Method for manufacturing frozen foods for oil preparation and method for manufacturing oil preparation foods

Abstract

To provide a technology capable of obtaining frying frozen food products with a coating of excellent shape and frying food products, in a short production time, simply and at low cost and good yield, by preventing shape collapse due to batter dripping on an ingredient surface.SOLUTION: A method for producing frozen food for frying, which includes the step of applying a batter at 0°C or higher and 7°C or lower to frozen ingredients to coat the surface of the ingredients with the batter. It is preferable to apply the batter to the ingredients at a temperature of -40°C or higher and below -15°C. It is further preferable to immerse the frozen ingredients in the batter to apply the batter.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for producing frozen food for frying, a method for producing fried food, and frozen food for frying.

Background Art

[0002] Fried foods with coatings such as tempura and fritters are produced by attaching liquid batter to the surface of frying ingredients and are eaten after frying. Regarding such fried foods, in terms of avoiding overheating of the ingredients due to re-frying, the demand for products frozen in the state where batter is attached to the surface of the ingredients has been increasing in recent years. However, in such unfried products, there is a problem that after attaching the flowing batter, the batter flows down from the ingredients and is likely to deform before complete freezing. If the batter coating is deformed during production, it is difficult to use the obtained frozen product as a product, resulting in a decrease in yield. Moreover, even when frying without freezing after attaching the flowing batter, there is a problem that the batter coating is deformed before frying after the batter coating is attached.

[0003] Regarding the above problems, Patent Document 1 proposes using a specific starch. Further, Patent Documents 2 and 3 use special storage containers.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the method described in Patent Document 1 still has room for improvement regarding the stabilization of the shape of the batter's coat. Patent Documents 2 and 3 have problems such as requiring special containers, limiting the product form, and incurring manufacturing and transportation costs for the containers. As described above, in a method for manufacturing frozen foods for oil preparation, in which a batter at room temperature is applied to refrigerated or room-temperature ingredients and then frozen, there has been no conventional method that can be used quickly, simply, and at low cost to prevent deformation due to the batter coating running off after application, and to obtain products with a good shape and high yield. Furthermore, even when oiling a liquid batter without freezing after application, there has been no conventional method that can quickly, easily, and inexpensively produce products with a good-shaped coating while preventing deformation due to the batter coating running off after application, and achieving a high yield. [Means for solving the problem]

[0006] The present invention provides a method for producing frozen food for oil preparation, comprising the step of applying a batter with a temperature between 0°C and 7°C to frozen ingredients, thereby coating the surface of the ingredients with the batter. Furthermore, the present invention provides a method for producing oil-based food products, comprising the step of applying a batter with a temperature between 0°C and 7°C to frozen ingredients, thereby coating the surface of the ingredients with the batter. [Effects of the Invention]

[0007] According to the present invention, it is possible to prevent deformation due to batter flowing off the surface of the ingredients, thereby enabling the production of fried frozen foods and fried foods with a good-shaped coating in a short time, simply and at low cost. It can be obtained with a good yield. Furthermore, this manufacturing method allows the batter to be applied to ingredients while they are still frozen, which suppresses dripping associated with thawing and refreezing of the ingredients, thus preventing deterioration of the ingredients' quality. [Brief explanation of the drawing]

[0008] [Figure 1]Figure 1 is a schematic diagram showing an example of a glazing apparatus that can be used in the present invention. [Figure 2] Figure 2 is a cross-sectional view of the frozen food for oil preparation obtained in Example 1. [Figure 3] Figure 3 is a cross-sectional view of the frozen food for oil preparation obtained in Comparative Example 1. [Figure 4] Figure 4 is a front view photograph of the fried frozen food product obtained in Example 4. [Modes for carrying out the invention]

[0009] The present invention will be described below based on its preferred embodiments. The ingredients used in this invention include seafood, vegetables, fruits, seaweed, meat, eggs, or processed foods. Seafood includes fish, shellfish, crustaceans such as shrimp and crab, and cephalopods such as octopus and squid. Vegetables include green onions, onions, burdock, carrots, pumpkins, spinach, eggplants, shishito peppers, asparagus, bell peppers, green peas, corn, lotus root, avocados, sweet potatoes, potatoes, aralia sprouts, udo, maitake mushrooms, matsutake mushrooms, enoki mushrooms, and shiitake mushrooms. Fruits include apples, figs, bananas, strawberries, and persimmons. Seaweed includes wakame, nori, mozuku, and hijiki. Meat includes chicken, beef, pork, whale meat, and other livestock meats. Examples of processed foods include fish paste products, natto (fermented soybeans), cheese, and confectionery. The ingredients may be uncooked or cooked, but uncooked ingredients are preferred because they are less susceptible to quality deterioration due to thawing and freezing. Generally, uncooked ingredients should consist of at least one selected from seafood, vegetables, and meat.

[0010] "Unheated" preferably means that the product has not been subjected to heat treatment at a temperature above 60°C for 10 minutes or more, and more preferably at a temperature above 50°C for 5 minutes or more. Here, "unheated" allows for cases where heated grain flour or granular material, as described later, is attached to the product.

[0011] Before applying batter to the ingredients, the ingredients may be dusted with flour. Typically, at least one of the following is used as dusting flour: wheat flour, rice flour, sorghum flour, corn flour, etc., with wheat flour being preferred. The starch may be processed or unprocessed. Examples of starch include those derived from these grain flours, as well as tapioca starch and potato starch. Examples of processed starch include those that have undergone one or more treatments selected from gelatinization, etherification, esterification, crosslinking, and oxidation. The total amount of grain flour and starch in the dusting flour is usually preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. The dusting flour may also contain breadcrumbs or powdered oils. In this specification, starch and grain flour are collectively referred to as "grain flours."

[0012] The ingredients may have granular material containing heated grain flour attached to their surface. When a batter at a specific temperature is applied to a frozen ingredient having granular material containing heated grain flour on its surface, the batter uniformly covers the spaces between and on top of the granular material, so that the batter fills the gaps between the granular material and the coating becomes one with the granular material. This suppresses uneven frying color that occurred when such granular material was conventionally attached to the outermost surface of the coating, suppresses hardening of the coating due to overheating of the granular material, and preserves the crispness provided by the granular material. In addition, a nearly uniform thickness of thin coating fills the gaps between the granular material. By embedding and solidifying the coating, it becomes easier to obtain a coating that has the appearance and texture of tempura when deep-fried. This invention is the first to achieve such a tempura-like appearance and texture in a frozen food product for deep-frying, where the coating is uncooked, using a simple method without the need for special containers.

[0013] Examples of the aforementioned granular material include tempura batter scraps and puffed grains of flour, among which the puffed grains are particularly preferred because they easily provide a crispy texture.

[0014] The expanded granules are usually obtained through an expansion process using an extrusion machine such as an extruder. As raw materials, there are cereal grains such as rice grains, corn grains, and wheat grains, as well as flours, that is, flour and / or starch. As the flour and starch, those similar to the starch and flour used for the dusting powder mentioned above can be cited. These are appropriately hydrated and heated and pressurized in an extrusion machine such as an extruder to expand. The obtained expanded product may be pulverized or cut to a size suitable as a coating material for oil-based products.

[0015] In terms of easily obtaining a crispy texture and a tempura-like appearance, as the granular material containing the heated flour material, for example, those having a specific gravity of 0.1 to 0.9 g / cm 3 are preferable, and those having a specific gravity of 0.2 to 0.5 g / cm 3 are more preferable. The specific gravity can be measured by putting the fried balls whose weight has been measured into a female cylinder containing edible oil (canola oil), measuring the volume from the increase amount, and dividing the above-mentioned weight by the volume.

[0016] Also, in the raw material powder of the granular material containing the heated flour material, the proportion of the flour material is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 80% by mass or more.

[0017] From the viewpoint of obtaining the above-mentioned texture improvement effect and color unevenness suppression effect, the granular material containing the heated flour material preferably has an average length value of 1 mm or more, and more preferably 4 mm or more. Also, the granular material containing the heated flour material preferably has an average length value of 15 mm or less, and more preferably 10 mm or less. The length of the granular material refers to the length of the longest cross-sectional line segment among the cross-sectional line segments that cross the cross-section obtained by cutting the granular material in an arbitrary direction. The average value of the length of the granular material is the average value measured for any 20 pieces.

[0018] Furthermore, when adding granular material containing heated grain flour, it is preferable to add 10 to 50 parts by mass per 100 parts by mass of the ingredients before adding the granular material, as this makes it easier to obtain a tempura-like appearance and crispy texture, and it is more preferable to add 20 to 40 parts by mass.

[0019] In this invention, in order to give the ingredients the granular material, a primary batter may be applied to the ingredients before adding the granular material, then the granular material may be applied, the ingredients may be frozen, and then a secondary batter with a temperature of greater than 0°C and less than or equal to 7°C may be applied. In this case, the temperature of the primary batter may or may not be greater than 0°C and less than or equal to 7°C, and the ingredients may or may not be frozen at the time the primary batter is applied. The composition of the primary batter may be the same as that of the secondary batter described later. As described above, the present invention allows for the batter to be applied to the ingredients multiple times, and in that case, it is sufficient to have at least one step of applying batter at a specific temperature to the frozen ingredients. Preferably, the final batter application step in the production of the frozen food for oil preparation is the step of the present invention, which is preferable in terms of ensuring high quality of the frozen food for oil preparation. Also, as mentioned above, the frozen ingredients may have batter or the aforementioned granular material applied to their surface.

[0020] In this invention, a batter with a temperature between 0°C and 7°C is applied to the frozen ingredients. This allows, A film of ice forms on the surface of the ingredients. This film of ice contains components dispersed or dissolved in the batter, and thus the film of ice becomes the batter coating. In this invention, because the film of ice forms the batter coating, the coating is less likely to deform, the thickness is more uniform, and it is easier to maintain a good shape without crumbling. Furthermore, handling after batter application is easy, and the shape of the coating can be maintained from batter application to the completion of freezing without the use of special containers. Moreover, if the ingredients were frozen from the beginning (for example, from the time of raw material acquisition), frozen food for deep frying can be manufactured without the need for thawing. Similarly, in this invention, handling after batter application is easy, and the shape of the coating can be maintained from batter application to the start of deep frying without the use of special containers. From these points, the present invention can reduce the manufacturing cost of frozen food for deep frying and deep-fried food.

[0021] Furthermore, in this invention, since a batter with a temperature between 0°C and 7°C is applied, the coating can be formed in a short time, and the frozen state of the ingredients can be maintained during the manufacturing process of frozen foods for oil preparation. Therefore, if the ingredients are already frozen, thawing is unnecessary, and the deterioration of the tissue and loss of nutrients due to drip during thawing of the ingredients can be prevented during the manufacturing process, thus maintaining the quality of the ingredients. Furthermore, in the manufacturing process of oil-fried foods, the frozen state of the ingredients can be maintained until the oil-fried food preparation begins, so the same quality preservation effect can be expected.

[0022] For example, the frozen state of the ingredients is below -15°C. This allows for the formation of an ice film upon contact with the batter, which is between 0°C and 7°C. From this perspective, the temperature of the ingredients at the time of batter application is preferably -40 to -18°C, more preferably -35 to -20°C, even more preferably -32 to -20°C, and particularly preferably -25 to -20°C. The temperature of the ingredients can be measured with a probe thermometer (e.g., SK-270WP manufactured by Sato Keiryoki Seisakusho Co., Ltd.), with the tip of the probe positioned 0 to 5 mm inside the surface of the ingredients. Any thermometer with accuracy equal to or greater than that of the measuring instrument mentioned above can be used. In the present invention, it is generally preferable that the temperature of the ingredients when they are coated with batter is sufficiently low, and that the batter freezes when it is coated with the ingredients. Reflecting this, the freezing temperature of the batter is usually more than +3°C above the temperature of the ingredients when they are coated with batter, and may be +4°C or higher.

[0023] The freezing method is not particularly limited in order to bring the ingredients to the aforementioned temperature when the batter adheres to them, but rapid freezing is preferable from the viewpoint of maintaining the quality of the ingredients. Rapid freezing is a freezing method in which the temperature of the food passes through the maximum ice crystal formation zone (-5°C to -1°C) within 30 minutes. Examples of freezers for rapid freezing include air blast type, liquid type, contact type, liquefied gas type, and special type, and any of these can be used. For example, a continuous air blast type freezer is a tunnel-shaped freezer in which the entrance to the exit of a belt conveyor is covered like a tunnel, and the ingredients are transported through the tunnel by the conveyor while low-temperature gas is injected to freeze them. Such freezers are sometimes called tunnel freezers (registered trademark).

[0024] The batter applied to the ingredients should be between 0°C and 7°C to facilitate the formation of a coating on the surface of the ingredients, making it easy to achieve a uniform coating thickness. For batter applied to frozen ingredients, a temperature between 0°C and 5°C is preferable, as this makes it even easier to achieve a uniform coating; in particular, a temperature between 0°C and 4°C is preferable.

[0025] As for the method of applying batter to the ingredients, a method that can cover almost the entire surface of the ingredients, for example, 80% or more of the surface area, and especially 90% or more, with the batter is preferred. Examples include spraying the batter onto the ingredients or immersing the ingredients in the batter. Among these, immersing the ingredients in the batter is preferred because it can easily cover almost the entire surface of the ingredients with batter, can be processed in a short time, and can be applied regardless of viscosity. Here, the ingredients are immersed in the batter. When immersing ingredients, the batter may be flowing or pooled at the point of contact with the ingredients. Submerging ingredients in the batter is also an example of immersing ingredients in the batter.

[0026] The total time for coating the ingredients with batter is preferably 1 to 60 seconds, as this makes it easier to form a batter coating of a desirable thickness while keeping the ingredients frozen and prevents melting due to temperature rise. A time of 5 to 50 seconds is particularly preferable, and a time of 5 to 40 seconds is most preferable. The time for the batter to adhere to the ingredients, as used here, refers to the immersion time if the ingredients are submerged in the batter, and the time the batter is in contact with the ingredients while being sprayed if the batter is sprayed onto the ingredients. Furthermore, if the batter is applied to frozen ingredients multiple times, it refers to the sum of the times for each application.

[0027] When applying the batter multiple times, the time required for each application is preferably 1 to 30 seconds, and particularly preferably 5 to 25 seconds, as this allows for easier formation of a batter coating of a desirable thickness while maintaining the ingredients in a frozen state, and enables the formation of multiple layers with different properties. Applying the batter multiple times includes cases where the ingredients are dipped in the batter multiple times or where the batter is sprayed onto the ingredients multiple times.

[0028] The method for applying the batter to the ingredients may be manual, or a battering device may be used. For example, the battering device may be continuous or batch type, and examples include submersible or shower type devices. The batter may be pre-cooled to about 0°C to 7°C before use, or it may be used while cooling the batter using a battering device with a batter cooling function, or both may be used. Furthermore, a glazing apparatus can also be used as a battering apparatus by replacing the glazing liquid with a batter. A glazing apparatus is a device that forms a thin layer of ice on the surface of frozen food by spraying or immersing it in a glazing liquid such as water, in order to suppress drying and oxidation of frozen food. Various types of glazing apparatuses can be used without any particular limitations. For example, the glazing function installed in various batch-type or continuous-type refrigeration systems may be used.

[0029] Figure 1 shows schematic diagrams of two continuous glazing systems: a) shower type and b) submersible type. Figure 1c) shows a schematic diagram of a batch type glazing system. a) In the shower type, the frozen ingredients 1 transported by the conveyor 12 are introduced into the shower chamber 13, and batter 3 is sprayed onto the surface of the ingredients 1 inside the shower chamber, so that the surface of the ingredients 1 is covered with batter 3. b) In the submersible type, the frozen ingredients 1 are transported by the conveyor belt 12 into the water tank 15 where the batter 3 is stored, and the ingredients 1 are immersed in the batter 3 so that the surface of the ingredients 1 is covered with batter 3. c) In the batch method, the ingredients are placed in a mesh basket 14 or the like, and immersed in a water tank 15 where batter 3 is stored, thereby covering the surface of the frozen ingredients 1 with batter 3. The ingredients 1 are then lifted out along with the mesh and proceed to the next processing, such as freezing or oiling. Through the above steps, a frozen food product 10 for oil preparation is obtained. In a) and b), in the resulting oil-cooked food product 10, the thickness of the batter 3 on the portion of the ingredients that comes into contact with the conveyor 12 may be thinner than the thickness on other portions. Considering this, it is preferable to reduce the contact area between the conveyor and the ingredients, for example, by using a wire conveyor. In c), it is also preferable to reduce variations in the thickness of the batter 3 on the surface of the ingredients by using a device that grips the ingredients at point contact and has a lifting function instead of the mesh 14. The room temperature when applying the batter to the ingredients is preferably, for example, 5 to 30°C, in order to efficiently form the coating, and is particularly preferably 10 to 20°C.

[0030] The viscosity of the batter is preferably 0.1 dPa·s to 200 dPa·s, as this ensures good coating shape and allows for easy batter coating formation. From this viewpoint, the viscosity of the batter is preferably 0.15 dPa·s to 30 dPa·s, more preferably 0.15 dPa·s to 25 dPa·s, particularly preferably 0.15 dPa·s to 15 dPa·s, and most preferably 0.2 dPa·s to 8 dPa·s. The viscosity referred to here is the viscosity at the batter temperature. A B-type viscometer is used to measure the viscosity of the batter. For example, a viscometer manufactured by Riontec Co., Ltd. (product name: Viscometer VT-06) can be used.

[0031] The batter is preferably prepared by mixing 100 to 500% by mass of water with the raw flour, as this allows the batter's flavor to easily adhere to the coating, facilitates the formation of the batter coating, and results in a good coating shape.

[0032] A batter is a coating material made by mixing granular raw materials such as flour or starch with liquid raw materials such as water or oil. At temperatures above 0°C and below 7°C, the batter is typically liquid or slurry-like. However, if neither flour nor starch is included, the material is not considered a batter.

[0033] The composition of the raw material powder used in the batter mainly consists of grain flour or starch. For example, the raw material powder composition for preparing the batter preferably has a total content of grain flour or starch of 70% by mass or more, more preferably 75% by mass or more. In particular, the grain flour content is preferably 55% by mass or more, more preferably 60 to 97% by mass. The starch content is preferably 0 to 30% by mass, more preferably 0.5 to 20% by mass. The raw material powder referred to here refers to all components of the batter other than water and liquid oils and fats. The liquid oils and fats referred to here are oils and fats that are liquid at 0°C.

[0034] Other components of the raw material powder may include, as needed, seasonings (salt, sugars, spices, amino acids, etc.), protein materials (egg white powder, milk protein, vegetable protein, etc.), oils and fats (animal fats and fats, vegetable oils and fats, etc.), emulsifiers (glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, lecithin, etc.), leavening agents (baking powder, etc.), and thickeners (gelatin, agar, alginic acid, carboxymethylcellulose, methylcellulose, gum arabic, curdlan, carrageenan, xanthan gum, locust bean gum, guar gum, gellan gum, tamarind seed gum, pectin, etc.). These can be used individually or in combination of two or more. Furthermore, the total amount of monosaccharides, disaccharides, oligosaccharides, dextrin, sorbitol, glycerin, sugar alcohols such as reduced starch syrup, and salt in the batter may be less than 18% by mass, and may also be 10% by mass or less.

[0035] The batter may be prepared by adding water at room temperature to the raw material flour, or by mixing water at a temperature between 0°C and 7°C with the raw material flour. The latter is preferable in terms of its bacteriostatic effect and inhibition of gluten formation.

[0036] In this invention, after applying a batter at over 0°C and below 7°C to the ingredients, breadcrumbs may or may not be applied. Not applying breadcrumbs to the batter is preferable because it allows the ingredients to be cooled immediately after application, thus suppressing thawing of the ingredients. Furthermore, this invention is preferable because it is particularly effective in addressing the problem of the coating shape easily deforming due to the fluidity of the batter.

[0037] In this embodiment, the oil-cooked food product, in which a batter between 0°C and 7°C is applied to frozen ingredients, is generally in a frozen state. To maintain this frozen state, the obtained oil-cooked food product can be stored in a freezer or other freezing device, and by maintaining the frozen state, it can be distributed as an oil-cooked frozen food product. In this case, the freezing temperature is preferably -40°C to -15°C, more preferably -32°C to -18°C, and even more preferably -25°C to -20°C. This temperature range is preferable in terms of maintaining the quality of the ingredients. As for the freezer or other freezing device in this case, a commercially available one, for example, the same one used for freezing the ingredients described above, can be used.

[0038] By performing the above operations, the oil condition of this embodiment is For cooling Frozen foods are available. The frozen food for oil preparation obtained in this invention is oil-prepared as appropriate. Oil preparation is preferably performed while the food is still frozen, in terms of stabilizing the quality after oil preparation.

[0039] Furthermore, in this invention, the ingredients coated with batter may be fried directly without going through the process of storing them in a freezing device such as a freezer, thereby obtaining fried food products with a uniform coating thickness and good shape.

[0040] In the frozen food for deep-frying, the CV value (ratio of the ratio Sc / Si) of the coating area (Sc) in a cross-section perpendicular to its longitudinal direction, where Si represents the area of ​​the ingredients and Sc represents the area of ​​the coating, is low. Thus, in the frozen food for deep-frying of the present invention, there is little variation in the ratio of coating area to ingredient area in the cross-section of each part. This means that the coating adheres to the ingredients with a uniform thickness. Specifically, in the frozen food for deep-frying of the present invention, the CV value [STDV / AV] is preferably 0.20 or less, more preferably 0.18 or less, and particularly preferably 0.15 or less. The CV value [STDV / AV] is preferably 0.05 or more, and more preferably 0.1 or more in terms of ease of manufacture. To make the CV value of Sc / Si below the above value, the above manufacturing method can be adopted. Specifically, the length of the frozen food for deep-frying is divided into 10 equal parts using a cross section perpendicular to the longitudinal direction. The area of ​​the batter and the area of ​​the ingredients are then measured for each of the 18 resulting cross-sections (two cross-sections are produced from each cut). An example of such a cross-section is shown in Figure 2. The area of ​​the ingredients (Si) and the area of ​​the batter (Sc) for a total of 18 cross-sections are determined, and the STDV and AV values ​​are calculated for these 18 values ​​to obtain the CV value [STDV / AV]. The area of ​​the ingredients (Si) and the area of ​​the batter (Sc) can be measured by taking images of the cross-sections with a digital camera and using image analysis software (e.g., ImageJ). The longitudinal direction refers to, for example, the direction in which a straight line segment has the maximum length when a projection image is obtained that maximizes the projected area when projected from directly above onto the frozen food product to be measured. The cutting by a cross section perpendicular to this method is performed by holding the frozen food product at the position and angle at which the aforementioned projection image is obtained.

[0041] For example, if multiple frozen foods for oil preparation of the same shape (e.g., cube shape) are packaged in bags (containers), these may be considered the same food, and a total of 18 cross-sections may be obtained from multiple samples contained in the same packaging container. For example, three frozen foods for oil preparation may be divided into four equal parts along their longitudinal direction, and a total of 18 cross-sections (6 cross-sections perpendicular to the longitudinal direction of each of the three foods) may be used as the measurement target. Even if only one of the following satisfies the above conditions, the food shall be deemed to satisfy the conditions: the CV value obtained from 18 cross-sections obtained by dividing the longitudinal length of one frozen food for oil preparation into 10 equal parts in cross-sections perpendicular to the longitudinal direction, or the CV value obtained from a total of 18 cross-sections obtained from two or more foods.

[0042] While not a strict requirement, a thinner coating makes it easier to achieve a more uniform thickness, so the average value of the Sc / Si ratio is preferably 0.4 or less, and more preferably 0.37 or less. A ratio of 0.35 or less is particularly preferred. Furthermore, the average value of the Sc / Si ratio is preferably 0.05 or higher, more preferably 0.1 or higher, and even more preferably 0.15 or higher, as this helps prevent overheating of the ingredients.

[0043] Furthermore, in the frozen food for deep-frying, it is preferable that the coating covers substantially the entire surface of the ingredients in each cross-section obtained by the above method (preferably all 18 cross-sections). For example, it is preferable that 80% or more of the total length of the outer edge of the ingredients is covered, more preferably 90% or more, particularly preferably 95% or more, and even more preferably 97% or more.

[0044] The frozen food for oil preparation according to the present invention preferably has a high amino acid content in its ingredients. This is because drip during the manufacturing process is effectively suppressed in the present invention. Therefore, the amino acid content of the frozen food for oil preparation according to the present invention, after thawing, will differ from that of conventional frozen foods for oil preparation. Thawing refers to the process of thawing something that has been frozen once. Histidine is one of the amino acids that is easily lost as drip. In contrast, the frozen food for oil preparation according to the present invention preferably contains a large amount of free histidine. Specifically, the free histidine content is preferably 110 mg / 100g or more, more preferably 113 mg / 100g or more, and even more preferably 120 mg / 100g or more. The amount of free histidine in the frozen food for oil preparation is preferably 300 mg / 100g or less from the viewpoint of ease of manufacturing the frozen food for oil preparation, and more preferably 200 mg / 100g or less. In this specification, "mg / 100g" refers to the mass per 100g of ingredients in the frozen food for oil preparation.

[0045] Furthermore, in light of the fact that dripping is suppressed in the present invention, it is preferable that the ingredients in the frozen food for oil preparation have one of the following configurations (2) to (10). (2) Preferably contains free hydroxypyrroline. (3) The free glycine content in the ingredients is preferably 26 mg / 100g or more, and more preferably 27 mg / 100g or more. The free glycine content in the ingredients is preferably 60 mg / 100g or less, and more preferably 45 mg / 100g or less.

[0046] (4) The free proline content in the ingredients is preferably 360 mg / 100g or more, and more preferably 370 mg / 100g or more. The free proline content in the ingredients is preferably 600 mg / 100g or less, and more preferably 500 mg / 100g or less.

[0047] (5) The free taurine content in the ingredients is preferably 44 mg / 100g or more, more preferably 45 mg / 100g or more, and most preferably 46 mg / 100g or more. The free taurine content in the ingredients is preferably 200 mg / 100g or less from the viewpoint of ease of manufacturing of frozen foods for oil preparation, and more preferably 100 mg / 100g or less.

[0048] (6) The free alanine content in the ingredients is preferably 49 mg / 100g or more, and more preferably 51 mg / 100g or more. The free alanine content in the ingredients is preferably 180 mg / 100g or less, and more preferably 100 mg / 100g or less.

[0049] (7) The free methionine content in the ingredients is preferably 58 mg / 100g or more, and more preferably 60 mg / 100g or more. For example, the free methionine content in the ingredients is 300 mg / 100g or less, which is preferable from the standpoint of ease of manufacturing of frozen foods for oil preparation. Preferably, the amount is 150 mg / 100 g or less.

[0050] (8) The free serine content in the ingredients is preferably 16 mg / 100g or more, and more preferably 17 mg / 100g or more. The free serine content in the ingredients is preferably 100 mg / 100g or less from the viewpoint of ease of manufacturing of frozen foods for oil preparation, and more preferably 80 mg / 100g or less.

[0051] (9) The free phenylalanine content in the ingredients is preferably 7 mg / 100g or more, and more preferably 8 mg / 100g or more. The free phenylalanine content in the ingredients is preferably 50 mg / 100g or less, and more preferably 40 mg / 100g or less.

[0052] (10) The free threonine content in the ingredients is preferably 39 mg / 100g or more, and more preferably 40 mg / 100g or more. The free threonine content in the ingredients is preferably 200 mg / 100g or less, and more preferably 100 mg / 100g or less.

[0053] Furthermore, it is preferable that the ratio of the content of a predetermined amino acid in the ingredients to the content of a specific group of amino acids is within the following range. This indicates that a larger amount of amino acids that are easily lost during the drip process remain, resulting in a different amino acid composition ratio compared to conventional products. The ratio of histidine content (in mg / 100g) to the total amount (in mg / 100g) of valine (V), isoleucine (I), lysine (K), glutamic acid (E), arginine (R), leucine (L), tyrosine (Y), and aspartic acid (D) is preferably 23% by mass or more, and more preferably 24% by mass or more. As an upper limit for this ratio, for example, 30% by mass or less is preferred. Furthermore, the ratio of taurine content (unit: mg / 100g) to the total amount (unit: mg / 100g) of valine (V), isoleucine (I), lysine (K), glutamic acid (E), arginine (R), leucine (L), tyrosine (Y), and aspartic acid (D) is preferably 72% by mass or more, and more preferably 74% by mass or more. As an upper limit for this ratio, for example, it is preferably 85% by mass or less, and more preferably 80% by mass or less. The free amino acid composition in the ingredients of the frozen food for oil preparation according to the present invention can be measured by the method described in the examples below. [Examples]

[0054] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to these examples. In each of the following examples, a viscometer manufactured by Riontec Co., Ltd. (product name: Viscometer VT-06) was used to measure the viscosity of the batter.

[0055] (Example 1) The dusting flour used contained 85.0% by mass of wheat flour and 15.0% by mass of starch. The batter's raw material flour also contained 85.0% by mass of wheat flour and 15.0% by mass of starch. 180 parts by mass of water were mixed with 100 parts by mass of the raw material flour. The viscosity of the batter at 4°C was 1.2 dPa·s. The batter was prepared and maintained at 4°C. Frozen squid fillets (-20°C, 3cm x 3cm x 15cm) were dusted with flour at room temperature (20°C). The frozen squid fillets were then dipped in 4°C batter to coat them. Each contact time between the frozen squid fillet and the batter was 20 seconds. This process was repeated twice at 20-second intervals, after which the liquid was drained after 20 seconds. The resulting oil-curing food product is cut with a knife in a cross-section perpendicular to the longitudinal direction, so that its length is divided into four equal parts, resulting in six cross-sections (for example, the cross-sections in Figure 2). For each of the following, the area of ​​the squid and the area of ​​the batter were measured using the method described above. This was done in three sets, and the area of ​​the squid and the area of ​​the batter were obtained for a total of 18 cross-sections. The mean AV, standard deviation STDV, and CV(STDV / AV) values ​​of the obtained data are shown in Table 1. In addition, the oil-based food products in each example were frozen at -35°C after area measurement, but there was no change in area before and after freezing.

[0056] (Comparative Example 1) The temperature of the batter applied to the ingredients was changed to 15°C. The squid ingredients were thawed and then coated with batter at 10°C. The resulting fried food product was frozen at -35°C. Other than these points, the procedure was the same as in Example 1. After freezing, the dimensions of the coating in the cross-section were measured as in each example. The results are shown in Table 1.

[0057] [Table 1]

[0058] As shown in Table 1, in Comparative Example 1, the ratio of the area of ​​the batter coating to the area of ​​the ingredients in the cross-section shows greater variation compared to Example 1. Figure 2 shows a cross-sectional view of the frozen food for oil preparation produced in Example 1, and Figure 3 shows a cross-sectional view of the frozen food for oil preparation produced in Comparative Example 1. As shown in Figures 2 and 3, compared to the comparative example 10' for oil-frying shown in Figure 3, which was manufactured using a conventional method, the frozen food for oil-frying 10 of the example shown in Figure 2 has a uniform thickness of the coating 2 and a uniform shape. As described above, in this invention, by applying a batter with a temperature between 0°C and 7°C to frozen ingredients, it is possible to easily and inexpensively produce frozen foods for deep-frying that have a good coating shape.

[0059] (Sensory evaluation of appearance, texture, and flavor) The frozen foods for oil preparation obtained in Example 1 and Comparative Example 1 were oil-prepared in edible oil at 170°C for 2.5 minutes while still frozen to obtain oil-prepared foods. Ten panelists each tasted these oil-prepared foods and evaluated their appearance, texture, and flavor on a 5-point scale, with 5 being the highest and 1 being the lowest. The average scores are shown in Table 2. (exterior) It looks very delicious as tempura. 5 points It looks delicious as tempura. 4 points It doesn't look very appetizing as tempura. 3 points It doesn't look appetizing as tempura. 2 points It doesn't look appetizing at all as tempura. 1 point (Texture) The squid meat is very tender. 5 points The squid meat was a little soft. 4 points The squid meat is tender. 3 points The squid meat was tough. 2 points The squid meat is very tough. 1 point (flavor) It has a very strong umami flavor. 5 points The umami flavor is very noticeable. 4 points It has a good umami flavor. 3 points It has a slight umami flavor. 2 points It has absolutely no flavor. 1 point.

[0060] [Table 2]

[0061] As shown in Table 2, the fried food obtained from the frozen food for fried food in Example 1 had a superior appearance and a superior texture of the ingredients compared to Comparative Example 1. This is thought to be because, according to the present invention, the coating adheres to the ingredients with a uniform thickness, and there are few thin areas of coating, so the ingredients inside do not come into direct contact with the oil and are less likely to be overheated, resulting in a fresh texture. Furthermore, the tendency for better flavor is thought to be because amino acids do not leak out as drip because repeated freezing and thawing is not performed.

[0062] (Amino acid content) (Example 2) For dusting, we used a powder containing 85.0% by mass of wheat flour and 15.0% by mass of starch. Batter A was prepared using a flour mixture containing 85.0% by mass of wheat flour and 15.0% by mass of starch. 180 parts by mass of water were mixed with 100 parts by mass of the flour mixture. The viscosity of batter A at 4°C was 1.2 dPa·s. The raw material flour used for batter B contained 85.0% by mass of wheat flour and 15.0% by mass of starch. 230 parts by mass of water were mixed with 100 parts by mass of the raw material flour. The viscosity of batter B at 4°C was 0.3 dPa·s. The squid fillets were rapidly frozen using a Hoshizaki Corporation shock freezer (model number: HBC-6TB3), then cut into 3cm x 3cm x 15cm pieces and used at -20°C. At room temperature (20°C), frozen squid fillets were coated with flour, dipped in batter A cooled to 4°C, then drained for 10 seconds, and then dipped in batter B. The contact time with the frozen squid fillets in each batch was 20 seconds and 20 seconds, respectively. Draining for 20 seconds.

[0063] (Comparative Example 2) In Example 2, instead of using frozen squid fillets as an ingredient, squid fillets (8°C) were used, which were cut from the same frozen squid as in Example 2, measuring 3cm x 3cm x 15cm, and then thawed. These squid fillets were then dipped in batters A and B in the same manner as in Example 2, and frozen in a -35°C freezer to obtain a food product for oil preparation.

[0064] (Evaluation 2: Analysis of free amino acids) The free amino acid content in the squid fillets of Example 2 and Comparative Example 2 was analyzed. For the measurement, the frozen food for oil preparation was left to stand at room temperature to thaw the surface batter, and then... After wiping off the batter with a paper towel and lightly rinsing with water, the surface moisture was removed again with a paper towel. The fillets were then ground in a food processor (Retsch GM200: VERDER Scientific), and approximately 3g of the resulting mixture was used as a sample for analysis according to the <Analysis Method for Free Amino Acids> described below. The results are shown in Table 3.

[0065] <Method for analyzing free amino acids> The analytical instrument used was a high-speed amino acid analyzer (LA8080AminoSAAYA) manufactured by Hitachi High-Tech Science Corporation. A Hitachi HPLC packed column (product name, #2622PF column), 4.6 mm ID × 60 mm, was used as the separation column. As an ammonia filter column, Hitachi HPLC packed column (product name, #2650L) A 4.6mm ID x 40mm ram was used. A Hitachi High-Tech Fielding TDE2 reactor 852-7700 was used as the reaction coil. As the buffer solution, we used the MCI BUFFER L-8500 PF kit (manufactured by Mitsubishi Chemical Corporation). (Sample preparation method) Approximately 3 g of the pulverized material obtained above was sampled into a homogenizing cup, 40 mL of 5% by mass trichloroacetic acid aqueous solution was added and stirred (3000 rpm, 5 min), and then transferred to a 100 mL volumetric flask. After making up the volume with 5% by mass trichloroacetic acid aqueous solution and stirring, the mixture was left to stand overnight in a refrigerator, stirred again, filtered through filter paper (Advantec No. 5B), and the resulting solution was subjected to an amino acid analyzer.

[0066] [Table 3]

[0067] As shown in Table 3 above, the squid fillets of Example 2 contain more free amino acids such as glycine, alanine, histidine, and proline than the squid fillets of Comparative Example 2. This is thought to be because, in Comparative Example 2, drip occurs and amino acids are lost due to thawing before battering and subsequent refreezing, whereas in Example 2, thawing before battering is unnecessary, thus suppressing drip and maintaining a higher amino acid content compared to Comparative Example 2. Therefore, it can be seen that the frozen food for oil preparation in Example 2 is able to suppress the decrease in nutritional content compared to Comparative Example 2.

[0068] As described above, the frozen food for oil preparation obtained by the present invention has reduced drip generation during the manufacturing process, maintains the nutritional content inherent in the ingredients, and has good quality ingredients.

[0069] (Example 3) Frozen shrimp (species name: Vannamei) were prepared by making cuts on the underside as part of the stretching process, and then refrigerated at 10°C or below. They were then coated with dusting flour (85% wheat flour, 15% starch) and the surface was covered with a primary batter solution (at 10°C or below). The primary batter solution was obtained by mixing 170 parts by mass of water with 100 parts by mass of raw material flour (85% wheat flour, 15% starch). The surface of the shrimp to which the primary batter has adhered is then expanded by an extruder to obtain the flour. Swollen granules (average length 8 mm, specific gravity 0.29 g / cm³) 3The raw material flour used was 70% wheat flour, 30% corn kernels, and 80% other grain flours (Kyoei Food Co., Ltd. "DX-4, A004"). 30 parts by mass of this flour were attached to 100 parts by mass of raw shrimp, and the shrimp were rapidly frozen in a -30°C freezer. The rapidly frozen shrimp (-20 to -15°C) were then immersed in a chilled secondary batter (over 2°C and under 4°C, viscosity 18 dPa·s), removed, and frozen using an air blast at -30°C to obtain a frozen food product for oil preparation. The secondary batter was a mixture of 28 parts wheat flour and 71.4 parts water. The time the shrimp were coated with the secondary batter was within the range of 1 to 60 seconds.

[0070] (Comparative Example 3) Without using a secondary batter, the expanded granules were attached and then frozen directly using an air blast at -30°C. Apart from this, the procedure was the same as in Example 3 to obtain a frozen food product for oil preparation.

[0071] (Comparative Example 4) Without attaching the swollen granules or immersing them in the secondary batter, the shrimp with the primary batter liquid attached were frozen directly using an air blast at -30°C.

[0072] (Example 4) Instead of puffed granules, use tempura batter scraps (average length 8mm, specific gravity 0.44g / cm²). 3 The raw material flour composition was 58% by mass of wheat flour and 37% by mass of starch, with a proportion of cereal flours in the raw material flour being 95% by mass). Except for this point, a frozen food for oil preparation was obtained in the same manner as in Example 3. In Example 4, the applicant cut a frozen food for oil preparation in which the secondary batter was colored with a pigment into a cross section perpendicular to its longitudinal direction, and confirmed that the secondary batter covered the granular ingredients with a nearly uniform thickness, indicating that the granular ingredients and the secondary batter were integrated (photo omitted).

[0073] The frozen foods for frying from Examples 3 and 4, and Comparative Examples 3 and 4, which were stored at -18°C for two days, were fried in edible oil at 170°C for three minutes while still frozen. Five adult panelists visually evaluated the unevenness of the fried color of the fried products, as well as the hardness of the coating and the overall crispness of the coating, according to the evaluation criteria below. The results are shown in Table 4.

[0074] (Color comparison: Uneven frying color (visual observation)) 5: It's golden brown and not burnt. 4: Burnt color can be seen on approximately 0-25% of the total surface area. 3: Burnt color is visible on approximately 25-50% of the total surface area, and there is uneven coloring. 2: Burnt color is visible on approximately 50-75% of the total surface area. 1: The entire surface area is brown and burnt.

[0075] (Texture: Hardness of the coating) 5: There are no hard parts. 4: Some parts are hard. 3: It's hard in places. 2: Most of it is hard. 1: Everything is hard.

[0076] (Texture: Crispy throughout the coating) 5: The crispiness of the coating is excellent. 4: The crispy texture of the coating is great. 3: The crispness of the coating is just right. 2: The batter wasn't crispy enough. 1: The batter isn't crispy.

[0077] [Table 4]

[0078] As shown in Table 4, fried foods prepared by simply attaching a specific granular material to the outermost surface of a batter, as in Comparative Example 3, tend to have uneven coloring and inferior crispness of the coating. Similarly, fried foods prepared by simply attaching a primary batter, as in Comparative Example 4, also suffer from inferior crispness of the coating. In contrast, by applying the present invention as in Examples 3 and 4, uneven coloring can be reduced, the coating becomes softer overall, and the crispness of the coating can be effectively improved. A photograph of the frozen tempura obtained in Example 4 is shown in Figure 4. As shown in Figure 4, it was confirmed that the fried frozen food product obtained by combining granular material containing heated grain flours with the manufacturing method of the present invention has a tempura-like appearance. [Explanation of symbols]

[0079] 10, 10' Frozen food for oil preparation 1. Ingredients 2 Batter's Suit 3 batters

Claims

1. A method for producing frozen food for oil preparation, comprising the step of immersing ingredients in a frozen state of -40°C or higher and below -15°C in a batter above 0°C and below 7°C to allow the batter to adhere to the ingredients and cover the surface of the ingredients with the batter, wherein the ingredients are one or more selected from seafood, vegetables, seaweed, meat, eggs, processed fish products, natto, and cheese, or granular material containing heated grain flour is attached to the surface of these ingredients.

2. A method for producing oil-cured frozen food according to claim 1, wherein the batter is applied to the ingredients in a glazing apparatus.

3. A method for producing frozen food for oil preparation according to claim 1 or 2, wherein the viscosity of the batter at the time of application to the ingredients is 0.1 dPa·s or more and 200 dPa·s or less at 4°C.

4. The method for producing a frozen food for oil preparation according to claim 1 or 2, wherein the ingredient has granular material containing heated grain flour attached to its surface.

5. The method for producing a frozen food for oil preparation according to claim 4, wherein the granular material is puffed grains of flour or fried batter bits.

6. A method for producing an oil-based food product, comprising the step of immersing ingredients in a frozen state of -40°C or higher and below -15°C in a batter above 0°C and below 7°C to allow the batter to adhere to the ingredients and cover the surface of the ingredients with the batter, wherein the ingredients are one or more selected from seafood, vegetables, seaweed, meat, eggs, processed fish products, natto, and cheese, or granular material containing heated grain flours is attached to the surface of these ingredients.

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