Method for producing refrigerated or frozen vegetables and method for producing prepared foods

Abstract

To provide a refrigerated or frozen vegetable which has a good texture and an appearance giving feeling of being cooked when reheated from a refrigerated or frozen state.SOLUTION: The present invention provides a production method of a refrigerated or frozen vegetable comprises: a steam treatment step of carrying out heating of a vegetable with steam of 100°C or more and 300°C or less; an oil heating step of bringing the vegetable treated in the steam treatment step into contact with an oil and fat of 120°C or more and 200°C or less for heating with a heating time of 1 s or more and 60 s or less; and a step of refrigerating or freezing the vegetable treated in the oil heating step.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a manufacturing method for producing refrigerated or frozen vegetables that have been heated, and a manufacturing method for prepared foods using the refrigerated or frozen vegetables obtained by the manufacturing method.

[0002] Conventionally, various cooking methods have been known to obtain a crispy texture of vegetables. Patent Document 1 describes a cooking method for vegetables including a step of uniformly oiling heated oil on the vegetables and a step of stir-frying the oiled vegetables. The document describes that by this method, stir-fried vegetables with excellent texture, good color tone and gloss, little water separation amount, maintained volume feeling, and excellent storage stability can be obtained.

[0003] Patent Document 2 describes that eggplants, radishes, turnips, cucumbers, etc. are heat-treated on the surface part under a reducing atmosphere with a relatively low oxygen concentration in a superheated steam atmosphere. The document describes that by this treatment, discoloration during subsequent pickling is suppressed, the permeability of salts, vinegar, etc. is improved, and when frozen and stored, the slimy feeling during thawing disappears and the freeze resistance is improved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, the ready-to-eat food market has been continuously expanding, and various products have been proposed as commercially available prepared foods. Among them, the demands for the taste and appearance of prepared foods are becoming increasingly strong. Among the ingredients of prepared foods, vegetables have a higher water content compared to meat, etc., so cooked vegetables are likely to have a degraded texture after refrigeration or freezing and subsequent reheating. In particular, for fried or stir-fried vegetables such as tempura, ching chao luo si, and hoi koror, an oil-cooking process or a stir-frying process at a high temperature is required to obtain an appearance with a cooked texture such as a fried or stir-fried feeling. However, when vegetables that have undergone oil-cooking or stir-frying at a high temperature are refrigerated or frozen, there has been a problem that it is difficult to obtain a crispy texture after reheating.

[0006] Regarding the above problems, Patent Document 1 does not consider obtaining a crispy texture after reheating cooked vegetables that have been refrigerated or frozen, and no process for this purpose has been studied at all. Also, as described in Patent Document 2, although refrigerated or frozen vegetables obtained through heat treatment with superheated steam can obtain a crispy texture to some extent when reheated, an appearance with a cooked texture such as a fried or stir-fried feeling cannot be obtained.

[0007] Therefore, an object of the present invention is to provide refrigerated or frozen vegetables that have a good texture and an appearance with a cooked texture even after reheating from a refrigerated or frozen state.

Means for Solving the Problems

[0008] The present invention provides a method for producing refrigerated or frozen vegetables, comprising a steam treatment step of heating vegetables with steam at 100°C or higher and 300°C or lower, an oil heating step of heating the vegetables treated in the steam treatment step by contacting them with an oil at 120°C or higher and 200°C or lower for a heating time of 1 second or more and 60 seconds or less, and a step of refrigerating or freezing the vegetables treated in the oil heating step.

[0009] The present invention also provides a method for producing prepared vegetables using the refrigerated or frozen vegetables obtained by the above method.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide refrigerated or frozen vegetables that have a good texture even after reheating after refrigeration or freezing and have an appearance with a cooked feeling. Further, according to the present invention, it is possible to provide prepared vegetables using the refrigerated or frozen vegetables.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the present invention will be described based on its preferred embodiments. The present invention includes a steam treatment step of heating vegetables using steam at 100°C or higher and 300°C or lower, an oil heating step of heating the vegetables treated in the steam treatment step by bringing them into contact with oil at 120°C or higher and 200°C or lower for a heating time of 1 second or longer and 60 seconds or shorter, and a step of refrigerating or freezing the vegetables treated in the oil heating step, and relates to a method for producing refrigerated or frozen vegetables. In addition, hereinafter, the descriptions of "N seconds" and "M minutes" regarding time respectively mean "for N seconds" and "for M minutes" (N and M are numerical values respectively).

[0012] The present inventors have intensively studied a method for producing cooked vegetables that have a crispy texture while having a fried or stir-fried appearance when reheated after refrigeration or freezing. In order to produce cooked refrigerated or frozen vegetables, it is necessary to heat them to 85°C from a hygienic standpoint. On the other hand, the present inventors have found that vegetables that are simply fried or fried in an unheated state and heated to 85°C before being refrigerated or frozen tend to burn or become soft or shriveled when reheated. The present inventors speculated that the above phenomenon is due to overheating, which causes the vegetables to burn, the moisture in the vegetables to evaporate and cause the vegetables to shrink, or the pectin in the vegetables to decompose and soften, resulting in a soft texture. In order to obtain a crispy texture while obtaining a fried or stir-fried appearance, it is necessary to avoid overheating. Furthermore, as a result of studying various production methods that are thought to be capable of heating vegetables while avoiding overheating, the above production method of the present invention was conceived.

[0013] (Steam treatment process) Examples of vegetables that are the subject of the present invention include leafy vegetables such as cabbage, green onion, Chinese cabbage, spinach, shiso, garland chrysanthemum, lettuce, komatsuna, and bok choy; flower vegetables such as broccoli and cauliflower; underground stem vegetables such as lotus root; sprout vegetables such as bean sprouts; sprout vegetables other than sprouts such as bamboo shoots; stem, bulb, and root vegetables such as asparagus, garlic, ginger, and onion; root vegetables such as carrots, turnips, radishes, and burdock; fruit vegetables such as eggplant, tomatoes, bell peppers, chili peppers, pumpkins, and shishito peppers; tubers such as sweet potatoes and potatoes; beans such as soybeans, green peas, and fava beans; mushrooms such as maitake mushrooms, shiitake mushrooms, matsutake mushrooms, enoki mushrooms, bunashimeji mushrooms, king oyster mushrooms, and wood ear mushrooms; and corn, sweet corn, baby corn, and other corns.

[0014] Among these, it is preferable to use at least one selected from leafy vegetables, flower vegetables, sprout vegetables, stem vegetables / bulb vegetables / rhizome vegetables, root vegetables, and fruit vegetables because the amount of moisture is large and the effect by applying to the present invention is high. In particular, from the viewpoints of versatility and improvement of texture, it is preferable that the vegetable is one or more selected from carrot, pepper, eggplant, broccoli, cauliflower, asparagus, shishitou, pumpkin, cabbage, Chinese cabbage, and mung bean sprouts, and it is particularly preferable that it is one or more selected from carrot, pepper, broccoli, asparagus, shishitou, pumpkin, cabbage, and mung bean sprouts.

[0015] The vegetable to be subjected to the steam treatment step is preferably in an unheated state in terms of easily obtaining the effect of the present invention related to a crispy texture. However, the vegetable to be subjected to the steam treatment step may be pre-heated as long as the effect of the present invention related to the texture is obtained. The unheated state means, for example, that no heat treatment of 70 ° C or higher for 1 second or more is performed, preferably means that no heat treatment of 60 ° C or higher for 1 second or more is performed, and particularly preferably means that no heat treatment of 50 ° C or higher for 1 second or more is performed.

[0016] The vegetable used in the present invention is preferably 15 g or less per piece in that it is easy to pass fire through the whole vegetable and it is easier to obtain a crispy texture while obtaining a cooking feeling. Here, "per piece" means per cut piece if it is a cut vegetable. Or, if it is a vegetable torn and separated by hand or the like, it means per torn piece. Also, in the case of mung bean sprouts, it means per stalk, in the case of shishitou, it means per shishitou fruit, and in the case of beans, it means per bean grain (hereinafter, when referring to one vegetable, it is used in this meaning). From these points, it is more preferable that the vegetable is 15 g or less per piece, and further preferably 10 g or less. In addition, as the lower limit of the weight of one vegetable, 0.1 g or more is preferably mentioned from the viewpoint of workability, and 1 g or more is more preferable.

[0017] When the wild vegetables are 15 g or less per piece, it is sufficient that at least one of the wild vegetables to be subjected to the steam treatment process is 15 g or less. However, preferably, among the wild vegetables to be subjected to the steam treatment process, in terms of the number standard, it is preferable that the weight of 60% or more is 15 g or less, more preferably 80% or more, and particularly preferably 90% or more.

[0018] The wild vegetables used in the present invention preferably have a size of 5 cm square or less per piece because it is easy to pass fire through the whole wild vegetables, and it is easier to obtain a crispy texture while obtaining a cooked appearance. The size of 5 cm square or less means that when the wild vegetables are placed on an arbitrary horizontal plane and the vertical, horizontal, and height of its outer shape are measured, among the vertical, horizontal, and height, the two dimensions other than the smallest dimension are each 5 cm or less. For example, when the wild vegetables are placed on a plane and the vertical, horizontal, and height are measured, and the vertical is 4 cm, the horizontal is 4 cm, and the height is 3 cm, the wild vegetables correspond to within 5 cm square. Here, the vertical refers to the maximum length in the shape projected onto the plane when the wild vegetables are placed on the above-mentioned plane and viewed from above, and the horizontal refers to the length in the direction orthogonal to the maximum length. The maximum length refers to the length of the largest line segment among the line segments crossing the shape projected onto the plane. The way of placing the wild vegetables on the above-mentioned plane during measurement is arbitrary. If it can be confirmed that among the vertical, horizontal, and height dimensions measured in one way of placing, the two dimensions other than the smallest dimension are 5 cm or less, even if the two dimensions other than the smallest dimension among the vertical, horizontal, and height dimensions measured in another way of placing are not 5 cm or less, it shall be regarded as "within 5 cm square". When the wild vegetables are placed on the above-mentioned plane and the vertical, horizontal, and height of its outer shape are measured, it is preferable that at least one of the vertical, horizontal, and height is 1 cm or more, and more preferably 2 cm or more. When the wild vegetables are placed on a plane and the vertical, horizontal, and height of its outer shape are measured, it is more preferable that at least two of the vertical, horizontal, and height are 1 cm or more, and even more preferably 2 cm or more. In particular, it is preferable that the size of each cut or torn-by-hand wild vegetable is within 5 cm square.

[0019] When the size of each wild vegetable is within 5 cm square, at least one wild vegetable to be subjected to the steam treatment process may be within 5 cm square. However, preferably, it is within 5 cm square for 60% or more based on the number, more preferably within 5 cm square for 80% or more, and particularly preferably within 5 cm square for 90% or more.

[0020] For the wild vegetables to be subjected to the steam treatment process, other ingredients such as meat and fish may be mixed with the wild vegetables. Also, various components such as seasonings, food additives such as coating materials, antioxidants and pH adjusters, and minerals may be added to the wild vegetables in advance. Among all the materials to be subjected to the steam treatment process, the proportion of wild vegetables is preferably 60% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0021] In the steam treatment process, the wild vegetables are heated using steam at 100°C or higher and 300°C or lower. The inventor has found that according to the steam treatment process in which high-temperature steam at 100°C or higher and 300°C or lower is brought into contact with the wild vegetables, even if it is then brought into contact with high-temperature oil and then refrigerated or frozen and then reheated, it is easy to maintain the hardness of the surface of the wild vegetables, a good texture can be obtained, and the appearance can also be good. The reason for this is not clear, but according to steam heating, uniform heating can be achieved without physical impact, the heating time is easy to control, and it is easy to suppress adverse effects on the color tone and yield. In this process, the advantage of the steam temperature being 100°C or higher is that the wild vegetables can be heated rapidly, and the advantage of the steam temperature being 300°C or lower is that the wild vegetables are not overheated. When the steam is above 100°C, superheated steam obtained by further heating saturated steam that has boiled and vaporized at 100°C or higher is used. From the viewpoint of imparting a drying effect to the surface of the wild vegetables and improving the cooking effect when heated oil is applied, the steam temperature is more preferably 140°C or higher. Also, from these viewpoints, the most preferable steam temperature is 180°C or higher and 270°C or lower.

[0022] The steam treatment step is preferably carried out until the core temperature of the vegetables reaches 85°C from the viewpoints of hygiene and obtaining an appropriate texture for the foodstuffs. Here, the core temperature of the vegetables can be measured by inserting a needle probe thermometer into the center of the vegetable. The central position of the vegetable where the temperature is measured is determined by visual inspection. The central position is determined within the scope of technical common sense in the food industry, and can be, for example, as follows. For example, in the case of broccoli, which is composed of a stem and a flower bud, the center point of the central axis of the thickest stem in the longitudinal direction is set as the central position. For asparagus stems, the center point of the central axis of the stem in the longitudinal direction is set as the central position. For bean sprouts, which are also cylindrical like asparagus, the center point of the central axis of the cylinder in the longitudinal direction is set as the central position. For cabbage, the center of the thickness direction at the center of the leaf when viewed in a plane is set as the central position. For bell peppers, the center of the thickness direction at the center of the skin surface when viewed in a plane is set as the central position. For shishito peppers, the thermometer is inserted into the central part surrounded by the seeds inside the approximately cylindrical skin to measure. In addition, for carrots, pumpkins, potatoes, sweet potatoes, etc., which are in an indefinite lump shape, the part of the food material that is farthest from any surface is set as the central position. For example, for an object surrounded by a flat cross section and a curved surface, the point that is the largest distance from the closest surface of the object among those surfaces is set as the central position. The core temperature of other vegetables can also be measured in the same manner as above.

[0023] The suitable heating time in the steam treatment step may be adjusted as appropriate depending on the type of vegetable and the size of each vegetable. However, for example, a heating time of 10 seconds or more and 10 minutes or less is preferable in terms of the texture and appearance of the resulting vegetable, more preferably a heating time of 20 seconds or more and 7 minutes or less, and particularly preferably a heating time of 30 seconds or more and 4 minutes or less. Here, the heating time in the steam treatment step refers to the time during which the vegetable is in contact with water vapor at 100°C or more and 300°C or less.

[0024] In particular, as an example of the heating time in the steam treatment step when the vegetables are root vegetables such as carrots, pumpkins, tubers such as sweet potatoes and lotus roots, legumes or corns, it is preferably 10 seconds or more and 10 minutes or less, more preferably 20 seconds or more and 7 minutes or less, and still more preferably 30 seconds or more and 5 minutes or less.

[0025] Further, as an example of the heating time in the steam treatment step when the vegetables are fruit vegetables other than pumpkins such as bell peppers and shishito peppers, mushrooms, flower vegetables, leaf vegetables such as cabbages, and sprout vegetables such as mung beans, it is preferably 10 seconds or more and 10 minutes or less, more preferably 15 seconds or more and 5 minutes or less, and still more preferably 20 seconds or more and 2 minutes or less.

[0026] Also, when the vegetables are stem vegetables, bulb vegetables, rhizome vegetables such as asparagus, or bamboo shoots, as an example of the heating time in the steam treatment step, it is preferably 10 seconds or more and 10 minutes or less, more preferably 20 seconds or more and 7 minutes or less, and still more preferably 30 seconds or more and 5 minutes or less.

[0027] As the amount of steam used in the steam treatment step, from the viewpoints of more easily obtaining vegetables with a good texture and appearance and more easily reducing the moisture on the vegetable surface, it is preferably 20 kg / hour or more and 300 kg / hour or less, and more preferably 30 kg / hour or more and 200 kg / hour or less.

[0028] The total amount of steam used in the steam treatment step is preferably in the range of 1 g or more and 100 g or less per 1 g of the vegetables to be subjected to the steam treatment step, from the viewpoint of more easily obtaining vegetables with a good texture and appearance, and more preferably in the range of 2 g or more and 50 g or less.

[0029] As cooking equipment using steam at 100°C or more and 300°C or less, there are two types: a steam injection type that directly blows steam onto the food ingredients, and a steam-filled type that fills the inside of the chamber with steam instead of directly blowing steam onto the food ingredients. Either type can be used.

[0030] The vegetables processed by the above-described steam treatment step are subjected to an oil heating step. The manufacturing method of the present invention may have a separate step between the steam treatment step and the oil heating step. Examples of such a separate step include a standing step, a seasoning step, an addition step of a food additive, a weight adjustment step, and the like. From the viewpoint of ease of temperature control of the vegetables, it is preferable that there is no active heating step or active cooling step between the steam treatment step and the oil heating step. In particular, it is preferable to perform the steam treatment step and the oil heating step continuously because it is easy to control the temperature of the vegetables. Performing the steam treatment step and the oil heating step continuously preferably means that the time from the end point of contact between the water vapor and the vegetables in the steam treatment step to the start point of contact between the vegetables and the oil in the oil heating step is within 1 hour, and particularly preferably means that it is within 20 minutes.

[0031] (Oil heating step) The oil heating step is a step in which the vegetables after being treated by the steam treatment step are brought into contact with oil and fat at 120°C or higher and 200°C or lower, and the heating time is 1 second or longer and 60 seconds or shorter. As a method of bringing the oil and fat into contact with the vegetables, a general deep-frying method in which the vegetables are fried in heated oil and fat in a pan may be used, or a method in which the heated oil and fat is allowed to flow down from above the vegetables to apply the heated oil and fat to the vegetables may be mentioned. In the latter case, it is preferable in terms of easy adjustment of the heating time in short-time heating and easy adjustment of the temperature of the oil and fat.

[0032] When the temperature of the oil and fat used in the oil heating step is 120°C or higher, an appearance with a fried or stir-fried feeling can be obtained, and it is also advantageous in terms of imparting a cooking aroma. When the temperature of the oil and fat used in the oil heating step is 200°C or lower, deterioration in appearance and texture due to overheating when reheating refrigerated or frozen vegetables can be avoided. From this viewpoint, the temperature of the oil and fat used in the oil heating step is more preferably 120°C or higher and 270°C or lower, and particularly preferably 150°C or higher and 210°C or lower.

[0033] The heating time in the oil heating step is 1 second or more and 60 seconds or less. By being 1 second or more, an appearance with a stir-fried or fried feeling can be obtained, and by being 60 seconds or less, deterioration in appearance and texture due to overheating when reheating refrigerated or frozen vegetables can be avoided. From this perspective, the heating time in the oil heating step is more preferably 2 seconds or more and 50 seconds or less, and particularly preferably 3 seconds or more and 15 seconds or less.

[0034] In the oil heating step, the contact between the oil and fat and the vegetables may be continuous or discontinuous. Discontinuous means, for example, the case where the oil and fat are intermittently applied to the vegetables. The heating time in the oil heating step refers to the contact time with oil at 120°C or more and 200°C or less. For example, when oiling is performed continuously, it refers to the time from when oiling starts and the heated oil and vegetables start to contact until the contact ends. When oiling is performed intermittently, it is the total time of the contact time between the vegetables and the heated oil and fat for each oiling, excluding the gap time between each oiling.

[0035] The total flow rate of the oil and fat used in the oil heating step is preferably 1 g or more and 200 g or less per 1 g of vegetables in terms of easily obtaining a fried or stir-fried feeling efficiently, and more preferably 2 g or more and 100 g or less.

[0036] The oil and fat used in the oil heating step is not particularly limited as long as it is edible oil, and can be used without particular limitation such as palm oil, palm kernel oil, coconut oil, cocoa butter, shea butter, sal fat, beef tallow, lard, illipe fat, soybean oil, rapeseed oil, cottonseed oil, safflower oil, sunflower oil, rice oil, corn oil, sesame oil, linseed oil, olive oil, milk fat, etc., and processed oils and fats thereof (hydrogenated oil, fractionated oil, transesterified oil). In particular, in the present invention, it is preferable to use a liquid oil at room temperature of 25°C because it is easy to handle in continuous production.

[0037] After the oil heating step, the vegetables are cooled if necessary and stored by refrigeration or freezing. After the oil heating step, the vegetables Refrigerated orIt is preferable that refrigerated or frozen vegetables having a crispy texture and good appearance upon reheating can be easily obtained by being frozen. It is preferable to cool the vegetables after the oil heating step before refrigeration or freezing in terms of ease of temperature control and hygiene. Various methods such as forced-air cooling and vacuum cooling can be employed for cooling. Refrigeration is usually carried out at a temperature above 0°C and below 15°C, more preferably 5°C or more and 10°C or less. Freezing is usually carried out at a temperature of -50°C or more and 0°C or less, more preferably -10°C or more and -45°C or less.

[0038] The refrigerated or frozen vegetables obtained as described above can be used, for example, in the production of prepared foods. Examples of types of prepared foods include boiled foods, grilled foods, boiled foods, steamed foods, stir-fried foods, fried foods, soup foods, donburi dishes, rice dishes other than donburi, noodle dishes, salad dishes, etc. In the method for producing prepared foods of the present invention, since the refrigerated or frozen vegetables are already heated, it is possible to complete the prepared foods by simple steps such as directly using them for plating or mixing them with other ingredients and seasoning liquids, etc.

[0039] The scene of heating refrigerated or frozen vegetables can be either when producing prepared foods or when eating. For example, it is possible to heat the refrigerated or frozen vegetables when using them for the production of prepared foods and then reheat the obtained prepared foods when eating, but in the present invention, vegetables having a good texture and good appearance can also be obtained even in such repeated reheating. In the production process of prepared foods, the heating method of the refrigerated or frozen vegetables may be appropriately selected according to the method suitable for the type of prepared foods to be obtained. Also, examples of the heating method of the refrigerated or frozen vegetables or the prepared foods obtained using them when eating include microwave heating, oven heating, etc. Further, it is also possible to stir-fry the refrigerated or frozen vegetables or foods containing them using a frying pan, etc., or boil-heat the foods in a sealed state in a packaging material, etc., and it is not particularly limited.

Examples

[0040] Hereinafter, the present invention will be described based on examples, but the present invention is not limited to the following examples. In each of the following examples and comparative examples, refrigerated storage was carried out at 10°C, and frozen storage was carried out at -18°C. Also, rapeseed oil was used as the oil and fat used in the oil heating step. For oiling, the vegetables were spread out without overlapping parts so that they were easily hit by the oil. When viewed from above in a projection view from above the flowing-down position, the flowing-down part of the heated oil and fat included the entire vegetable position and the flowing-down amount per area was uniform over the entire flowing-down part.

[0041] [Examples 1-1 to 1-4] The skin of the root of unheated carrots was peeled and cut into irregular pieces within a 5 cm square (length about 3 cm, width about 3 cm, height less than 3 cm). The weight per piece was about 7.0 g. 200 g of the obtained irregularly cut carrots were heated in a continuous steam cooker (manufactured by Nakanishi Seisakusho, SV Roaster, steam injection type) with steam at the temperature shown in Table 1 for the heating time shown in Table 1 as a steam treatment step. The steam amount was set to 100 kg / hour. It was confirmed that the central temperature of the carrots after steam heating reached 85°C. Next, as an oil heating step, for the carrots after the steam treatment step, oil at the temperature shown in Table 1 was poured from above with an oiling machine for the heating time shown in Table 1. The total flow rate of the oil of the oiling machine was 10 g per 1 g of green peppers. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling, the carrots were cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 1.

[0042] [Comparative Examples 1-1 to 1-2, 1-4 to 1-5] Except that the oil heating step was not performed, it was the same as Examples 1-1 to 1-4 respectively.

[0043] [Comparative Examples 1-3, 1-6] An oil heating step similar to Example 1-1 was performed except that the steam treatment step was not performed and the oiling time (heating time of the oil heating step) was the time shown in Table 1. Other than that, it was the same as Examples 1-1 and 1-3 respectively.

[0044] (Evaluation) After placing 100 g of refrigerated carrots stored for 1 day on a plate, they were heated in a microwave oven at 600 W for 20 seconds. Also, after placing 100 g of frozen carrots stored for 7 days on a plate, they were heated in a microwave oven at 600 W for 1 minute and 40 seconds. The carrots after heating were evaluated according to the following evaluation criteria.

[0045] <Evaluation Criteria> ● Appearance 〇: There is a cooking texture (fried or stir-fried texture). △: There is little cooking texture (fried or stir-fried texture). ×: There is no cooking texture (fried or stir-fried texture), or it is burnt. ● Texture 〇: It has a good bite. △: It has little bite. ×: It is soft or mushy.

[0046]

Table 1

[0047] As shown in Table 1, it can be seen that in each example combining a steam treatment step at a predetermined temperature and time and an oil heating step at a predetermined temperature and time, an appearance with a cooking texture and a texture with a good bite can be obtained.

[0048] 〔Examples 2-1 to 2-4〕 The unheated bell pepper fruits were cut into pieces within 5 cm square (length about 3 cm, width about 3 cm, height less than about 1 cm). The weight per piece was about 2.1 g. For 200 g of the obtained cut bell peppers, as a steam treatment step, they were heated with steam at the temperature described in Table 2 for the heating time described in Table 2 using the same cooking machine as used in Example 1-1. The steam amount was set to 100 kg / hour. It was confirmed that the central temperature of the bell peppers after steam heating reached 85°C. Next, for the bell peppers after the steam treatment process, as an oil heating process, using an oiling machine, oil at the temperature described in Table 2 was poured from above for the heating time described in Table 2. The total flow rate of the oil in the oiling machine was 34 g per 1 g of bell pepper. The flow rate of the oil in the oiling machine was 5 g / (cm 2 ·s). The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling, the bell peppers were cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 2.

[0049] 〔Comparative Examples 2-1 to 2-2, 2-4 to 2-5〕 Except for not performing the oil heating process, it was the same as Examples 2-1 to 2-4 respectively.

[0050] 〔Comparative Examples 2-3, 2-6〕 An oil heating process similar to that of Example 2-1 was performed except that the steam treatment process was not performed and the oiling time was set to the time in Table 2. Otherwise, it was the same as Examples 2-1 and 2-3 respectively.

[0051] (Evaluation) For the refrigerated bell peppers refrigerated for 1 day, after putting 100 g on a plate, they were heated in a microwave oven at 600 W for 20 seconds. Also, for the frozen bell peppers frozen for 7 days, after putting 100 g on a plate, they were heated in a microwave oven at 600 W for 1 minute and 40 seconds. The bell peppers after heating were evaluated according to the above <Evaluation Criteria>. The results are shown in Table 2.

[0052]

Table 2

[0053] 〔Examples 3-1 to 3-4〕 The unheated broccoli was cut into individual florets and sized to within 5 cm square (less than 3 cm in length, less than 3 cm in width, and less than 3 cm in height). The weight of each cut broccoli floret was approximately 4.0 g. For 200 g of the obtained cut broccoli, as a steam treatment step, it was heated with steam at the temperature described in Table 3 for the heating time described in Table 3 using the same cooking machine as used in Example 1-1. The steam amount was set to 100 kg / hour. It was confirmed that the central temperature of the broccoli after steam heating had reached 85°C. Next, for the broccoli after the steam treatment step, as an oil heating step, oil at the temperature described in Table 3 was poured from above using an oiling machine for the heating time described in Table 3. The total flow rate of the oil of the oiling machine was 18 g per 1 g of broccoli. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling was completed, the broccoli was cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 3.

[0054] 〔Comparative Examples 3-1 to 3-2, 3-4 to 3-5〕 Except for not performing the oil heating step, it was the same as in Examples 3-1 to 3-4 respectively.

[0055] 〔Comparative Examples 3-3, 3-6〕 An oil heating step similar to that of Example 3-1 was performed, except that the steam treatment step was not performed and the oiling time was the time shown in Table 3. Other than that, it was the same as in Examples 3-1 and 3-3 respectively.

[0056] (Evaluation) For the refrigerated broccoli stored refrigerated for 1 day, after putting 200 g on a plate, it was heated in a microwave oven at 600 W for 20 seconds. Also, for the frozen broccoli stored frozen for 7 days, after putting 100 g on a plate, it was heated in a microwave oven at 600 W for 1 minute and 40 seconds. The heated broccoli was evaluated according to the above <Evaluation Criteria>. The results are shown in Table 3.

[0057]

Table 3

[0058] [Examples 4-1 to 4-4] Unheated asparagus was cut into pieces about 5 cm long. The weight of each cut asparagus piece was about 3.4 g. For 200 g of the obtained cut asparagus, as a steam treatment step, it was heated with steam at the temperature described in Table 4 for the heating time described in Table 4 using the same cooking machine as that used in Example 1-1. The amount of steam was set to 100 kg / hour. It was confirmed that the central temperature of the asparagus after steam heating reached 85°C. Next, for the asparagus after the steam treatment step, as an oil heating step, oil at the temperature described in Table 4 was poured from above with the oiling machine for the heating time described in Table 4. The total flow rate of the oil in the oiling machine was 7 g per 1 g of asparagus. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling was completed, the asparagus was cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 4.

[0059] [Comparative Examples 4-1 to 4-2, 4-4 to 4-5] Except that the oil heating step was not performed, it was the same as Examples 4-1 to 4-4 respectively.

[0060] [Comparative Examples 4-3, 4-6] An oil heating step similar to that of Example 4-1 was performed except that the steam treatment step was not performed and the oiling time was the time shown in Table 4. Otherwise, it was the same as Examples 4-1 and 4-3 respectively.

[0061] (Evaluation) After placing 100 g of the refrigerated asparagus stored refrigerated for 1 day on a plate, it was heated in a microwave oven at 600 W for 20 seconds. Also, after placing 100 g of the frozen asparagus stored frozen for 7 days on a plate, it was heated in a microwave oven at 600 W for 1 minute and 40 seconds. The heated asparagus was evaluated according to the above <Evaluation Criteria>. The results are shown in Table 4.

[0062] [Table 4]

[0063] [Examples 5-1 to 5-4] Regarding 200 g of unheated shishito fruits (each weighing approximately 4.8 g), as a steam treatment step, using the same cooking machine as used in Example 1-1, they were heated with steam at the temperature described in Table 5 for the heating time described in Table 5. The steam amount was set at 100 kg / hour. It was confirmed that the central temperature of the shishito after steam heating reached 85°C. Next, for the shishito after the steam treatment step, as an oil heating step, using an oiling machine, oil at the temperature described in Table 5 was poured from above for the heating time described in Table 5. The total oil flow rate of the oiling machine was 5 g per 1 g of shishito. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling was completed, the shishito were cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 5.

[0064] [Comparative Examples 5-1 to 5-2, 5-4 to 5-5] Except for not performing the oil heating step, it was the same as in Examples 5-1 to 5-4 respectively.

[0065] [Comparative Examples 5-3, 5-6] An oil heating step similar to that of Example 5-1 was performed except that the steam treatment step was not performed and the oiling time was the time in Table 5. Otherwise, it was the same as in Examples 5-1 and 5-3 respectively.

[0066] (Evaluation) After placing 100 g of the refrigerated shishito stored refrigerated for 1 day on a plate, it was heated in a microwave oven at 600 W for 20 seconds. Also, after placing 100 g of the frozen shishito stored frozen for 7 days on a plate, it was heated in a microwave oven at 600 W for 1 minute and 40 seconds. The heated shishito were evaluated according to the above <Evaluation Criteria>. The results are shown in Table 5.

[0067]

Table 5

[0068] [Examples 6-1 to 6-4] An unheated pumpkin was cut into pieces within 5 cm square (length approximately 3 cm, width approximately 3 cm, height less than 3 cm) (the weight per piece was approximately 12.8 g). For 200 g of the cut pumpkin, as a steam treatment step, it was heated with steam at the temperature described in Table 6 for the heating time described in Table 6 using the same cooking machine as that used in Example 1-1. The steam volume was set at 100 kg / hour. It was confirmed that the central temperature of the pumpkin after steam heating had reached 85°C. Next, for the pumpkin after the steam treatment step, as an oil heating step, oil at the temperature described in Table 6 was poured from above with an oiling machine for the heating time described in Table 6. The total flow rate of the oil in the oiling machine was 6 g per 1 g of the pumpkin. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling was completed, the pumpkin was cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 6.

[0069] [Comparative Examples 6-1 to 6-2, 6-4 to 6-5] Except for not performing the oil heating step, it was the same as Examples 6-1 to 6-4 respectively.

[0070] [Comparative Examples 6-3, 6-6] An oil heating step similar to that of Example 6-1 was performed except that the steam treatment step was not performed and the oiling time was the time shown in Table 6. Otherwise, it was the same as Examples 6-1 and 6-3 respectively.

[0071] (Evaluation) For the refrigerated pumpkin stored refrigerated for 1 day, after 100 g was placed on a plate, it was heated in a microwave oven at 600 W for 20 seconds. Also, for the frozen pumpkin stored frozen for 7 days, after 100 g was placed on a plate, it was heated in a microwave oven at 600 W for 1 minute and 40 seconds. The pumpkin after heating was evaluated according to the above <Evaluation Criteria>. The results are shown in Table 6.

[0072] [Table 6]

[0073] [Examples 7-1 to 7-4] An unheated cabbage was cut so that the weight per head was about 3.7 g. For 200 g of the cut cabbage, as a steam treatment step, it was heated with steam at the temperature described in Table 7 for the heating time described in Table 7 using the same cooking machine as that used in Example 1-1. The steam amount was set to 100 kg / hour. It was confirmed that the central temperature of the cabbage after steam heating reached 85°C. Next, for the cabbage after the steam treatment step, as an oil heating step, oil at the temperature described in Table 7 was poured from above with an oiling machine for the heating time described in Table 7. The total flow rate of the oil in the oiling machine was 19 g per 1 g of the cabbage. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling was completed, the cabbage was cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 7.

[0074] [Comparative Examples 7-1 to 7-2, 7-4 to 7-5] Except that the oil heating step was not performed, it was the same as Examples 7-1 to 7-4, respectively. However, the steam heating time of Comparative Example 7-4 was the time shown in Table 7.

[0075] [Comparative Examples 7-3, 7-6] An oil heating step similar to that of Example 7-1 was performed except that the steam treatment step was not performed and the oiling time was the time in Table 7. Other than that, it was the same as Examples 7-1 and 7-3, respectively.

[0076] (Evaluation) For the refrigerated cabbage stored refrigerated for 1 day, after 100 g was placed on a plate, it was heated in a microwave oven at 600 W for 20 seconds. Also, for the frozen cabbage stored frozen for 7 days, after 100 g was placed on a plate, it was heated in a microwave oven at 600 W for 1 minute and 40 seconds. The heated cabbage was evaluated according to the above <Evaluation Criteria>. The results are shown in Table 7.

[0077]

Table 7

[0078] [Examples 8-1 to 8-4] Regarding 200 g of unheated bean sprouts (weight per sprout: 0.8 g), as a steam treatment step, using the same cooking machine as that used in Example 1-1, they were heated with steam at the temperature described in Table 8 for the heating time described in Table 8. The steam amount was set at 100 kg / hour. It was confirmed that the central temperature of the bean sprouts after steam heating reached 85°C. Next, for the bean sprouts after the steam treatment step, as an oil heating step, using an oiling machine, oil at the temperature described in Table 8 was poured from above for the heating time described in Table 8. The total oil flow rate of the oiling machine was 15 g per 1 g of bean sprouts. The time from the end of steam heating to the start of oiling was within 10 minutes. After the oiling was completed, the bean sprouts were cooled with cold air at 10°C and then subjected to the storage treatment shown in Table 8.

[0079] 〔Comparative Examples 8-1 to 8-2, 8-4 to 8-5〕 Except for not performing the oil heating step, it was the same as Examples 8-1 to 8-4 respectively.

[0080] 〔Comparative Examples 8-3, 8-6〕 A steam treatment step was not performed, and an oil heating step similar to that of Example 8-1 was performed except that the oiling time was the time in Table 8. Other than that point, it was the same as Examples 8-1 and 8-3 respectively.

[0081] (Evaluation) For the refrigerated bean sprouts stored refrigerated for 1 day, after putting 100 g on a plate, they were heated in a microwave oven at 600 W for 20 seconds. Also, for the frozen bean sprouts stored frozen for 7 days, after putting 100 g on a plate, they were heated in a microwave oven at 600 W for 1 minute and 40 seconds. The bean sprouts after heating were evaluated according to the above <Evaluation Criteria>. The results are shown in Table 8.

[0082]

Table 8

Claims

1. A steam treatment step of heating at least one kind of vegetable selected from leafy vegetables, cauliflower, sprout vegetables, stem vegetables, bulb vegetables, rhizome vegetables, root vegetables excluding tubers and fruit vegetables using steam at 100°C or higher and 300°C or lower, An oil heating step of heating the vegetables treated in the steam treatment step by bringing them into contact with oil at 120°C or higher and 200°C or lower for a heating time of 3 seconds or more and 60 seconds or less, and A method for producing refrigerated or frozen vegetables, comprising a step of refrigerating or freezing the vegetables treated in the oil heating step without heating, In the steam treatment step, steam at 20 kg / hour or more and 300 kg / hour or less is used in a range of 2 g or more and 50 g or less per 1 g of the vegetables, In the oil heating step, oiling is performed by flowing 2 g or more and 100 g or less of oil per 1 g of the vegetables onto the vegetables, A method for producing refrigerated or frozen vegetables, wherein the time from the end of contact between the steam and the vegetables in the steam treatment step to the start of contact between the vegetables and the oil in the oil heating step is within 20 minutes.

2. The method for producing refrigerated or frozen vegetables according to claim 1, wherein the size of each vegetable is within 5 cm square.

3. The method for producing refrigerated or frozen vegetables according to claim 1 or 2, wherein the weight of each vegetable is 15 g or less.

4. The method for producing refrigerated or frozen vegetables according to any one of claims 1 to 3, wherein the vegetables are one kind or two or more kinds selected from carrots, peppers, broccoli, asparagus, shishitou, pumpkins, cabbages and bean sprouts.

5. The method for producing refrigerated or frozen vegetables according to any one of claims 1 to 4, wherein the oil heating step is a step of pouring heated oil onto the vegetables for oiling.

6. The method for producing refrigerated or frozen vegetables according to any one of claims 1 to 5, wherein in the steam treatment step, steam at 140°C or higher and 300°C or lower is used.

7. The method for producing refrigerated or frozen vegetables according to any one of claims 1 to 6, wherein the heating time of the steam treatment step is 30 seconds or more and 4 minutes or less.

8. The method for producing refrigerated or frozen vegetables according to any one of claims 1 to 7, wherein in the steam treatment step, the vegetables are heated until the central temperature of the vegetables reaches 85°C.

9. The method for producing refrigerated or frozen vegetables according to any one of claims 1 to 8, wherein the steam treatment step and the oil heating step are performed continuously.

10. A method for producing ready-to-eat vegetables, which comprises producing ready-to-eat vegetables using refrigerated or frozen vegetables obtained by the production method according to any one of claims 1 to 9.

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