JP2010246501A - Squid processed food and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a squid processed food that has less shrinkage of squid flesh during a processing step and does not harden flesh even by heat sterilization. <P>SOLUTION: The squid processed food is obtained by aging a squid flesh part with a protease and has a flesh state in which squid meat is softened to its central part to have a texture of softness and chewability. The method for producing a squid processed food includes controlling a squid flesh part by using a protease in a temperature range of 45-65°C and mildly aging the squid flesh part under an aging condition of 7-48 hours. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for producing a squid processed food, and more specifically, the present invention relates to a novel squid processed food that does not become hard even after heat sterilization and a method for producing the same.

  In general, squid has a property of shrinking to a small extent by heating, and it is denatured into a hard rubber under conditions of general heat sterilization in processed foods. In order to finish the processed food of squid softly, it is necessary to perform a powerful heat treatment at 115 ° C. for about 60 minutes like canned food.

  As a technique for preventing squid or mollusks from becoming hard or softening, there is a technique of re-forming squid in a paste form (for example, JP-A-6-62808). (Patent Document 1), this processed food is different from the texture of squid meat.Japanese Patent Laid-Open No. 7-184607 (Patent Document 2) describes a method of performing an alkali treatment on a mollusk such as squid after boil treatment. Japanese Patent Laid-Open No. 2006-34263 (Patent Document 3) discloses a method in which a mollusk is combined with reduced pressure heating and pressure heat treatment. No. 4 (Patent Document 4) is a mixture of a squid containing a proteolytic enzyme with a paste-like aging part and a squid meat part refined. JP-A-48-96400 (Patent Document 5) discloses a method for producing a squid-utilized homogeneous food by allowing a proteolytic enzyme to act on the squid meat part. A method for softening squids by a combined treatment is disclosed.

JP-A-6-62808 JP-A-7-184607 JP 2006-34263 A JP-A-10-113152 JP-A-48-96400

  Processed foods according to the prior art as described above do not have crispness like squid meat (Patent Documents 1 and 4), and need to be treated with an alkali agent that is a non-natural chemical substance after heat treatment (patents) Document 2), the manufacturing process by the combination of reduced pressure heating and pressure heating is complicated (Patent Document 3), and as pointed out in Patent Document 2 ([0003]), molluscs are degraded by proteolytic enzymes. The surface may be excessively softened and the commercial value may be lowered in appearance, and the protein degradation product produced during the enzymatic reaction may adversely affect the taste and odor (Patent Document 5). The present invention is a squid process that has little shrinkage of the meat in the processing step, does not become hard even after heat sterilization, is softened but does not change to a rubbery shape with a chewy texture and flavor The purpose is to provide food.

  In order to solve the above-mentioned problems, the present inventors have found that the above-mentioned object can be achieved by gently ripening squid meat in a temperature zone accompanied by intermediate protein denaturation. It came to complete.

That is, the present invention relates to a processed squid food and a method for producing the same, having the following configuration.
(1) It is obtained by aging the meat part of squid using a proteolytic enzyme agent, and has a flesh state softened to a texture with a soft chewy texture to the center part of the squid meat, Squid processed food.
(2) The squid processed food according to (1) above, wherein the proteolytic enzyme agent is squid viscera ripened or crushed, soy sauce, or proteolytic enzyme.
(3) The squid processed food according to (1) or (2) above, wherein the rupture stress of the softened squid meat is 5 to 20 × 10 ⁵ Pa.
(4) It is obtained by further heat-sterilizing the processed food according to any one of (1) to (3) at a temperature of 70 to 125 ° C., and the breaking stress is 5 to 20 × 10 ⁵ Pa. A squid processed food characterized by that.
(5) The meat part of the squid is regulated to a temperature range of 45 ° C. to 65 ° C. using a proteolytic enzyme agent, and gently ripened under the aging conditions of 7 to 48 hours, and the soft bite to the center of the squid meat A method for producing a processed squid food, characterized by softening to a fleshy state with a pleasant texture.
(6) The method for producing a squid processed food according to the above (5), wherein the proteolytic enzyme agent is a matured and crushed product of squid viscera, soy sauce, or a proteolytic enzyme.
(7) The manufacturing method of the squid processed food as described in said (5) or (6) whose breaking stress of the softened squid meat is 5-20 * 10 < ⁵ > Pa.
(8) The processed squid food obtained by subjecting the processed squid food obtained by the method according to any one of (5) to (7) above to a heat sterilization treatment step at a temperature of 70 to 125 ° C. Manufacturing method.

  In the present invention, the squid meat is less shrunk in the processing process, and even when subjected to heat sterilization, it is uniformly softened to the center without causing any taste or bitterness, and also has a chewy texture like a heated squid It is possible to provide a squid processed food that does not change to a rubbery shape while leaving a flavor. Such squid processed food can be typically produced by the method of the present invention in which mild ripening is performed using a proteolytic enzyme agent in a temperature zone with intermediate protein denaturation. In addition, when a squid viscera ripened or crushed product is used as a proteolytic enzyme agent, aging progresses more gently, and the umami and flavor can be further increased. Furthermore, even when using ripened or crushed squid organs, the amount used is very small, and there is no intermediate protein denaturation caused by heat, so that a salty-like raw odor does not occur.

  In connection with the present invention, treatment of other molluscs such as octopus under the same conditions as those for squid according to the present invention did not yield the same results as for squid. Processing conditions are not common conditions that can be generally applied to molluscs, and it is therefore surprising that the above-described effects were obtained in squid.

A graph of the data of Example 3 of the present invention. (A) uses 0.05-0.5 weight% of aging goro. (B) uses aging goro 1 to 3% by weight.

  Hereinafter, embodiments of the present invention will be described in detail.

  The squid processed food according to the present invention is obtained by aging the meat part of the squid using a proteolytic enzyme agent, and has a fleshy state softened to a soft chewy texture to the center of the squid meat As described above, such processed squid foods typically have a meat portion of squid as described above at 45 ° C. to 65 ° C. using a proteolytic enzyme agent. It can be produced by the method of the present invention which is controlled to a temperature range and is gently aged under aging conditions of 7 to 48 hours to soften the squid meat to a fleshy texture with a soft chewy texture. In the present invention, squid as a raw material of processed foods can be any food parts such as trunk, ears, legs, etc., regardless of the type such as squid, mongo squid, squid and the like. In addition, squid as a raw material can be either raw or heat-denatured.

  In the present invention, specific examples of the proteolytic enzyme include squid viscera ripened and crushed products, soy sauce, proteolytic enzymes, etc., and squid visceral ripened and crushed products are particularly preferred.

  Aged and crushed squid viscera are ripened and crushed viscera, especially squid liver (so-called squid goro). Aged and crushed squid viscera are especially pasteurized by adding an appropriate amount of salt (usually about 10 to 20% by weight) to the squid liver, and aging at low temperatures (usually around 5 to 20 ° C for several weeks). This is crushed (the order of salt addition, aging and crushing is arbitrary). Hereinafter, this is also referred to as aging goro. When using soy sauce as a proteolytic enzyme agent, there are various types of soy sauce, raw soy sauce, dark soy sauce, light soy sauce, etc., but any type of soy sauce may be used, and those that are generally commercially available Can be used. In addition, the same effect can be obtained by using a proteolytic enzyme itself as a proteolytic enzyme in the present invention in an appropriate amount with a low enzyme action amount. Examples of proteolytic enzymes include acidic proteases, neutral proteases, alkaline proteases and the like, and commercially available ones can be used.

  In a specific embodiment of the method of the present invention, typically, a weak degradation using a proteolytic enzyme agent having a low enzyme action amount (or low enzyme amount) under the aging conditions including the specific temperature zone and the aging time described above. The squid processed food according to the present invention can be produced by carrying out mild aging. Here, the above-mentioned low enzyme action amount is a small amount or low activity that can be gently aged so as to uniformly soften to the center of the squid meat in a temperature range of 45 to 65 ° C., usually in about 7 to 48 hours. The amount of enzyme. Therefore, the above-mentioned mild aging is associated with a low enzyme action amount or a low enzyme amount in addition to the temperature zone and time conditions. When using squid viscera ripened and crushed as a proteolytic enzyme agent, the traditional “squid salted” uses 3 to 10% by weight of squid meat (liver ripened and crushed). In the present invention, the amount of maturation / crushed product of squid viscera is usually 0.05 to 3% by weight, preferably about 0.1 to 1% by weight (in terms of squid liver) with respect to squid meat. It is characteristic to use quantities.

  When soy sauce is used as a proteolytic enzyme agent, the amount used is 1 to 6 units (U) of protease activity, preferably 50 g of squid meat, when the protease activity of soy sauce is measured by the method shown in Experimental Example 1. Is an amount that provides a low enzyme action amount of about 3 to 6 units. In addition, the basic principle of the method for measuring the protease activity of soy sauce shown in Experimental Example 1 is that TCA (trichloroacetic acid) soluble component under the reaction conditions of pH 7.3, reaction temperature 30 ° C., reaction time 30 minutes, using salmine sulfate as a substrate. Is measured with a phenol reagent (forinthiocult reagent), the absorbance at 660 nm is measured, and the activity to liberate 1 μmol of tyrosine-equivalent amino group per minute at 30 ° C. is defined as 1 unit ( Here, it is also called the salmine sulfate method).

  When using the proteolytic enzyme itself, for the commercially available enzyme, the indicated activity unit can be referred to as the standard value, but the method of determining the activity unit may differ depending on the company, so the aging state of the squid meat once through the aging test It should be used after checking the appropriate range of use. For example, in the case of the enzyme shown in Example 6, the enzyme activity is measured by the Amano method (protein digestion test method), and the protease activity is similarly 10 to 300 units (U), preferably 30 for 50 g of squid meat. Add an amount of low enzyme action amount of about ~ 150 units. The basic principle of the method for measuring the protease activity by the Amano method of the enzyme used in Example 6 is that casein is used as a substrate, and TCA-soluble content is obtained under the reaction conditions of pH 3.0, reaction temperature of 37 ° C., and reaction time of 60 minutes. The substance to be measured is colored with a forin reagent, the absorbance at 660 nm is measured, and the activity to produce 100 μg of tyrosine-equivalent amino acid at 37 ° C. for 60 minutes is defined as 1 unit (see Reference Example 1).

  In a form in which a proteolytic enzyme agent is actually used, the squid viscera ripened and crushed product is usually a paste as it is, soy sauce is a commercially available liquid soy sauce or diluted, and a proteolytic enzyme is a solution. However, if necessary, it can be used in the form of powder. When soy sauce (liquid) or proteolytic enzyme (liquid) is used as the enzyme agent, the amount of the enzyme agent solution used is usually about 0.1 to 200%, preferably about 1 to 100% with respect to the squid meat. is there.

  Regarding the enzyme activity of proteolytic enzyme agents, in the case of squid viscera ripened or crushed, a method for measuring enzyme activity cannot be established in relation to the desired properties of squid meat finally obtained by processing. In the present invention, the amount used (low enzyme action amount) is defined by the weight percentage (converted as ripened and crushed squid liver) as described above. In the case of soy sauce, enzyme activity (softening activity) may be partially weak or ineffective depending on the production lot, etc. Therefore, for example, protease activity can be obtained by the method described in Experimental Example 1 below. Is selected soy sauce having a desired activity (generally about 0.08 to 0.15 (U / g) for raw soy sauce, about 0.01 to 0.03 (U / g) for hot soy sauce) Is possible. In addition, when using a proteolytic enzyme itself, as described above, with respect to a commercially available enzyme, an appropriate amount of use from the aging state of the squid meat once in the aging test with reference to the indicated activity unit as a reference value You should use it after checking the range.

  If the enzyme activity is high, the ripening time can be shortened, but the difference in physical properties between the outside and inside of the squid meat tends to occur. It will be damaged. On the other hand, when the enzyme activity (or enzyme action) is weak as in the present invention, it acts gently, there is little difference in physical properties inside and outside the squid meat, and no core remains. Moreover, the texture which seems to be squid meat is maintained, without softening too rapidly due to weak enzyme activity (refer FIG. 1 (a) (b)). Moreover, in this invention, although the effect that umami | flavor and flavor increase and a squid meat becomes more delicious is acquired, this is estimated by the influence of a mild proteolysis. The amount of the proteolytic enzyme agent used in the present invention can be appropriately determined within the range of the low enzyme action amount as described above in consideration of the state of the material, the desired texture, the working time, and the like.

  As for the aging temperature, generally at 40 ° C. or less, it takes too much time to ripen and is easily spoiled (temperature range in which many microorganisms can grow), and when sterilized by heating, the meat quality shrinks and becomes hard. Conversely, at a temperature of 70 ° C. or higher, the meat does not become soft due to enzyme deactivation. In the present invention, the temperature zone of the aging step is a central temperature of about 45 to 65 ° C, preferably about 50 to 60 ° C. The present invention can solve the above problems by using such an aging temperature zone.

  The period of the aging step in the present invention may vary depending on the state of the squid material, the temperature, the amount of enzyme (or activity), etc., but is usually about 7 to 48 hours, preferably about 17 to 24 hours.

If the specific aspect of the manufacturing method of the squid processed food by this invention is illustrated, normally, first, cut a squid meat into a suitable size as needed, and this is a proteolytic enzyme of low enzyme action amount as mentioned above The mixture is mixed with an agent and slowly aged in a predetermined temperature range (45 to 65 ° C.). At this time, the squid viscera ripened and crushed material (paste form) is used as it is, and soy sauce is a commercially available liquid as it is or diluted with water or the like as needed, and then the low enzyme action amount as described above is used. In the case of a proteolytic enzyme, it may be mixed using a low enzyme action amount as described above in the form of a solution dissolved in water or the like at an appropriate concentration in consideration of the known or indicated activity value. The aging period is usually about 7 to 48 hours, preferably about 17 to 24 hours, but in the range of the aging temperature (45 to 65 ° C.), when the proteolytic enzyme agent is relatively small, a long aging period is required. When it is necessary and there are many proteolytic enzyme agents, the aging period may be short. For example, the aging period is about 17 to 48 hours on the low enzyme action range of 0.05 to 0.5% by weight of squid viscera ripened and crushed material, and 1.0 to 3.0 weight of the ripened and crushed material. On the high enzyme activity range side, the aging period is about 7 to 17 hours. Therefore, as a measure of completion of the ripening process, the amount of the proteolytic enzyme agent is considered in consideration of the properties of the squid meat finally required in the present invention, particularly the softened texture of the meat texture. And the aging period can be adjusted as appropriate. In addition, the processed squid food obtained in the aging step in the present invention has a softened meat state and has a breaking stress of 5 to 20 × 10 ⁵ Pa (based on the method shown in Example 1) as described later. Such a breaking stress value can be further considered as a reference value in the indication of the completion of the aging process.

  In the above processing steps, in addition to squid meat and proteolytic enzyme agents, additives such as sodium chloride and ethanol may be mixed as necessary. In addition, it is necessary to consider mixing | blending so that it may not rot during a ripening process, For example, it is preferable to set it as a salt content about 5 weight% and ethanol about 1 weight% with respect to squid meat.

The squid meat which completed the aging process as mentioned above can be manufactured. The processed squid processed food according to the present invention is obtained by gently aging the meat part of the squid using a proteolytic enzyme agent, and has been softened to a soft chewy texture to the center of the squid meat It has a fleshy state, and preferably has a breaking stress of squid meat of 5 to 20 × 10 ⁵ Pa. The processed squid food of the present invention can be typically produced by the method of the present invention as described above, and the squid meat is uniformly softened with little difference in physical properties between the outside and inside of the squid meat. Flavor is maintained or increased. As will be described later, in the present invention, such properties are maintained even when heat sterilized.

Regarding the above breaking stress, “hardness”, which is generally used for evaluating the physical properties of protein foods, is expressed in terms of breaking strength or breaking stress (force per unit area) when food is pressed and broken with a plunger. The force is divided by the contact area of the plunger and the force (stress = force / plunger cross-sectional area), and the force per unit area (stress) represents the mechanical properties of the object. As a unit of breaking strength or breaking stress, Pa (Pascal, = N / m ² ) is usually used. As a test method for measuring the stress, there are generally a penetration test or a compression test using a rheometer, and these tests are based on conditions of a plunger shape (mainly a cross-sectional diameter), a sample shape, a compression speed, and a measurement temperature. Done. For physical property testing of foods, refer to, for example, “Examination of Factors Affecting Physical Property Measurement of Tofu” (Nippon Shokuhin Kogyo Gakkaishi Vol.39, No.8, 715-721 (1992) (Technical Report)) Can do.

  In the present invention, the squid meat that has been aged is usually stored refrigerated. In addition, the squid meat after aging can be eaten as it is, but can be used as a raw material for processed foods accompanied by heat sterilization.

  Heat sterilization is usually performed by heat sterilization at about 70 to 125 ° C. after putting the aged squid meat into a container such as a bottle. In the case of raw squid, heating at 70 ° C for 30 minutes, boiling water for 20 minutes, 60 minutes, 110 ° C (autoclave heating) for 15 minutes results in rubber-like physical properties, and softening occurs at 110 ° C for 60 minutes and 121 ° C for 15 minutes. Confirmed by the inventor (see Example 4 below). However, it was also confirmed that the heat treatment at 110 ° C. for 60 minutes produced some bitterness and a peculiar taste, and that the squid-like flavor was weakened at 121 ° C. for 15 minutes (Example 4 described later). On the other hand, the squid treated by the method of the present invention was less shrunken under any of the above-mentioned sterilization conditions and maintained the texture and flavor typical of squid meat, as shown in the examples below.

In the squid processed food according to the present invention, the squid meat after the end of the heat treatment process has a softened texture like a squid meat after the end of the aging process and has a soft texture and a breaking stress. Has 5 to 20 × 10 ⁵ Pa. In the present invention, the squid meat softened as desired in the aging step is maintained in its meat quality state without any substantial change in meat quality due to the heat treatment.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by this. Moreover, in the following Examples,% display means weight% unless there is particular notice.

  Cut squid having a length of 15 mm × width of 15 mm (thickness is the thickness of squid meat) was prepared from the body of a commercially available squid (defrosted and used). 50g cut squid and seasoning containing squid (ripening goro 0.25g, salt 2.1g, citric acid 0.05g, ethanol 0.5g) are filled in a glass bottle, capped and aged at 50 ° C for 17 hours. As a result, the cuttlefish meat was easy to break even though it was denatured by heating, and changed to an appropriate texture with a soft chewy texture throughout. Furthermore, the whole glass bottle was sterilized by heating in boiling water for 20 minutes, but the soft texture was maintained with the texture after aging.

  Similarly, when it was aged with a formulation not containing squid (cut squid 50 g, salt 2.1 g, citric acid 0.05 g, ethanol 0.5 g), the squid meat was in a state of elasticity that was difficult to break. After sterilization, it became harder and had a rubbery texture that was difficult to chew.

  Each breaking stress was measured (Table 1). The break stress was measured by the following method including the following examples.

<Device used>
Rheometer (RHEOMETER CR-200D Sun Chemical Co., Ltd.)
<terms of use>
-Plunger shape: cylindrical shape with a diameter of 1.5 mm-Compression speed: 1 mm / s
・ Measurement temperature: Room temperature (20 ℃)
Sample shape: Squid = almost (length 15mm x width 15mm x thickness 8mm)
(It may shrink due to aging and sterilization.)
Test method: The plunger was pushed vertically into the sample, and the measurement data (maximum load value) for five times of the sample prepared under the same conditions were averaged, and this was divided by the contact area of the plunger to determine the breaking stress.

  In the same manner as in Example 1, 50 g of cut squid prepared from the body of a commercially available squid was packed into a glass bottle together with a seasoning containing squid and capped. These were aged at respective temperatures of 30 ° C., 40 ° C., 50 ° C., 60 ° C., and 70 ° C. One sample was taken out over time, and the breaking stress after aging and after heat sterilization was measured (Table 2).

  50 g of cut squid prepared from the body of commercially available squid, 0%, 0.005%, 0.1%, 0.5%, 1%, 2%, 3% squid goro (excluding salt) A glass bottle was capped with a seasoning similar to that of Example 1 except that it was contained, and the mixture was aged at 54 ° C. One sample was taken out over time, and the rupture stress after aging and heat sterilization in boiling water for 20 minutes was measured. Depending on the amount of Ikagoro, the time required for moderate softening and the time for maintaining moderate softening differed (Table 3).

  Cut squid aged by the same method as in Example 1 and bottled cut squid containing no squid goro were heat-sterilized under various conditions, and the breaking stress was measured. The aged squid has a moderate texture and flavor that is soft and chewy even under conditions of 70 ° C for 30 minutes, boiling water for 20 minutes, 60 minutes, 110 ° C for 15 minutes, 60 minutes, and 121 ° C for 15 minutes. It was. The squid that had not been aged was in a state where it was difficult to bite due to its elastic properties like rubber at 70 ° C. for 30 minutes, boiling water for 20 minutes, 60 minutes, and 110 ° C. for 15 minutes. At 110 ° C. for 60 minutes, a soft and chewy texture was obtained, but some bitterness and taste were felt. Even at 121 ° C for 15 minutes, a soft chewing response was obtained, but the squid-like flavor was weakened (Table 4).

  A glass bottle was filled with 50 g of cuttlefish cut in the same manner as in Example 1 and 100 g of commercially available raw soy sauce A diluted stepwise by 50% or less. For dilution of less than 50%, soy sauce of 50% dilution that was autoclaved at 121 ° C. for 15 minutes was used. After aging at 54 ° C. for 24 hours, heat sterilization was performed in boiling water for 20 minutes, and the breaking stress of each squid meat was measured. As a result, as with ripening using squid goro, it was confirmed that there was a use amount range in which softening progressed stepwise depending on the concentration of raw soy sauce, and moderate softening was achieved in 24 hours of aging. In 100% soy sauce, the concentration of salt and the like is too high, so aging was carried out with 50% or less of soy sauce with a salinity of about 6% during aging.

  The commercial aging soy sauce B diluted to 50% was similarly aged at 54 ° C. for 24 hours. After sterilization by heating for 20 minutes in boiling water, when the rupture stress of squid meat was measured, moderate softening was confirmed.

  According to the method for measuring the protease activity of soy sauce in Experimental Example 1, the protease activity of raw soy sauce A was 0.113 (U / g), and the protease activity of soy sauce B was 0.024 (U / g). The activity unit contained in the soy sauce used for 50 g of squid meat was calculated (Table 5).

  Instead of squid goro, commercially available protease A ("Protease M" Amano "G" containing acid and neutral protease and peptidase: Amano Enzyme Co., Ltd.) is graded from 0% to 0.2% of squid meat In the same manner as in Example 1 except that it was contained at a proper concentration, 50 g of cut squid prepared from the body of a commercially available squid was packed in a glass bottle with a seasoning, capped, and aged at 54 ° C. for 17 hours. Protease was dissolved in distilled water, diluted stepwise and added each 500 μl After aging, the breaking stress of squid meat after sterilization by heating in boiling water for 20 minutes was measured, and as a result, squid softened moderately It was confirmed that there was a range of enzyme amounts.

  The activity value of the protease was calculated by referring to the value written on the product by the Amano method (protein digestion test method). It is different from the active unit of soy sauce in Example 5 (Table 6).

  Example 1 except that commercially available protease B (alkaline protease “ALCALASE 2.4L FG”: manufactured by novozymes) is included instead of squid in a stepwise concentration from 0% to 0.1% with respect to squid meat. Similarly, 50 g of cut squid prepared from the body of a commercially available squid was packed in a glass bottle with a seasoning, capped and aged at 54 ° C. for 17 hours. The protease was diluted stepwise with distilled water, and 500 μl of each was added. After aging, the breaking stress of squid meat after sterilization by heating in boiling water for 20 minutes was measured. As a result, it was confirmed that there was a range of enzyme amounts that moderately softens squid.

  The activity value of the protease was calculated with reference to the value indicated on the product. It is different from the soy sauce of Example 5 and the activity unit of protease A of Example 6 (Table 7).

Experimental example 1

<Method for measuring protease activity of soy sauce>
Sample soy sauce (those with confirmed softening activity in the present invention) was passed through a 0.45 μm filter. 0.5 g of the permeate was precisely weighed and treated with an ultrafiltration membrane (MICROCON YM-10, manufactured by Millipore) having a molecular weight cut-off of 10,000. The enzyme collected on the membrane was made up to 1 ml with pure water to prepare an enzyme solution. Put 0.1 ml of the obtained enzyme solution, 0.1 ml of 0.1 M (mol / L) Tris buffer (pH 7.3), and 0.1 ml of 1.0% salmine sulfate as a substrate into a microtube. After reacting at 30 ° C. for 30 minutes (90 minutes when the activity is weak), 0.4 ml of 0.4M TCA solution was added to stop the reaction. Add 200 μl of 0.4M sodium carbonate solution and 200 μl of 5-fold diluted phenol reagent to 200 μl of the reaction solution, and perform color development at 40 ° C. for 30 minutes (Phenol reagent (Folin-Ciocalteu's phenol reagent) manufactured by Kanto Chemical Co., Ltd.) Available), the precipitate was centrifuged and the absorbance of the supernatant was measured at 660 nm. The control was calculated by adding the enzyme solution immediately before the addition of the TCA solution and subtracting it from the measured value of the test solution. A calibration curve was prepared using L-tyrosine.

The amount of enzyme that liberates 1 micromole of amino group (corresponding to tyrosine) per minute was defined as 1 unit (U) and calculated per 1 g of soy sauce. (Reference: Commentary on the Analytical Method of the Fourth Revision of the National Tax Agency (2006) 211-8 “Solid Koji” and H. Sekine, Agr. Biol. Chem. 36, p198 (1972), “Neutral Proteinase I and II of Aspergillus sojae Isolation in Homogeneous Form ”)

  As a result, the value of the protease activity of the sample raw soy sauce was 0.087 to 0.143 (U / g). Moreover, the value of the protease activity of sample-fired soy sauce was 0.01 to 0.03 (U / g).

Reference example 1

<Method for measuring protease activity by Amano method>
(Casein solution (pH 3.0) preparation method): Weigh 1.500 g of milk casein, add 60 mL of 0.1 mol / L lactic acid test solution, dissolve by heating at 90-95 ° C. with occasional mixing for 10 minutes, and then cool. After cooling, adjust to pH 3.00 by adding dilute sodium hydroxide test solution, and add 20 mL of 0.1 mol / L lactic acid / sodium hydroxide buffer (pH 3.0) and water to make 100 mL.

(Sample solution preparation method): Weigh 0.5 g of sample (enzyme powder), add a small amount (4 to 10 mL) of test water, stir and dissolve to 150 mL. Take 1 mL of the solution and make up to 100 mL with water.

(Measurement operation method): Weigh 1 mL of casein solution in a test tube (15 × 150 mm), leave it at 37 ° C. for 10 to 15 minutes, add 1 mL of the sample solution and shake. After leaving this solution at 37 ° C. for 60 minutes, add 2 mL of 0.4 mol / L trichloroacetic acid test solution, shake well, leave it at 37 ° C. for 25 minutes, and filter (filter paper, No. 131, 7 cm). Next, weigh 5 mL of 0.4 mol / L sodium carbonate test solution into a test tube (18 x 180 mm), add 1 mL of the above filtrate and 1 mL of diluted forin test solution (1 → 5), shake well and leave at 37 ° C for 20 minutes. . (Forin test solution is available as a phenol reagent (forin thiocarto reagent) manufactured by Wako Pure Chemical Industries, Ltd.) The absorbance (A ₆₀ ) at a wavelength of 660 nm is measured using water as a control. Separately, add 2 mL of 0.4 mol / L trichloroacetic acid test solution to 1 mL of casein solution, shake and mix with water (when the dilution factor of the sample solution is 1000 or more) or sample solution (when the dilution factor of the sample solution is less than 1000) Absorbance (A ₀ ) is measured in the same manner with 1 mL added.

(Method for preparing tyrosine calibration curve): Weigh 1 mL, 2 mL, 3 mL, 4 mL, and 5 mL of tyrosine standard solution (1 mg / mL), add 0.1 mol / L hydrochloric acid test solution to make 100 mL each (10, 20, 30, 40,50 μg / mL). Next, weigh 5 mL of 0.4 mol / L sodium carbonate test solution into a test tube (18 × 180 mm), add 1 mL of each tyrosine standard solution of the above concentrations and 1 mL of diluted forin test solution (1 → 5) well. Shake for 20 minutes at 37 ° C. With respect to this solution, the absorbance at a wavelength of 660 nm (As ₁₀ , As ₂₀ , As ₃₀ , As ₄₀ , As ₅₀ ) is measured using water as a control. Separately, 1 mL of 0.1 mol / L hydrochloric acid test solution is used in place of the tyrosine standard solution, and the same procedure is followed to measure the absorbance (As ₀ ). Than this, the absorbance difference on the vertical axis _{(As 10 -As 0, As 20} -As 0, As 30 -As 0, As 40 -As 0, As 50 -As 0), respectively on the horizontal axis the liquid 1mL solution of Take the amount of tyrosine (μg) and use it as a calibration curve. The amount of tyrosine F (μg) with respect to an absorbance difference of 1.000 is determined.
・ Calculation method of F (μg): F = {(10 / As ₁₀ −As ₀ ) + (20 / As ₂₀ −As ₀ ) + (30 / As ₃₀ −As ₀ ) + (40 / As ₄₀ −As ₀ ) + (50 / As ₅₀ −As ₀ )} / 5

(Activity calculation method): Under this condition, the amount of enzyme that produces an amino acid corresponding to 100 μg of tyrosine in 1 mL of the reaction filtrate in 60 minutes is defined as 1 unit, and is calculated from the following formula.
・ Protein digestion (u / g) = (A ₆₀ −A ₀ ) × {F × (1/100)} × n
(A ₆₀ : Absorbance of enzyme reaction solution, A ₀ : Absorbance of blank solution, F: Tyrosine amount (μg) when absorbance difference obtained from tyrosine calibration curve is 1, 1/100: Unit conversion factor, n: Sample Dilution multiple per gram)

Reference example 2

  Table 8 shows a comparison of the amount of the proteolytic enzyme agent used in the present invention and that in the prior art, roughly converted as a range of the amount of enzyme used for 50 g of squid. These are considered to be able to roughly compare the activities even if there are some differences in measurement methods. In the case of JP-A-48-96400 (Patent Document 5) described in the background art, the amount of enzyme used is 30,000 to 70,000 units, soy sauce as a proteolytic enzyme agent in the present invention, proteolysis It was confirmed that any of the enzymes (protease M Amano G) had an enzyme action amount significantly lower than the activity value range of the conventionally used enzyme. The basic principle of the method for measuring protease activity in Patent Document 5 is that the TCA-soluble component is measured under the reaction conditions of pH 3.0 or 7.0 and the reaction temperature of 30 ° C., and 1γ (1 μg / min at 30 ° C. per minute) ) Is an activity that produces an amino acid corresponding to tyrosine. As described above, the soy sauce as a proteolytic enzyme agent in the present invention is the salmine sulfate method, and the proteolytic enzyme (protease M Amano G) is the Amano method.

  The processed squid food obtained by the present invention has little shrinkage of squid meat in the processing process, and even after heat sterilization, it does not produce a taste or bitterness, leaving a texture like a heated squid. It is useful as a new processed squid food that does not change in shape.

Claims (8)

  Squid processed food obtained by aging the meat part of squid using a proteolytic enzyme agent and having a soft texture with a soft chewy texture to the center of the squid meat .   The squid processed food according to claim 1, wherein the proteolytic enzyme agent is squid viscera ripened or crushed, soy sauce, or proteolytic enzyme. The squid processed food according to claim 1 or 2, wherein the rupture stress of the softened squid meat is 5 to 20 × 10 ⁵ Pa. The processed food as claimed in claim 1, obtained by heat sterilization further at a temperature of 70 to 125 ° C., and wherein the breaking stress is 5 to 20 × ¹⁰ 5 Pa Squid processed food.   The meat part of the squid is regulated to a temperature range of 45 ° C. to 65 ° C. using a proteolytic enzyme agent, and gently ripened under the aging conditions of 7 to 48 hours, and the squid meat has a soft texture to the center of the squid meat A method for producing a processed squid food, characterized by softening to a fleshy texture.   The method for producing a squid processed food according to claim 5, wherein the proteolytic enzyme is squid viscera ripened or crushed, soy sauce, or proteolytic enzyme. The manufacturing method of the squid processed food of Claim 5 or 6 whose rupture stress of the softened squid meat is 5-20 * 10 < ⁵ > Pa.   The manufacturing method of the squid processed food characterized by attaching | subjecting the squid processed food obtained by the method of any one of Claims 5-7 to the process of a heat sterilization process at the temperature of 70-125 degreeC further.

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