JP4977827B2 - How to thaw frozen whale meat - Google Patents

Description

  The present invention relates to a method of thawing frozen whale meat under conditions set based on scientific knowledge to obtain whale meat having an excellent flavor.

When captured, whales are generally frozen in a fresh state, transported and stored, and thawed immediately before distribution to the market.
Since whale meat contains a large amount of ATP, it is already empirically known that it stiffens upon thawing, leaks a large amount of drip, and causes hardening and deformation of the meat. That is, when the fresh fresh whale meat frozen with ATP remaining is thawed in a temperature range of 0 ° C. or higher, the thaw becomes stiff and a large amount of drip is produced, resulting in a decrease in quality. However, no attempt has been made to grasp scientific knowledge such as changes in ATP content before and after freezing and thawing, and whale meat thawing is currently set by each company that handles whale meat based on experience. Currently, the decompression conditions are used.

  Under such circumstances, the patent literature describes that frozen whale meat is aged and thawed at a temperature of 48 to 120 hours under ice temperature, boiled in 2 steps, and then defrosted during thawing or heat processing. A method for reducing blood is disclosed.

  The above method is intended to produce the final boiled whale meat, which retains the tenderness and umami of the meat after boiling, but defrosts at -1 to + 2.5 ° C. Since it is carried out in a temperature-controlled room, partial thawing occurs and drips are unavoidable, and it is not satisfactory as a thawing method that assumes use in raw meat.

On the other hand, with the increase in the number of survey whalers and the improvement of freezing technology, the production volume of frozen whale meat with high freshness will increase, and the distribution of frozen whale meat is expected to increase due to the expansion of consumption in general households. For widespread use of whale meat, it is essential to develop a thawing method that can maintain high quality without causing thawing rigidity when thawing high-quality frozen meat, including its use in raw meat.
JP 2004-121106 A

  The present invention aims to solve such problems, and an object of the present invention is to provide a method for thawing frozen whale meat that can obtain a thawing whale meat having a preferred flavor. is there.

  The present inventors left the rapidly frozen whale meat at −10 to 0 ° C. for 0 to 10 days and studied the relationship between the ATP change in the meat and the drip amount, etc. When left in a frozen state at -3 ° C for 2-7 days, the ATP concentration decreases to 10% or less of the total amount of ATP-related compounds contained in the meat, and thus whale meat with reduced ATP is Then, even after rapid thawing, it has been found that thawing stiffness does not occur, drip generation is suppressed, and a thawing whale meat having a favorable texture and flavor can be obtained, leading to the present invention.

  That is, in the present invention, before thawing frozen whale meat stored at −30 ° C. or lower, it is allowed to stand at −5 ° C. to −3 ° C. for 2-7 days in advance, and ATP in the meat disappears to 10% or lower. And then thawed in a temperature range of 0 ° C. or higher.

  According to the present invention, since ATP contained in a large amount in the whale meat with high freshness is decomposed under the conditions of the present invention, it becomes possible to suppress thawing rigidity, there is little outflow of drip, and it is soft and delicious. It can be thawed into the preserved meat, and further, it can be expected to suppress the freezing of proteins by ATP during cryopreservation.

  The types of whales targeted by the present invention are subject to research and local traditional whaling, including sperm whales, horn whales, dolphins and other whales, and blue whales, fin whales, sei whales, minke whales and other baleen whales. Includes all species.

  The frozen whale meat used in the present invention may be frozen by a conventionally known method, but is preferably rapidly frozen to −30 ° C. or less from the viewpoint of maintaining freshness. The whale meat thus frozen contains a high concentration of ATP, and since this ATP functions to suppress protein denaturation during frozen storage, it can maintain high freshness.

  The means for raising the temperature of the frozen whale meat to −5 ° C. to −3 ° C. may be any known method, but finally raises all the portions from the surface to the center of the meat block to the temperature range. There is a need. Specifically, the frozen whale meat may be left in a temperature-controlled room set at -5 ° C to -3 ° C.

  It is necessary to leave frozen whale meat until the ATP concentration is 10% or less at all sites. If the ATP concentration is reduced to 10% or less, the drip at the time of thawing can be suppressed to less than 5%.

  The period of reduction for reducing the ATP concentration to 10% or less depends on the ATP concentration of whale meat, and the higher the concentration of whale meat, the longer the standing time must be. Usually it takes 2-7 days.

As long as the ATP in the whale meat is decomposed and lost to 10% or less by being left in the above temperature range, any subsequent method for thawing to room temperature may be used.
For example, it can be thawed by rapid thawing by contact with warm water, and the obtained thawed whale meat has excellent flavor and can be used for raw food.

[Example]
Next, the actual implementation of the present invention will be shown as examples.
In the examples, ATP (%) pH and the amount of drip were measured by the following method.
ATP (%): First, an extract extracted with 10% perchloric acid was neutralized with an aqueous potassium hydroxide solution, and then ATP-related compounds (ATP, ADP, AMP, IMP, HxR, Hx) were analyzed by high performance liquid chromatography. ) Was measured. It calculated with the following formula | equation using the measured value.

ATP content (%) = ATP / ATP + ADP + AMP + IMP + HxR + Hx x100

pH: 25 mL of 0.02M sodium monoiodoacetate aqueous solution was added to 5 g of meat, homogenized, and measured with a pH meter.
Drip amount (%): The weight of meat before and after thawing was measured, the difference in weight (decrease amount) was calculated, and the ratio (%) of meat before thawing of the decrease amount was calculated.

  ATP (%) and pH were measured after leaving 200-300 g whale meat having an ATP content of 60% when frozen at −5 ° C., −10 ° C., and −15 ° C. for 10 days. Next, in each case, quickly thawed (put in a plastic bag, thawed with flowing water (18-27 ° C) until the center temperature reaches 2 ° C so that the drip does not leak) and slowly thawed (put in a plastic bag, centered at 5 ° C) Thawed until the temperature reached 2 ° C.) and the drip amount, ATP content and pH of the thawed meat were measured. The results are shown in FIGS. ATP and pH decreased at −5 ° C. for 10 days of cryopreservation, and the amount of drip at the time of rapid thawing was about 10% when the meat center temperature was 2 ° C., which was less than other conditions.

  ATP (%) and pH were measured after leaving 150 g whale meat with 70% ATP content at freezing at -1 ° C and -3 ° C for 1, 2, 3, 5 and 7 days. Next, each sample was left in a constant temperature room at 25 ° C. and rapidly thawed until the center temperature reached 2 ° C., and the drip amount, ATP content and pH of the thawed meat were measured. At that time, the product was left in a 2 ° C. refrigerator until the center temperature reached 2 ° C., and the drip amount, ATP content and pH were measured in the same manner. A taste test was also conducted. The results are shown in FIGS. ATP and pH were decreased in frozen storage at -3 ° C for 2-7 days, and the drip amount could be suppressed to 5% or less. In addition, as a result of the taste test (Table 1), it was evaluated that it was delicious and the texture was good.

  According to the method of the present invention, a high freshness whale meat having an ATP content of 60% or more can be cryopreserved at -5 to -3 ° C for 2 to 7 days, and the drip amount can be suppressed to 5% or less. Even good thawed whale meat can be obtained. By the method of the present invention, it is expected that the spread of whale meat will proceed.

The graph which shows the pH value of Example 1 The graph which shows the ATP density | concentration of Example 1 The graph which shows the drip amount of Example 1 The graph which shows the pH value of Example 2 The graph which shows the ATP density | concentration of Example 2 The graph which shows the drip amount of Example 2

Claims (1)

ATP-related ATP, ADP, AMP, IMP, HxR, Hx contained in meat by maintaining frozen Whale meat with ATP remaining in the temperature range of -5 to -3 ° C A method for thawing frozen whale meat, comprising reducing to 10% or less of the total amount of the compound and then thawing at 0 ° C or higher.