Methods for aging and freezing food ingredients

Abstract

The objective is to provide a method for aging and freezing food ingredients that maintains the peak of maturation and preserves the extracted umami flavor during thawing, by appropriately controlling the temperature from maturation through freezing to thawing according to the type of food ingredient. [Solution] By aging the ingredients in a liquid refrigerant at a temperature range of -5°C to 10°C depending on the type of ingredient, and then rapidly freezing the aged ingredients in a liquid refrigerant at a temperature range of -45°C or lower without delay, it is possible to minimize cell damage to the ingredients and maintain the umami flavor at the peak of aging for a long period of time. Preferably, the aging, rapid freezing, and thawing processes of the ingredients are carried out in a liquid freezer.

Description

Technical Field

[0001] The present invention relates to a method for processing and freezing matured food ingredients. More specifically, by integrating the processing steps of maturation, freezing, and thawing into a series and implementing consistent temperature control, it aims to minimize physical and chemical deterioration of food ingredients, maximize the extraction of umami components, and maintain their quality over a long period.

Background Art

[0002] Needless to say, maturation is the process of reaching a favorable state over time. For example, in the case of meat, as maturation progresses, proteins change into amino acids and peptides, increasing in quantity. These amino acids are one of the umami components, which are perceived by the human tongue as umami and give a delicious taste. Also, an increase in amino acids makes them more easily absorbed by the body and results in a tender texture. However, if the processing time for maturation is short, maturation does not progress, and if it is long, it leads to spoilage. That is, maturation and spoilage are a hair's breadth apart, and it is important to distinguish between them, which requires sufficient management and experience.

[0003] Examples of maturation methods include, for meat, dry aging (a method of removing moisture while adjusting humidity, temperature, and circulating air in a dedicated storage for about 2 weeks to 2 months), withering maturation (an old technique in Japan where the whole carcass is hung in a refrigerator for maturation over 3 - 4 weeks), and wet aging (a method of separating each part, creating a vacuum to prevent contact with outside air, and leaving it in a refrigerator at 0°C - 1°C for about 1 - 2 weeks). Most of the beef on display at stores has undergone a certain amount of time in the distribution process and is mostly wet aged.

[0004] Aging is relevant not only to meat, but also to fish, fermented foods, fruits, dairy products, and more. In all cases, there is a peak in the aging process, and maintaining that peak state is crucial. However, as mentioned above, maintaining the peak of aging is an extremely difficult task, and failure to do so results in quality deterioration due to oxidation and drying. The optimal aging temperature varies depending on the type of food, and maintaining that optimal temperature is difficult, yet there is currently no established aging technology that focuses on this aspect.

[0005] Furthermore, regarding the freezing process, freezing at around -30°C takes a long time to completely freeze, during which time the ice crystals inside the food grow larger, leading to cell damage and drip (loss of flavor components) during thawing. Therefore, rapid freezing at lower temperatures is desirable. However, conventionally used freezers (liquid freezers) are limited to -30°C, and the exploration of technologies that can sufficiently suppress cell damage and maintain the peak of maturation has not been carried out.

[0006] Furthermore, regarding thawing, rapid thawing using a microwave oven or similar method can result in excessive dripping and loss of flavor. Also, refrigerated thawing at around 4°C takes time and is prone to uneven thawing. While thawing requires setting an appropriate thawing temperature for each ingredient and optimizing maturation during thawing while minimizing dripping, no technology has yet been proposed that adequately meets these requirements. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-79039 [Patent Document 2] Japanese Patent Publication No. 2002-125584 [Patent Document 3] Japanese Patent Publication No. 2002-247 [Overview of the project] [Problems that the invention aims to solve]

[0008] As mentioned above, aging is effective in bringing out the umami of ingredients, and in order to maintain the peak of this aging process, it is important to freeze the ingredients and thaw them under optimal conditions that do not cause dripping. However, conventionally, there has been no attempt to minimize the physical and chemical deterioration of ingredients and maximize and maintain the umami components of the ingredients by treating the aging, freezing, and thawing processes as a series and maintaining consistent temperature control.

[0009] This invention was made against this background, and aims to provide a method for aging and freezing food ingredients that allows for the full extraction of the umami flavor of the ingredients through aging, maintaining the peak of aging through rapid freezing, and thawing without losing the extracted umami flavor, by appropriately controlling the temperature from aging through freezing to thawing according to the type of food ingredient. [Means for solving the problem]

[0010] The invention described in claim 1, which solves the above problems, is a method for maturing and freezing food ingredients, characterized by performing the maturation, rapid freezing at -45°C or below, and thawing processes in a series of steps while controlling the temperature of each step.

[0011] In one embodiment, the maturation and rapid freezing processes of the food are carried out continuously without interruption in a liquid freezer. Preferably, the maturation and rapid freezing processes of the food are carried out in a single liquid freezer. In another embodiment, the maturation, rapid freezing, and thawing processes of the food are carried out in a liquid freezer. In yet another embodiment, the maturation and thawing processes of the food are carried out in a single liquid freezer.

[0012] The invention described in claim 6, which solves the above problems, is a method for aging and freezing food ingredients, characterized in that food ingredients are aged in a liquid refrigerant at a temperature range of -5°C to 10°C depending on their type, and the aged food ingredients are rapidly frozen without delay in a liquid refrigerant at a temperature range of -45°C or lower, thereby minimizing cell damage to the food ingredients and making it possible to maintain the umami flavor at the peak of aging for a long period of time.

[0013] In one embodiment, the frozen food is further thawed in a range of -5°C to 5°C depending on the type of food, thereby minimizing the temperature gradient of the food and suppressing the occurrence of drip.

[0014] In one embodiment, the aging process and the rapid freezing process are performed using a liquid freezer. Preferably, the aging process and the rapid freezing process are performed using a single liquid freezer. In another embodiment, the aging process and the thawing process of the food ingredients are performed using a single liquid freezer. [Effects of the Invention]

[0015] The aging and freezing method for food ingredients according to the present invention is as described above. By consistently controlling the temperature from the aging process through the freezing process to the thawing process, the method effectively brings out the full flavor of the food ingredients, maintains the peak of their aging, and allows for thawing without losing the extracted flavor. [Modes for carrying out the invention]

[0016] The embodiments for carrying out the present invention will now be described in detail. The first embodiment of the food aging and freezing method according to the present invention is characterized by carrying out the aging, rapid freezing at -45°C or below, and thawing processes of the food in a series while controlling the temperature of each process. In this case, it is preferable to carry out the aging and freezing processes of the food in a series using a liquid freezer. In this case, as will be described later, the aging and rapid freezing processes of the food can be carried out using a single liquid freezer. Furthermore, the thawing process can be carried out in a series using a liquid freezer following the aging and rapid freezing processes of the food. In this case, the aging and thawing processes of the food can be carried out using a single liquid freezer. When using a liquid freezer, the food should be vacuum-packed in a plastic bag or the like before the aging process.

[0017] Furthermore, a second aspect of the food aging and freezing method according to the present invention is characterized by aging the food at a temperature range of -5°C to 10°C depending on its type, and then, without delay, rapidly freezing the aged food with a liquid refrigerant at a temperature range of -45°C or lower, thereby minimizing cell damage to the food and maintaining the umami flavor at the peak of aging for a long period of time. The thawing of the frozen food is then performed at a temperature range of -5°C to 5°C, which allows for optimization of the umami flavor and texture while maintaining the tissue structure of the food. Each process will be described in more detail below.

[0018] Mature Engineering As described above, the conventional aging methods include dry aging, aging with withering, and wet aging. However, in dry aging and aging with withering, microorganisms adhere during the aging process. If the microorganisms work effectively for humans, the food will be aged deliciously. However, depending on changes in humidity and temperature, harmful microorganisms may adhere and cause spoilage. Also, in any technique, if the change in protein goes too far, it will change to spoilage such as hydrogen sulfide and ammonia beyond amino acids. And above all, there is a problem that the aging process takes time and aging unevenness is likely to occur. The aging process in the method according to the present invention is, for example, performed while controlling the temperature in a coolant using a liquid freezer described later, so there is an advantage that the entire food can be aged quickly, evenly, and without variation.

[0019] The foods to which the method according to the present invention is applicable are mainly meats and fish, but in addition, there are also dairy products, fruits, vegetables, and fermented foods such as miso, soy sauce, and sake that contain a large amount of moisture. For these foods, there is an optimal aging temperature range for increasing umami components as follows, so an optimal aging temperature range is set in advance for each type of food.

[0020] Also, since the time required for aging, in other words, the time until the peak of aging, differs for each type of food, it is necessary to set the aging time in advance for each food. It is effective to use a taste sensor for setting the aging time, and it can also be set based on the results of taste tests by a large number of monitors. Examples of appropriate aging temperature ranges and aging treatment periods for each food are as follows.

[0021] · Meats (beef, pork, chicken) Aging for 10 to 14 days in the temperature range of -5°C to 2°C In this temperature range, cathepsin enzyme works, protein decomposition progresses, and umami increases. · Fishes (tuna, salmon, etc.) Aging for 3 to 7 days in the temperature range of -2°C to 5°C In this temperature range, inosinic acid (IMP) increases due to ATP decomposition. · Dairy products (cheese, yogurt) are aged in the temperature range of 0°C to 8°C In this temperature range, the fermentation of lactic acid bacteria progresses and the flavor is improved. · Fruits (grapes, mangoes, etc.) are aged in the temperature range of 2°C to 10°C In this temperature range, the sugar content increases due to the action of enzymes. · Fermented ingredients (miso, soy sauce, sake) are aged in the temperature range of 5°C to 10°C In this temperature range, the microbial fermentation is optimized and the aging deepens.

[0022] Meat is rich in protein and also contains nutrients such as iron, vitamin B12, and zinc that are likely to be lacking. In addition, aging increases the amino acid (glutamate), which is a umami component. Proteins necessary for building the human body are not absorbed as they are, but are broken down into peptides and amino acids and then absorbed. When it has changed to amino acids like aged meat, the nutrients are more easily absorbed. In addition, due to the action of enzymes, the muscle fibers are decomposed into amino acids, resulting in tender meat.

[0023] The aging process in the method according to the present invention is carried out for a predetermined time by using a liquid freezer described later and setting it to the above temperature range according to the food material. At that time, the food material is vacuum-packed in a plastic bag or the like.

[0024] Refrigeration Engineering In the method according to the present invention, following the above aging process, a rapid freezing process is carried out without a break. The rapid freezing process is carried out at an ultra-low temperature of -45°C or lower in a short time (usually about 五分钟 to 十分钟). Rapid freezing in such a short time has a time advantage, but the main reason is to quickly pass through the temperature range of -1°C to -5°C, which is called the maximum ice crystal formation temperature range. That is, this temperature range is the temperature range in which the water in the food changes to ice. If this temperature range is not quickly passed through, the water expands when it changes to ice crystals, the ice crystals break the cell membrane of the food, and the umami components flow out. Not only that, when the cell membrane is broken, the gap between the cell membranes decreases, so the penetration of the seasoning liquid and the like is inhibited.

[0025] In the method according to the present invention, rapid freezing at ultra-low temperatures is recommended to be performed using a liquid freezer invented by the present inventor, which is a non-CFC type and freezes vacuum-packed food while flowing a cooling liquid (for example, an antifreeze such as ethanol brine based on ethanol) at -50°C or below using a screw drive (Japanese Patent Application No. 2024-119275).

[0026] This liquid freezer is designed for temperatures of -50°C or lower, a level not previously considered practical. At such low temperatures, the viscosity of the coolant increases considerably, becoming thick and sludgy, requiring thorough stirring. To address this, this liquid freezer uses stirring blades with their axes oriented horizontally below the partition plate to create a horizontal water flow directly towards the cooling coil, while also creating a circulating flow above and below the partition plate. This allows for efficient and waste-free stirring, enabling it to handle coolants at -50°C or lower.

[0027] Furthermore, this liquid freezer can be made in a compact size, for example, with dimensions of approximately 70cm, 90cm, and 110cm in length, width, and height, respectively, which has the advantage of not taking up much space even when installed in a small store.

[0028] The above aging process can be carried out using this liquid freezer. In this case, an aging chamber surrounded by insulated walls and capable of adjusting the room temperature is placed inside a cooling tank filled with coolant, so as to be isolated from the coolant. In this configuration, the food to be aged is vacuum-packed and placed in the aging chamber, the aging chamber is cooled to a temperature range appropriate for the food for a predetermined time, and immediately after the predetermined time has elapsed, the food, still vacuum-packed, is transferred to the coolant for rapid cooling. In the commonly used air blast method, there is no need to vacuum-pack the food, but it has the disadvantages of taking a long time to complete freezing and being prone to uneven freezing. However, in the method according to the present invention, since the aging process and rapid freezing process are carried out in liquid, it is possible to achieve even aging and freezing throughout in a short time.

[0029] Alternatively, separate liquid freezers may be prepared for aging and rapid freezing. In this case, it is preferable to use the liquid freezer for aging, which has a similar processing temperature range, as well as the liquid freezer for thawing described below.

[0030] Thawing Project This process involves thawing frozen ingredients at a temperature range of -5°C to 5°C to optimize their flavor and texture while maintaining their tissue structure. Thawing at -5°C to 5°C allows for proper moisture retention and minimizes drip loss. The optimal thawing temperature varies depending on the ingredient; for meat and fish, -2°C to 0°C is ideal, as this temperature range allows for flavor preservation while minimizing drip loss. For dairy products and fermented foods, the optimal temperature range is 0°C to 5°C, as this temperature range reactivates enzyme reactions and maximizes flavor.

[0031] Thawing can be done by various methods depending on the food, such as natural thawing, refrigerator thawing, running water thawing, or ice water thawing. However, it is recommended to thaw using a liquid refrigerant with the above-mentioned liquid freezer or another type of liquid freezer (which, as mentioned above, can be used in conjunction with a liquid freezer for aging). Thawing with a liquid refrigerant allows for uniform heating of the entire food item, minimizing the temperature gradient between the outside and inside of the food, thereby suppressing drip and improving the moisture retention rate of the food. [Industrial applicability]

[0032] The aging and freezing method for food ingredients according to the present invention is as described above and can be applied to various food ingredients. By consistently controlling the temperature from the aging process through the freezing process to the thawing process, it is possible to fully extract the umami flavor of the food ingredients, maintain the peak of their aging, and thaw them without losing the extracted umami flavor. It can be easily utilized by food manufacturers, supermarkets, high-end restaurants, hotels, and various other factories and stores, so its industrial applicability is great.

Claims

1. A method for maturing and freezing food ingredients, characterized by performing the maturation, rapid freezing at -45°C or below, and thawing processes in a series of steps while controlling the temperature of each step.

2. The method for maturing and freezing food ingredients according to claim 1, wherein the maturation process and rapid freezing process of the food ingredients are carried out continuously without interruption in a liquid freezer.

3. The method for maturing and freezing food ingredients according to claim 2, wherein the maturation process and rapid freezing process of the food ingredients are performed in a single liquid freezer.

4. The method for maturing and freezing food ingredients according to claim 1, wherein the maturation, rapid freezing, and thawing processes of the food ingredients are performed in a liquid freezer.

5. The method for aging and freezing food ingredients according to claim 4, wherein the aging and thawing processes of the food ingredients are performed in a single liquid freezer.

6. A method for aging and freezing food ingredients, characterized by aging the ingredients with a liquid refrigerant in a temperature range of -5°C to 10°C depending on the type of ingredient, and then rapidly freezing the aged ingredients with a liquid refrigerant in a temperature range of -45°C or lower without delay, thereby minimizing cell damage to the ingredients and enabling the maintenance of the umami flavor at the peak of aging for a long period of time.

7. The method for aging and freezing food ingredients according to claim 6, further comprising the step of thawing the frozen food ingredients in a range of -5°C to 5°C depending on the type of food ingredient.

8. The method for aging and freezing food ingredients according to claim 6, wherein the aging process and rapid freezing process are performed in a liquid freezer.

9. The method for aging and freezing food ingredients according to claim 8, wherein the aging process and the rapid freezing process are performed in a single liquid freezer.

10. The method for aging and freezing food ingredients according to claim 7, wherein the aging and thawing processes of the food ingredients are performed in a single liquid freezer.