Frozen food manufacturing method

Abstract

To provide a new production method of a frozen food which prevents deterioration of texture due to separation of water after thawing.SOLUTION: A vegetable as a subject to be frozen is dewatered, is then brought into contact with a carbohydrate by, for example, mixing, and then is frozen. The dewatering of the vegetable is preferably carried out by salting. A salt concentration after the salting is preferably 1 to 4 mass%. What the vegetable is brought into contact with is preferably a carbohydrate-containing composition including 50 mass% or more of the carbohydrate. The carbohydrate-containing composition to be used preferably has a sugar composition in which a proportion of a carbohydrate having a polymerization degree of 3 or less is 30 mass% or more. A seasoning composition may be mixed after the vegetable is brought into contact with the carbohydrate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing frozen foods. [Background technology]

[0002] Frozen pickles, such as frozen kimchi, are widely available. However, the growth of ice crystals during freezing can destroy cells, resulting in problems such as a deterioration in texture and taste due to water separation upon thawing.

[0003] In order to improve the texture after thawing, methods that have been reported include heating and drying at high temperatures before freezing (Patent Document 1), frying at 40 to 70°C without using oils and fats (Patent Document 2), treating at high temperatures and heat-treating in an aqueous solution containing calcium (Patent Document 3), and drying to a degree that prevents heat from being transmitted to the inside (Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-147892 [Patent Document 2] Japanese Patent Application Publication No. 7-250643 [Patent Document 3] Japanese Patent Application Publication No. 8-140570 [Patent Document 4] Japanese Patent Application Laid-Open No. 2005-143366 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned prior art involves heating ingredients before freezing. This method is not suitable for producing products that require the texture and flavor of uncooked vegetables, such as pickles. In light of this situation, the problem to be solved by the present invention is to provide a novel frozen food production technology that prevents deterioration of texture due to water separation after thawing. [Means for solving the problem]

[0006] In view of the above problems, the present inventors have conducted extensive research and found that contacting dehydrated vegetables with carbohydrates before freezing can reduce the deterioration of texture caused by syneresis during thawing. The present invention was completed based on this novel discovery.

[0007] In other words, the present invention, which solves the above-mentioned problems, is a method for producing frozen foods, characterized by comprising a dehydration process for dehydrating vegetables, a contact process for contacting the dehydrated vegetables with carbohydrates, and a freezing process for freezing the vegetables that have been contacted with the carbohydrates. According to the method of the present invention, it is possible to reduce syneresis and inhibit deterioration of texture when thawing frozen foods.

[0008] In a preferred embodiment of the present invention, the contacting step is a step of mixing the dehydrated vegetables with carbohydrates. The mixing operation allows the vegetables and carbohydrates to come into contact efficiently, thereby reducing syneresis and improving the effect of preventing deterioration in texture when the frozen food is thawed.

[0009] In a preferred embodiment of the present invention, the contacting step is a step of contacting the vegetable with a carbohydrate-containing composition containing carbohydrates at a concentration of 50% by mass or more. According to this aspect of the present invention, deterioration in the texture of frozen foods can be more effectively reduced.

[0010] In a preferred embodiment of the present invention, the carbohydrate has a sugar composition in which carbohydrates having a degree of polymerization of 3 or less account for 30% by mass or more. By contacting vegetables with carbohydrates having such sugar composition, a frozen food that exhibits a better texture when thawed can be provided.

[0011] In a preferred embodiment of the present invention, the dehydration step is a salting step in which the vegetables are salted. In this form, dehydration is carried out by the action of osmotic pressure, so undesirable phenomena such as cell destruction do not occur as in dehydration by physical pressure, and frozen foods with an even better texture can be provided.

[0012] In a preferred embodiment of the present invention, the salt concentration in the vegetables after the salting step is 1 to 4 mass %. By freezing vegetables having a salt concentration within the above range, a frozen food with a better texture can be provided.

[0013] In a preferred embodiment of the present invention, a seasoning step of mixing the vegetables with a seasoning composition is provided, and the seasoning step is carried out after the contact step. By bringing the vegetables into contact with the carbohydrates before seasoning with the seasoning composition in this way, the effect of reducing the deterioration of the texture can be more effectively achieved.

[0014] The present invention also relates to a frozen food produced by the above-mentioned production method. The frozen food of the present invention has reduced deterioration in texture due to syneresis upon thawing. [Effects of the Invention]

[0015] According to the present invention, a frozen food can be provided in which deterioration of texture due to syneresis upon thawing is reduced. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention is directed to treating vegetables and includes a dehydration step, a contact step, and a freezing step as essential steps. Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to the embodiment described below.

[0017] <1> vegetables The subject of the present invention is vegetables, and there are no particular limitations on the vegetables that can be used for pickling, including vegetables that are typically used for pickling, such as Chinese cabbage, cucumber, radish, turnip, eggplant, cabbage, carrot, nozawana (green mustard greens), and takana (green mustard greens), as well as leafy vegetables such as komatsuna (green mustard greens), mizuna (mizuna), and lettuce, root vegetables such as lotus, fruit vegetables such as tomatoes, bell peppers, shishito peppers, pumpkins, peas, green beans, broad beans, corn, okra, and zucchini, stem vegetables such as asparagus, onions, leeks, garlic, and ginger, flower vegetables such as broccoli, cauliflower, and mioga (ginger), seaweed such as kelp, and mushrooms. These vegetables may be pre-treated as needed by washing, peeling, chamfering, or removing unnecessary parts, and may also be cut into appropriate sizes as needed. One type of vegetable may be treated alone in the present invention, or two or more types may be treated in combination.

[0018] <2> Dehydration process The dehydration process is a process of dehydrating vegetables. Specific embodiments of the dehydration process are not particularly limited, and examples include dehydration methods that utilize osmotic pressure, such as salting or sugaring, dehydration methods using pressure, and dehydration methods by drying. From the viewpoint of improving texture, a dehydration method that utilizes osmotic pressure is a preferred example, and dehydration by salting is more preferred.

[0019] When dehydration is achieved by a salting step, the embodiment is not particularly limited, and the salt concentration in the soaking liquid and the soaking time can be adjusted as appropriate. The salt concentration of the vegetables after the salting process is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.3% by mass or more, and even more preferably 1.5% by mass or more. Furthermore, the salt concentration of the vegetables after the salting process is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, even more preferably 6% by mass or less, even more preferably 5% by mass or less, even more preferably 4% by mass or less, even more preferably 3.5% by mass or less, and even more preferably 3% by mass or less. By carrying out the salting process so that the salt concentration of the vegetables falls within the above range, the texture of the frozen food after thawing can be improved. The salt concentration after the salting process can be adjusted to the desired range by adjusting the salt concentration of the soaking liquid and the soaking time.

[0020] The salt concentration can be measured by known methods, such as potentiometric titration. Specifically, a platinum indicator electrode and a reference electrode are inserted into a nitric acid-containing measurement solution containing chloride ions, and the solution is titrated with a silver nitrate standard solution while stirring to form a silver chloride precipitate. A potential change (mV) curve corresponding to the titration volume (ml) is plotted, and the titration endpoint is determined. The sodium chloride content can then be calculated from the volume of silver nitrate standard solution required for titration. The measuring instrument is not particularly limited, and examples include the Hiranuma Automatic Titrator COM1750 (manufactured by Hiranuma Sangyo Co., Ltd.).

[0021] The salt concentration can be measured using the juice squeezed from the vegetables after the salting process as a sample to be measured. It is preferable to wash the vegetables after the salting process with water to remove the salt water adhering to the surface, and then squeeze the juice obtained by squeezing it with a known juicer, and use the resulting juice to measure the salt concentration.

[0022] For example, Chinese cabbage is composed of a core and leaves. In such cases where the vegetable is not homogenous but is composed of multiple elements, it is preferable to obtain juice from all of the multiple elements so that the average salt concentration of the entire tissue can be measured.

[0023] When dehydration is performed by osmotic pressure, such as salting, it is preferable to wash the vegetables with water to remove the soaking liquid adhering to the surface. Furthermore, after washing, it is preferable to remove the water adhering to the surface. Any known method can be used to remove the water, such as using a colander or leaving the vegetables to stand for a certain period of time to drain the water. When leaving the vegetables to stand for a certain period of time to drain the water, it is preferable to do so in a refrigerator to prevent deterioration of the vegetables. The time for leaving the vegetables to stand is not particularly limited, but is preferably in the range of 30 minutes to 10 hours, more preferably 1 hour to 8 hours, and even more preferably 3 hours to 7 hours.

[0024] <3> Contact process The contacting step is a step in which the vegetables that have been subjected to the dehydration step are brought into contact with carbohydrates. In this specification, the term "contacting" includes all modes in which carbohydrates come into contact with part or all of the vegetables, and includes, without limitation, modes in which carbohydrates are attached to the surface of the vegetables and modes in which carbohydrates are impregnated into the interior of the vegetables. The specific form of the contacting step is not particularly limited as long as it can bring the vegetables and the carbohydrate into contact with each other. For example, the contacting step may include mixing the vegetables and the carbohydrate, immersing the vegetables in the carbohydrate, spraying the carbohydrate onto the vegetables, or applying the carbohydrate onto the vegetables. In particular, mixing the vegetables and the carbohydrate is preferred because it can bring the vegetables and the carbohydrate into contact with each other efficiently.

[0025] The contacting step naturally includes a form in which the saccharide alone is brought into contact with the vegetable, and also includes a form in which the saccharide-containing composition containing the saccharide is brought into contact with the vegetable. The carbohydrate-containing composition used in the contact step is preferably a composition containing carbohydrate at a concentration of 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass.More preferably, a carbohydrate-containing composition containing 100% by mass of carbohydrate, that is, a form in which the vegetable is contacted with carbohydrate alone, is exemplified.

[0026] The carbohydrate-containing composition may contain ingredients that are commonly used in foods, as listed in the seasoning step section below.

[0027] The carbohydrate-containing composition may be in any form, such as liquid, semi-solid, or solid. In the case of a solid form, it is preferably in powder form.

[0028] Examples of carbohydrates used in the contacting step include monosaccharides such as glucose, galactose, xylulose, and fructose; disaccharides such as sucrose, lactose, maltose, and trehalose; trisaccharide or higher polysaccharides such as oligosaccharides, starch syrup, and dextrin; and sugar alcohols such as glycerin, diglycerin, polyglycerin, erythritol, xylitol, sorbitol, mannitol, inositol, maltitol, xylitol, erythritol, sorbitol, lactitol, mannitol, and reduced starch syrup.

[0029] The carbohydrates used in the present invention include monosaccharides having a carbon number of triose, tetraose, pentose, hexose, heptose or more, oligosaccharides and polysaccharides formed by combining these, and reduced products thereof. Preferred examples include monosaccharides having preferably 3 to 7 carbon atoms, more preferably 4 to 7 carbon atoms, and even more preferably 5 to 6 carbon atoms, and oligosaccharides and polysaccharides formed by combining these, and reduced products thereof.

[0030] The degree of polymerization of the carbohydrate is not particularly limited, but preferably, a carbohydrate having a degree of polymerization of 10 or less, more preferably, 8 or less, even more preferably, 6 or less, and even more preferably, 4 or less is used. Preferably, a carbohydrate having a degree of polymerization of 1 or more, more preferably, 2 or more is used (note that a carbohydrate having a degree of polymerization of 1 refers to a monosaccharide). By using a carbohydrate having a degree of polymerization within this range, the texture of the frozen food after thawing can be improved.

[0031] The above-mentioned carbohydrates may be used alone or in combination of two or more. When vegetables are contacted with a mixture of multiple types of carbohydrates, the proportion of carbohydrates having a degree of polymerization within the preferred range described above in the sugar composition of the carbohydrate mixture is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0032] Furthermore, in the sugar composition of the carbohydrate mixture, the proportion of carbohydrates with a degree of polymerization of 1 to 4, more preferably 1 to 3, even more preferably 2 to 3, and even more preferably 2, is preferably 10% by mass or more, more preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, and even more preferably 40% by mass or more.

[0033] It is also preferable that the proportion of carbohydrates with a degree of polymerization of 1 to 4, more preferably 1 to 3, even more preferably 2 to 3, and even more preferably 2, accounts for the largest proportion in the sugar composition of the carbohydrate mixture.

[0034] In the contacting step, the vegetable is contacted with carbohydrates in an amount of preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.3% by mass or more, even more preferably 1.5% by mass or more, even more preferably 1.7% by mass or more, even more preferably 2% by mass or more, and even more preferably 2.5% by mass or more, relative to the mass of the vegetable to be contacted. Furthermore, the vegetables are contacted with carbohydrates in an amount of preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, even more preferably 6% by mass or less, even more preferably 5% by mass or less, and even more preferably 4.5% by mass or less, relative to the mass of the vegetables to be contacted. By contacting the vegetables with the carbohydrates in such a ratio range, the texture of the frozen food after thawing can be improved.

[0035] Furthermore, in the contacting step, the vegetables are mixed with carbohydrates in an amount of preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.3% by mass or more, even more preferably 1.5% by mass or more, even more preferably 1.7% by mass or more, even more preferably 2% by mass or more, and even more preferably 2.5% by mass or more, relative to the mass of the vegetables to be contacted. In addition, the vegetables are mixed with carbohydrates in an amount of preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, even more preferably 6% by mass or less, even more preferably 5% by mass or less, and even more preferably 4.5% by mass or less, relative to the mass of the vegetables to be contacted. By mixing the vegetables and carbohydrates in such a ratio range, the texture of the frozen food after thawing can be improved.

[0036] Furthermore, in the contacting step, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, even more preferably 1.3% by mass or more, even more preferably 1.5% by mass or more, even more preferably 1.7% by mass or more, even more preferably 2% by mass or more, and even more preferably 2.5% by mass or more of carbohydrates are attached to the vegetables relative to the mass of the vegetables to be contacted. In addition, the amount of carbohydrates attached to the vegetables is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, even more preferably 8% by mass or less, even more preferably 6% by mass or less, even more preferably 5% by mass or less, and even more preferably 4.5% by mass or less, relative to the mass of the vegetables to be contacted. By attaching carbohydrates to vegetables in such a ratio range, the texture of the frozen food after thawing can be improved.

[0037] <4> Seasoning process The present invention may optionally include a seasoning step of mixing the vegetables with a seasoning composition, which is preferably carried out after the contact step. The seasoning composition is not limited in composition, and may contain ingredients commonly used in foods, without limitation. For example, spices and seasonings such as black pepper, red pepper, green pepper, pepper, cinnamon, nutmeg, cloves, allspice, cumin, chili pepper, coriander, anise, sage, thyme, laurel, oregano, curry leaves, saffron, Japanese pepper, chili pepper, mustard, ginger, garlic, paprika, onion, radish, green onion, sesame, five-spice powder, garam masala, curry powder, shichimi pepper, chili powder, etc.; flavor seasonings such as bonito stock, kelp stock, vegetable extract, bonito extract, kelp extract, seafood extract, meat extract, etc.; Oils and fats such as soybean oil, soybean germ oil, rapeseed oil, corn oil, sesame oil, perilla oil, linseed oil, peanut oil, safflower oil, high oleic safflower oil, sunflower oil, cottonseed oil, grape seed oil, macadamia nut oil, hazelnut oil, pumpkin seed oil, walnut oil, camellia oil, tea seed oil, perilla oil, olive oil, rice bran oil, wheat germ oil, palm oil, and algae oil; sodium L-glutamate, DL-alanine, glycine, L- or DL-tryptophan, L-phenylalanine, L- or DL-methionine, L-lysine, L-aspartic acid, sodium L-aspartate Amino acid-based seasonings such as sodium 5'-inosinate, disodium 5'-guanylate, disodium 5'-uridylate, disodium 5'-cytidylate, calcium 5'-ribonucleotide, disodium 5'-ribonucleotide; nucleic acid-based seasonings such as calcium citrate, trisodium citrate, potassium gluconate, sodium gluconate, succinic acid, monosodium succinate, disodium succinate, sodium acetate, potassium hydrogen DL-tartrate, potassium hydrogen L-tartrate, sodium DL-tartrate Organic acid seasonings such as sodium, L-sodium tartrate, potassium lactate, calcium lactate, sodium lactate, monosodium fumarate, and DL-sodium malate; acidulants such as lactic acid, malic acid, citric acid, gluconic acid, succinic acid, tartaric acid, phytic acid, fumaric acid, and phosphoric acid; vinegars such as rice vinegar, grain vinegar (brown rice vinegar, black vinegar, lees vinegar, malt vinegar, adlay vinegar, and soybean vinegar), fruit vinegar (apple vinegar, grape vinegar, lemon vinegar, kabosu vinegar, plum vinegar, wine vinegar, and balsamic vinegar), and vinegars produced by acetic acid fermentation using ethanol as a raw material, Chinese vinegar, and sherry vinegar;Soy sauces such as dark soy sauce, light soy sauce, white soy sauce, tamari soy sauce, and re-brewed soy sauce; sugars such as sugar, maltose, fructose, isomerized liquid sugar, glucose, brown sugar, honey, starch syrup, dextrin, lactose, galactose, and sugar alcohols such as sorbitol, maltitol, and xylitol; viscosity modifiers such as xanthan gum, guar gum, gellan gum, gum arabic, tamarind seed gum, tara gum, tragacanth gum, pectin, cellulose, carrageenan, agar, starch, alginic acid, sodium alginate, karaya gum, pullulan, chitin, and chitosan;

[0038] The form of the seasoning composition is not particularly limited, and may be any of liquid, semi-solid, and solid forms. Specific examples of the seasoning composition include soy sauce-based liquid seasonings such as yakunin, miso, bran, and yakiniku sauce.

[0039] When a seasoning process is included, the proportion of the carbohydrates to the total mass of the carbohydrates and the seasoning composition used in the contact process is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, even more preferably 7% by mass or more, and even more preferably 8% by mass or more. Furthermore, the proportion of the carbohydrates in the total mass of the carbohydrates and seasoning composition used in the contact step is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 15% by mass or less, and even more preferably 12% by mass or less. By adjusting the ratio of the saccharide used in the contacting step to the seasoning composition used in the seasoning step to the above ratio, the texture can be further improved.

[0040] <5> Freezing process The freezing step is a step of freezing the vegetables that have been subjected to the contact step (or the vegetables after the seasoning step, if a seasoning step is included). The specific embodiment of the freezing step is not particularly limited, and any known method, such as a freezing method in which the vegetables are left standing in a freezer, such as a household freezer or a commercial freezer, can be used. The freezing temperature is also not particularly limited, and the vegetables can be frozen at a temperature of, for example, -10°C or lower, preferably -15°C or lower.

[0041] <Frozen food> The frozen food produced through the above-mentioned steps exhibits reduced syneresis upon thawing and a pleasant texture. The frozen food of the present invention is not limited to any particular embodiment, but specific examples include frozen pickles such as rice bran pickles, salt pickles, sake lees pickles, miso pickles, kimchi pickles, vinegar pickles, soy sauce pickles, etc. By appropriately designing the specific aspects of the seasoning step described above, it is possible to provide a variety of frozen food types.

[0042] In this specification, "frozen food" is not limited to frozen foods as defined in the Standards and Criteria for Frozen Foods (Standards and Criteria for Foods, Additives, etc. (Ministry of Health and Welfare Notification No. 370, December 28, 1959)), but is a concept that includes all frozen foods without restriction. [Example]

[0043] Examples of the present invention will be described below. In the following description, the notation "%" refers to "w / w% (mass percent concentration)" unless otherwise specified.

[0044] <1> Test Example 1 <Dehydration process> Chinese cabbage was immersed in salt water until the various salt concentrations shown in Table 2 were reached. The salted Chinese cabbage was scooped out of the salt water using a colander, washed with water, and left to stand in a refrigerator for 5 hours. The salt concentration was measured by potentiometric titration using a Hiranuma automatic titrator COM1750 (Hiranuma Sangyo Co., Ltd.) The sample to be measured was the juice obtained by cutting Chinese cabbage into bite-sized pieces containing the core and leaves in a 1:1 ratio and squeezing it with a juice press (Pearl Metal Co., Ltd.). For comparison, unsalted Chinese cabbage was also prepared, with the salt concentration of the unsalted Chinese cabbage considered to be 0%.

[0045] <Contact process> 231 g of the Chinese cabbage prepared in the above-mentioned process was mixed with sugar or reduced starch syrup in various ratios shown in Table 2. For comparison, Chinese cabbage not mixed with any of the sugars was also prepared.

[0046] <Seasoning process>

[0047] The ingredients were prepared according to Table 1. This ingredient was mixed with the Chinese cabbage prepared in the above process to prepare kimchi. The ingredients were added so that the weight of the kimchi (total weight of Chinese cabbage, carbohydrates, and ingredients) was 300 g. [Table 1]

[0048] <Freezing process> The mixture was packed in small plastic containers (20 g each), sealed, and frozen in a freezer at -20°C.

[0049] <Evaluation> The frozen kimchi prepared in the above-mentioned steps in the Examples and Comparative Examples were thawed naturally and then tasted by experts skilled in sensory evaluation of food products, who evaluated them based on the following criteria. The results are shown in Table 2. ◎: Has a crunchy texture and little separation of water. 〇: It has a crunchy texture and some separation of water is observed. △: The texture is soft and some separation of water is observed. ×: The texture is soft and there is a lot of separation of water.

[0050] [Table 2]

[0051] As shown in Table 2, the frozen kimchi of Comparative Examples 1 to 3, which were prepared without going through the contact step with carbohydrates, all had a soft texture and exhibited significant syneresis. Also, as shown in Table 2, the frozen kimchi of Comparative Example 4, which went through the contact step but not the dehydration step, had a soft texture and exhibited significant syneresis. In contrast, the frozen kimchi of Examples 1 to 14, which were prepared through a salting dehydration process and a carbohydrate contact process, all had a superior texture and reduced syneresis compared to the frozen kimchi of Comparative Examples 1 to 4. The above results show that by carrying out the dehydration step and the contact step, it is possible to provide a frozen food in which syneresis after thawing is reduced and deterioration of texture is suppressed.

[0052] Although the frozen kimchi of Examples 1 to 14 contained carbohydrates in the contact step, the use of carbohydrates did not affect the taste when compared with frozen kimchi prepared without carbohydrates.

[0053] <2> Test Example 2 Frozen kimchi was prepared using reduced starch syrup, isomerized sugar, and starch syrup as carbohydrates in the same manner as in Test Example 1. In this test example, 231 g of Chinese cabbage, 6.9 g of carbohydrates, and 62.1 g of herbs were used. The prepared frozen kimchi was evaluated using the same evaluation method as in Test Example 1. The results are shown in Table 3. The details of the carbohydrates used in this test example are as shown in Table 4.

[0054] [Table 3]

[0055] [Table 4]

[0056] As shown in Table 3, even when various carbohydrates were used in the contact step, syneresis was reduced and deterioration of texture was prevented. Furthermore, when the appearance was observed, the frozen kimchi of the comparative example had a shriveled appearance due to syneresis, while the frozen kimchi of the example had a fresh appearance.

[0057] <3> Consideration When frozen vegetables are thawed, syneresis and a deterioration in texture are observed. This is because the growth of ice crystals during the freezing process destroys the cells, causing the water inside the cells to leak out. In other words, the mechanism by which syneresis occurs when vegetables are frozen is the same regardless of the type. The above-mentioned Test Examples 1 and 2 use Chinese cabbage to demonstrate the effects of the present invention, i.e., reducing syneresis and inhibiting deterioration of texture. These test results simply demonstrate that performing the dehydration and contact steps before freezing can reduce cell destruction and intracellular water leakage due to freezing. As described above, the mechanism by which syneresis occurs due to freezing is the same regardless of the type of vegetable. Therefore, even if the present invention is applied to vegetables other than Chinese cabbage, it can be understood that the effects of reducing syneresis and inhibiting deterioration of texture will be achieved through a similar mechanism of action. In other words, the results of Test Examples 1 and 2 demonstrate that the present invention is applicable to vegetables in general. [Industrial Applicability]

[0058] The present invention can be applied to a method for producing frozen pickles.

Claims

1. a dehydration process for dehydrating vegetables; a contacting step of contacting the dehydrated vegetables with a carbohydrate-containing composition containing carbohydrates at a concentration of 50% by mass or more; a freezing step of freezing the vegetables that have been brought into contact with carbohydrates; In the contacting step, the carbohydrate is contacted with the vegetable in an amount of 15% by mass or less relative to the mass of the vegetable to be contacted, In the sugar composition of the carbohydrate, the proportion of carbohydrates having a degree of polymerization of 4 or less is 90% by mass or more; The freezing temperature in the freezing step is −20° C. to −10° C., or The freezing step is a step of leaving the vegetables in a home freezer or a commercial freezer. Methods for producing frozen foods.

2. A dehydration step for dehydrating vegetables; a contacting step of contacting the dehydrated vegetables with a carbohydrate-containing composition containing carbohydrates at a concentration of 50% by mass or more; a freezing step of freezing the vegetables that have been brought into contact with carbohydrates; The freezing temperature in the freezing step is −20° C. to −10° C., or The freezing step is a step of leaving the vegetables in a home freezer or a commercial freezer. A method for producing a frozen food (excluding the step of draining off the liquid exuded from the vegetables after the contact step).

3. The dehydration step is a salting step of salting the vegetables, The method for producing a frozen food according to claim 1 or 2, wherein the salt concentration in the vegetables after the salting step is 1.3 to 4% by mass.

4. A method for producing a frozen food according to any one of claims 1 to 3, wherein the sugar composition of the carbohydrates is dominated by carbohydrates with a degree of polymerization of 2 to 3.

5. 5. The method for producing a frozen food according to claim 1, wherein the contacting step is a step of mixing the dehydrated vegetables with carbohydrates.

6. The method for producing a frozen food according to any one of claims 1 to 5, further comprising a seasoning step of mixing the vegetables with a seasoning composition, the seasoning step being carried out after the contact step.

7. A frozen food produced by the method according to any one of claims 1 to 6.

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