaging bag As the resin film, an anti-fog biaxially stretched polypropylene film manufactured by Gunze Co., Ltd., trade name "Silfan MV2" (thickness 30 μm) was prepared. The resin film was irradiated with a pulsed laser with respect to the resin film to provide holes (through holes) having a diameter of 70 μm. The density of the holes was appropriately adjusted so as to be a value of 5 holes / package. Two pieces of the obtained resin film cut into a rectangle of a predetermined size were prepared, and these were overlapped, and three sides out of the four sides of the rectangle were heat-sealed to create a bag-shaped packaging container (packaging bag) having the size shown in Table 1. For heat sealing, P-300 manufactured by Fuji Impulse Co., Ltd. was used. Thereafter, in the same manner as in Example 1, a package was created and measurement was performed.

[0059] [Example 3] A package was created in the same manner as in Example 1, except that the density of the holes was appropriately adjusted so as to be a value of 1 hole / package. Thereafter, in the same manner as in Example 1, a package was created and measurement was performed.

[0060] [Comparative Example 1] A package was created in the same manner as in Example 1, except that through holes were not formed. Thereafter, in the same manner as in Example 1, a package was created and measurement was performed.

[0061] [Measurement method] [Oxygen permeation rate (cc / m 2 ·day·atm) at 23 °C and 60% RH] (1) Enclosure of nitrogen gas A bag was formed using a resin film. After sealing the bag by heat sealing or the like, the bag was degassed using an aspirator or the like. The degassing was performed until both sides of the bag adhered to each other. Next, the bag was filled with nitrogen gas (purity 99.9% or higher) using a white rigid syringe. The injection amount of the nitrogen gas was adjusted according to the bag size, and as much nitrogen gas as possible was injected within the range where the film constituting the bag was not tensioned and was slightly loose, and the measurement was made using the scale of the white rigid syringe. Note that the degassing and injection of the nitrogen gas were performed, for example, by piercing a syringe needle into the bag. When piercing the syringe needle, double-sided tape was attached to the film constituting the bag, and an adhesive tape made of polypropylene film (hereinafter referred to as "PP tape") was further attached thereon. Also, after removing the syringe needle, the needle hole was quickly closed with the PP tape. The tape attached to the bag was made to fit within an area of 4.5 cm 2 or less. Also, when the film constituting the bag was a microporous film, the micropores were not blocked with tape. (2) Measurement of initial oxygen concentration The initial oxygen concentration (C0) inside the bag immediately after filling with nitrogen gas (t = 0) was measured. The gas inside the bag was sampled, and the initial oxygen concentration (C0) inside the bag was determined by gas chromatography (TCD). C0 was 0.2% or less, and if it exceeded this value, the operation was repeated. The sampling gas for oxygen concentration measurement was 10 cc or less. When injecting into the gas chromatograph, a fixed amount of about 1 cc was injected. Also, the measurement of the standard gas (including two or more points of about 1% and about 10% oxygen) was performed by injecting the same amount of gas, and a calibration curve was created. (3) Storage of the bag The bag in which the initial oxygen concentration was measured was stored at 23°C and 60% RH (constant temperature and humidity chamber). At this time, it was left stationary so that no object was placed on the bag and the wind of the fan in the constant temperature and humidity chamber did not directly hit the bag. (4) Measurement of the oxygen concentration inside the bag during storage and calculation of the oxygen transmission rate The measurement of the oxygen concentration inside the bag shall be carried out by measuring a total of 3 to 5 points at 2 or more points within the range of 1% or more and 7% or less of the oxygen concentration immediately after nitrogen gas filling and 3 hours or more later. It is necessary that a proportional relationship (correlation coefficient of 0.98 or more) holds between the elapsed time t (hr) and the oxygen concentration inside the bag. If the correlation coefficient does not hold, a retest shall be conducted. If the oxygen permeation rate of the film constituting the bag is too high and the increase in the oxygen concentration inside the bag is too fast, and this condition cannot be cleared, a part of the film may be laminated with a film of the same known material whose oxygen permeation rate is smaller than the film being measured to create a bag and the same procedure may be carried out. At this time, excluding the part laminated with another known film, the oxygen permeation rate of the measured film is the oxygen permeation rate of the known film part subtracted from the obtained oxygen permeation rate. The oxygen permeation rate was calculated using the following calculation formula (1) with the value at the longer elapsed time. F = 1.143×(Ct - C0)×V / t (1) However, F: Oxygen permeation rate (cc / bag·day·atm) Ct: Oxygen concentration inside the bag t hours after nitrogen gas filling (%) C0: Oxygen concentration inside the bag immediately after nitrogen gas filling (%) V: Amount of nitrogen gas filled (cc) t: Elapsed time since gas filling (hr)

[0062] <Evaluation> For each of the packages obtained in the above examples and comparative examples, the following evaluations were carried out. The results are shown in Table 1. · Presence or absence of abnormal odor; After storing each package in a refrigerator at a set temperature of 10°C for 72 hours, a professional technician directly smelled the odor inside the package and evaluated the presence or absence of abnormal odor according to the following criteria. (Criteria) ◎ No abnormal odor was felt. ○ A faint abnormal odor was felt. △ An abnormal odor was felt. × A strong abnormal odor was felt.

[0063] ·Freshness retention days - 1; The contents were taken out from two samples (packages), and the total viable count was measured using a 3M Petri film (AC plate) for each. The number of days until the average value of the total viable count reached 10 6 or more was measured. A plurality of samples were prepared, and the measurement was performed once a day. Since the gas concentration in the package of the measured sample changed significantly, it was not used for subsequent measurements, and the process of performing the next day's measurement using another sample was repeated.

[0064] ·Freshness retention days - 2; The contents were taken out from two samples (packages), and the number of Escherichia coli was measured using a 3M Petri film (CC plate) for each. The number of days until the average value of the number of Escherichia coli reached 10 2 or more was measured. A plurality of samples were prepared, and the measurement was performed once a day. Since the gas concentration in the package of the measured sample changed significantly, it was not used for subsequent measurements, and the process of performing the next day's measurement using another sample was repeated.

[0065]

Table 1

Claims

1. A package in which cut vegetables are sealed and packaged in a packaging container made of a resin film, (a) The volume of the cut vegetables when sealed (cm ３ ) to the air volume (cm ) in the packaging container ３ The ratio of the volume of the cut vegetables (cm 3 ) after 72 hours at 10° C. from the sealed packaging is defined as HS1. ３ ) to the air volume (cm ) in the packaging container ３ ) is HS2, HS2 / HS1 is 1 to 1.5, (b) the oxygen concentration in the packaging container 72 hours after the sealing packaging is 0.1 to 20%; The package contains cut cabbage in an amount of 90% by mass or more relative to the total mass of the cut vegetables when sealed and packaged.

2. The package according to claim 1, (c) A package having an HS1 of 2.5 to 4.

0.

3. The packaging according to claim 1 or 2, The oxygen transmission rate of the resin film at 23° C. and 60% RH is 200 to 62,500 cc / m ２ A packaging material that is day atm.

4. The packaging according to any one of claims 1 to 3, (d) A package having an HS2 of 2.5 to 4.

0.

5. The packaging according to any one of claims 1 to 4, The packaging body is provided with a resin film comprising one or more resins selected from polyethylene, ethylene copolymer, polypropylene, polyvinyl chloride, polystyrene, acrylic resin, polyester resin, and polyamide resin, and / or a stretched version of the resin film.

6. The packaging according to any one of claims 1 to 5, The packaging body, wherein the resin film has a thickness of 5 to 300 μm.

7. The packaging according to any one of claims 1 to 6, The packaging body, wherein the resin film has a through hole.

8. The packaging according to any one of claims 1 to 7, The packaging body, wherein the packaging container is bag-shaped.

9. A packaging method for sealingly packaging cut vegetables in a packaging container made of a resin film, comprising: (a) The volume of the cut vegetables when sealed (cm ３ ) to the air volume (cm ) in the packaging container ３ The ratio of the volume of the cut vegetables (cm 3 ) after 72 hours at 10° C. from the sealed packaging is defined as HS1. ３ ) to the air volume (cm ) in the packaging container ３ ) is HS2, HS2 / HS1 is 1 to 1.5, (b) the oxygen concentration in the packaging container 72 hours after the sealing packaging is 0.1 to 20%; The packaging method, wherein the cut cabbage comprises 90% by mass or more of the total mass of the cut vegetables during the sealed packaging.

10. 10. The packaging method of claim 9, Packaging method: Store at an environmental temperature of 10°C.

11. The packaging method according to claim 9 or 10, The packaging method comprises hermetically packaging the cut vegetables together with the atmosphere in the packaging container.

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