Packed roasted salted alaska pollack roe and production method of the same

Abstract

To provide roasted salted Alaska pollack roe which is excellent in taste and a texture relative to packed roasted salted Alaska pollack roe which is subjected to low temperature sterilization processing, and is reduced in bacterial contamination at a degree in which the roasted salted Alaska pollack roe can be distributed to the market as roasted salted Alaska pollack roe, and a production method of the same.SOLUTION: There is provided packed roasted salted Alaska pollack roe in which roasted salted Alaska pollack roe subjected to aging and salting, is packaged in a pack, the roasted salted Alaska pollack roe is excellent in taste and texture relative to roasted salted Alaska pollack roe which is packaged in a pack after salting, aging, roasting and is subjected to low temperature sterilization processing until a bacteria number level becomes a prescribed bacteria number level, and the roasted salted Alaska pollack roe of the invention has a general viable cell number measured after opening the pack and immediately after taking out the same from the pack of 10000 CFU / g or less, and a coliform group is negativity. There is also provided a production method of the same.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a packaged grilled cod roe and a method for producing the same. [Background technology]

[0002] Grilled cod roe is a type of fish roe processed product obtained by salting the ovaries of Alaska pollock and then baking them. Grilled cod roe is slightly different from unbaked salted cod roe, as the surface is baked and somewhat hard, while the inside retains a fresh texture and the crunchy texture of the fish roe, allowing you to enjoy the texture, umami, and flavor of grilled cod roe. It has been enjoyed not only as a side dish for rice, but also as a rice ball filling. Grilled cod roe can be easily prepared by baking salted cod roe in a toaster oven, grill, frying pan, etc., so it is a popular ingredient in rice balls, along with pickled plums, salmon, and kelp (Non-Patent Document 1, Non-Patent Document 2).

[0003] Grilled cod roe can be made relatively easily at home if salted cod roe is available, but special consideration is required in terms of hygiene when supplying grilled cod roe as an ingredient for onigiri rice balls sold at convenience stores, supermarkets, etc. (hereinafter referred to as "convenience stores, etc."). That is, unlike grilled cod roe made at home, which is usually eaten immediately after cooking, grilled cod roe used in foods such as onigiri rice balls sold at convenience stores, etc. is processed into the desired food form, transported to a sales store, displayed on a product shelf, and eaten after purchase by consumers, so that consumers can eat it with peace of mind, more thorough hygiene management is required. In this regard, various methods for sterilizing cod roe have been proposed in the past. For example, Patent Document 1 discloses a sterilization method that does not impair the taste of salted cod roe by bagging and sealing salted, unsterilized cod roe and processing it for about 20 minutes to 3 hours at a heating temperature of 60°C to 80°C, which is said not to boil an egg.

[0004] As far as the applicant knows, grilled cod roe currently distributed as an ingredient in rice balls sold at convenience stores and the like is also baked, packed, and then pasteurized at low temperature by boiling the pack in a water bath at about 63° C. However, according to the knowledge independently obtained by the present inventors, packaged grilled cod roe produced by baking and packaging and then pasteurizing at low temperature is significantly impaired in the texture and flavor peculiar to grilled cod roe, particularly the contrast between the slightly hard texture of the baked cod roe surface and the raw texture of the cod roe inside that remains uncooked, and the popping, umami flavor of the fish roe, compared to grilled cod roe obtained by baking commercially available salted cod roe in a toaster oven, grill, frying pan, etc., in other words, grilled cod roe produced by cooking at an ordinary home. Perhaps reflecting this, when online media were used to survey the popularity rankings of onigiri rice balls sold at convenience stores, it was surprising to find that the most popular were dominated by tuna mayonnaise, pickled plum, and salmon, with grilled cod roe making little headway (Non-Patent Document 3, Non-Patent Document 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-273636 A [Patent Document 2] JP 2012-034616 A [Non-patent literature]

[0006] [Non-Patent Document 1] “Popular onigiri ingredients ranking! Introducing recommended easy recipes”, [оnline], JeLLy, February 17, 2019, [Retrieved June 23, 2019], Internet<URL:https: / / jelly-media.jp / posts / 1928> [Non-Patent Document 2] “Top 20 onigiri fillings for [national food], what do you like the most about onigiri right now?”, [оnline], Naver Matome, July 31, 2012, [Retrieved June 23, 2019], Internet<URL:https: / / matome.naver.jp / odai / 2134359745609300101> [Non-Patent Document 3] “2018 Convenience Store Onigiri Popularity Survey: The trend is “the rise of health consciousness”. As a change, “Gattsuri” is back. “Salmon, Tuna, and Plum” remain popular”, [online], Onigiri Association, June 15, 2018, [Retrieved June 23, 2019], Internet<URL:https: / / www.onigiri.or.jp / archives / 4620> [Non-Patent Document 4] “Top 85 Convenience Store Onigiri Popularity Rankings! A thorough comparison focusing on the three major companies [latest]”, [оnline], Rank Best, October 23, 2018, [Retrieved June 23, 2019], Internet<URL:https: / / ranking-best.net / 1465> Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the problems associated with conventional grilled cod roe products, and has an object to provide a grilled cod roe that has the same texture and flavor as grilled cod roe obtained at home in a toaster oven, grill, frying pan, etc., and that is sufficiently bacterially contaminated that it can be distributed on the market as a grilled cod roe product, and a method for producing the same. [Means for solving the problem]

[0008] As a result of intensive research and efforts to solve the above problems, the inventor has come to the knowledge that the reason why low-temperature sterilized grilled cod roe that reproduces the grilled cod roe currently available on the market is often inferior in texture, taste, and flavor to the grilled cod roe obtained by baking salted cod roe commercially available at ordinary households is due to the following reasons in the low-temperature sterilization process. That is, in order to thoroughly sterilize the inside of a thick grilled cod roe, it is necessary to heat the inside of the grilled cod roe sufficiently, even if it is at a low temperature of about 60°C. Therefore, in the low-temperature sterilization process, the grilled cod roe is placed in a state that is like being boiled for a long time, so that the protein in the grilled cod roe is thermally denatured, and the protein in the inside of the egg membrane and the fish egg grains is also denatured, resulting in a crumbly texture and moisture contained in the grilled cod roe seeping out into the bag. As a result, the grilled cod roe that is produced through a low-temperature pasteurization process after baking not only loses the fragrant taste that comes with baking, but also the contrast in texture between a slightly hard surface and a fresh interior, as well as the crunchy texture of the fish roe. It also becomes watery overall, and the fragrant flavor is lost.

[0009] Based on the above findings, and through further trial and error, the inventors noticed that in the process of grilling cod roe, only the surface of the roe is heated and this surface is sterilized. They came up with the idea that by suppressing bacterial contamination inside the bunches of cod roe to a level that poses no hygienic problems before the grilling process, it might be possible to obtain packed grilled cod roe that would remain sufficiently hygienic even during storage and after the pack is opened, without the need for low-temperature sterilization after grilling.

[0010] However, in order to fully bring out the flavor, umami, and graininess of cod roe, a salting process and a maturing process are necessary, and it was previously thought that it was inevitable that the inside of the cod roe bunches would become contaminated to some extent during these salting and maturing processes. For example, Patent Document 2 discloses a technique for allowing kefir bacteria to coexist during the salting and maturing processes of cod roe, but this is merely a technique for suppressing bacterial growth and is not a technique for reducing bacterial contamination itself.

[0011] Under these circumstances, the inventors further conducted trial and error and found that by making improvements to the pretreatment process before baking the cod roe, particularly the salting process, it is possible to suppress bacterial contamination inside the bunches of cod roe to an extremely low level while fully bringing out the inherent flavor, umami, and graininess of the cod roe.Then, after salting and maturing, by baking only the surface of the cod roe with superheated steam and packaging the baked cod roe while it is still in a relatively high temperature state, it is possible to obtain packaged grilled cod roe with bacterial contamination reduced to a level that is completely problem-free for distribution to the market, without going through the low-temperature sterilization process that was previously considered essential, and with a texture and flavor comparable to those of grilled cod roe cooked and produced in an ordinary home, and thus completed the present invention.

[0012] In other words, the present invention solves the above-mentioned problems by providing a packaged grilled cod roe in which grilled cod roe made by baking salted and aged cod roe is sealed in a package, the grilled cod roe having a superior texture and flavor compared to grilled cod roe that has been salted, aged, baked, sealed in a package and pasteurized at low temperature until a predetermined bacterial count level is reached, and in which the general viable bacterial count measured immediately after opening and removing the package is 10,000 CFU / g or less and the coliform bacteria are negative.

[0013] The above-mentioned predetermined bacterial count level refers to a bacterial count level that is suppressed to a level sufficient for distribution on the market, specifically, for example, a level where the general viable bacterial count measured after removing grilled cod roe from the pack and storing it at 25° C. for 48 hours is 10,000 CFU / g or less and the coliform bacteria is negative, and more preferably, a level where the general viable bacterial count measured after removing grilled cod roe from the pack and storing it at 25° C. for 72 hours is 10,000 CFU / g or less and the coliform bacteria is negative. If the general viable bacterial count and coliform bacteria count are at this level, as described below, the packed grilled cod roe can be removed from the pack and used as a filling for rice balls, etc., and displayed and sold on the shelves of convenience stores, etc., which are usually in a room temperature environment.

[0014] From another perspective, the packaged grilled cod roe according to the present invention has the same texture and flavor as grilled cod roe that has been salted and aged and then baked, and has not been pasteurized at low temperature. The salted and aged cod roe referred to here refers to so-called salted cod roe, such as salted cod roe that is commercially available in supermarkets. In other words, the grilled cod roe that has been salted and aged and then baked, and has not been pasteurized at low temperature, corresponds to the grilled cod roe obtained in an ordinary household by baking commercially available salted cod roe using an appropriate cooking utensil such as a toaster oven, grill, or frying pan. Therefore, the packaged grilled cod roe of the present invention has the same texture and flavor as grilled cod roe that has not been pasteurized after being salted and aged and then grilled, which means that the packaged grilled cod roe of the present invention has the same texture and flavor as grilled cod roe handmade in an ordinary household, even though the general viable bacterial count and coliform bacteria count have been reduced to a level sufficient for distribution on the market, as will be described later.

[0015] In addition, the packaged grilled cod roe of the present invention has a general viable bacterial count of 10,000 CFU / g or less and negative for coliform bacteria when measured immediately after removal from the package; in a preferred embodiment, the general viable bacterial count of 1,000 CFU / g or less and negative for coliform bacteria when measured immediately after removal from the package; in a more preferred embodiment, the general viable bacterial count of 100 CFU / g or less and negative for coliform bacteria when measured immediately after removal from the package; and in an even more preferred embodiment, the general viable bacterial count of 30 CFU / g or less and negative for coliform bacteria when measured immediately after removal from the package.

[0016] Packaged grilled cod roe that satisfies the above general viable bacteria count and coliform bacteria count meets the standard criteria for frozen foods (general viable bacteria count 100,000 CFU / g or less, coliform bacteria negative) set out in each article of the "Specifications and Standards for Foods, Additives, etc." (Ministry of Health and Welfare Notification No. 370, 1959) and is therefore fully eligible to be shipped and distributed as a frozen food.

[0017] In a preferred embodiment, the packaged grilled cod roe according to the present invention has a general viable bacteria count of 10,000 CFU / g or less and a negative coliform bacteria count when measured after being removed from the package and stored at 25° C. for 48 hours, and in a more preferred embodiment, the general viable bacteria count of 5,000 CFU / g or less and a negative coliform bacteria count when measured after being removed from the package and stored at 25° C. for 48 hours, and in an even more preferred embodiment, the general viable bacteria count of 1,000 CFU / g or less and a negative coliform bacteria count when measured after being removed from the package and stored at 25° C. for 48 hours. The packaged grilled cod roe having a general viable bacteria count of 10,000 CFU / g or less and a negative coliform bacteria count when measured after being removed from the package and stored at 25° C. for 48 hours can be eaten without any problems in terms of food hygiene even 48 hours after the package has been opened. This means that the packaged grilled cod roe according to the present invention can be used as a filling for rice balls and the like, and can be displayed and sold on the shelves of convenience stores and the like, which are normally kept in a room temperature environment.

[0018] In a further preferred embodiment, the packaged grilled cod roe according to the present invention has a general viable bacterial count of 10,000 CFU / g or less and a negative coliform bacteria count when measured after being removed from the package and stored at 25° C. for 72 hours, and in a more preferred embodiment, the general viable bacterial count measured under the same conditions is 5,000 CFU / g or less and a negative coliform bacteria count, and in an even more preferred embodiment, the general viable bacterial count is 1,000 CFU / g or less and a negative coliform bacteria count. Such packaged grilled cod roe can be eaten without any hygienic problems even after 72 hours have passed at room temperature since the package was opened, and is therefore more preferred from the viewpoint of extending the expiration date.

[0019] Incidentally, the fact that the packaged grilled cod roe according to the present invention has a superior texture and flavor compared to grilled cod roe that has been salted, aged, baked, sealed in a package, and pasteurized at low temperature until a specified bacterial count level is reached, and furthermore has a texture substantially equivalent to that of grilled cod roe produced by cooking at home, is also supported by the fact that the difference in moisture content between the roe membrane and the inside of the tufts of the grilled cod roe measured immediately after removal from the package is 1.0% by mass to 2.5% by mass, more preferably 1.5% by mass to 2.0% by mass. Note that when the packaged grilled cod roe is in a frozen state, the moisture content is measured after it has been thawed and returned to room temperature.

[0020] That is, as described above, grilled cod roe produced by cooking in an ordinary household has two different textures at the same time: the surface is grilled and somewhat hard, while the inside is soft with a raw feel and a crunchy texture of fish eggs, but the difference in moisture content between the roe membrane and the inside of the clusters, as measured by the inventor, is about 1.8% by mass, as described below, and the moisture content of the roe membrane is lower than the moisture content of the inside of the clusters. In this way, the fact that the moisture content of the roe membrane is lower than the inside of the clusters, and the difference of about 1.8% by mass, is thought to reflect the unique texture of grilled cod roe, which is the slightly hard grilled feel of the surface of the cod roe and the raw feel of the inside of the cod roe.

[0021] Therefore, when the difference in moisture content between the roe membrane and the inside of the clusters of the packaged grilled cod roe according to the present invention is 1.0% by mass or more and 2.5% by mass or less, more preferably 1.5% by mass or more and 2.0% by mass or less, including the above-mentioned approximately 1.8% by mass in the middle, and the moisture content of the roe membrane is lower than that of the inside of the clusters, it can be reasonably assumed that the grilled cod roe has a texture almost equivalent to that produced by cooking at home. Furthermore, grilled cod roe that is salted, aged, baked, and then pasteurized at low temperature while sealed in a package has a small difference in moisture content between the roe membrane and the inside of the clusters of less than 1.0% by mass, which is thought to be related to the loss of texture and flavor. Therefore, when the difference in moisture content between the roe membrane and the inside of the clusters of the packaged grilled cod roe of the present invention is 1.0% by mass or more and 2.5% by mass or less, more preferably 1.5% by mass or more and 2.0% by mass or less, with the above-mentioned approximately 1.8% by mass in the middle, and the roe membrane has a lower moisture content than the inside of the clusters, it can be reasonably inferred that the texture and flavor will be superior to that of grilled cod roe that has been pasteurized at low temperature until the bacteria count reaches a specified level.

[0022] The present invention also solves the above-mentioned problems by providing a method for producing packaged grilled cod roe, comprising: (1) a salting step of soaking the cod roe in a salting liquid for a predetermined time at a predetermined atmospheric temperature; (2) an aging step of aging the cod roe that has undergone the salting step for a predetermined time at a predetermined atmospheric temperature; (3) a baking step of baking the cod roe that has undergone the aging step; and (4) a packaging step of sealing the cod roe that has undergone the baking step into a pack, wherein the salting step (1) comprises, in this order, (1A) a first salting step in which the predetermined atmospheric temperature is 15°C or higher and 25°C or lower and the predetermined time is 20 hours or higher and 30 hours or lower, and (1B) a second salting step in which the predetermined atmospheric temperature is 5°C or higher and 15°C or lower and the predetermined time is 20 hours or higher and 30 hours or lower, and further wherein the baking step (3) is superheated steam baking using superheated steam.

[0023] One of the features of the method for producing packaged grilled cod roe of the present invention is that a first salting step at a relatively high temperature and a second salting step at a relatively low temperature are carried out in that order. This allows the salting step to fully fulfill its original role of bringing out the granular texture of the fish roe inside the cod roe clusters, while suppressing an increase in general viable bacterial counts and coliform bacteria counts inside the cod roe clusters after the salting step and also after the maturation step.

[0024] The predetermined atmospheric temperature in the first salting step (1A) is preferably from 15° C. to 25° C., more preferably from 16° C. to 24° C., and even more preferably from 17° C. to 23° C. The predetermined time in the first salting step (1A) is preferably from 18 hours to 30 hours, more preferably from 20 hours to 28 hours, and even more preferably from 22 hours to 26 hours.

[0025] On the other hand, the predetermined atmospheric temperature in the second salting step (1B) is preferably from 5° C. to 15° C., more preferably from 7° C. to 13° C., and even more preferably from 9° C. to 11° C. The predetermined time in the second salting step (1B) is preferably from 18 hours to 30 hours, more preferably from 20 hours to 28 hours, and even more preferably from 22 hours to 26 hours.

[0026] Although there is some overlap between the preferred ambient temperature ranges in the first salting step and the second salting step, the second salting step is carried out at a lower ambient temperature than the first salting step, and the ambient temperatures in which the two salting steps are carried out are not the same. The duration of the first salting step and the second salting step may be different, but is preferably the same, and the total salting time for both steps combined is more preferably about 48 hours.

[0027] The method for producing packaged grilled cod roe according to the present invention is further characterized in that the baking step (3) is performed by superheated steam baking, and does not include a low-temperature sterilization step by hot water bath, which was previously considered essential. In other words, by including the above-mentioned two-stage salting step, in the method for producing packaged grilled cod roe according to the present invention, the general viable bacteria count inside the bunches of cod roe subjected to the baking step (3) is 100 CFU / g or less, and the coliform bacteria are negatively suppressed. If the general viable bacteria count and the coliform bacteria count inside the bunches are at this level, the general viable bacteria count and the coliform bacteria count can be reduced to a level sufficient to be distributed on the market as a grilled cod roe product without going through a low-temperature sterilization step, simply by baking the surface of the cod roe with superheated steam in the baking step (3). This finding was completely unexpected from the conventional manufacturing method in which low-temperature sterilization was performed by immersing the bagged product in warm water. As is well known, superheated steam is steam that has been heated to over 100°C, and in addition to the latent heat of steam, it has sensible heat due to superheating. This has the advantage that the target substance, cod roe, can be cooked more evenly and efficiently than with conventional grilling methods.

[0028] In a preferred embodiment of the method for producing packaged grilled cod roe according to the present invention, the predetermined atmospheric temperature in the cod roe maturation step (2) is from 5° C. to 15° C., more preferably from 7° C. to 13° C., and even more preferably from 9° C. to 11° C., and the predetermined time in the step (2) is from 36 hours to 60 hours, more preferably from 40 hours to 56 hours, and even more preferably from 44 hours to 52 hours. By including the maturation step (2) under such conditions, the texture, flavor, and preferably the taste of the cod roe can be fully and uniformly brought out while suppressing an increase in general viable bacterial count and coliform bacteria count.

[0029] In a preferred embodiment of the method for producing packaged grilled cod roe according to the present invention, the grilling with superheated steam in the grilling step (3) is carried out by placing the cod roe to be grilled for 2 to 3 minutes in a space from which superheated steam at 240° C. to 260° C. is blown out. By grilling with superheated steam under the conditions described above, the surface of the cod roe can be sufficiently grilled and sterilized, and grilled cod roe with excellent texture, flavor, and preferably aroma can be produced.

[0030] If the temperature of the superheated steam is too high, the surface of the cod roe will be overcooked, resulting in a hard texture. Therefore, from the viewpoint of obtaining grilled cod roe with an excellent texture, the temperature of the superheated steam is preferably less than 270°C, and more preferably 260°C or less. On the other hand, if the temperature of the superheated steam is too low, the surface of the cod roe will not be cooked sufficiently, and sufficiently sterilized grilled cod roe will not be obtained. Therefore, the temperature of the superheated steam is preferably 230°C or more, and more preferably 240°C or more.

[0031] On the other hand, the time for which the cod roe to be grilled is kept in the space from which the superheated steam is blown out is preferably not too short from the viewpoint of sufficient surface sterilization through uniform grilling, and is preferably not too long from the viewpoint of avoiding deterioration of the texture due to excessive grilling. Therefore, the time for which the cod roe to be grilled is kept in the space from which the superheated steam is blown out is preferably from 1 minute to 4 minutes, more preferably from 1 minute 30 seconds to 3 minutes 30 seconds, and even more preferably from 2 minutes to 3 minutes.

[0032] In a preferred embodiment of the method for producing packaged grilled cod roe according to the present invention, the grilled cod roe that has been subjected to the grilling step (3) is filled and sealed into a packaging container (pack) while being maintained at a relatively high predetermined temperature or higher immediately after grilling. This makes it possible to reduce bacterial contamination during the packaging process. In a more preferred embodiment of the method for producing packaged grilled cod roe according to the present invention, the predetermined temperature is 60°C or higher, in an even more preferred embodiment, the predetermined temperature is 70°C or higher, and in an even more preferred embodiment, the predetermined temperature is 80°C or higher.

[0033] In the present invention, the pack in which the grilled cod roe is filled may be one whose opening can be closed, and there is no particular limitation on the material, type, or size of the pack. The pack may be made of not only a flexible material, but also a hard material such as glass, plastic, or metal, or a material made of two or more materials. However, since the method for producing the grilled cod roe in a pack according to the present invention involves filling the pack with the grilled cod roe grilled by an appropriate means while maintaining the temperature at or above a predetermined level, it is preferable to use a pack made of a material with excellent heat resistance. In addition, the pack may be a vacuum pack in which a vacuum is drawn inside, or may have some air remaining, or may be filled with an inert gas.

[0034] The cod roe targeted by the present invention may be any fish ovary that can be baked to make grilled cod roe, and may be any fish ovary that belongs to the family Codidae or Hake family that has been used in the past. Preferably, the ovaries of Alaska pollock, Pacific cod, Southern cod, and Hoki, and more preferably, the ovaries of Alaska pollock, may be used. In addition, there are various grades of cod roe, such as Gamko, Mako, and Mizuko, depending on the maturity and thickness, but the cod roe targeted by the present invention may be any cod roe that can be baked to make grilled cod roe, and there is no particular restriction on the grade of cod roe. In addition, the grilled cod roe referred to in the present invention may be any that can be obtained by baking the surface of salted and aged cod roe, and so-called grilled cod roe and grilled spicy cod roe are naturally included in the grilled cod roe referred to in this specification. Effect of the Invention

[0035] According to the packaged grilled cod roe and its manufacturing method of the present invention, it is possible to provide a grilled cod roe that has a better texture and flavor than pasteurized grilled cod roe and is so little contaminated by bacteria that it can be distributed in the market without any problems as a grilled cod roe product, and a manufacturing method thereof. [Brief description of the drawings]

[0036] [Figure 1] FIG. 1 is a process diagram comparing a method for producing packaged grilled cod roe of the present invention (Example 1) (A), an existing method for producing packaged grilled cod roe (Comparative Example 1) (B), and an existing method for producing packaged grilled cod roe that omits the low-temperature sterilization step (Comparative Example 2) (C). [Diagram 2] 1 is a photograph of a cross section of packaged grilled cod roe of the present invention. [Diagram 3] This is a photograph of a cross section of existing packaged grilled cod roe that has been pasteurized at low temperatures. [Figure 4] This is a photo of a cross-section of grilled cod roe as prepared in an ordinary household. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] 1. Manufacturing method of packaged grilled cod roe The following describes the packaged grilled cod roe and its manufacturing method according to the present invention. Note that in this specification, grilled cod roe made from Alaska pollock roe as a raw material will be described, but it goes without saying that the packaged grilled cod roe and its manufacturing method according to the present invention are not limited to grilled cod roe made from Alaska pollock roe as a raw material. Also, the present invention is not limited to the examples specifically disclosed in this specification.

[0038] 1.1. Existing manufacturing method for packaged grilled cod roe The existing method for manufacturing packaged grilled cod roe is as shown in Figure 1 (B), and includes the steps of: bringing in frozen cod roe as the raw material (step 1); thawing the frozen cod roe brought in as the raw material (step 2); washing the thawed cod roe (step 3); removing foreign bodies and intestines from the washed cod roe (step 4); soaking the washed cod roe in a salting solution containing a specified concentration of salt (the so-called salting process) (step 5); removing parasites, peritoneum, fins, bones, etc. from the salted cod roe (step 6); The process comprises a step of maturing the matured cod roe (the so-called maturing step) (step 7), a step of baking the matured cod roe (step 8), a step of vacuum-packaging the baked cod roe (step 9), a step of pasteurizing the vacuum-packaged packed grilled cod roe by immersing it in hot water held at about 63°C for about 40 minutes (step 10), and a step of cooling, freezing, and packaging the pasteurized packed grilled cod roe (steps 11 to 13). Through the above steps, packaged grilled cod roe is produced.

[0039] 1.2. The method for producing packaged grilled cod roe of the present invention On the other hand, the method for producing packaged grilled cod roe of the present invention is as shown in Figure 1(A), and steps 1 to 4, steps 6 and 7, and steps 11 to 13 are common to the existing method for producing packaged grilled cod roe shown in Figure 1(B).

[0040] However, instead of the conventional salting step 5 in which the salting step of soaking washed cod roe in a salting solution of a predetermined salt concentration is consistently performed at an atmospheric temperature around room temperature (20°C), the method for producing packaged grilled cod roe of the present invention is different from the existing method shown in Fig. 1(B) in that it includes a first salting step (step 5Aα) in which salting is performed at a relatively high atmospheric temperature around room temperature (20°C) and a second salting step (step 5Aβ) in which salting is performed at an atmospheric temperature lower than around room temperature (20°C). The salting step of the method for producing packaged grilled cod roe of the present invention combines the first salting step (step 5Aα) and the second salting step (step 5Aβ) to fully bring out the granular texture of the fish roe while suppressing an increase in the general viable bacterial count and the coliform bacteria count during the salting step, particularly an increase in the general viable bacterial count and the coliform bacteria count inside the cod roe bunches.

[0041] In addition, the method for producing packaged grilled cod roe of the present invention shown in Fig. 1(A) differs from the existing method for producing packaged grilled cod roe shown in Fig. 1(B) in that it includes a baking step 8A using a superheated steam baking machine instead of the baking step 8 using a grill baking machine. The use of a superheated steam baking machine has the advantage that the surface of the cod roe can be baked and sterilized more efficiently and uniformly by exposing the cod roe to a space filled with superheated steam that has sensible heat due to superheating in addition to the latent heat of evaporation.

[0042] In addition, the method for producing packaged grilled cod roe of the present invention shown in FIG. 1(A) differs from the existing method for producing packaged grilled cod roe shown in FIG. 1(B) in that, instead of the vacuum packaging step 9, it includes a step 9A for packaging the grilled cod roe while maintaining it at a predetermined temperature or higher. By packaging the grilled cod roe while maintaining it at a predetermined temperature or higher, in other words, while maintaining the high temperature immediately after grilling, it is possible to reduce bacterial contamination during the period from grilling to packaging. In addition, the method for producing packaged grilled cod roe of the present invention does not include a low-temperature sterilization step 10, as described below. Therefore, the packaging container for packaging the cod roe after grilling only needs to be one that can be closed, and it is not necessary to vacuum package the cod roe so that the packaging container and the cod roe are in close contact with each other in order to increase the sterilization efficiency in the low-temperature sterilization step, as in the existing manufacturing method shown in FIG. 1(B), and it is also not necessary to seal the packaging container.

[0043] In addition, the method for producing packaged grilled cod roe of the present invention shown in Fig. 1(A) differs from the existing method for producing packaged grilled cod roe shown in Fig. 1(B) in that it does not include a low-temperature sterilization step 10. That is, the method for producing packaged grilled cod roe of the present invention has the production steps as described above, and is therefore capable of reducing the general viable bacterial count and coliform count in grilled cod roe to a level that is acceptable for use as a frozen food and as a rice ball ingredient without the need for low-temperature sterilization (water bath) step 10. Therefore, according to the method for producing packaged grilled cod roe of the present invention, it is possible to produce packaged grilled cod roe that has a texture, umami, and preferably a flavor equivalent to that of grilled cod roe obtained by grilling salted cod roe in an ordinary household after salted and aged cod roe is baked.

[0044] In the manufacturing method of packaged grilled cod roe of the present invention, in the step of thawing the frozen cod roe (step 2), any appropriate thawing method can be used, including thawing by blowing air at room temperature, as is commonly done, but it is preferable to use a thawing method that reduces the risk of bacteria attaching to the cod roe during thawing, and it is particularly preferable to thaw in salt water.

[0045] In the method for producing packaged grilled cod roe of the present invention, the salt concentration of the salting solution used in the salting steps (step 5, step 5Aα, and step 5Aβ) is not particularly limited, but a salting solution with a salt concentration of preferably 5 to 20% by mass, more preferably 8 to 15% by mass, can be suitably used depending on the size of the cod roe clusters, etc. Furthermore, colorings, seasonings, chili peppers, etc. may be added to the salting solution as necessary.

[0046] The method for producing packaged grilled cod roe according to the present invention does not fundamentally require the use of a bacteriostatic agent, and although it is not necessary to use a bacteriostatic agent, the use of a bacteriostatic agent is not excluded if necessary. The type of bacteriostatic agent used is not particularly limited, but preferably, organic acids and organic acid salts can be suitably used. More preferably, glacial acetic acid (acetic acid), acetate, citrate, gluconate, lactate, fumarate, sorbate, and the like can be used, and even more preferably, glacial acetic acid (acetic acid), sodium acetate, and sodium gluconate can be used. By adding these bacteriostatic agents to the salt-cured liquid at a concentration of, for example, less than 1.0% by mass, more preferably 0.9% by mass or less, and even more preferably 0.7% by mass or less, relative to the mass of the cod roe, the texture, flavor, and preferably the taste of the grilled cod roe obtained can be maintained excellent while suppressing the variation in the number of bacteria between products.

[0047] 2. Method for measuring general viable bacteria count and coliform bacteria count Before describing the present invention in more detail through experiments, the methods for measuring the viable cell count and coliform bacteria count used in the following experiments will be described first.

[0048] In this specification, the measurement of general viable bacterial count was performed using the standard agar culture method in accordance with the method for measuring general viable bacterial count described in the "Food Sanitation Inspection Guidelines, 2018," and the measurement of coliform bacteria count was performed using desoxycholate agar medium in accordance with the method for measuring coliform bacteria count described in the "Food Sanitation Inspection Guidelines, 2018."

[0049] Measurements of the viable bacteria count and coliform bacteria count were performed on the whole cod roe or on the roe membrane and inside the bunch. The amount of sample used for the measurement was 10 g for the whole cod roe, the roe membrane, and inside the bunch. In this specification, unless otherwise specified, the measurement results and standard values ​​for the viable bacteria count and coliform bacteria count are the measurement results or standard values ​​for the whole cod roe.

[0050] In this specification, the whole cod roe means the whole cod roe including both the roe membrane part and the inside of the bunch, which will be described below, without separating them. Meanwhile, in this specification, the roe membrane part means the part of the roe membrane itself that envelops the cod roe, but in baked cod roe, the fish eggs present near the roe membrane are thermally denatured by baking and adhere to the roe membrane, and are peeled off together with the roe membrane, so in baked cod roe, the roe membrane part includes not only the part of the roe membrane itself, but also the fish eggs peeled off together with the roe membrane. The thickness of the roe membrane part peeled off from the baked cod roe was within the range of about 1 to 2 mm in all cases of Sample 1, Control Product 1, Control Product 2, and Control Product 3 described below. Meanwhile, in this specification, the inside of the bunch means the internal part of the cod roe present inside the roe membrane part.

[0051] 3. Experiment 1: Effect of manufacturing methods on total viable bacteria and coliform bacteria counts We investigated the effects of the difference between the manufacturing method of the packaged grilled cod roe of the present invention and the existing manufacturing method of the packaged grilled cod roe on the cod roe during the manufacturing process and on the general viable bacterial count and coliform bacteria count of the resulting packaged grilled cod roe. First, we will explain the specific manufacturing methods of Sample 1 and Control Products 1 to 3, which are the samples to be measured. EXAMPLES

[0052] <Sample 1: Packed grilled cod roe according to the present invention> As an example of the packaged grilled cod roe according to the present invention, sample 1 was produced according to the steps in FIG. 1(A). That is, the raw material, frozen ovaries of Alaska pollock, were thawed by soaking in 5% by mass salt solution overnight (step 2). Next, the thawed cod roe was rinsed for about 10 seconds in a chlorine water bath with a chlorine concentration of 200 ppm, and then rinsed for about 10 seconds in a salt water bath with a salt concentration of 3% by mass to wash the cod roe (step 3). For washing, half the amount of chlorine water (chlorine concentration 200 ppm) and salt water with a salt concentration of 3% by mass were used. After removing foreign objects and intestines from the washed cod roe (step 4), the cod roe was soaked in salt water with a salt concentration of 13.8% by mass (hereinafter referred to as "salted liquid" in this embodiment) for 24 hours at room temperature, i.e., an ambient temperature of 20°C (step 5Aα). The temperature of the salting liquid at the start of salting in step 5Aα was 20° C. After appropriate hand-turning and kneading, the cod roe was then moved to a chilled cabinet with an internal temperature of 10° C. while still immersed in the same salting liquid, and left to stand for another 24 hours while still immersed in the salting liquid (step 5Aβ). The salted cod roe was lifted into a thin basket and removed from the salting liquid, after which the peritoneum, fins, bones, and parasites were removed by an appropriate method (step 6), and then left to stand for 48 hours in a chilled cabinet with an internal temperature of 10° C. to allow maturation (step 7). The matured cod roe was baked using a commercially available superheated steam baking machine (model "QFB-5980C", manufactured by Naomoto Kogyo Co., Ltd., model name "Steam DC Oven") under the conditions that the temperature of the superheated steam blown into the baking machine was 250°C, and the time for the cod roe to pass through the baking machine was 2 minutes and 30 seconds (step 8A). After baking, the cod roe was filled into a packaging container (pack) while maintaining a product temperature of 80°C or higher, and packaged by closing the opening of the packaging container (step 9A). After that, it was cooled to about room temperature (20°C) and frozen in a commercially available tunnel freezer (model "MMF-2512FL", manufactured by Maekawa Manufacturing Co., Ltd., model name "Microcomputer Mesh Freezer"). The packaged baked cod roe produced in this way was designated as Sample 1. Comparative Example 1

[0053] <Comparison product 1: Existing packaged grilled cod roe that has been pasteurized at low temperatures> As a reproduction of an existing packaged grilled cod roe, a control product 1 was produced according to the steps in FIG. 1(B). The cod roe treated in steps 1 to 4 in the same manner as in Example 1 was soaked in a salt solution with a salt concentration of 13.8% by mass (hereinafter referred to as "salting solution" in this comparative example) for 48 hours at room temperature of 20°C (step 5). The temperature of the salting solution at the start of salting was 20°C. A commercially available bacteriostatic agent (product name "SM-P", manufactured by Ueno Food Techno Co., Ltd.) was added to the salting solution in an amount of 0.4% by mass relative to the cod roe. Thereafter, in the same manner as in Example 1, the salted cod roe was lifted into a thin basket, and after removing the cod roe from the salting solution, the peritoneum, fins, bones, and parasites were removed by an appropriate method (step 6), and then the cod roe was left to stand in a chilled cabinet with an internal temperature of 10°C for 48 hours to be aged (step 7). The matured cod roe was baked using a commercially available far-infrared baking machine (model "ICB-20S-WB", manufactured by Ishino Seisakusho Co., Ltd., model name "Far-infrared ceramic burner") at an internal temperature of 250°C and a baking time of 3 minutes (step 8). The baked cod roe was vacuum-packed in an appropriate packaging container (step 9), and the packaging container was immersed in a water bath at 63°C for 40 minutes for low-temperature sterilization (step 10). After removing the packaged grilled cod roe from the water bath, it was cooled to room temperature (20°C) and then frozen in a commercially available tunnel freezer (model "MMF-2512FL", manufactured by Maekawa Seisakusho Co., Ltd., model name "Microcomputer Mesh Freezer"). The packaged grilled cod roe produced in this way was designated Control Product 1. Comparative Example 2

[0054] <Control 2: Existing packaged grilled cod roe without low-temperature pasteurization> In order to examine the effect of the presence or absence of a pasteurization process on the general viable cell count and coliform bacteria count of packaged grilled cod roe, packaged grilled cod roe was produced in the same manner as in Comparative Example 1, according to the process shown in Figure 1 (C), except that (1) no bacteriostatic agent was added to the salting liquid, and (2) the process of pasteurizing the packaged grilled cod roe at low temperature (step 10) was not carried out. The packaged grilled cod roe produced in this manner was designated Control Product 2. Comparative Example 3

[0055] <Comparison product 3: Grilled cod roe cooked at home> Control product 3 was prepared as a replica of grilled cod roe prepared in a typical household, using the following procedure. The surface of commercially available salted cod roe was grilled using a commercially available toaster oven (model "ET-FA28", manufactured by Zojirushi Corporation) at a heat setting of 1300 W for a grilling time of 3 minutes. The grilled cod roe was vacuum-packed in an appropriate packaging container and frozen in a commercially available tunnel freezer (model "MMF-2512FL", manufactured by Maekawa Manufacturing Co., Ltd., model name "Microcomputer Mesh Freezer"). The packaged grilled cod roe produced in this way was designated Control product 3.

[0056] Below, with appropriate reference to Example 1 (Sample 1) and Comparative Examples 1 to 3 (Control Products 1 to 3), we will explain the effects that differences in the manufacturing processes in the methods for manufacturing packaged grilled cod roe have on the general viable bacterial count and coliform bacteria count of the cod roe during the manufacturing process and on the packaged grilled cod roe obtained by each manufacturing method, i.e., Sample 1 and Control Products 1 to 3.

[0057] 3.1. Viable bacteria count and coliform bacteria count in cod roe after salting First, we investigated the effect of differences in the salting process on the general viable bacterial count and coliform bacteria count of cod roe after the salting process. The salting process was carried out using the methods described in Example 1, Comparative Example 1, and Comparative Example 2, and the general viable bacterial count and coliform bacteria count of the cod roe immediately after the salting process were measured separately for the inside of the bunch and the roe membrane. Note that steps 1 to 4 up to the salting process are common to all of Example 1, Comparative Example 1, and Comparative Example 2. The results are shown in Table 1.

[0058] [Table 1]

[0059] As shown in Table 1, the cod roe that underwent the salting process of Example 1, which consists of a first salting process in which the cod roe is immersed in a salting solution at an ambient temperature of 20°C for 24 hours and a second salting process in which the cod roe is immersed in a salting solution at an ambient temperature of 10°C for 24 hours, had a general viable bacterial count inside the cod roe bunches of less than 10 CFU / g and was negative for coliform bacteria, and the same was true for the cod roe membrane.

[0060] In contrast, cod roe that underwent the salting process of Comparative Example 1, in which the cod roe was immersed in a salting solution containing 0.4% by mass of a bacteriostatic agent relative to the mass of the cod roe for 48 hours at an atmospheric temperature of 20°C, had a general viable bacterial count of 210 CFU / g and a coliform bacteria count of 60 CFU / g inside the cod roe bunches, a general viable bacterial count of 1300 CFU / g and a coliform bacteria count of 280 CFU / g in the roe membrane part of the cod roe. These measured values ​​are significantly higher than those of the cod roe that underwent the salting process of Example 1 for both the cod roe membrane part and the inside of the bunches, and are significantly different from the cod roe that underwent the salting process of Example 1 in that the general viable bacterial count inside the bunches exceeded 100 CFU / g and coliform bacteria were also detected.

[0061] In addition, the cod roe of Comparative Example 2, which underwent the same salting process as Comparative Example 1 except that no bacteriostatic agent was added to the salting solution, had a general viable bacteria count of 120 CFU / g and a coliform bacteria count of 40 CFU / g inside the cod roe bunches, a general viable bacteria count of 1000 CFU / g and a coliform bacteria count of 160 CFU / g in the roe membrane part of the cod roe. These measured values ​​are significantly higher than those of the cod roe that underwent the salting process of Example 1 for both the cod roe membrane part and the inside of the bunches, and are significantly different from the cod roe that underwent the salting process of Example 1 in that the general viable bacteria count inside the bunches exceeded 100 CFU / g and coliform bacteria were also detected. The measured values ​​of Comparative Example 2 were close to those of Comparative Example 1, and no significant difference was observed in the general viable bacteria count and coliform bacteria count immediately after salting depending on whether or not a bacteriostatic agent was added.

[0062] The above results show that differences in the salting process have a significant effect on the general viable bacterial counts and E. coli group counts inside the bunches and in the roe membrane of cod roe immediately after salting, and that by carrying out the salting process in two stages, a first salting process at a relatively high temperature and a second salting process at a relatively low temperature, the general viable bacterial counts and E. coli group counts of cod roe immediately after salting can be significantly reduced both inside the bunches and in the roe membrane.

[0063] 3.2. Total viable bacteria and coliform bacteria counts after aging process Next, using each cod roe that had been subjected to the salting process in 3.1 above, the aging process was carried out using the methods described in Example 1, Comparative Example 1, and Comparative Example 2, and the general viable bacterial count and coliform bacteria count of the cod roe immediately after the aging process were measured in the inside of the bunch and the roe membrane. Note that the aging process is the same in all of Example 1, Comparative Example 1, and Comparative Example 2. The results are shown in Table 2.

[0064] [Table 2]

[0065] As shown in Table 2, the cod roe that had been subjected to the salting process in Example 1 was further subjected to an aging process in which it was aged for 48 hours at an atmospheric temperature of 10° C., and the general viable bacteria count measured immediately thereafter was 10 CFU / g both inside the cod roe bunches and in the roe membrane, and the coliform bacteria count was negative both inside the cod roe bunches and in the roe membrane. Thus, when the production method of Example 1 was used, the general viable bacteria count and coliform bacteria count remained almost unchanged from the values ​​immediately after the salting process, even after the aging process.

[0066] In contrast, the cod roe after the salting process in Comparative Example 1 and Comparative Example 2 was subjected to a further maturing process in which it was matured at an atmospheric temperature of 10° C. for 48 hours, and immediately thereafter, the general viable bacteria count and the coliform bacteria count were measured. The general viable bacteria count inside the cod roe clusters was 250 CFU / g (Comparative Example 1) and 180 CFU / g (Comparative Example 2), the coliform bacteria count was 90 CFU / g (Comparative Example 1) and 90 CFU / g (Comparative Example 2), the general viable bacteria count in the roe membrane part was 1500 CFU / g (Comparative Example 1) and 1200 CFU / g (Comparative Example 2), and the coliform bacteria count was 350 CFU / g (Comparative Example 1) and 200 CFU / g (Comparative Example 2). Thus, in both cases of Comparative Example 1 and Comparative Example 2, the measurement results of the general viable bacteria count after the maturing process were about 20% higher than the measurement value after the salting process, and the coliform bacteria count was about 20% to 50% higher than the measurement value after the salting process.

[0067] In contrast, in the cod roe after the salting step in Example 1, which is an example of the method for producing packaged grilled cod roe according to the present invention, the viable bacteria count was suppressed to less than 10 CFU / g and the coliform bacteria was negative, so that even after the maturation step, the viable bacteria count and the coliform bacteria count could be maintained at low levels of 10 CFU / g and negative for coliform bacteria. In other words, according to the salting step in the method for producing packaged grilled cod roe according to the present invention, the viable bacteria count and the coliform bacteria count after the salting step, which is an upstream step, can be suppressed to very low levels, and the proliferation of the viable bacteria and the coliform bacteria in the subsequent maturation step can be significantly reduced.

[0068] 3.3. General viable bacteria count and coliform bacteria count in packaged grilled cod roe Next, using each cod roe that had been subjected to the aging process in 3.2 above, packaged grilled cod roe was further baked, packaged, pasteurized (only Comparative Example 1), and frozen according to the methods described in Example 1, Comparative Example 1, and Comparative Example 2 to produce packaged grilled cod roe, i.e., Sample 1 in Example 1, Control Product 1 in Comparative Example 1, and Control Product 2 in Comparative Example 2. For each sample, the general viable bacterial count and coliform bacteria count were measured in the inside of the bunch and in the roe membrane immediately after opening the pack, after 48 hours of storage at 25°C after opening the pack, and after 72 hours of storage at 25°C after opening the pack. The results are shown in Table 3. Table 3 also lists the measurement results after the salting process and the aging process shown in Tables 1 and 2.

[0069] [Table 3]

[0070] As shown in Table 3, in sample 1, which is a packaged grilled cod roe according to the present invention, the salting process was carried out in two stages, a first salting process and a second salting process, the general viable bacteria count inside the bunches immediately after the salting process was 100 CFU / g or less, the coliform bacteria inside the bunches immediately after the salting process was negative, and then the package was baked with superheated steam, the general viable bacteria count inside the bunches immediately after opening the package was less than 10 CFU / g, the coliform bacteria were negative, and the general viable bacteria count in the cod roe roe membrane was also less than 10 CFU / g, the coliform bacteria were negative. Meanwhile, when the general viable bacteria count immediately after opening and after the maturation process was compared, it can be seen that the general viable bacteria count in the roe membrane was reduced by the baking process with superheated steam, and the surface of the cod roe was heated and sterilized. The above results regarding the viable bacterial count and coliform bacteria fully satisfy the standards for frozen foods (viable bacterial count of 100,000 CFU / g or less, negative for coliform bacteria) set out in each article of the "Specifications and Criteria for Foods, Additives, etc." (Ministry of Health and Welfare Notification No. 370, 1959), which shows that the packaged grilled cod roe of the present invention can be shipped and used as a frozen food without any problems from a hygienic standpoint, even though it has not been pasteurized at low temperature.

[0071] Furthermore, after opening the packaged grilled cod roe of sample 1 and storing it at 25°C for 48 hours, the viable bacterial counts inside the tufts and the roe membrane were both less than 10 CFU / g, and the coliform bacteria were both negative. Even after storing it at 25°C for 72 hours after opening the package, the viable bacterial counts inside the tufts and the roe membrane were less than 10 CFU / g, and the coliform bacteria were negative. These results show that the packaged grilled cod roe of the present invention has low viable bacterial counts and coliform bacteria counts to a level that allows it to be eaten without any problems even 48 or 72 hours after opening the package.

[0072] On the other hand, in Control Product 1, which corresponds to an existing packaged grilled cod roe produced by a conventional manufacturing method, the general viable bacteria count immediately after the salting process exceeded 100 CFU / g in both the inside of the bunch and the roe membrane, and the coliform bacteria count was 60 CFU / g (inside the bunch) or 280 CFU / g (roe membrane). However, after the subsequent baking and pasteurization processes, the general viable bacteria count inside the bunch immediately after opening the pack was less than 10 CFU / g, and the coliform bacteria was negative, as was the case in the cod roe membrane. Furthermore, after opening Control Product 1 and storing it at 25°C for 48 hours, the general viable bacteria count inside the bunch and the roe membrane was measured at less than 10 CFU / g, and the coliform bacteria was negative, and the same was true even after storing it at 25°C for 72 hours after opening the pack.

[0073] The above results regarding the general viable bacterial count and coliform bacteria for Sample 1 produced by the production method of the present invention are almost equivalent to the corresponding measurement results for Control Product 1, which is equivalent to existing packaged grilled cod roe that has been pasteurized at low temperature. This shows that the production method for packaged grilled cod roe of the present invention is able to reduce the general viable bacterial count and coliform bacteria to a level equivalent to that of grilled cod roe that has been pasteurized at low temperature using the existing production method for packaged grilled cod roe, despite not performing pasteurization.

[0074] In contrast, control product 2, which is grilled cod roe produced through the same process as control product 1 except that it was not pasteurized at low temperature, had a general viable bacterial count inside the bunches of 90 CFU / g, coliform bacteria count of 10 CFU / g, general viable bacterial count in the roe membrane of less than 60 CFU / g, and coliform bacteria count of 30 CFU / g. Comparing this to the measurement results after the maturation process, the general viable bacterial count in the roe membrane of the cod roe was reduced to 1 / 20 after the baking process, but the general viable bacterial count inside the bunches of cod roe was only reduced to 1 / 2 even after the baking process. In addition, coliform bacteria were not sterilized until they were negative in both the roe membrane and inside the bunches. These results show that for cod roe in which the general viable bacterial count exceeds 100 CFU / g both inside the bunches and in the roe membrane after the salting and aging processes, and in which coliform bacteria are also detected, the roe membrane and inside the bunches cannot be sufficiently sterilized by just the surface baking that is usually used in the production of grilled cod roe, and that a low-temperature sterilization process in which the roe is maintained at a specified temperature for a certain period of time or more is essential to produce a packaged grilled cod roe product.In particular, the inside of the bunches of cod roe is not heated sufficiently during the baking process, so the sterilization efficiency inside the bunches of cod roe is extremely low.

[0075] Furthermore, when the pack of Control Product 2 was opened and stored at 25°C for 48 hours, the general viable bacteria count and coliform bacteria count were measured. The general viable bacteria count inside the cod roe chamber was 21,000 CFU / g, the coliform bacteria count was 1,200 CFU / g, the general viable bacteria count in the cod roe membrane was 35,000 CFU / g, and the coliform bacteria count was 1,500 CFU / g. After storage at 25°C for 72 hours, the general viable bacteria count inside the cod roe chamber was 64,000 CFU / g, the coliform bacteria count was 9,800 CFU / g, the general viable bacteria count in the cod roe membrane was 78,000 CFU / g, and the coliform bacteria count was 12,000 CFU / g. In other words, Control Product 2 cannot be used as a rice ball filling that is expected to be eaten after storage at room temperature for 48 or 72 hours.

[0076] In summary, the two-stage salting process adopted in the present invention, which combines the first salting process performed under a relatively high atmospheric temperature and the second salting process performed under a relatively low atmospheric temperature, was shown to be able to significantly reduce the viable bacterial count and the coliform bacteria count compared to the one-stage salting process performed under a relatively high constant temperature atmosphere adopted in the conventional method for producing packaged grilled cod roe. As a result, in the method for producing packaged grilled cod roe of the present invention, packaged grilled cod roe with low viable bacterial count and coliform bacteria count to a level that is completely acceptable for shipping as a frozen food or an ingredient for rice balls can be produced by only surface baking with superheated steam. As will be clear from the sensory test described below, the salting process of the method for producing packaged grilled cod roe of the present invention, although the second salting process is performed under a relatively low atmospheric temperature of 10°C, can fully bring out the flavor, taste, and texture of the cod roe, and the texture, flavor, and flavor of the packaged grilled cod roe obtained are in no way inferior to those of grilled cod roe cooked at home.

[0077] 4. Experiment 2. General viable bacteria count and coliform bacteria count in grilled cod roe made at home For Control Product 3 of Comparative Example 3, which is a reproduction of grilled cod roe made at home, the general viable bacteria count and coliform bacteria count were measured in the inside of the bunch and in the egg membrane before grilling, immediately after opening the pack, after 48 hours of storage at 25°C after opening, and after 72 hours of storage at 25°C after opening. The results are shown in Table 4.

[0078] [Table 4]

[0079] Control product 3, which was produced in Comparative Example 3 and corresponds to a replica of grilled cod roe cooked at home, had a general viable bacteria count of 60 CFU / g, a coliform bacteria count of 20 CFU / g, a general viable bacteria count of less than 10 CFU / g in the cod roe membrane immediately after opening the pack, and a negative coliform bacteria count. Since the coliform bacteria count was positive, this result does not meet the standard criteria for frozen foods (general viable bacteria count of 100,000 CFU / g or less, coliform bacteria negative) set out in each article of the aforementioned "Standards for Foods, Additives, etc." (Ministry of Health and Welfare Notification No. 370, 1959). In other words, grilled cod roe cooked at home is not suitable for shipping as a frozen food, unless it is eaten on the spot.

[0080] Next, after opening the pack of Control 3 and storing it at 25°C for 48 hours, the total viable bacteria count and coliform bacteria count of the grilled cod roe of Control 3 were measured. The total viable bacteria count inside the cod roe bunches was 16,000 CFU / g and the coliform bacteria count was 1,400 CFU / g. Also, although the total viable bacteria count in the egg membrane immediately after opening the pack was less than 10 CFU / g and the coliform bacteria count was negative, surprisingly, after storing it at 25°C for 48 hours after opening the pack, the total viable bacteria count had increased to 18,000 CFU / g and the coliform bacteria count to 980 CFU / g. This means that the commercially available salted cod roe, which shows the total viable bacteria count and coliform bacteria count shown in the "Before baking" column in Table 4, could not sufficiently reduce the total viable bacteria count and coliform bacteria count by the baking process alone. Furthermore, after storing at 25°C for 72 hours, the grilled cod roe from control product 3 was measured for viable bacteria counts and coliform bacteria counts. The viable bacteria count inside the cod roe compartment was 48,000 CFU / g, the coliform bacteria count was 8,800 CFU / g, and the viable bacteria count in the cod roe membrane was 56,000 CFU / g, and the coliform bacteria count was 7,200 CFU / g. In other words, it was shown that grilled cod roe prepared at home cannot possibly be used as a rice ball filling that is expected to be eaten after 48 or 72 hours of room temperature storage.

[0081] 5. Experiment 3: Evaluation of texture, umami, and flavor After thawing and returning to room temperature, Sample 1 produced in Example 1 was sampled by a panel of 10 healthy men and women to evaluate its texture, umami, and flavor. The panel also evaluated the texture, umami, and flavor of Control Product 1 (pasteurized at low temperature), which is equivalent to the existing packaged grilled cod roe produced in Comparative Example 1, in the same manner. The evaluation was performed on a 5-point scale, with Control Product 3, which is equivalent to grilled cod roe produced by a typical household cooking method, compared to Control Product 3, with "very good = 5", "good = 4", "same = 3", "poor = 2", and "very bad = 1", and the average value was calculated. The results are shown in Tables 5 and 6.

[0082] [Table 5]

[0083] [Table 6]

[0084] The results are shown in Table 5, and sample 1, which is the packaged grilled cod roe of the present invention, received an excellent rating of "equivalent = 3" in all aspects of texture, taste, and flavor, compared to control product 3, which was obtained by replicating the cooking method used in an ordinary home. This means that the packaged grilled cod roe of the present invention has, in addition to the flavor and taste unique to grilled cod roe, a contrast in texture in which the surface is grilled and somewhat hard, while the inside of the cod roe still has a raw texture, and a popping texture like popping fish roe.

[0085] In contrast, as shown in Table 6, control product 1, a conventional packaged grilled cod roe produced through a pasteurization process, received a rating below "equivalent = 3" in all aspects of texture, taste, and flavor when compared to control product 3, which was obtained by replicating cooking methods used in an ordinary household. In particular, the decline in the rating for texture was significant, with an average score of 1.2 points, close to "very poor = 1." This result clearly shows that the texture, taste, and flavor unique to grilled cod roe are lost in packaged grilled cod roe produced through the conventional pasteurization process.

[0086] Furthermore, as is clear from a comparison of the evaluations of Sample 1 and Control Product 1, Sample 1, which is the packaged grilled cod roe of the present invention, exceeded the evaluations of Control Product 1, an existing packaged grilled cod roe produced through a low-temperature sterilization process, in all aspects of texture, taste, and flavor, and was rated as being superior to Control Product 1 in all aspects of texture, taste, and flavor.

[0087] As shown in Table 3, Control Product 1 is a packaged grilled cod roe in which the viable bacteria count and coliform bacteria count are almost the same as those of Sample 1 even after storage at 25° C. for 48 hours or 72 hours after opening the package, and which is subjected to a low-temperature sterilization process after packaging to reduce the viable bacteria count and coliform bacteria count to a level sufficient for distribution in the market, i.e., a viable bacteria count of 10,000 CFU / g or less and coliform bacteria negative even after storage for 48 or 72 hours at 25° C. Thus, Sample 1, which is a packaged grilled cod roe according to the present invention, is a packaged grilled cod roe in which the viable bacteria count and coliform bacteria count are reduced to a level sufficient for distribution in the market, yet is a packaged grilled cod roe that is superior in texture, taste, and flavor to Control Product 1, which is a conventional packaged grilled cod roe in which the viable bacteria count and coliform bacteria count are reduced to a level sufficient for distribution in the market by low-temperature sterilization after packaging.

[0088] 6. Experiment 4: Comparison of appearance of grilled cod roe cross sections In addition to the texture, taste, and flavor felt when food is put into the mouth, the appearance of food, which is visually confirmed before putting the food in the mouth, also greatly affects consumers' willingness to purchase and satisfaction. In light of this, the appearances of the above-mentioned Sample 1, Control Product 1, and Control Product 3 were observed with the naked eye and compared. For the observation, the grilled cod roe of Sample 1, Control Product 1, and Control Product 3 were sliced ​​into rings at intervals of approximately 2 cm in width, and the cross sections of the sliced ​​grilled cod roe were observed, and photographs of the cross sections were taken.

[0089] The photographs are shown in Figures 2 to 4. Figure 2 is a cross-sectional photograph of Sample 1, which is a packaged grilled cod roe according to the present invention, Figure 3 is a cross-sectional photograph of Control Product 1, which is an existing packaged grilled cod roe that has been subjected to a low-temperature pasteurization process, and Figure 4 is a cross-sectional photograph of Control Product 3, which is a replica of grilled cod roe cooked in an ordinary household.

[0090] As is clear from Figure 4, when observing a cross-section of grilled cod roe prepared in a typical household, i.e., control product 3, only the roe near the roe membrane has turned white, and no whitening is observed in the roe inside the clusters. This indicates that only the roe near the roe membrane has been thermally denatured by the grilling process, and corresponds to the unique texture of grilled cod roe, where the surface is grilled and somewhat hard, while the inside is raw and the roe is poppy.

[0091] In contrast, as shown in Figure 3, when observing a cross-section of a conventional packaged grilled cod roe that had been pasteurized, i.e., Control Product 1, it was observed that not only the fish eggs near the egg membrane, but also the fish eggs inside the clusters had turned white. This is thought to be because the fish eggs inside the clusters of cod roe were thermally denatured by the low-temperature pasteurization process of immersing them in hot water for a relatively long period of time. From a cross-sectional observation with the naked eye, it can be seen that the grilled cod roe of Control Product 1 has already lost its unique texture, which is that the surface is grilled and somewhat hard, while the inside of the clusters still retains a raw texture, and this is consistent with the results of the sensory evaluation in Experiment 3.

[0092] On the other hand, as shown in Figure 2, when observing a cross-section of the packaged grilled cod roe of the present invention, i.e., Sample 1, the fish roe near the roe membrane appears white, but no obvious whitening is observed in the fish roe inside the clusters. The appearance of this cross-section is similar to that of Control Product 3 (Figure 4), which corresponds to the grilled cod roe cooked in a typical household, and this supports the idea that the packaged grilled cod roe of the present invention has a slightly hard surface due to being grilled, while still retaining the characteristic texture of grilled cod roe, with a fresh feel inside and the fish roe being poppy. Thus, Sample 1, which is the packaged grilled cod roe of the present invention, is superior in appearance to Control Product 1, which has been pasteurized at low temperature.

[0093] 7. Experiment 5: Moisture content measurement In order to physically verify the difference in texture of grilled cod roe, we focused on the difference in moisture content between the roe membrane and the inside of the bunches of grilled cod roe, and measured the moisture content of the roe membrane and the inside of the bunches for Sample 1, Control Product 1, and Control Product 3, and calculated the difference.

[0094] <Measurement sample> In this experiment, to avoid data variation due to individual differences in the shape of the grilled cod roe, the grilled cod roe was sliced ​​into rings about 2 cm wide from the center in the longitudinal direction, and the sliced ​​grilled cod roe was divided into the roe membrane and the inside of the bunch, and about 5 g of each was used as one sample for moisture content measurement. In addition, the roe membrane and the inside of the bunch of Sample 1, which is the packaged grilled cod roe of the present invention, Control Product 1, which is an existing packaged grilled cod roe that has been subjected to a low-temperature pasteurization process, and Control Product 3, which is a replica of grilled cod roe cooked in ordinary households, were used for moisture content measurement, and the moisture content was measured for four samples each of Sample 1 and Control Product 1, and one sample of Control Product 3.

[0095] <Method of measuring moisture content> The moisture content of each sample was measured by the dry weight method using a commercially available infrared moisture meter (model "FD-660", Kett Scientific Co., Ltd.) That is, using the infrared moisture meter, about 5 g of the sample was heated at a heating temperature of 120°C for 50 minutes, and the moisture content (mass%) was calculated from the difference in mass before and after heating according to the following formula.

[0096]

number

[0097] The moisture content of the inside of the egg chamber and the egg membrane of each sample, as well as the difference between them, are shown in Table 7.

[0098] [Table 7]

[0099] As shown in Table 7, the moisture content of the inside of the clusters of control product 3, which corresponds to grilled cod roe prepared in a typical household, was 71.0% by mass, and the moisture content of the roe membrane was 69.2% by mass, a difference of 1.8% by mass. The result that the moisture content of the roe membrane was lower than that of the inside of the clusters, with a difference of 1.8% by mass, is thought to reflect the fact that the surface of the cod roe prepared in a typical household is grilled and somewhat hard, while the inside of the clusters has a raw feel and the fish roe has a popping texture. The reason for this difference in moisture content between the roe membrane and the inside of the clusters is presumably because the surface of the cod roe is heated more strongly during the grilling process, making it easier to lose moisture than the inside of the clusters.

[0100] On the other hand, the moisture content of the inside of the bunches of packaged grilled cod roe that had been pasteurized, i.e., control product 1, was measured to be 70.9% by mass on average, and the moisture content of the roe membrane was 70.4% by mass on average, with the difference in moisture content between the roe membrane and the inside of the bunches being 0.5% by mass on average for the four samples. This difference in moisture content is significantly smaller, about 1 / 3 to 1 / 4, than the moisture content difference of 1.8% by mass in control product 3, which corresponds to grilled cod roe cooked in a typical home, and the moisture content of the roe membrane of the cod roe is almost the same as the moisture content inside the bunches. This result indicates that in packaged grilled cod roe that had been pasteurized, not only the surface but also the inside of the bunches was heated, and the fish roe tissue in the roe membrane and inside the bunches was in an almost uniform state, which is thought to reflect the loss of the texture unique to grilled cod roe.

[0101] In contrast, in Sample 1, which is packaged grilled cod roe of the present invention, the moisture content inside the flaxseeds was 70.2% by mass on average, the moisture content of the roe membrane was 68.5% by mass on average, and the difference in moisture content between the roe membrane and inside the flaxseeds was 1.7% by mass on average for the four samples, which was almost the same as Control Product 3. This result shows that the grilled cod roe of the present invention has a texture that is comparable to that of grilled cod roe cooked in an ordinary home (the surface is grilled and slightly hard, while the inside has a raw texture with a popping texture of the fish roe), and corresponds to the result of the sensory evaluation in Experiment 3.

[0102] 8. Experiment 6: Effect of salting liquid temperature and maturation temperature on total viable bacteria and coliform bacteria count 8.1 Effect of salting liquid temperature on total viable bacteria and coliform bacteria counts in cod roe after salting The same procedures as in Example 1 were carried out up to the second salting step (step 5Aβ) except that the temperature of the salting solution at the start of the first salting step (step 5Aα) was 10°C or 30°C, and the general viable bacterial count and the coliform bacteria count of the cod roe immediately after the second salting step were measured in the inside of the bunch and in the roe membrane. The results are shown in Table 8. In Table 8, the data from Table 1 are repeated for the results when the temperature of the salting solution at the start of the first salting step was 20°C.

[0103] [Table 8]

[0104] As shown in Table 8, the total viable bacteria count and total coliform bacteria count in the cod roe after the salting process were suppressed to very low levels regardless of whether the temperature of the salting liquid at the start of salting was 10°C, 20°C, or 30°C. This shows that the total viable bacteria count and total coliform bacteria count immediately after the salting process can be suppressed to extremely low levels regardless of whether the temperature of the salting liquid at the start of salting was 10°C to 30°C. This result is thought to be due to the fact that even if the salting liquid temperature changes to 10°C or 30°C, the salting liquid temperature converges to the ambient temperature of 20°C during the 24-hour first salting process at an ambient temperature of 20°C.

[0105] 8.2 Effect of ambient temperature during aging on the total viable bacteria count and coliform bacteria count in cod roe after the aging process The salting and maturation steps were carried out in the same manner as in Example 1, except that the temperature of the salting liquid at the start of the first salting step (step 5Aα) was 10°C, 20°C, or 30°C, and the atmospheric temperature during maturation was 5°C, 10°C, or 15°C. The general viable bacterial count and the coliform bacteria count of the cod roe immediately after the maturation step were measured in the inside of the bunch and in the roe membrane. The results are shown in Table 9. In Table 9, the sample in which the salting liquid temperature at the start of the first salting step was 20°C and the maturation temperature was 10°C is the same sample as in Experiment 1, so the data in Table 2 is relisted.

[0106] [Table 9]

[0107] As shown in Table 9, under all production conditions, the viable bacterial count and coliform bacteria count in the cod roe roe membrane and inside the tufts after the aging process were suppressed to very low levels. In other words, it was shown that aging temperatures in the range of at least 5°C to 15°C can be suitably used for producing the packaged grilled cod roe of the present invention. As will be described later, the viable bacterial count and coliform bacteria count in the roe membrane and inside the tufts are at a level that can be sufficiently sterilized by surface baking with superheated steam.

[0108] 8.3 Effect of salting liquid temperature and maturation liquid temperature on general viable bacteria count and coliform bacteria count in packaged grilled cod roe In experiment 6, the cod roe was subjected to the same aging process as in Example 1, except that the temperature of the salting liquid at the start of the first salting process (step 5Aα) was 10°C, 20°C, or 30°C, and the atmospheric temperature during aging was 5°C, 10°C, or 15°C. The production process after the aging process was carried out in the same manner as in Example 1, and samples A to I corresponding to the packaged grilled cod roe of the present invention were produced. The general viable count and the coliform bacteria count were measured for the inside of the bunch and the egg membrane of the produced samples A to I immediately after opening the packs and after storing them at 25°C for 48 hours after opening. The results are shown in Table 10. In Table 10, sample E, which was produced with a salting liquid temperature of 20°C at the start of the first salting process and a aging temperature of 10°C, is the same as sample 1 produced in experiment 1, so the data in Table 3 are relisted.

[0109] [Table 10]

[0110] As shown in Table 10, the general viable bacteria count immediately after opening for the obtained samples A to I was less than 10 CFU / g in both the inside of the bunch and the egg membrane, and the coliform bacteria were negative. This satisfies the standards for frozen foods set forth in each article of the aforementioned "Specifications and Standards for Foods, Additives, etc." (Ministry of Health and Welfare Notification No. 370, 1959). In other words, all the packed grilled cod roe produced with the salting liquid temperature at the start of salting at 10°C, 20°C, and 30°C, and with the maturation temperature at 5°C, 10°C, and 15°C, are completely free of hygiene problems when shipped as frozen foods.

[0111] Furthermore, even after storing samples A to I for 48 hours at 25°C after opening, the general viable bacteria counts tended to increase as the temperature of the salting solution at the start of salting or the aging temperature increased, but the general viable bacteria counts were low and the coliform bacteria counts were suppressed to negative. This shows that all of samples A to I, which were produced at salting solution temperatures of 10°C, 20°C, and 30°C at the start of salting and at aging temperatures of 5°C, 10°C, and 15°C, were shipped as onigiri ingredients, and the onigiri produced using these ingredients were shipped to convenience stores, displayed, and purchased by consumers, and the general viable bacteria counts and coliform bacteria counts were suppressed to a level that could be eaten safely without any problems.

[0112] 8.4 Effect of salting liquid temperature and liquid temperature during aging on the texture, umami, and flavor of packaged grilled cod roe The sensory test of Samples A to I was carried out in the same manner as in Experiment 3. That is, a panel of 10 healthy men and women tasted the grilled cod roe in a pack of the present invention immediately after opening the pack, and evaluated its texture, taste, and flavor. The evaluation was carried out on a 5-point scale, with the control product 3 obtained by reproducing the cooking method in a general household as the standard: "very good = 5", "good = 4", "same = 3", "poor = 2", and "very bad = 1", and the results were calculated as the average. The results are shown in Table 11. The results for Control Product 1 and Sample 1 are transcribed from Tables 5 and 6.

[0113] [Table 11]

[0114] The results are shown in Table 11. Samples A to I, which are packaged grilled cod roe of the present invention, were evaluated as excellent in terms of texture, umami, and flavor, and were almost equivalent to Control Product 3, which was obtained by reproducing the cooking method used in ordinary households. The above results mean that the packaged grilled cod roe of the present invention has sufficient umami, a savory flavor unique to grilled cod roe, and a slightly hard surface due to being grilled, while having a raw texture inside and a texture that makes the fish roe pop. In addition, the evaluations of the texture, umami, and flavor of Samples A to I all exceeded those of Control Product 1, indicating that Samples A to I are superior to Control Product 1 in terms of texture, umami, and flavor.

[0115] Also, from Table 11, as the temperature of the atmosphere during aging increases from 5°C to 10°C to 15°C, the evaluations tend to increase, especially in terms of umami and flavor. From this result, it can be seen that the temperature of the atmosphere during aging is more preferable in the range of 10°C to 15°C from the viewpoint of enhancing the umami and flavor of grilled cod roe. The above tendency does not contradict the knowledge in the art that the higher the temperature of the atmosphere during aging, the more the umami and flavor of the cod roe can be brought out. In particular, samples B, C, E, and F, which were produced with a salting liquid temperature of 10°C or 20°C at the start of salting and an atmosphere temperature of 10°C or 15°C during aging, were rated much higher than control product 3, which was obtained by reproducing the cooking method in a general household. From this result, it can be seen that the combination of a salting liquid temperature of 10°C to 20°C at the start of aging and an atmosphere temperature of 10°C to 15°C during aging is more preferable in terms of enhancing the umami and flavor of grilled cod roe. It is unclear why the grilled cod roe produced with the above combination received a much higher rating than control product 3, but it is speculated that the method for producing packaged grilled cod roe of the present invention can suppress the general viable bacterial count and coliform bacteria count in the cod roe to extremely low levels while still bringing out the graininess, flavor, and umami of the cod roe, thereby reducing unpleasant flavors derived from bacteria or bacterial metabolites, etc., allowing the consumer to feel the original flavor and umami of the cod roe more strongly. The evaluation results of each panelist for each of samples A to I (excluding sample E, which is the same as sample 1) are shown in Tables 12 to 19.

[0116] [Table 12]

[0117] [Table 13]

[0118] [Table 14]

[0119] [Table 15]

[0120] [Table 16]

[0121] [Table 17]

[0122] [Table 18]

[0123] [Table 19]

[0124] 9. Experiment 7: Examination of baking temperature The superheated steam temperature blown into the baking machine was set to 240°C, 250°C, 260°C, and 270°C, and samples J to M, which are examples of the packaged grilled cod roe of the present invention, were produced in the same manner as in Example 1, except for the superheated steam temperature. After the maturation process, the general viable bacterial count and coliform bacteria count of the whole packaged grilled cod roe were measured immediately after opening the packaged grilled cod roe produced, and after storing the package at 25°C for 48 hours after opening the package. In addition, immediately after opening the product package, an experimenter ate the grilled cod roe and evaluated its texture. The above results are also shown in Table 20.

[0125] [Table 20]

[0126] As shown in Table 20, regardless of the temperature at which superheated steam was used for baking, the packed grilled cod roe products, which were produced by baking the surface with superheated steam, packing the product while maintaining the relatively high product temperature after baking, cooling, and freezing, all had viable bacteria and coliform bacteria counts suppressed to a level sufficient for shipping as frozen foods. Furthermore, the viable bacteria and coliform bacteria counts after storing the product at 25°C for 48 hours after opening the product package were also suppressed to a low level in all samples. This means that regardless of the temperature at which superheated steam was used for baking, the viable bacteria and coliform bacteria counts of the packed grilled cod roe products produced were reduced to a level that would be completely acceptable for use as a rice ball filling. Therefore, it was shown that if the surface was baked at a superheated steam temperature of at least 240°C or higher, a grilled cod roe product with no hygienic problems could be obtained.

[0127] On the other hand, looking at the texture evaluation results shown in Table 20, each product baked with a superheated steam temperature of 260° C. or less showed a result of "good", but the product baked with a superheated steam temperature of 270° C. had a hard texture. The above results mean that in the method for producing packaged grilled cod roe of the present invention, when the surface is baked using superheated steam at a temperature of 240° C. or more and 260° C. or less, a packaged grilled cod roe product with a suitable texture can be produced.

[0128] In addition, when the baking time was changed to 2 or 3 minutes in the same manner as the above experiment, the same results as those described above were obtained in either case. This shows that when the time for which the cod roe to be baked is present in the space from which the superheated steam is blown out is between 2 and 3 minutes, it is possible to obtain packaged grilled cod roe of the present invention that has the same texture and flavor as grilled cod roe for home use and in which the general viable bacterial count and coliform bacteria count are suppressed to extremely low levels.

[0129] 10. Experiment 8: Examination of the presence or absence of bacteriostatic agents Samples N to R, which are packaged grilled cod roe, were produced in the same manner as in Example 1, except that a commercially available bacteriostatic agent (product name "SM-P", manufactured by Ueno Food Techno Co., Ltd.) was added to the salting liquid in an amount of 0.4, 0.6, 0.7, 0.9, 1.0, or 1.5% by mass relative to the cod roe. After the aging process, the general viable bacterial count and coliform count of the whole packaged grilled cod roe were measured immediately after opening the packaged grilled cod roe produced, and after storing the package at 25°C for 48 hours after opening the package. In addition, immediately after opening the package of the product, an experimenter ate the grilled cod roe and evaluated whether or not the taste of the bacteriostatic agent could be felt. The above results are also shown in Table 21.

[0130] [Table 21]

[0131] As shown in Table 21, regardless of the concentration of the bacteriostatic agent used, the general viable bacteria count for the whole cod roe after the aging process was suppressed to a low level, and in addition, the coliform bacteria count was negative. This is the same result as the result shown in Table 2 of Experiment 1, which was measured for the cod roe after the salting process when the salting solution did not contain a bacteriostatic agent. The general viable bacteria count and the coliform bacteria count of Samples N to R, which are packed grilled cod roe produced by further surface-cooking these aged cod roes with superheated steam, packaging, cooling, and freezing, were both suppressed to a low level immediately after opening, similar to Sample 1 shown in Table 3 of Experiment 1, which did not contain a bacteriostatic agent. Furthermore, the general viable bacteria count and the coliform bacteria count after storing the product at 25°C for 48 hours after opening the pack were also suppressed to a low level in all samples. This means that the general viable bacteria count and the coliform bacteria count of the packed grilled cod roe of the present invention produced using a bacteriostatic agent are reduced to a completely problem-free level when used as a rice ball filling.

[0132] On the other hand, looking at the results of the sensory evaluation shown in Table 21, although each product with 0.9% or less of the bacteriostatic agent added showed a result of "no effect", the packaged grilled cod roe produced using a salted solution containing 1.0% of the bacteriostatic agent "had a taste of the bacteriostatic agent". Furthermore, the packaged grilled cod roe produced using a salted solution containing 1.5% of the bacteriostatic agent "had a strong taste of the bacteriostatic agent". The above results mean that in the method of producing packaged grilled cod roe of the present invention, when a bacteriostatic agent is added to the salted solution at a concentration of 0.9% or less by mass relative to the cod roe, the variation in the number of bacteria in the production process can be suppressed without affecting the taste of the packaged grilled cod roe product.

[0133] 11. Experiment 9: Examination of salting and aging conditions in the presence of bacteriostatic agents Samples a to i, which are examples of packaged grilled cod roe of the present invention, were produced in the same manner as in Experiment 6, except that a commercially available bacteriostatic agent (product name "SM-P", manufactured by Ueno Food Techno Co., Ltd.) was added to the salting liquid at a concentration of 0.7% by mass relative to the cod roe. The general viable bacterial count and coliform bacteria count were measured for the produced samples a to i immediately after opening the packs and after storing the packs at 25°C for 48 hours after opening the packs. The results are shown in Table 22.

[0134] [Table 22]

[0135] As shown in Table 22, the obtained samples a to i had a general viable bacterial count of less than 10 CFU / g in both the inside of the bunch and the egg membrane immediately after opening the pack, and the coliform bacteria were negative. This meets the standards for frozen foods set out in each article of the aforementioned "Specifications and Criteria for Foods, Additives, etc." (Ministry of Health and Welfare Notification No. 370, 1959), and all of the packed grilled cod roe are perfectly hygienic for shipping as frozen foods.

[0136] Furthermore, even after storing samples a to i at 25°C for 48 or 72 hours after opening the pack, the bacterial counts tended to increase as the temperature of the salting liquid at the start of salting or the aging temperature increased, but the general viable bacterial counts were very low and the coliform bacteria were suppressed to negative. This means that all of samples a to i are shipped as onigiri ingredients, and if a processor removes them from the pack and uses them as onigiri ingredients, the onigiri can be eaten without any hygienic problems at a temperature of about 25°C for up to 72 hours from the time the pack was opened.

[0137] Next, the sensory test of the produced samples a to i was carried out in the same manner as in Experiment 3. That is, a panel of 10 healthy men and women tried the packaged grilled cod roe of the present invention and evaluated its texture, umami, and flavor. The evaluation was carried out on a five-level scale of "very good = 5", "good = 4", "same = 3", "bad = 2", and "very bad = 1", based on the control product 3 obtained by reproducing the cooking method in a general household, and the average value was used as the evaluation value. In addition, a packaged grilled cod roe that had been subjected to low-temperature sterilization was newly produced as control product 1 by the method described in Comparative Example 1, and the panel tried it as in the case of samples a to i, and evaluated its texture, umami, and flavor. The results are shown in Table 23. In addition, control product 3 was also newly prepared by the method described in Comparative Example 3.

[0138] [Table 23]

[0139] As shown in Table 23, the samples a to i, which are packaged grilled cod roe, were evaluated as excellent in terms of texture, taste, and flavor, being equal or almost equal to the control product 3 obtained by reproducing the cooking method used in a general household. The above results mean that the packaged grilled cod roe of the present invention, even when salted using a salting solution containing 0.7% by mass of a bacteriostatic agent added to the cod roe, has the same taste as grilled cod roe cooked in a general household, a savory flavor unique to grilled cod roe, and a texture contrast in which the surface is baked and slightly hard, while the inside remains raw, and a texture that makes the fish roe pop. In addition, the evaluations of the taste, texture, and flavor of the samples a to i all exceeded those of the control product 1, and were evaluated as being superior to the control product 1 that was pasteurized at low temperature.

[0140] Also, from Table 23, as the temperature of the atmosphere during aging increases from 5°C to 10°C to 15°C, the evaluations tend to increase, especially in terms of umami and flavor. This tendency is the same as that in Table 11 for the samples produced without using a bacteriostatic agent in the salting solution. Also, this does not contradict the knowledge in the art that a higher aging temperature can bring out the umami and flavor of cod roe. In particular, samples b, c, e, f, h, and i produced at an atmospheric temperature of 10°C or 15°C during aging were rated much higher than control product 3, which was obtained by reproducing the cooking method in a general household. From this result, it can be seen that an atmospheric temperature during aging within the range of 10°C to 15°C is more preferable from the viewpoint of enhancing the umami and flavor of grilled cod roe. This result does not contradict that in Table 11 for the samples produced without using a bacteriostatic agent in the salting solution. It is unclear why the above samples received a much higher rating than Control Product 3, but it is speculated that the manufacturing method of packaged grilled cod roe of the present invention can sufficiently bring out the graininess, flavor, and umami of the cod roe while suppressing the general viable bacterial count and coliform bacteria count in the cod roe to a low level, thereby reducing unpleasant flavors derived from bacteria or bacterial metabolites, etc., allowing diners to feel the original flavor and umami of the cod roe more strongly. The evaluation results of each panelist for the newly prepared Control Product 1 and Samples a to i are shown in Tables 24 to 33.

[0141] [Table 24]

[0142] [Table 25]

[0143] [Table 26]

[0144] [Table 27]

[0145] [Table 28]

[0146] [Table 29]

[0147] [Table 30]

[0148] [Table 31]

[0149] [Table 32]

[0150] [Table 33] [Industrial Applicability]

[0151] As explained above, the packaged grilled cod roe of the present invention has a sufficient reduction in the general viable bacteria count and the coliform bacteria count to be distributed on the market as a product, yet has a texture and taste superior to conventional packaged grilled cod roe that has been pasteurized at low temperature to reduce the bacteria count, and preferably has a flavor superior to conventional packaged grilled cod roe, and more preferably has the appearance, texture, taste, and preferably flavor of grilled cod roe prepared at a general home, which is obtained by heating and baking the surface of commercially available salted cod roe. In other words, the packaged grilled cod roe of the present invention has a homemade feel, and for example, rice balls containing this as a filling give the eater such a sense of satisfaction that they seem to be homemade rice balls. Thus, the packaged grilled cod roe of the present invention and its manufacturing method contribute to the improvement of life through food, and have great industrial applicability.

Claims

1. This packaged grilled cod roe is made by baking salted and aged cod roe and sealing the grilled cod roe in a package, and is characterized in that the general viable bacteria count measured immediately after opening and removing the package from the package is 10,000 CFU / g or less and the coliform bacteria is negative, and the difference in moisture content between the roe membrane and the inside of the tufts of the grilled cod roe measured immediately after removing the package from the package is 1.0% by mass or more and 2.5% by mass or less.

2. The packaged grilled cod roe according to claim 1, characterized in that the general viable bacterial count of the grilled cod roe measured after removal from the package and storage at 25°C for 48 hours is 10,000 CFU / g or less and the coliform bacteria is negative.

3. The packaged grilled cod roe according to claim 1 or 2, wherein the predetermined bacterial count level is a level in which the general viable bacterial count measured after removal from the package and storage at 25°C for 48 hours is 10,000 CFU / g or less and the coliform bacteria is negative.

4. The packaged grilled cod roe according to any one of claims 1 to 3, which has a texture and flavor equivalent to that of grilled cod roe that has not been pasteurized after salting, aging and baking.

Images