JPS6147137A - Freezing of fish body - Google Patents

Abstract

PURPOSE:To freeze a fish body, keeping the excellent meat color, preventing the surface cracking and the splitting of the meat, by precooling a fish body in a low-temperature brine, uniformizing the temperature of the meat in a high-temperature brine, and freezing the body in a low-temperature brine. CONSTITUTION:A (pretreated) fish body such as tuna is immersed in a low-temperature brine of about 45 deg.C until the inner layer of the fish meat is precooled to about -5 deg.C, and then immersed in a high-temperature brine of -20-0 deg.C to uniformize the temperature of the whole body without causing the freezing of the outer layer at a time. Thereafter, the body is immersed in a low-temperature brine of about -45 deg.C to effect the complete cooling and freezing. The freezing action progresses gradually from the surface to the inner part of the fish body having uniformized temperature distribution and free from the quickly frozen outer layer, and accordingly, the cracking and meat-splitting phenomena caused by the freezing of only the outer layer can be prevented. Furthermore, the discoloration of the surface skin caused by oxidization, etc. can also be prevented, and a frozen fish body having original red color of the meat throughout the body can be prepared.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は鮪等の大型肉厚の魚体を凍結させるに当って、
最初から一４５℃程度の低温な塩化カルシウム液中に収
容凍結すれば表層部が急速に凍結し、中心部は冷却し難
いので両層の温度差により表層部に亀裂を生じ外観を損
すると共に、該亀裂より外部の塩化カルシウム液が内向
部に侵入して味の低下を来たし商品価値を甚だしく低下
するので、此の如き亀裂を生ずる惧のない凍結方法を提
供するものである。[Detailed Description of the Invention] (Industrial Application Field) The present invention is applicable to freezing large and thick fish bodies such as tuna.
If the product is stored and frozen in a calcium chloride solution at a low temperature of about -45°C from the beginning, the surface layer will freeze rapidly, and the center will be difficult to cool, so the temperature difference between the two layers will cause cracks in the surface layer and spoil the appearance. The calcium chloride solution from the outside enters the inward portion through the cracks, causing a deterioration in taste and greatly reducing the commercial value. Therefore, it is an object of the present invention to provide a freezing method that does not cause such cracks.

（従来の技術） 近時鮪等の大型肉厚の魚体を漁船上に釣り上げ船中にて
凍結するに当っては、−４５℃程度の塩化カルシウム・
ブライン中に直接浸漬して凍結する方法が採用され在来
の空気凍結によるものに比し、肉質がよく、凍結所要時
間が短縮され、省エネルギー効果がある等価れた手段と
して認められるに至った次第である。処が此の種方法に
よるときは魚体の表面に塩化カルシウム・ブラインが浸
入したり、表層のみが急速に凍結し内向に及ばないため
内外の温度差のため表層に亀裂又は身割れを生じて外観
上商品価値を低下すると共に、該亀裂等の部分より多量
の塩化カルシウム・ブラインが浸み込んで味の低下を来
たす等重大な欠点は避は難いものとされた次第である。(Prior art) Recently, when large, thick fish such as tuna are caught on a fishing boat and frozen on board, calcium chloride and
The method of freezing by direct immersion in brine has been adopted, and compared to the conventional air freezing method, it has been recognized as an equivalent method with better meat quality, shorter freezing time, and energy saving effect. It is. However, when this seeding method is used, calcium chloride and brine may seep into the surface of the fish body, and only the surface layer freezes rapidly and does not extend inward, resulting in cracks or splits in the surface layer due to the temperature difference between the inside and outside, resulting in poor appearance. In addition to lowering the product value, serious drawbacks were inevitable, such as a large amount of calcium chloride and brine seeping into the cracks and other areas, resulting in a deterioration in taste.

即ち該直接浸漬凍結の方法は、非常に急速な凍結である
ため魚体の表層は直ちに凍結し、該凍結層は緻密で完全
で硬いため、次に内層が凍って膨張しようとしても凍結
表層に遮られて膨張出来ず、内圧現象を生じ該内圧は順
次及んで、遂に表面の凍結層を破壊し、身割れ又は亀裂
を生ずるものである。In other words, in the direct immersion freezing method, the surface layer of the fish body freezes immediately because it freezes very quickly, and the frozen layer is dense, complete, and hard, so even if the inner layer freezes and tries to expand next time, it will not be blocked by the frozen surface layer. This causes an internal pressure phenomenon, which gradually spreads and eventually destroys the frozen layer on the surface, causing cracks or cracks.

（発明が解決しようとする問題点） 本発明は大型肉厚の魚体を低温の塩化カルシウム・ブラ
インに直接浸漬凍結する方法を採用しながら、表層の亀
裂、身割れ現象を生ずることなく、且つ表皮面に゛変色
を生ぜず、肉色の良好な赤色を保持し得る凍結手段を開
発しようとするものである。(Problems to be Solved by the Invention) The present invention adopts a method of directly immersing and freezing a large, thick fish body in low-temperature calcium chloride brine, and without causing cracks or splitting of the surface layer, The objective is to develop a freezing method that does not cause discoloration on the surface and can maintain a good red flesh color.

（問題点を解決するための手段） 鮪等の大型肉厚の魚体を一度−４５℃程度の塩化カルシ
ウム・ブライン槽中に浸漬して魚体内層が一５℃程度ま
で冷却するまで置き、該時点で該低温塩化カルシウム・
ブラインを槽外に排除し、−２０−０℃程度の塩化ナト
リウム・ブライン又は海水を該槽内に注入し液体による
均温処理を施し、更に該均温処理に使用した液を槽外に
排除し、最後に一４５℃程度の塩化カルシウム・ブライ
ンを核種に注入し、所期する凍結層に内外肉層が凍結し
た時点に於いて該ブラインを排除し任意冷蔵室等に収容
するものである。(Means for solving the problem) A large, thick fish such as a tuna is immersed in a calcium chloride brine bath at about -45°C until the inner layer of the fish is cooled to about 15°C. At this point, the low temperature calcium chloride
Brine is removed from the tank, and sodium chloride brine or seawater at around -20-0°C is injected into the tank to perform temperature soaking treatment with liquid, and the liquid used for the temperature soaking process is further removed from the tank. Finally, calcium chloride brine at about -45°C is injected into the nuclide, and when the internal and external meat layers have frozen to the desired frozen layer, the brine is removed and the nuclide is stored in an optional refrigerator. .

（作用） 本発明に於いては前記の如く一度魚肉の内層が一５℃程
度に冷却するまで低温プライン中にて豫冷した後、一旦
これを−２０−０’Ｃの高温プライン中に浸漬すること
により外層をして一度に凍結せしめず、内外均等の温度
にさせるため次に低温の一４５℃程度のブライン中にて
徹底的に冷却凍結させても外層のみの急凍結層を生ずる
ことなく一度均温化した魚体は順次内部にも凍結作用が
及び、外層のみの凍結に基づく亀裂、身割れ現象を生ず
ることなく、したがって塩化カルシウム・ブラインが魚
肉内に浸入して変色、変質させる惧もなく、良好な凍結
作用を得るものである。(Function) In the present invention, as described above, the inner layer of fish meat is cooled in a low-temperature prine until it cools to about 15°C, and then it is immersed in a high-temperature prine at -20-0'C. By doing this, the outer layer does not freeze all at once, and in order to maintain an even temperature inside and outside, even if the outer layer is thoroughly cooled and frozen in a brine at a low temperature of about -45°C, only the outer layer becomes a rapidly frozen layer. Once the temperature of the fish body has been homogenized, the freezing effect is applied to the inside of the fish, without causing cracks or splitting caused by freezing only the outer layer.Therefore, there is no risk that calcium chloride and brine will penetrate into the fish meat and cause discoloration and deterioration. However, it provides a good freezing effect.

（実施例） 鮪等の大型肉厚の魚類を漁船上に釣り上げ、内臓、尾、
其の他の実質上不要部分を除去する前処理を施し、冷蔵
して一１〜０℃の１尾４５ｋｇ程度の魚体を（所望によ
り前処理を施さず全形のまま凍結処理に移る場合もある
）−４５℃程度の低温塩化カルシウム・ブラインを充満
した槽中に直接浸漬する。すると約５時間にして魚体内
層の温度が一５℃程度まで低下する。芸に於いて該低温
塩化カルシウム・ブラインを槽外に排除し、代って一１
０℃の塩化ナトリウム・ブラインを注入した場合は約１
時間、または−５℃の同様ブラインでは約３０分間、或
いはＯ″Ｃのブラインでは約１５分間浸漬する。芸に於
いて魚体の表層部は次第に昇温しで表層部と中心部の温
度はほぼ均一となる。之が即ち液中均温処理である。芸
に於いて該最終の均温化処理ブラインを槽より排除し、
再び一４５℃程度の塩化カルシウム・ブラインを核種に
注入し、魚体内層が一４０℃程度となるまで凍結させる
。(Example) Large, thick fish such as tuna are caught on a fishing boat, and the internal organs, tail,
Pre-process the fish to remove virtually any other unnecessary parts, and then refrigerate the fish, weighing approximately 45 kg per fish, at -11 to 0°C (if desired, the fish may be frozen in its entirety without pre-processing). ) Direct immersion in a tank filled with low-temperature calcium chloride brine at about -45°C. Then, in about 5 hours, the temperature of the inner layer of the fish drops to about 15°C. In the process, the low-temperature calcium chloride brine is removed from the tank and replaced with
When injecting sodium chloride brine at 0°C, approximately 1
Soak for about 30 minutes in the same brine at -5℃, or about 15 minutes in brine at O''C.During the trick, the temperature of the surface layer of the fish gradually rises, and the temperature of the surface layer and center is about the same. This is called submerged temperature soaking. In the process, the final soaked brine is removed from the tank,
Calcium chloride brine at about -45°C is injected into the nuclide again, and the inner layer of the fish is frozen until it reaches about -40°C.

以上に要した時間は最初より１５〜１６時間である。The time required for the above was 15 to 16 hours from the beginning.

（発明の効果） 本発明に於ける液中均温化処理を介在させて鮪等の大型
肉厚の魚体を凍結させると、魚体の如何なる部分にも身
割れ又は亀裂を生ずることなく、表皮部に於いても酸化
等の変色を生ずることな（、肉色も何れの部分も赤く美
しく良好な商品価値を維持しながら凍結することを得る
もので効果顕著である。(Effects of the Invention) When a large, thick fish body such as a tuna is frozen using the submerged temperature soaking treatment according to the present invention, no cracks or cracks occur in any part of the fish body, and the skin can be frozen. It is highly effective in freezing while maintaining a beautiful red flesh color and good commercial value without causing any discoloration due to oxidation.

Claims (1)

【特許請求の範囲】[Claims] 魚体を前処理し又は前処理せずして、−４５℃程度の低
温ブライン中に浸漬し、魚体内層が−５℃程度になるま
で冷却し、次に−２０〜０℃程度の低温液中に浸漬して
液中均温処理し、更に−４５℃程度の低温ブライン中に
浸漬して魚体内部も−４０℃程度になるまで凍結するこ
とを特徴とする魚体凍結方法。The fish body, with or without pretreatment, is immersed in low-temperature brine at around -45°C, cooled until the inner layer of the fish reaches around -5°C, and then immersed in low-temperature brine at around -20 to 0°C. A method for freezing a fish body, which is characterized by immersing the fish body in a solution, subjecting it to soaking temperature, and further immersing it in a low-temperature brine of about -45°C to freeze the inside of the fish body until the temperature reaches about -40°C.