Oil-starch mixture for creating viscosity in frozen food soups and frozen food

Abstract

To provide an oil and fat-starch mixed liquid for expressing viscosity of a soup of a frozen food which homogeneously disperses starch in oil and fat, and is easy to be attached to a main food material when being directly filled into the main food material, in a frozen food having a viscous soup when eaten, and a frozen food using the oil and fat-starch mixed liquid.SOLUTION: An oil and fat-starch mixed liquid for expressing viscosity of a soup of a frozen food is directly filled into a main food material of a frozen food, wherein a starch content of the oil and fat-starch mixed liquid is 25 wt.% or less, and oil and fat of the oil and fat-starch mixed liquid is a non-Newtonian fluid at 25°C.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an oil-starch mixture for developing viscosity in soups of frozen foods, and to frozen foods.

[0002] Conventionally, various frozen foods that can be easily eaten through microwave cooking have been launched on the market. Many products utilizing microwave cooking have been developed for frozen noodles and frozen cooked rice, and particularly in recent years, for frozen noodles, not only products such as pasta and yakisoba that can be eaten only by microwave heating, but also soupy products such as ramen that can be eaten by adding microwave-cooked noodles and ingredients to separately prepared soup have been developed.

[0003] In the case of soupy frozen noodles for microwave cooking, the soup is usually packaged separately, which not only incurs packaging costs, but also is stored in the packaged state before manufacturing. Therefore, it is necessary to reduce packaging costs through concentration, adjust water activity to maintain storage stability, adjust pH, etc., which leads to differences in flavor compared to soups served in restaurants. Furthermore, for viscous soups such as ankake ramen, rich tonkotsu ramen, and chicken paitan ramen, modified starch or thickeners are used to achieve thickness, which results in an artificial and unnatural mouthfeel regarding the thickness.

[0004] Regarding technologies related to foods having viscous soups such as ankake ramen, the technologies disclosed in Patent Documents 1 and 2 are known.

[0005] Patent Document 1 describes a thickening soup base that suppresses starch from clumping and provides sufficient thickness to the soup, comprising at least two packets: packet A containing oil and fat and 10-70% by mass of starch with a gelatinization onset temperature of 60°C or lower, and no water-soluble liquid components; and packet B containing a seasoning composition. However, while the soup made by dissolving and mixing the thickening soup base described in Patent Document 1 by adding hot water or water does not clump easily and has sufficient viscosity and thickness, it is difficult to express the natural thickness that comes from simmering meat, bones, vegetables, and other ingredients, such as the rich tonkotsu ramen and chicken broth ramen served in restaurants.

[0006] Patent Document 2 describes a starch composition for frozen foods and a technology relating to frozen foods using the same, which suppresses clumping of starch added to soup to give it high viscosity during cooking and consumption, enabling consumption after quick and easy cooking. The technology describes a frozen food in which a portion of the starch composition, in which the mass ratio of starch to fat is 3:7 to 7:3, is mixed into the gaps between the main ingredient and the secondary ingredient, or both, and frozen as a whole. However, the technology in Patent Document 2 mainly involves boiling cooking, where the food can be stirred with chopsticks or the like while heating. In order to freeze the starch composition and the main ingredient together, a large amount of destarch is added to suppress fluidity. When cooked in a microwave oven, the starch composition is also heated by the microwave cooking process, which makes it prone to clumping. This tendency is particularly pronounced when the food contains noodles or ingredients with high moisture content, and it is thought that this is because the starch absorbs moisture and gelatinizes when cooked in a microwave oven while in contact with a lot of moisture. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6228755 [Patent Document 2] Patent No. 5409700 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a frozen food having a viscous soup when consumed, in which starch is homogeneously dispersed in the oil and fat, and which readily adheres to the main ingredients when directly filled into the main ingredients, and a frozen food using the oil and fat-starch mixture for generating the viscosity of the soup. [Means for solving the problem]

[0009] The inventor diligently researched how to reproduce the thick, viscous soups of rich tonkotsu ramen and toripaitan ramen, which are extracted by simmering pork bones, chicken bones, and vegetables for a long time in restaurants, using frozen noodles for microwave cooking. This research led to the present invention.

[0010] In other words, an oil-starch mixture for generating viscosity in soups that are directly filled into the main ingredients of frozen foods, characterized in that the starch content of the oil-starch mixture is 25% by weight or less, and the oil in the oil-starch mixture is a non-Newtonian fluid at 25°C.

[0011] Furthermore, the oils and fats used in the oil-starch mixture according to the present invention preferably have a shear strength of at least 100 mPa·s to 500 mPa·s at 25°C and a shear rate of 10.2 [1 / s].

[0012] Furthermore, the starch used in the oil-starch mixture according to the present invention preferably has a gelatinization onset temperature of 60°C or lower.

[0013] Furthermore, the frozen food according to the present invention comprises a main ingredient and a viscosity-generating oil-starch mixture according to the present invention, which is directly filled into the main ingredient. [Effects of the Invention]

[0014] According to the present invention, provided are an oil-fat-starch mixture for expressing viscosity of soup, which is used in frozen food having a viscous soup when eaten, wherein starch is uniformly dispersed in the oil and fat and the mixture easily adheres to the main food material when directly filled into the main food material, and a frozen food using said oil-fat-starch mixture. [BRIEF DESCRIPTION OF DRAWINGS]

[0015] [Figure 1] It is an explanatory view of a frozen food (frozen food for microwave oven cooking) according to an embodiment of the present invention. [Figure 2] It is an explanatory view of a modified example of the frozen food (frozen food for microwave oven cooking) according to an embodiment of the present invention. [Figure 3] It is a graph showing the relationship between shear rate and viscosity of oil and fat in Formulation Examples 1-1 to 1-3 used in the oil-fat-starch mixture according to an embodiment of the present invention. [DESCRIPTION OF REFERENCE NUMERALS]

[0016] 1 Main food material 2 Upper surface portion 3 Oil-fat-starch mixture 4 Concentrated liquid soup [MODE FOR CARRYING OUT THE INVENTION]

[0017] Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the following description.

[0018] 1. Main ingredients Examples of the main food material according to the present invention include noodles and cooked rice. The type of noodles is not particularly limited, and examples include udon, soba, Chinese noodles, spaghetti, macaroni, etc. Raw noodles or dried noodles of these noodles, which are pre-cooked by a cooking method such as boiling or steaming, are used as the main food material. There is also no particular limitation on the type of cooked rice, and examples include polished rice, brown rice, and multi-grain rice. Cooked products of these, fried rice obtained by frying the cooked products, and cooked products such as pilaf obtained by frying these and then cooking with soup are used as the main food material.

[0019] 2.Oil-starch mixture The oil-fat-starch mixture according to the present invention is a mixture of oil and fat and starch, and contains no water. The oil and fat in the oil-fat-starch mixture according to the present invention is not particularly limited as long as it is edible, and examples thereof include oil and fats such as lard, beef tallow, chicken fat, palm oil, corn oil, rapeseed oil, sesame oil, olive oil, rice white pressed oil, soybean oil, safflower oil and hardened oils thereof, and one or more of these oil and fats can be selected and used.

[0020] In particular, the oil and fat in the oil-fat-starch mixture according to the present invention is preferably a non-Newtonian fluid at 25°C. Oils that are liquid at ordinary 25°C are Newtonian fluids, but by mixing oil and fat such as shortening, the oil and fat can be imparted with viscosity to become a non-Newtonian oil and fat at 25°C. If the viscosity is too low, starch will not be uniformly dispersed in the oil and fat in the oil-fat-starch mixture, and it will become difficult for the mixture to adhere to the main food material. Therefore, the oil and fat in the oil-fat-starch mixture according to the present invention preferably has a viscosity of at least 100 mPa·s, more preferably 250 mPa·s or more, at 25°C and a shear rate of 10.2 [1 / s]. Conversely, if the viscosity is too high, it becomes difficult to take out the frozen food from the frozen container after freezing. Therefore, the viscosity is preferably at most 500 mPa·s, more preferably 450 mPa·s or less, at 25°C and a shear rate of 10.2 [1 / s]. Viscosity may be measured with a cone-plate rotational viscometer.

[0021] In addition, the starch in the oil-fat-starch mixture according to the present invention is not particularly limited, and examples thereof include starches such as potato starch, tapioca starch, corn starch, waxy corn starch, sago starch, mung bean starch, wheat starch and rice starch, as well as modified starches obtained by subjecting these starches to treatments such as gelatinization, etherification, esterification and oxidation treatment, and one or more of these starches can be selected and used. Preferable examples of the starch used in the present invention include starch having a gelatinization initiation temperature of 60°C or lower, and most preferably hydroxypropylated starch (etherified starch).

[0022] Furthermore, the starch content in the oil-starch mixture according to the present invention is preferably 25% by weight or less of the total weight of the oil-starch mixture. If the amount of starch is too high, it is difficult for the starch to disperse uniformly, and it tends to gelatinize during microwave cooking, resulting in lumps when eaten. There is no particular lower limit, but if it is too low, the amount of oil-starch mixture to be added will increase depending on the type of soup, so 10% by weight or more is preferred.

[0023] Furthermore, it is preferable to add the oil-starch mixture according to the present invention so as to cover the top surface or the entire surface of the main ingredient, as shown in Figure 1 or Figure 2. Doing so not only prevents the moisture from the concentrated liquid soup described later from transferring to the noodles, but also prevents the main ingredients from sticking together during microwave cooking. For homogeneous cooking, it is preferable to add the mixture so as to cover the entire surface of the main ingredient, as shown in Figure 2.

[0024] Furthermore, the amount of oil-starch mixture added according to the present invention is preferably 3 to 20% by weight relative to the weight of the cooked main ingredient. If it is less than 3% by weight, it is difficult to cover the top surface or the entire surface of the main ingredient when it is filled into a freezer container. Conversely, if it is more than 20% by weight, a large amount of excess oil-starch mixture will accumulate at the bottom of the freezer container, causing the starch to clump together during microwave cooking and making it difficult to remove the frozen food from the freezer container. More preferably, it is about 5 to 12% by weight.

[0025] 3. Concentrated liquid soup When the concentrated liquid soup according to the present invention is directly filled into the main ingredients, it is preferable that the viscosity at 25°C be 5 Pa·s or higher. The viscosity can be measured using a B-type viscometer. If the viscosity is less than 5 Pa·s, not only will moisture easily migrate from the concentrated liquid soup to the main ingredients, but the concentrated liquid soup will also easily drip down from the top surface of the main ingredients, making it easier for the concentrated liquid soup to burn or for the main ingredients to stick together during microwave cooking. More preferably, it should be 8 Pa·s or higher. There is no particular upper limit, but if the viscosity is too high, it becomes difficult to fill the concentrated liquid soup, so it is preferable that the upper limit of viscosity be 25 Pa·s or less.

[0026] The salt concentration of the concentrated liquid soup according to the present invention is preferably 7% (W / V) or less when directly filled into the main ingredients. If the salt concentration is higher than 7%, the concentrated liquid soup may burn or the main ingredients may stick together when cooked in a microwave oven. The salt concentration can be measured by the Mohr method. Furthermore, since the concentrated liquid soup according to the present invention is directly filled into frozen food and frozen, the filling weight of the soup can be increased compared to separate-package type concentrated liquid soups, and because pH adjustment for preservation is unnecessary, the degree of concentration can be lowered, and the flavor can be improved. There is no particular lower limit, but if the degree of concentration is too low, the amount of liquid soup to be filled will be large, which will not only increase the cooking time in a microwave oven, but the texture of the main ingredients will also deteriorate due to moisture transfer to the main ingredients during storage. Therefore, it is preferable to adjust the salt concentration of the concentrated liquid soup to 3% or more.

[0027] Furthermore, when directly filling the main ingredient with the concentrated liquid soup according to the present invention, it is preferable that the amount of soup filled is 75% by weight or less of the weight of the cooked main ingredient. If the amount filled is too much, the concentrated liquid soup will not be able to cover the top surface of the main ingredient and will easily drip down, and the microwave cooking time will be longer, making it easier for the concentrated liquid soup to burn or the main ingredient to stick together during microwave cooking. There is no particular lower limit, but if the amount filled is too little, the concentration of the concentrated liquid soup will be too high, and the concentrated liquid soup will be overheated during microwave cooking, making it easier for it to burn or for the main ingredient to stick together, so it is preferable that the amount be 25% by weight or more of the weight of the main ingredient. A more preferable range is 50 to 70% by weight.

[0028] 3. Manufacturing process Prepare cooked main ingredients. Specifically, for noodles, use fresh or dried noodles prepared by boiling or steaming, and rinse and cool them if necessary. For rice dishes, use cooked rice, fried rice (made by stir-frying cooked rice), or pilaf (made by stir-frying rice and then cooking it with soup).

[0029] Next, the cooked main ingredients are placed into freezer containers. The freezer containers are not particularly limited as long as they are freeze-resistant; flexible plastic or metal containers are suitable. The shape of the containers is also not particularly limited; they can be rectangular, circular, or have a central protrusion.

[0030] After the main ingredients are filled into the freezer container, the oil-starch mixture is filled in such a way that it covers the top surface or the entire surface of the main ingredients, as shown in Figure 1 or Figure 2. There are no particular limitations on the filling method, but as shown in Figure 1, when filling the top surface of the main ingredients, it is preferable to fill it in such a way that it covers a wider area than the top surface where the concentrated liquid soup described later will be filled. Also, as shown in Figure 2, when covering the entire surface of the main ingredients, one method is to fill the oil-starch mixture and then blow air onto it to evenly coat the surface of the main ingredients with the oil-starch mixture. Covering the entire surface of the main ingredients is preferable in terms of suppressing moisture transfer to the main ingredients overall, allowing the main ingredients to break down well, ensuring uniform heating, and resulting in a good texture for the main ingredients and the natural viscosity development of the soup.

[0031] After coating the main ingredient with a fat-starch mixture, the concentrated liquid soup can be filled onto the top surface of the main ingredient as shown in Figure 1 or Figure 2. There are no particular limitations on the filling method, but if the fat-starch mixture is filled to cover the top surface of the main ingredient as shown in Figure 1, the soup should be filled uniformly within the area covered by the fat-starch mixture. If the fat-starch mixture covers the entire surface of the main ingredient as shown in Figure 2, the soup should be filled uniformly onto the top surface of the main ingredient.

[0032] When filling the main ingredients with concentrated liquid soup, the container is placed in a freezer after filling with the concentrated liquid soup and then frozen. There are no particular limitations on the freezing method, and conventional techniques can be applied. For example, not only commercial freezing equipment such as air blast type tunnel freezers, spiral freezers, wagon freezers, rapid freezers, and brine type flexible freezers can be used, but also general commercial and household freezers. Particularly preferred is rapid freezing using a tunnel freezer or spiral freezer at a temperature of -35°C or lower.

[0033] Next, remove the frozen food from the freezer container. There are no particular limitations on the removal method; the food can be removed by deforming a flexible freezer container or by striking the bottom of the container. The removed frozen food can be placed in a microwave-safe bag if necessary and sealed, and then sealed with outer packaging material along with any additional packets of condiments or seasonings, and sold as frozen food.

[0034] 4.Cooking method In the case of typical frozen foods with broth, cooking is completed by either simmering in a pot or microwaving the frozen main ingredients, then transferring the main ingredients to a soup prepared beforehand by dissolving a separate packet of soup in hot water. While the frozen food according to the present invention is preferably microwave-cooked, it may also be cooked in a pot as usual. If the frozen food according to the present invention is a microwave-cooked frozen food, cooking is completed by microwaving it, transferring it to a container such as a bowl, pouring in hot water, and stirring. Since there is no need to prepare a separate soup, cooking is not only simpler, but if the concentrated liquid soup is directly filled, it also reduces packaging materials, making it environmentally friendly. Furthermore, because it is microwave-cooked in the state of an oil-starch mixture, the starch contained in the oil absorbs water and undergoes slight gelatinization before hot water is poured in. As a result, the viscosity that develops when hot water is poured in does not feel artificially adjusted, as in cases where viscosity is developed using an oil-starch mixture of a separate soup packet as in Patent Document 1, but rather has a natural thickness similar to that of food served in a restaurant. Furthermore, if the concentrated liquid soup is directly filled into the package, the concentrated liquid soup is also heated in the microwave, which enhances the feeling of cooking, allows the soup to blend well with the main ingredients, and creates a more cohesive overall flavor.

[0035] The embodiment will be described in more detail below with reference to examples. [Examples]

[0036] <Experiment 1> Examination of oil-starch mixture (main ingredients) A mixture of 950g wheat flour and 50g starch was used to make the raw flour. 10g of salt and 10g of a lye solution (50g sodium carbonate, 45g potassium carbonate, 5g polyphosphate) were dissolved in 350ml of water to make the dough. The mixture was kneaded in a mixer for 15 minutes to produce the noodle dough. This dough was rolled out to a thickness of 1.5mm using rollers, and then cut out using a No. 20 cutting blade (square blade) to make the raw noodle strands. Next, the obtained raw noodle strands were cut into 25-30cm portions, boiled in boiling water for 30 seconds, rinsed in cold water for 1 minute, immersed in ice water for 30 seconds to cool, drained, and served as pre-cooked Chinese noodles (main ingredient).

[0037] (Oil-starch mixture) After mixing rapeseed oil and shortening according to formulation examples 1-1 to 1-5 listed in Table 1 below, starch was added to prepare an oil-starch mixture. For formulation examples 1-1 to 1-3, the viscosity of the oils (rapeseed oil and shortening) used was measured. The measurement method involved using a digital viscometer (LVDVNeat) from Eikoh Seiki Co., Ltd., employing a cone spindle (CPA-52Z) and adapter (SC4-27). The rotation speed was varied from 1 rpm to 80 rpm (shear rate from 0.34 to 27.2) every 60 seconds to measure viscosity. The measurement results are shown in Table 2 and Figure 3. Note that for formulation example 1-1, viscosity could not be measured at shear rates below 10.2. Similarly, for formulation examples 1-1 to 1-3, the oil-starch mixture was left to stand for 1 minute, and the dispersibility of the starch was visually confirmed. Samples with a large amount of starch precipitate were marked with an "X," while those with little starch precipitate and generally maintained dispersion were marked with a "O."

[0038] [Table 1]

[0039] [Table 2]

[0040] (Concentrated liquid soup) Next, a concentrated liquid soup (chicken broth) was prepared by mixing the ingredients of Formula Example 2-1 in Table 3 below and heating and dissolving them. For Formula Examples 2-1, 2-2, and 2-3, the viscosity at 25°C was measured using a B-type viscometer (VISCOMETER TVB-15M rotor No. 3, manufactured by Toki Sangyo Co., Ltd.).

[0041] [Table 3]

[0042] (Test Example 1-1) After filling a freezer container (container opening diameter: 150mm, container bottom diameter: 140mm, container height: 54mm, container protrusion opening diameter: 108mm, container protrusion bottom diameter: 96.5mm, container protrusion height: 8mm) with 170g of pre-cooked Chinese noodles as the main ingredient, 12g of the oil-starch mixture from example 1-1 was added on top of the noodles, and compressed air was blown from above the container to coat the entire surface of the noodles with the oil-starch mixture.

[0043] Next, 115g of the concentrated liquid soup from formulation example 2-1 was evenly poured over the Chinese noodles, which were coated with the oil-starch mixture, ensuring that it did not drip down from the edge of the freezer container, as shown in Figure 2.

[0044] After filling with concentrated liquid soup, the entire freezer container was placed in an air-blast type rapid freezer at -35°C for 45 minutes. The frozen food (Chinese noodles) was then removed from the freezer container and placed in a microwave-safe plastic bag to create microwave-safe frozen food (frozen Chinese noodles).

[0045] (Test Example 1-2) Frozen foods for microwave cooking were prepared using the method described in Test Example 1-1, except that the oil-starch mixture was used in Formula Example 1-2.

[0046] (Test Examples 1-3) Except for using the oil-starch mixture in Example 1-3, microwaveable frozen foods were prepared using the method described in Test Example 1-1.

[0047] (Test Examples 1-4) Frozen foods for microwave cooking were prepared using the method described in Test Example 1-1, except that the oil-starch mixture was used in Formula Example 1-4.

[0048] (Test Examples 1-5) Except for using the oil-starch mixture in Formula Examples 1-5, microwaveable frozen foods were prepared using the method described in Test Example 1-1.

[0049] (Test Examples 1-6) Frozen foods for microwave cooking were prepared using the method described in Test Example 1-2, except that the amount of oil-starch mixture added was 5g.

[0050] (Test Examples 1-7) Frozen foods for microwave cooking were prepared using the method described in Test Example 1-2, except that the amount of oil-starch mixture added was 34 g.

[0051] (Test Examples 1-8) 12g of the oil-starch mixture from formulation example 1-2 was filled into a separate package, and 92g of the concentrated liquid soup from formulation example 2-4 was filled into a separate package. The main ingredient, pre-cooked Chinese noodles, was frozen according to the method of test example 1-1 without adding the oil-starch mixture or concentrated liquid soup, and placed in a microwave-safe bag to produce a microwave-safe frozen food product.

[0052] For Test Examples 1-2 and 1-8, the products were cooked in a microwave oven, consumed, and evaluated sensoryly. For Test Example 1-2, the frozen food was cooked at 600W for 4 minutes, then transferred to a container, 200ml of hot water was added, the concentrated liquid soup was dissolved while stirring, and the product was consumed and evaluated. For Test Example 1-8, the frozen food was heated at 600W for 4 minutes, then the oil-starch mixture from Formula Example 1-2 and the concentrated liquid soup from Formula Example 2-4 were placed in a container beforehand, 220ml of hot water was added to dissolve the soup, and the product was added and consumed and evaluated. For the evaluation, the thickness of the rich chicken broth soup (Tenkaippin) from a restaurant was used as the standard. Products with a natural thickness almost equivalent to that of a restaurant were rated ◎, products with a natural thickness and generally good were rated ○, products with an artificial thickness and inferior were rated △, and products with a strongly artificial thickness and very poor were rated ×.

[0053] Furthermore, for Test Examples 1-1 to 1-7, the manufacturing suitability was evaluated, including the degree of adhesion of the oil-starch mixture to the noodles, oil dripping, and removal of frozen food after freezing. For Test Examples 1-1 to 1-8, the cooking suitability was evaluated, including how easily the noodles separated and how clumps formed in the soup when cooked in a microwave oven. Test Examples 1-1 to 1-7 were cooked using the same method as Test Example 1-2.

[0054] The evaluation results are shown in Table 4.

[0055] [Table 4]

[0056] From the sensory evaluation results of Test Examples 1-2 and 1-8, the microwaveable frozen food (frozen Chinese noodles) according to the present invention, compared to the liquid soup and oil-starch mixture described in Patent Document 1 which are packaged separately, had a reduced artificial viscosity similar to that made with starch, approaching a natural viscosity that is thick but clean, like that served in restaurants. This is presumed to be because, during microwave cooking, the starch in the oil-starch mixture absorbs moisture from the directly filled concentrated liquid soup and the noodles as it is heated, partially gelatinizing the starch. Then, when hot water is poured in, the gelatinization is completed, resulting in a reduced artificial viscosity compared to Test Example 1-8, where gelatinization is completed with hot water alone. Furthermore, in the sample of Test Example 1-2, the concentrated liquid soup was directly filled, and the concentrated liquid soup was heated together with the noodles in the microwave. As a result, compared to Test Example 1-8, the soup itself had a more cooked feel, the noodles and soup blended well, and the overall flavor was well-balanced.

[0057] The relationship between shear rate and viscosity at 25°C was measured for the oils and fats of formulation examples 1-1 to 1-3. As shown in Table 2 and Figure 3, the oil in formulation example 1-1 shows almost no change in viscosity even when the shear rate changes, indicating that it is a Newtonian fluid. The oils and fats in formulation examples 1-2 and 1-3 show a decrease in viscosity as the shear rate increases, indicating that they are non-Newtonian fluids.

[0058] From the evaluation results of the oil-starch mixtures in Test Examples 1-1 to 1-3, it can be shown that by adding shortening to the oils in Formula Examples 1-2 and 1-3, rather than to the oil in Formula Example 1-1, the mixture becomes a non-Newtonian fluid, thereby reducing the amount of oil-starch mixture that drips onto the bottom of the container after being applied to the noodles. While it is difficult to compare the viscosity of non-Newtonian fluids with that of Newtonian fluids, as shown in Figure 3 and Table 2, a fluid can be considered non-Newtonian if its viscosity is greater than 100 mPa·s at a shear rate of 10.2 at 25°C. Furthermore, if it is 250 mPa·s or higher, as in Formula Example 1-2, it is possible to prevent the oil-starch mixture from dripping.

[0059] Conversely, as shown in Test Example 1-3, increasing the viscosity of the non-Newtonian fluid of the fat by adding shortening to the fat-starch mixture makes it difficult to fill the mixture, difficult to diffuse over the entire surface of the noodles after filling, and difficult to remove the frozen food from the container when frozen. Therefore, as shown in Blending Example 1-3, the viscosity of the fat is preferably 500 mPa·s or less, more preferably 450 mPa·s or less, at a shear rate of 10.2 at 25°C. However, as shown in Figure 1, when the fat-starch mixture covers the top surface of the frozen food, it is possible to further increase the viscosity of the non-Newtonian fluid by increasing the capacity of the filling machine or by employing a process of forcibly removing the mixture using inflexible plastic or metal containers.

[0060] Based on the evaluation results of the oil-starch mixtures in Test Examples 1-4 and 1-5, it is clear that while a low amount of starch in the oil-starch mixture is not problematic, as shown in Test Example 1-5, the noodles begin to loosen slightly during cooking, and lumps begin to form slightly in the soup. Therefore, it is preferable that the amount of starch in the oil-starch mixture be 25% by weight or less. However, if the amount of starch is too low, depending on the type of soup, it may be necessary to add a large amount of the oil-starch mixture to achieve viscosity. Therefore, it is preferable that the amount of starch in the oil-starch mixture be 10% by weight or more.

[0061] As shown in Test Examples 1-6 and 1-7, if the amount of oil-starch mixture added to the main ingredient is too small, it is difficult to coat the entire surface of the main ingredient with the oil-starch mixture. Conversely, if there is too much, the excess will accumulate at the bottom of the container, making it difficult to remove the frozen food from the freezer. Furthermore, if the oil-starch mixture that accumulates at the bottom of the freezer solidifies in one place, it can easily cause lumps to form in the soup, and when heated, it can make it difficult to separate the noodles. Therefore, the amount of oil-starch mixture added is preferably in the range of 3 to 20% by weight relative to the weight of the cooked main ingredient.

[0062] <Experiment 2> Examination of concentrated liquid soup (Test Example 2-1) A concentrated liquid soup was prepared by mixing the ingredients of Formula Example 2-2 in Table 2 and heating and dissolving them. A frozen food product for microwave cooking (frozen Chinese noodles) was prepared according to the method of Test Example 1-2, except that the soup prepared was the concentrated liquid soup of Formula Example 2-2.

[0063] (Test Example 2-2) A concentrated liquid soup was prepared by mixing and heating the materials of the following formulation examples 2-3 in Table 2. A frozen microwaveable food product (frozen Chinese noodles) was prepared according to the method of Test Example 1-2, except that 127g of the prepared concentrated liquid soup of formulation example 2-3 was filled into the container.

[0064] (Test Example 2-3) A concentrated liquid soup (for ramen with thick sauce) was prepared by mixing the ingredients in Example 3 of Table 5 below and heating and dissolving them.

[0065] [Table 5]

[0066] Next, 180g of the cooked Chinese noodles prepared in Experiment 1 were filled into a freezer container (container opening diameter: 150mm, container bottom diameter: 140mm, container height: 54mm, container protrusion opening diameter: 108mm, container protrusion bottom diameter: 96.5mm, container protrusion height: 8mm) as the main ingredient. Then, 12.5g of the oil-starch mixture from Formula Example 1-2 was added on top of the Chinese noodles, and compressed air was blown from above the container to coat the entire surface of the noodles with the oil-starch mixture.

[0067] Next, 85g of the concentrated liquid soup from formulation example 3 was evenly poured over the Chinese noodles, which were coated with the oil-starch mixture, ensuring that it did not drip down from the edge of the container, as shown in Figure 2.

[0068] After filling with concentrated liquid soup, the entire freezer container was placed in an air-blast type rapid freezer at -35°C for 45 minutes. The frozen food (Chinese noodles) was then removed from the freezer container and placed in a microwave-safe plastic bag to create microwave-safe frozen food (frozen Chinese noodles).

[0069] (Test Example 2-4) A concentrated liquid soup (sesame tantanmen) was prepared by mixing the ingredients in Example 4 of Table 6 below and heating and dissolving them.

[0070] [Table 6]

[0071] Next, 200g of the pre-cooked Chinese noodles prepared in Experiment 1-1 were filled into a freezer container (container opening diameter: 150mm, container bottom diameter: 140mm, container height: 54mm, container protrusion opening diameter: 108mm, container protrusion bottom diameter: 96.5mm, container protrusion height: 8mm) as the main ingredient. Then, 6g of the oil-starch mixture from Formula Example 1-2 was added on top of the Chinese noodles, and compressed air was blown from above the container to coat the entire surface of the noodles with the oil-starch mixture.

[0072] Next, 105g of the concentrated liquid soup from formulation example 4 was evenly poured over the Chinese noodles, which were coated with the oil-starch mixture, ensuring that it did not drip down from the edge of the container, as shown in Figure 2.

[0073] After filling with concentrated liquid soup, the entire freezer container was placed in an air-blast type rapid freezer at -35°C for 45 minutes. The frozen food (Chinese noodles) was then removed from the freezer container and placed in a microwave-safe plastic bag to create microwave-safe frozen food (frozen Chinese noodles).

[0074] For Test Examples 2-1 to 2-4, microwave cooking was performed, the food was consumed, and sensory evaluation was conducted. For Test Examples 2-1 and 2-2, the frozen food was cooked at 600W for 4 minutes, then transferred to a container, 200ml of hot water was added, the concentrated liquid soup was dissolved while stirring, and the food was consumed and evaluated. For Test Example 2-3, the frozen food was cooked at 600W for 4 minutes, then transferred to a container, 200ml of hot water was added, the concentrated liquid soup was dissolved while stirring, and the food was consumed and evaluated. For Test Example 2-4, the frozen food was cooked at 600W for 4 minutes and 30 seconds, then transferred to a container, 220ml of hot water was added, the concentrated liquid soup was dissolved while stirring, and the food was consumed and evaluated.

[0075] Furthermore, for test examples 2-1 to 2-4, we evaluated manufacturing suitability such as the filling ability of the liquid soup, dripping from the top of the main ingredients, and removal of frozen foods, as well as cooking suitability such as scorching of the soup, loosening of the noodles, and formation of soup clumps during cooking. The evaluation results are shown in Table 7 below.

[0076] [Table 7]

[0077] In Experiment 2, as shown in Table 7, the suitability for manufacturing and cooking was investigated when using different concentrated liquid soups, such as Formula Example 2-2 (a reduced viscosity version of Formula Example 2-1), Formula Example 2-3 (a diluted version of Formula Example 2-1), Formula Example 3 (a thickened soup), and Formula Example 4 (sesame tantan soup). The results showed that, as shown in Test Example 2-1, if the viscosity of the concentrated liquid soup at 25°C was around 5 Pa·s, some dripping of the concentrated liquid soup was observed, but the suitability for manufacturing and cooking was generally at an acceptable level. Furthermore, as shown in Test Example 2-2, the amount of concentrated liquid soup that could be filled up to about 75% by weight relative to the main ingredient could be used to fill the top surface of the main ingredient.

[0078] Furthermore, as shown in Test Example 2-3, when the soup had a high salt concentration, it was slightly overheated by microwave heating, although it did not burn. As a result, some parts of the soup became slightly less tender. Therefore, we believe that a salt concentration of 7% or less is preferable.

[0079] Furthermore, as shown in Test Example 2-4, the filling properties deteriorate as the viscosity of the soup increases; therefore, a soup viscosity of 25 Pa·s or less at 25°C is considered preferable.

[0080] Furthermore, although not shown in the data, the sensory evaluation results for each sample showed that in all test cases, viscosity was properly developed, and the main ingredients blended better with the soup than when viscosity was developed with a separate soup packet. The viscosity of the soup also had a natural viscosity similar to that served in restaurants.

Claims

1. A fat-starch mixture for developing viscosity in soup, which is filled directly into the main ingredients of frozen food without being filled into separate packaging, The starch content of the oil-starch mixture is 25% by weight or less. The oil-starch mixture is characterized in that the oil is a non-Newtonian fluid at 25°C, and has a viscosity of at least 100 mPa·s to 500 mPa·s at 25°C and a shear rate of 10.2 [1 / s].

2. The oil-starch mixture according to claim 1, characterized in that the starch used in the oil-starch mixture has a gelatinization onset temperature of 60°C or lower.

3. A frozen food characterized by comprising a main ingredient and an oil-starch mixture according to claim 1 or 2, which is directly filled into the main ingredient without being filled into a separate packaging material.

4. The frozen food according to Claim 3, characterized in that the oil-starch mixture covers the upper surface or the entire surface of the main ingredient, and the concentrated liquid soup is not filled into a separate package but is directly filled into the area on the upper surface of the main ingredient that is covered by the oil-starch mixture.

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