JP2787269B2 - Food packaging material and food preservation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food packaging material and a method for preserving food. More specifically, packaging having characteristics that the food is hardly adhered to the packaging material when the emulsified aqueous food is packaged in a packaging material such as a film, a tray, a sheet, and stored at a low temperature, and then the packaging material is peeled off from the food. The present invention relates to a material and a storage method using the packaging material.

[0002]

2. Description of the Related Art Raw materials and properties of foods, or preservation thereof,
Processing conditions are also various, and suitable packaging materials have been developed and used. For example, when the food is packaged in contact with the packaging material, stored and processed, and then the packaging material is removed, the adhesive strength between the food and the packaging material is greater than the structural viscosity (or cohesion) of the food itself. This causes an undesirable phenomenon that a part of the food adheres to the packaging material. As a method for solving such a problem, for example, a method is used in which a release agent is kneaded into a resin film as a packaging material, and the action of the release agent that leaches out to the film surface with the passage of time is employed.

[0003] For example, Japanese Patent Application Laid-Open No. 2-127236 discloses a tray for fermented steamed food, which is formed by kneading a release agent into a heat-resistant plastic raw material that can withstand the temperature of steam steam and forming the mixture into a tray. ing. Examples of the plastic raw material include polypropylene and high-density polyethylene. In addition, polyethylene glycol as a food additive emulsifier, glycerin esters of higher fatty acids, sucrose esters, and the like are used as release agents. As a specific example, 100 parts of polypropylene contains 4 parts of glycerin ester of polyethylene glycol ("Polyethylene glycol" and "glycerin ester of higher fatty acid" are shown in the detailed description of the invention) in the final tray. It is added at such a ratio. Further, it is described that, even when steaming the fermented raw material such as Amman or Butaman on a tray, the release agent is leached on the tray due to the heat, and the steamed product does not stick to the tray.

[0004]

By the way, chocolate cream, custard cream, mayonnaise and the like contain fat, but the fat is dispersed in water in an emulsified state, so-called oil-in-water (O / W) type. Food
Again disperse in water. Such emulsified foods dispersed in water (hereinafter referred to as "emulsified aqueous foods" in the present invention) are packaged in direct contact with these foods in the process of distributing the foods and in the process of using them for other foods. As the packaging material to be used, films, sheets, trays, cups and the like made of synthetic resin are used. However, after packaging and storing in such a packaging material, in order to take out only the food, when trying to peel the packaging material from the food, a part of the food is packaged in the same manner as in the case of Amman. Not only does it adhere to the material and the peeling operability is poor, but also the appearance of the taken out food is disturbed or the food is lost. Such a phenomenon often occurs when the food has low structural viscosity or cohesion.

[0005] In the packaging of the emulsified aqueous food as described above, after it is packaged in a packaging material, the temperature is usually lower than room temperature by a refrigerator or the like and the food is not frozen.
In the present invention, it is defined as "low temperature". ), And is not usually heated to a temperature much higher than room temperature together with the wrapping material before it is peeled and used, as in the case of steaming Amman or Butaman. In the packaging of such low-temperature storage emulsified aqueous food, JP-A-2-12-1
The leaching of the release agent onto the surface of the packaging material by heat and the effect of preventing the food from adhering to the packaging material due to the heat, which is the premise of the invention described in Japanese Patent No. 27236, cannot be expected. However, there are problems such as the necessity of further increasing the amount of the release agent, and new measures have been required.

[0006]

SUMMARY OF THE INVENTION The inventors of the present invention have proposed a method for storing an emulsified aqueous food having a low storage temperature together with a packaging material as described above and a small structural viscosity after storing the food. As a result of diligent research to develop a packaging material having excellent releasability in which little food adheres to the packaging material even if it is peeled off, a polyolefin-based blended with a specific amount of an additive having a specific freezing point and HLB The present inventors have found that a packaging material obtained from a resin is extremely effective, and have completed the present invention.

That is, according to the present invention, an additive (B) having a freezing point of 10 ° C. or less and an HLB (hydrophilic lipophilic balance) of 5.0 or less is added to 100 parts by weight of the polyolefin resin (A). The present invention relates to a low-temperature storage emulsified aqueous food packaging material comprising the composition (C) blended in a range of 3 to 3 parts by weight. Further, the present invention provides the packaging material, wherein the additive (B) selected from the group of fatty acid esters of monohydric or polyhydric alcohols and epoxy compounds and having an HLB in the range of 2.0 or less is a polyolefin resin (A). ) 100
It relates to a composition comprising a composition blended in a range of 0.5 to 2 parts by weight with respect to parts by weight. Further, in the present invention, in the packaging material, as a target food, the viscosity of a food diluted with water of equal weight by an E-type viscometer is V (centipoise), and the shear rate at the time of measurement is S (sec ^-1 ). , Temperature 10
° C at a shear rate of 1.5 to 1000 sec ^-1
The slope of the line representing logV with respect to gS is 0.8 to 0.
Regarding what is 3. Further, the present invention relates to the packaging material, wherein the storage temperature of the target food is 10 ° C. or less. Further, the present invention relates to a polyolefin resin (A) 10
0 parts by weight, the freezing point is 10 ° C. or less, and HL
The present invention relates to a low-temperature preservation method for emulsified aqueous food, characterized by using a packaging material comprising a composition (C) in which an additive (B) having B of 5.0 or less is blended in a range of 0.3 to 3 parts by weight. .
Hereinafter, the present invention will be described in detail.

In the present invention, the polyolefin resin (A) serving as the base material of the composition (C) is not particularly limited as long as it can be molded into packaging materials such as films, trays, sheets, etc. LDPE), linear low density polyethylene (LLDPE), high density polyethylene (H
DPE), polypropylene, polymethylpentene, and the like. These are used individually,
Two or more kinds may be mixed and used for the purpose of improving the moldability and the mechanical properties of the packaging material. Particularly, polyethylene is suitable as the polyolefin resin of the present invention. Furthermore, as long as the effect of the present invention is not impaired, even if an ethylene-vinyl acetate copolymer or a modified polyolefin-based resin is mixed and used, it also improves the machine suitability for rollers and forming plates of an automatic filling and packaging machine. For the purpose, a slipping agent such as an organic amide, silica, calcium carbonate, talc or the like may be added in a proportion of about 0.1 to 5 parts by weight to the polyolefin resin.

The freezing point of the additive (B) used in the present invention is 10 ° C. or lower, preferably 5 ° C. or lower, more preferably 0 ° C. or lower. By using an additive having a lower freezing point, it is possible to achieve the object of the present invention without unnecessarily increasing the amount of the additive because the additive is easily leached on the surface of the packaging material because it is liquid at a temperature exceeding the freezing point. it can. Further, since the exuded additive does not solidify, the packaging material is not clouded by the solidification of the additive, which is preferable. The HLB of the additive (B) used in the present invention needs to be 5.0 or less, preferably 2.0 or less, and more preferably fats and oils (HLB: 0). By using one having an HLB of 5.0 or less, the additive can be easily and uniformly compounded in the polyolefin-based resin, and even if the compounding amount is slightly increased, the film-forming performance when forming into a film is good. .
Further, by using an additive having an HLB of 5.0 or less,
The object of the present invention can be achieved without unnecessarily increasing the amount of the additive. Conversely, if an additive having an HLB of 5.0 or more is used, the additive will leach out during the production of the masterbatch, making it impossible to obtain a uniform dispersion of the additive in the packaging material or to make the packaging material sticky. For this reason, inconveniences such as a decrease in suitability for a packaging machine may occur.

The mixing ratio of the additive (B) to the polyolefin resin (A) is in the range of 0.3 to 3 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the former. is there. Generally, the smaller the HLB additive is,
The effect of the present invention can be easily exerted even if the amount is small. By ensuring that the amount is at least the lower limit specified in the present invention, good releasability from the low-temperature storage emulsified aqueous food is ensured, and by setting the amount to be no more than the upper limit, stickiness of the resulting packaging material such as a film is suppressed. Therefore, it is easy to handle and troubles in the packaging machine and the like can be prevented.

Examples of such additives (B) include butyl oleate (freezing point: -10 ° C. or less, HLB: 0), di-n-hexyl adipate (freezing point: -8 ° C., HLB:
0), di-2-ethylhexyl adipate (DOA, freezing point: -75 ° C, HLB: 0), azelaic acid di-2-
Ethylhexyl (freezing point: -65 ° C, HLB: 0), dibutyl sebacate (DBS, freezing point: -11 ° C, HL)
B: 0), di-2-ethylhexyl sebacate (freezing point: -55 ° C, HLB: 0), butyl acetyl ricinoleate (freezing point: -32 ° C or less, HLB: 0), tributyl acetylcitrate (ATBC, freezing point: -80 ° C, H
Monohydric or polyhydric fatty acid esters of monohydric alcohols such as LB: 0), triglycerides of fatty acids having 8 to 22 carbon atoms (freezing point: -5 to -12 ° C, HLB: 0), polyglycerin fatty acid esters (freezing point:- 10 to 10 ° C, HL
B: 1.5 to 5.8, 5.0 or less)
Fatty acid esters of polyhydric alcohols such as epoxidized soybean oil (HLB: 0), epoxidized linseed oil (HLB: 0)
And the like. Among these, those having an HLB of 2 or less, particularly those having an HLB of 0 are preferably used. Note that the additive (B) is preferably selected from compounds that are approved to be added to a food packaging resin because of a high possibility of contact with food.

In order to produce the packaging material of the present invention, a composition is first produced from a predetermined amount of the polyolefin resin (A) and the additive (B), and then formed into a film, sheet, tray or the like by a known method. do it. Alternatively, a packaging material may be produced directly from a mixture of both. In this case, a relatively large amount and a predetermined amount of the additive (B) are mixed in advance with the polyolefin resin (A) to form a masterbatch pellet, which is then mixed with unblended polyolefin resin (A) pellets and molded. Is preferred. The packaging material of the present invention is usually a single layer, but may be a laminate with another resin as long as the surface in contact with food is a film or the like obtained from the composition specified in the present invention.

Although the thickness of the packaging material of the present invention is not particularly limited, it is usually set in consideration of moldability, peelability, strength, economy and the like. For example, in the case of a film, usually 10 to 1
It is in the range of 50 μm, preferably 20-70 μm.

Foods to which the packaging material of the present invention is particularly preferably applied are pastes at storage temperatures, and oil-in-water (O / W) such as chocolate cream, mayonnaise and custard cream. Is an emulsified aqueous food. The packaging material of the present invention is applied to such emulsified aqueous foods which are stored at a low temperature of normal temperature or lower, preferably 10 ° C or lower, more preferably 5 ° C or lower.

Particularly preferred foods to which the packaging material of the present invention is applied are those having a low structural viscosity. That is, although there is a predetermined lower limit as described below,
In general, the smaller the structural viscosity of food, the smaller the shape retention and cohesion of the food itself, and the easier it is for the food to adhere to the packaging during peeling, even if the adhesion between the packaging and the food is low. is there. The packaging material of the present invention is also effective for foods having a low structural viscosity, and the significance of using the packaging material of the present invention increases. As an index of the structural viscosity of the food, when the viscosity of the food diluted with water of the same weight is determined by V (centipoise) by an E-type viscometer and the shear rate at the time of measurement is S (sec ⁻¹ ), the temperature is 10
° C at a shear rate of 1.5 to 1000 sec ^-1
The slope of a straight line representing logV with respect to gS can be used. The target food for which the packaging material of the present invention is suitably used has a slope of 0.8 to 0.3, preferably 0.5 to 0.3.
It is in the range of 0.3. When the inclination is smaller than 0.3, the property of the food becomes close to that of water, and the food does not easily adhere to the packaging material without using the packaging material of the present invention, and the packaging material of the present invention is used. Significance is reduced. On the other hand, the food having the inclination exceeding 0.8 also has a high structural viscosity, so that the food does not easily adhere to the packaging material to which the additive is not added, and similarly, the significance of using the packaging material of the present invention is reduced.

[0016]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.

(Examples 1 to 13, Comparative Examples 1 to 7) LDP
E (melt index 2g / 10min) 30% by weight and L
LDPE (melt index 0.8 g / 10 min) 70
Table 100 parts by weight of the resin pellet mixture consisting of
A film having a thickness of 50 µm was formed by a direct inflation method from a composition in which the additives shown in Tables 1 and 2 were blended in the proportions shown in Tables 1 and 2. Table 3 shows the abbreviations of the additives and the compound names.
Using a film left at room temperature for 2 days after molding, a commercially available chocolate cream (water content of 4
4.8% by weight, fat content by Soxhlet extraction method 2
9.2% by weight) and commercial custard cream (1)
Approximately 100 g of each (the same water content of 42.7% by weight and the same fat content of 29.2% by weight) were shaped into a plate of 12 × 15 × 0.5 cm and the whole was packaged. In addition, the temperature of the chocolate cream and the custard cream (1) at the time of packaging were both 60 ° C. Next, the packaged food was rapidly cooled to 5 ° C., left in a refrigerator at 5 ° C. for 3 days, and then subjected to a manual peeling sensory test. The results are shown in Tables 1 and 2. The custard cream (1) and the chocolate cream were each diluted with an equal weight of distilled water, and the mixture was diluted with an E-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) at a temperature of 10 ° C. and a shear rate of 1.5 to 1000 sec ⁻¹ . When the slope of a straight line represented by logV (vertical axis in FIG. 1) with respect to −logS (horizontal axis in FIG. 1) was obtained, they were 0.65 (plotted with ○) and 0.38 (plotted with ●), respectively. Was.

In the evaluation results of the peeling test in Tables 1 and 2, ◎ indicates that the food did not adhere to the film at all and the peelability was very good, ○ indicates that the food hardly adhered, and Δ indicates that the food slightly adhered. , × indicate that the adhesion was extremely poor.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

REFERENCE EXAMPLE To the custard cream (1) used in Example 1, 1.25% by weight of a thickener (xanthan gum) was added to obtain a custard cream (2). The custard cream (2) was similarly packaged with each of the films used in Comparative Examples 1, 2, 4, 6, and 7, and Examples 5, 8, and 11, and subjected to a manual peeling sensory test.
As a result, the custard cream (2) did not adhere to any of the films at all, and the peelability was very good (良好). In addition, about custard cream (2), logV with respect to -logS was measured with an E-type viscometer similarly to Example 1.
(Indicated by the squares in FIG. 1) was found to be 0.90.

[0023]

As described above in detail, by using the packaging material and the method for preserving food at a low temperature provided by the present invention, an emulsified aqueous food having a low storage temperature and a low structural viscosity at room temperature or lower can be obtained. Even if the packaging material is peeled off after being packaged and stored, little adhesion of food to the packaging material is observed.

[Brief description of the drawings]

FIG. 1 shows a linear relationship of logV to -logS measured by an E-type viscometer for foods used in Examples and the like.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hitoshi Morii 3-33, Ueda-cho, Iwaki City, Fukushima Prefecture (72) Inventor Fumio Honjo 3576-1, Kashiwara-cho, Kashiwara-cho, Hikami-gun, Hyogo (56) References JP Akira 50-33090 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) A23L 1/00 B65D 65/02 C08K 5/00 C08L 23/00

Claims (5)

(57) [Claims] 1. An additive (B) having a freezing point of 10 ° C. or less and an HLB of 5.0 or less, in an amount of 0.3 to 3 parts by weight, based on 100 parts by weight of the polyolefin resin (A). A packaging material for low-temperature storage emulsified aqueous food, comprising the blended composition (C). 2. HL selected from the group of fatty acid esters of monohydric or polyhydric alcohols and epoxy compounds
A composition comprising an additive (B) in which B is in the range of 2.0 or less and 0.5 to 2 parts by weight per 100 parts by weight of the polyolefin resin (A). Item 4. A packaging material for low-temperature storage emulsified aqueous food according to Item 1. 3. When the viscosity of a food diluted with water of the same weight is measured with an E-type viscometer as V (centipoise) and the shear rate at the time of measurement is S (sec ^-1 ), the temperature is 10 ° C. and the shear rate is 1. The packaging material for low-temperature storage emulsified aqueous food according to claim 1, wherein the food is packaged such that the slope of a straight line representing logV with respect to -logS at 5 to 1000 sec- ¹ is 0.8 to 0.3. 4. The packaging material for low-temperature storage emulsified aqueous food according to claim 1, wherein the storage temperature of the food is 10 ° C. or lower. 5. An additive (B) having a freezing point of 10 ° C. or less and an HLB of 5.0 or less based on 100 parts by weight of the polyolefin resin (A) in an amount of 0.3 to 3 parts by weight. A method for preserving an emulsified aqueous food at a low temperature, comprising using a packaging material comprising the composition (C).