JPS60110239A - Method for storing salted herring roe - Google Patents

Abstract

PURPOSE:To store salted herring roe stably for a long period without deteriorating the commodity value, by sealing and packaging a drained herring roe with a disoxidizing agent in an oxygen-permeation resistant material, reducing the oxygen concentration in the interior of the packaging material at the start of the storage at a low temperature, and specifying the operating time. CONSTITUTION:Drained salted herring roe is sealed and packaged, and stored at <=0 deg.C temperature. In the process, the drained salted herring roe and disoxidizing agent, e.g. sodium dithionite, are sealed and packaged in a material having improved oxygen permeation resistance, e.g. polyamide film coated with vinylidene chloride resin. The oxygen concentration in the interior of the packaging material at the start of the storage at <=0 deg.C temperature is reduced to <=4%, and the operating time from the draining to the storing is within 8hr to store the salted herring roe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for storing salted herring roe, and more particularly to a method for storing salted herring roe that can be stored stably over a long period of time without reducing its commercial value.

Conventionally, salt roe is stored in a synthetic resin tray, shrink-wrapped, and refrigerated at -15 to -18°C. However, even in this refrigerated storage, salt roe undergoes browning called ``oil burn'' due to oxidation of fats and oils, and there is a problem in that the commercial value decreases to a large extent.

In order to solve this problem, the present inventors have already proposed a new packaging method of packaging herring roe in the coexistence of an oxygen absorber using a specific packaging material (Japanese Patent Application No. 178,269/1982). According to this packaging method, it is possible to considerably prevent the browning that occurs during storage of salted herring roe, but the amount of oxygen absorber used and after draining are sealed.

Depending on the working conditions prior to storage, and depending on the first step in the filling method for herring roe, browning may occur even during long-term storage at low temperatures below 0°C, which is commonly used, and deterioration such as loss of gloss may occur. It turns out that a phenomenon occurs.

Therefore, the present inventors investigated the most common storage form, 0°C.
As a result of intensive research into a stable storage method for salted herring roe that does not cause browning or loss of luster even during long-term storage at the following low temperatures, we have found that the process from draining salted herring roe to storage can be done within a specified amount of time. It has been discovered that the above-mentioned problems can be solved by using a specific packaging material and reducing the oxygen concentration inside the packaging material to a predetermined value or less at the start of storage, and based on this knowledge, the present invention was completed.

That is, the present invention is a method of tightly packaging drained salted herring roe and then storing it at a temperature below 0°C. In addition, the salt herring roe is characterized in that the oxygen concentration inside the package R+4 is 4% or less when storage starts at a temperature of 0°C or less, and the working time from draining to storage is within 8 hours. The present invention provides a storage method.

Salted herring roe is usually made by cleaning, bleaching, and salting raw eggs.

It is manufactured through a draining process. Next, the salted herring roe goes through a process of sorting, weighing, storing in a container, sealing, packaging, and refrigeration before being stored.

In the present invention, drained salted herring roe is sorted and weighed, and then sealed and packaged in a material with excellent oxygen permeation resistance in the presence of an oxygen scavenger.

There are no particular restrictions on the form of sealed packaging used in the present invention, as long as it can prevent oxidation of the salted herring roe. For example, after storing salt roe in a tray made of an oxygen-permeable material such as polystyrene or expanded polystyrene, the whole thing is sealed and packaged with a resin film that has excellent oxygen permeability. For example, after storing salt roe in a tray, it is tightly wrapped with a lidding film that has excellent oxygen permeability.

Here, resin films with excellent oxygen permeability are:
For example, films such as ethylene-vinyl acetate copolymer saponide, polyvinylidene chloride, polyacrylonitrile, polyamide, polyester, polyvinyl chloride, vinylidene chloride, polyvinylidene chloride coated polyamide film, polyvinylidene chloride coated polyester film, etc. These films may be used as a single layer film or as a multilayer film of two or more types.Additionally, polyethylene resins, ethylene-vinyl acetate copolymers, and ionomer resins.

It can also be used as a multilayer film with polypropylene resin or the like.

In addition, the material used for the tray, which is made of a material with excellent oxygen permeability, is the same as the above-mentioned film, but it has a multilayer structure made of a resin with excellent oxygen permeability and a polyolefin resin, especially a polypropylene resin. Preferably, it is made of material. Here, the polypropylene resin includes, in addition to a propylene homopolymer, a random copolymer of propylene and ethylene or an α-olefin having 4 or more carbon atoms, a block copolymer, or a mixture thereof. In the present invention, it is preferable to use a multilayer structure material containing a polypropylene resin because the polypropylene resin has a moisture permeability resistance of 1 strength.

This is because properties such as rigidity, water resistance, oil resistance, and heat resistance are most suitable for the packaging form of the present invention. Therefore, for example, ethylene polymers, copolymers of ethylene and α-olefins, copolymers of ethylene and unsaturated carboxylic acids, ethylene-propylene elastomers, etc. can be added as long as these purposes are not impaired.

The tray preferably used in the present invention is usually made by co-extruding a resin with excellent oxygen permeability and a polypropylene resin to obtain a laminated sheet, and then forming the laminated sheet by thermoforming means such as vacuum or compressed air for the food to be packaged. It is obtained by molding it into the most suitable shape. In addition to the tray made of a two-layer laminated material, if necessary, the outer layer may be made of polypropylene resin as the third layer, or a material laminated with a material other than polypropylene resin, such as polystyrene resin. In addition, a more aesthetic container can be made by laminating metallized films such as apgnium, colored films, printed films, etc.The layer ratio of the laminated materials depends on the storage period, oxygen gas permeation of the resin, etc. The shape of the tray may be determined by taking into consideration the temperature, moisture permeability, etc., and the shape of the tray may be any shape as long as it can accommodate a predetermined amount of herring roe and an oxygen scavenger.

Next, as the oxygen absorber used in the present invention, those generally used for various food packaging can be used, and specifically, dithionite, sulfite, bisulfite, etc. can be used. , pyrogallol, iron, zinc, and other reducing substances as main ingredients. Particularly suitable are those containing iron and metal halides, sodium dithionite, calcium hydroxide, and activated carbon. If necessary, these oxygen scavengers are mixed with fillers, or supported, and then packaged in a powder, tablet, plate, or the like, and packaged in a breathable material.

The oxygen scavenger may contain an agent that has oxygen scavenging ability and generates carbon dioxide gas. Hereinafter, a packaging form using an oxygen-resistant permeable resin tray and a lidding film will be specifically explained.

That is, after storing herring roe in a tray in the presence of an oxygen scavenger, the seventh rank portion of the container body is sealed with a lidding film made of a resin with excellent oxygen permeability. There are various kinds of lidding films used here without particular limitation, such as polyamide film, vinylidene chloride coated polyamide film, ethylene-vinyl acetate copolymer saponified film, vinylidene chloride coated polyester film, polyvinylidene chloride film, etc. There is.

These films can be used not only as a single layer film but also as a laminated film 11 of two or more types. Furthermore, laminated films with tampons, polyethylene films, ethylene 7-vinyl acetate copolymer films, ionomer resin films, polypropylene films, etc., which improve heat fusion properties with the container body, are also preferably used.

Sealing with the lidding film can be performed by various methods, but preferably by a heat sealing method or a method using a pressure-sensitive adhesive.

Furthermore, in the present invention, the child 0 of the base number is hermetically packaged as described above.
It is necessary to keep the oxygen concentration inside the packaging material at 4% or less when starting storage at a temperature below .degree. Oxygen concentration can be detected by conventional methods using an oxygen detector.

In order to reduce the oxygen concentration inside the packaging material to 4% or less, an oxygen absorber is used as described above, but in this case, the amount of oxygen absorber used is at least 2.5 times, preferably 3 times, the specified amount. As described above, it is desirable to reduce the oxygen concentration in a short time.

Here, the specified usage amount of the oxygen absorber refers to the waste that reduces the oxygen concentration in the package U to 0.1% or less after 12 hours. The activity of oxygen scavengers decreases at low temperatures below 0°C, but during storage the oxygen gas concentration can be reduced to 4.
% or less. Further, the oxygen scavenging ability is maintained during storage, and becomes active again when taken out after storage for a predetermined period and placed in a circulation mechanism at room temperature. Therefore, even after storage is released, browning of the radix roe can be prevented.

Furthermore, in the present invention, it is necessary that the working time from the draining step to the storage step be within 8 hours, preferably within 5 hours. Further, the work from the draining step to the sealing packaging step with the lidding film should be within 60 minutes, preferably within 30 minutes. If the working time exceeds 8 hours, it is not preferable because the gloss will decrease due to the temperature of the radix.

The radix child that has gone through the above operations should be stored below 0°C, preferably below 15°C, for example in a freezer commonly used as a freezer.
It lasts for a desired period of time at temperatures between .degree. C. and -20.degree.

According to the present invention, the storage stability of the radix child is good;
The herring roe does not brown or lose its luster, and can be stored for a long time without reducing its commercial value.

Next, the present invention will be explained in detail with reference to examples.

Example 1 500 g of drained radish roe was placed in a multilayer container tray (boriglobylene/saponified ethylene-vinyl acetate copolymer/polypropylene = 190μ/20μ/190μ) 200
It was stored in imX 250mrnX 20y+m together with three times the predetermined amount of iron-based oxygen scavenger. Next, a three-layer lidding film (polyvinylidene chloride coated polyamide/saponified ethylene-vinyl acetate copolymer/unstretched polypropylene - 15μ/12μ730μ) was sealed and packaged on the flange of the container body using the polypropylene layer as an adhesive layer by heat sealing. did. It was then refrigerated at -5-c. The time from draining the roe to refrigeration was 2.5 hours, and the oxygen concentration in the container was 2.5%.

When refrigerated in this state, a sensory test of browning dust by visual observation of the salted herring roe after one month revealed a significant difference in the x2 test compared to the current packaging form.

It should be noted that almost no decrease in gloss was observed, and there were no quality problems.

Comparative Example 1 Storage was carried out in the same manner as in Example 1, except that a predetermined amount of deoxidizing agent (iron-based) was used.

The oxygen concentration in the container at the start of refrigeration was 10%. After one month, the browning dust observed visually on the salted herring roe was not significantly different from that of the current 1j packaged product.

Comparative Example 2 The same procedure as in Example 1 was carried out for one month except that the amount of oxygen scavenger (iron-based) used was a predetermined amount and the time from draining the salted herring roe to refrigeration was 10 hours. Stored. However, in this case, the gloss had already decreased at the start of refrigeration, and the product had low commercial value.

Patent applicant: Idemitsu Petrochemical Co., Ltd.

Claims (1)

[Claims] 1. In the method of sealing and packaging the drained salted herring roe and then storing it at a temperature below 0''C, the drained salted herring roe is hermetically packed in a material with excellent oxygen permeability in the coexistence of an oxygen scavenger, and A method for storing salt herring roe, characterized in that the oxygen concentration inside the packaging material is 4% or less when storage is started at a temperature of ``C or less, and the working time from draining to storage is within 8 hours.