JP4730778B2 - Freezing pretreatment method and pretreatment electrode for bivalves - Google Patents

Description

  The present invention relates to a freezing pretreatment method for preserving bivalves such as clams, clams, red shellfish and oysters while maintaining quality, and a pretreatment electrode used for the pretreatment.

  Various refrigeration and freezing techniques have been developed in order to maintain the quality and freshness of foodstuffs, and the freezing technique has become widespread because it preserves various foodstuffs for a long period of time. Technically, the utilization rate of quick freezing methods such as block freezing and IQF (Individual Quick Frozen) to maintain the quality of foodstuffs increased, and special processing such as voltage processing and electric field processing was adopted during freezing. Freezing methods are also being developed. In addition, freezing degeneration inhibitors and techniques for adjusting the moisture content of foods have been introduced as pre-treatments for freezing, and foods such as meat, fish, vegetables, and processed foods are being frozen and can be frozen while maintaining high quality. is there.

  Moreover, as a method for separating the shellfish and shellfish from the bivalve shellfish, one that is immersed in low temperature hot water at about 30 to 80 ° C. for 20 to 80 seconds as a pretreatment for cooking is known (for example, (See Patent Document 1).

  In addition, in order to produce frozen fresh vegetables with high freshness, it is known that a fresh vegetable is rapidly cooled to a predetermined temperature under the action of a static magnetic field and a variable magnetic field in a closed space in a freezer and then immediately frozen at that temperature. (For example, refer to Patent Document 2).

JP-A-9-98713 JP 2004-81133 A

  However, shellfish, especially those obtained by freezing bivalves, have a problem in that there are many bivalves that lose their commercial value because current freezing techniques often cause poor opening that prevents the shells from opening during cooking.

  In addition, most frozen bivalve products freeze completely boiled, but most of the umami is lost during the boiling process, and it is frozen in a state containing a large amount of water, so it is prone to freeze denaturation. There has been a problem that the texture of the soft body (meat) is extremely lowered. Other pretreatments include a state in which half of the shell is removed (half shell) and a freezing method in which the front and rear closed shell muscles (shells) engaged in opening and closing the shell are individually cut. However, all this method is currently performed manually, and low processing capacity and high cost are problems.

  Furthermore, the method according to Patent Document 1 is not a treatment method in which quality is maintained, but the protein is denatured by low-temperature hot water treatment, and even if the bivalve mollusks after the denaturation are frozen, they are frozen and denatured as described above. In addition to a decrease in feeling, there was a problem that umami components were lost.

  In addition, although the method according to Patent Document 2 is effective for raw vegetables, when applied to bivalves, sufficient voltage is not applied to the front and rear closed shell muscles (shells). There was a problem of not opening when thawed or cooked after freezing.

  The present invention solves or improves these problems, and provides a freezing pretreatment method for preserving bivalves while maintaining freshness, and a pretreatment electrode used for the pretreatment.

The bivalve pretreatment method for bivalve of the present invention for solving the above-mentioned problem is as follows. First, the bivalve S before freezing is interposed between the electrodes 1 and 1 to which a voltage of | 5 to 30 | kV is applied. It is characterized by improving the aperture ratio during cooking after freezing.

  Secondly, a bivalve S is sandwiched between the electrodes 1 and 1.

  3rdly, the thing which stuck the insulating cover 4 which consists of an insulating member on the opposing surface of each electrode 1 is used as the electrode 1, and it is characterized by pinching a bivalve.

  A fourth feature is that a high voltage is applied to the bivalve shell S by holding the bivalve shell S in the holding means that moves and passes relative to the electrodes 1 and 1 between the electrodes 1 and 1.

  Fifth, the applied voltage is AC, DC, or pulse voltage.

In addition, as for the bivalve pretreatment freezing electrode, first, an insulating cover 4 made of an insulating member is attached to each facing surface of a pair of flat plate plates 2 and 2 which are connected to a high voltage applying device and face each other. The bivalve shell S is sandwiched through the insulating cover 4 and a voltage of | 5 to 30 | kV is applied between the electrode plates 2 and 2 .

  Second, the discharge space 6 is provided in the center of each insulating cover 4.

  Third, the insulating cover 4 is provided at the center position of the electrode plate 2, and the discharge space 6 is provided on the outer peripheral side of the insulating cover 4.

  According to the bivalve pretreatment method for freezing bivalves according to the present invention configured as described above, sufficient energization is possible for the front and rear closed shell muscles (shells), so that the opening ratio when cooking after freezing treatment is set. Can be raised.

  Further, according to the pretreatment method, the influence on the meat is reduced as compared with heat treatment such as boil, and further, freezing denaturation after the freezing treatment is suppressed, and the umami component can be shipped in a confined state. .

  Furthermore, the electrode for carrying out the above method is capable of reliably grasping (clamping) the bivalve by providing an insulating cover between the electrode and the bivalve, and providing the discharge space to provide an inside of the discharge space. In the air, an electric discharge occurs, the potential moves to the shell surface, and a high voltage can be applied to the bivalve equivalently.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present invention, a high voltage is applied as a pre-freezing treatment for clams such as clams, clams, and red clams, and the slow freezing treatment is performed in a normal freezer. And it distribute | circulates through a wholesale store and a retail store, maintaining a frozen state, and it is delivered to a consumer's hand, thaw | decompresses, or uses for cooking in a frozen state.

  As shown in FIG. 1, a high voltage is applied to the bivalve S in a state of being sandwiched between two plate-like electrode plates 2 and 2 connected to a voltage application device (not shown) via an energization unit 3. The The electrode 1 shown in FIG. 1 is a basic electrode used when there is little moisture outside the shell of the bivalve S. In this case, as shown in FIGS. Electrodes are arranged at both ends in the direction to apply a high voltage. The electrode plate 2 can be made of a metal material such as stainless steel, brass, or aluminum, or other conductive material, and preferably has corrosion resistance.

  Energization was performed by sufficiently contacting the electrode plates 2 and 2 and the outer shell of the bivalve S, energization conditions were ± 5 to 30 kV (high voltage), current was several mA, and energization time was within minutes.

  Next, the determination of the effect when the high voltage application process is performed by the above method will be described. The inventors boiled the frozen bivalve after the energization process and visually determined the openness of the shell.

  As shown in Fig. 1 (A), clams are placed between a pair of electrodes, and as a pretreatment, high voltage is applied under conditions of AC voltage ± 10kV, DC voltage -20kV to + 10kV, energization time 10 seconds or 30 seconds. did. After processing under each condition, it was frozen in a -4 ° C freezer. The untreated clam was also put in the freezer and frozen as a control. Regarding the effect of the application treatment, boiled clams were boiled and a boil test was conducted to examine the opening of the shell. The results are shown in Table 1.

  As shown in Table 1, the untreated frozen clam does not open even when it is boiled, but the open ratio of the applied frozen clam is high, and in particular, refrigeration that is energized for 30 seconds at -5 kV or for 10 seconds at -10 kV, -15 kV. The clam has the highest aperture ratio, which is 100%, and it was found that the freezing pretreatment method by applying a high voltage of the present invention is effective. From the above results, in order to increase the aperture ratio, it is effective to set the absolute value of the voltage to a certain amount or more, and when this is low, it is effective to lengthen the application time, and the same applies to the case of AC voltage. The applied voltage is also effective as a pulse voltage.

  As the mechanism of opening, by applying a high voltage to the bivalve S, it is possible to hold the charge in the front and rear shell muscles (shells), frozen while holding the charge, by subsequent cooking (boil), This is thought to be because the front and rear closed shell muscles (shells) are cut and the shells and shells are easily separated. The applied voltage used in the above processing may be either AC or DC, and any pulse voltage can be used.

  As described above, the plate 2 of the electrode 1 may be made of a plate-like conductive material when the shell surface of the bivalve shell S is in a dry state, but the shell itself is sufficient when there is a lot of moisture on the shell surface. Since it becomes conductive, for example, an insulating material having elasticity made of polyethylene, polypropylene sponge, or the like is used as the insulating cover 4 on the opposing surface of the electrode plate 2 as shown in FIGS. 2 (A) and 2 (B). It is desirable.

  The insulating cover 4 needs only to have a thickness of about 1 to 5 mm, and maintains an efficient discharge function of the electrode by using a conductive epoxy or urethane adhesive. In such an electrode using an insulating material, a hollow hole-like discharge space 6 is formed in the center of the electrode so as to form a space for discharge without a barrier between the shell surface. When the insulating cover 4 is thick, a higher applied voltage is required.

  According to the electrode configured as described above, even if there is some variation in the shape and size of the shell of the bivalve S to which high voltage is applied, the bivalve S is securely held between the electrodes 1 and 1 by its elasticity. it can. Further, a local high voltage can be applied to the center of the bivalve S by the discharge space 6. The insulating cover 4 does not necessarily have elasticity, and may be, for example, acrylic or other insulating material.

  FIG. 3 shows an insulating cover 4 provided at both ends of the opposing surface of the electrode plate 2 to provide a wider discharge space than that of FIG. 2, or insulation only at the center of the electrode 1 as shown in FIG. A cover 4 provided with a discharge space on its outer periphery can also be used. Then, a stable air discharge (discharge in the gas) occurs in the discharge space 6 of the electrode 1 as described above, and the potential is transferred to the shell surface, and the voltage can be applied to the bivalve equivalently.

  In each of the above examples, the case where the bivalve is directly sandwiched between the electrodes 1 has been shown. However, as a more practical apparatus for processing a large amount of bivalve molluscs, conveyance (holding) such as a belt conveyor that also serves as a dielectric between the electrodes is possible. ) Means, and a method in which a large amount of bivalves are placed on the transport means and a high voltage is applied for a predetermined time can be employed. In this case, the applied voltage needs to be higher, and the voltage value varies depending on the distance between the electrodes (electrode plates) and the type of dielectric (dielectric constant). Further, in this case, the movement with respect to the electrode is sufficient, so that the electrode side may be moved.

It is a side view which shows the processing method of the bivalve by the electrode for freezing pre-processing, (A) arrange | positions the electrode in the shell width direction, (B) arranges the electrode in the shell length direction. (A) is a side view which shows the processing method by the example of the 2nd electrode for freezing pretreatment of this invention, (B) is a top view of the insulating cover affixed on the electrode for pretreatment. It is a side view which shows the processing method by the example of the 3rd electrode for freezing pretreatment of this invention. It is a side view which shows the processing method by the example of the 4th electrode for freezing pretreatment of this invention.

DESCRIPTION OF SYMBOLS 1 Electrode 2 Electrode plate 3 Current supply part 4 Insulation cover 6 Discharge space S Bivalve

Claims (8)

Before freezing bivalve, which improves the aperture ratio during cooking after freezing by interposing bivalve (S) before freezing between electrodes (1) and (1) to which a voltage of | 5 to 30 | kV is applied Processing method.   The bivalve pretreatment method for freezing clams according to claim 1, wherein the clams (S) are sandwiched between the electrodes (1), (1).   3. The bivalve pretreatment method for freezing clams according to claim 2, wherein an electrode (1) having an insulating cover (4) made of an insulating member attached to the opposing surface of each electrode (1) is used to sandwich the clams.   The bivalve (S) is held by the holding means that moves and passes relative to the electrodes (1), (1) between the electrodes (1), (1), and a high voltage is applied to the bivalve (S). The method for pretreatment of bivalve freezing according to Item 1.   The method for pretreatment of bivalve freezing according to claim 1, 2, 3 or 4, wherein the applied voltage is alternating current, direct current or pulse voltage. An insulating cover (4) made of an insulating member is attached to each facing surface of a pair of flat plate electrodes (2) and (2) which are connected to a high voltage applying device and face each other, and the insulating cover (4) is attached A bivalve pretreatment freezing electrode in which a bivalve (S) is sandwiched between them and a voltage of | 5 to 30 | kV is applied between the electrode plates (2) and (2) . The pretreatment electrode for a bivalve shell according to claim 6, wherein a discharge space (6) is provided at the center of each insulating cover (4). 8. The bivalve pretreatment freezing treatment electrode according to claim 7 , wherein an insulating cover (4) is provided at a central position of the electrode plate (2), and a discharge space (6) is provided on the outer peripheral side of the insulating cover (4).

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