Processing method of seasoned corn

Abstract

The invention belongs to the field of food, and particularly relates to a processing method of seasoned corn, which comprises the following steps: a pretreatment step: peeling corn; a first heat treatment step: carrying out water vapor heating treatment on the pretreated corn so as to enable the temperature of the corn detection position to be 90-100 DEG C; a freezing treatment step: cooling and freezing the corn subjected to the first heating treatment, so that the temperature of the detection position of the corn is-20 DEG C or below, and the cooling rate is 1 DEG C / min or above; a second heat treatment step: boiling and heating the frozen corn in water so as to enable the temperature of the corn detection position to be 35 DEG C or above; and a seasoning step of applying a seasoning to the corn after the second heat treatment step. The corn processing technology provided by the invention is convenient to operate, and the seasoning can more uniformly penetrate into the corn to improve the taste; and the product has a good shelf life.

Description

Technical Field

[0001] The invention belongs to the field of food, and relates to a corn processing method, in particular to a method for preparing a vacuum-packaged corn product, in particular to a method for processing a vacuum-packaged seasoned corn product coated with a sauce. Background Art

[0002] Corn is now a staple food. Because of its delicious taste and easy to carry, it has become a necessary staple food for meals, such as breakfast.

[0003] Fresh corn refers to corn cobs or corn kernels harvested during the milky stage, also known as fresh corn. Fresh corn kernels produce more sugar, starch, crude fat, and a variety of vitamins and amino acids during the milky stage. Compared with dry corn and old corn, fresh corn has better taste and nutritional value, and is more convenient to eat. It usually only needs to be boiled or steamed. Fresh corn can usually be divided into sweet corn, glutinous corn, and sweet glutinous corn.

[0004] There are many processing methods for fresh corn, and traditional fresh corn foods generally include quick-frozen corn cobs and vacuum-packed corn cobs. In addition, in these processes, the corn cobs may be packaged with sauces according to the needs of the final edible taste or the requirements of the processing method.

[0005] Generally speaking, corn is not easy to taste because of its large cob shape and thick corn skin. Therefore, the production process of flavored corn is mainly based on soaking and pickling. First, pour the flavor ingredients into a container, then add the corn, and soak and pickle it with or without heating to make the corn taste good. Then, the final corn product is made by combining the usual sterilization, freezing and other technologies.

[0006] Reference 1 discloses a method for preparing mustard-flavored fresh corn, the production process of which includes peeling, washing, drying, preparing a cooking liquid, boiling and soaking, sterilizing, cooling, bagging, and vacuuming to produce the mustard-flavored fresh corn, which can be stored at -20 degrees for 80 to 100 days.

[0007] Reference 2 discloses a fresh corn food and a preparation method thereof, comprising sequentially performing a pre-treatment process, an enzyme inactivation process and a post-treatment process on the material to be processed to obtain the fresh corn food; wherein the enzyme inactivation process comprises covering the material to be inactivated with a flexible protective member and then performing microwave enzyme inactivation under a microwave environment. The method can effectively improve the enzyme inactivation effect of the fresh corn food while retaining its rich nutrients, thereby significantly improving the quality of the fresh corn food.

[0008] Reference document 3 provides a quick-frozen corn food and a preparation method thereof, comprising: performing a pre-treatment process on the quick-frozen corn to be processed to obtain a product to be thawed; performing a thawing process on the product to be thawed, and then performing a post-treatment process to obtain a finished product; wherein the thawing process includes covering the product to be thawed with a flexible protective member and then thawing it in a microwave environment. According to the preparation method provided by the present invention, the energy loss in the preparation process of the quick-frozen corn food can be effectively reduced to obtain a quick-frozen corn food with rich nutrients and excellent quality.

[0009] Although the processing method of fresh corn has been explored to a certain extent, it is still not completely sufficient to prepare a preparation method that is excellent in taste, rich in nutrition and convenient in processing.

[0010] References:

[0011] Reference 1: CN 107647259A

[0012] Reference 2: CN 119157223A

[0013] Reference 3: CN 118985819A Summary of the invention

[0014] Problem that the invention aims to solve

[0015] The above-mentioned references 2 and 3 respectively relate to the preparation of a quick-frozen fresh corn product, which focuses on the heat treatment, enzyme inactivation or freezing treatment process of the fresh corn itself, but do not involve the use of seasonings to more advantageously improve the taste of the product.

[0016] In addition, reference 1 provides a method for preparing flavored fresh corn, which uses a soup base containing seasonings for boiling to give the corn a specific flavor.

[0017] However, in further industrial practice, it was also found that: for flavored corn products, although flavors, extracts, sauces and other condiments are added to give corn cobs flavor, due to the unique grain structure of corn, the skin is thick, so it is not easy to taste. For example, as in Reference 1, most current processes boil corn in a seasoning soup over low heat, which takes a long time and the flavor is unstable. In addition, flavor raw materials are easy to volatilize after high temperature heating; extracts and sauces are boiled for a long time, and flavor substances are easy to volatilize. In addition, long-term boiling is also prone to cause the loss of nutrients.

[0018] In addition, when applying seasonings, it is necessary to apply them manually or by machine, which requires a lot of manpower and increases the cost; machine application requires investment in equipment and sites, which increases production investment costs. However, these methods usually affect the taste of the final product due to poor flavor. Moreover, in the case of vacuum packaging filling, which is commonly used in advanced technology, the characteristics of corn itself also have a significant impact on the uniform distribution of seasonings.

[0019] In the practice of the present invention, in order to solve the above problems and provide a vacuum-packed corn product with a deep flavor and good taste, the present invention optimizes and improves the processing method of corn. By combining heating treatment and freezing treatment, corn and seasoning can be better compounded while ensuring that the nutrients of corn are basically not lost, and the seasoning can penetrate deeper into the corn particles. As a result, not only can the flavored corn be more flavorful, but the sauce can also be more easily and evenly distributed in the corn, so that better packability can be obtained and the taste can be more uniform. In addition, due to the relatively mild processing conditions, combined with sterilization and vacuum packaging, the final product also has a good shelf life.

[0020] Solutions for solving problems

[0021] It has been found that the above technical problems can be solved by implementing the following technical solutions:

[0022] [1]. The present invention first provides a method for processing seasoned corn, wherein the method comprises:

[0023] A pretreatment step, wherein the pretreatment step includes peeling the corn;

[0024] The first heat treatment step is to heat the pretreated corn with water vapor so that the temperature at the corn detection position reaches 90° C. to 100° C.;

[0025] A freezing treatment step, cooling and freezing the corn obtained by the first heating treatment so that the temperature at the corn detection position reaches below -20°C, and the cooling rate is above 1°C / min;

[0026] A second heat treatment step of boiling the frozen corn in water to heat the corn so that the temperature at the detection position of the corn reaches above 35° C.;

[0027] The step of seasoning and packaging is to season the corn after the second heat treatment step and then package it.

[0028] Among them, the detection position of the corn is determined in the following way: there are two cross-sections in the axial direction of the corn, and there is an equivalent circle at each of the two interfaces. The cross-section with the larger area of ​​the equivalent circle is taken as the reference, and the detection position is 1.5cm±2mm inward in the axial direction of the corn cob from the center of the equivalent circle where the cross-section is located.

[0029] [2] The method according to [1], wherein the corn is a whole corn or corn cut into segments, and the length of the corn in the axial direction of the corn cob is greater than 3 cm.

[0030] [3] The method according to [1] or [2], wherein in the first heat treatment step, the pressure of the water vapor is less than 0.6 bar.

[0031] [4] The method according to any one of [1] to [3], wherein the cooling rate is 1 to 2°C / min; and the temperature at the corn detection position is above -27°C.

[0032] [5] The method according to any one of [1] to [4], wherein before the freezing treatment step, the temperature at the corn detection position is adjusted to 20 to 35°C.

[0033] [6] The method according to any one of [1] to [5], wherein in the second heat treatment step, the water temperature is 87 to 97°C; and the temperature at the corn detection position is 35 to 42°C.

[0034] [7] The method according to any one of [1] to [6], wherein the second heat treatment step is performed directly after the freezing treatment step.

[0035] [8] The method according to any one of [1] to [7], wherein the packaging is a vacuum packaging.

[0036] [9] The method according to [8], wherein the vacuum-packed corn is sterilized.

[0037]

[10] . Furthermore, the present invention also provides a vacuum-packaged corn product with a sauce, wherein the corn product is prepared by the method according to any one of [1] to [9], and the sauce comprises one or more of barbecue sauce, spicy sauce, and cheese sauce.

[0038] Effects of the Invention

[0039] By implementing the above technical solution, the present invention can achieve the following technical effects:

[0040] 1) The corn processing technology provided by the present invention is relatively convenient to operate, the conditions are relatively mild, and it is easier to be used on an industrial scale;

[0041] 2) The corn processing method provided by the present invention can retain the nutrients of corn without losing them, and at the same time can make the seasoning penetrate into the corn kernels more evenly, thereby improving the taste;

[0042] 3) The corn product processed by the present invention can be stored at room temperature or frozen and has a good shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 : Temperature change at the detection position of corn during steam heating treatment in Example 1 of the present invention

[0044] Figure 2 : Temperature change at the detection position of corn during freezing treatment in Example 1 of the present invention

[0045] Figure 3 : Temperature change at the detection position of corn during boiling and heating treatment in Example 1 of the present invention

[0046] Figure 4 : Comparison of the appearance of the products of Example 1 of the present invention and the comparative example

[0047] Figure 5 : Vacuum packaging in Example 1, Comparative Example 1 and Comparative Example 4 DETAILED DESCRIPTION

[0048] The following is a detailed description of the present invention. The following description of the technical features is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0049] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0050] In the present specification, the use of “substantially” or “essentially” means that the standard deviation from the theoretical model or theoretical data is within 1%, preferably 0.8%, and more preferably 0.5%, and the deviation here also includes systematic deviation.

[0051] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0052] In this specification, the term "normal temperature" refers to a room temperature of 23±2°C.

[0053] In the present specification, "optional" or "optionally" means that the event or situation described below may or may not occur, and the description includes cases where the event occurs and cases where it does not occur.

[0054] In this specification, the references to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0055] The present invention mainly provides an improved corn processing method, which is mainly based on the following insights:

[0056] The traditional method based on boiling or simply applying seasoning has the disadvantages of serious loss of nutrients, insufficient flavor, uneven flavor, etc. The present invention finds that the structure of corn kernels can be improved by combining different heating and cooling methods without excessive boiling, thereby ensuring that nutrients are not lost. At the same time, when adding seasonings, especially sauces, it can cooperate well with the vacuum packaging process, so that the sauce can penetrate into the corn more evenly, so that the final product can be more flavorful and more uniform.

[0057] (Corn raw material)

[0058] In principle, there is no particular restriction on the original source of the corn of the present invention, and it can be fresh corn produced in various places. It should be noted that this is related to the regulations of local laws and regulations, and such corn can be non-genetically modified corn or genetically modified corn.

[0059] In addition, although there is no particular limitation, the corn raw material of the present invention is preferably edible corn (excluding silage corn), and among these corns, edible corn produced in areas with (north) latitudes of 30 to 50° is very suitable.

[0060] In some specific embodiments, the corn suitable for the present invention can be common white corn, yellow corn, black corn, colored corn, or one or more of sweet corn, fruit corn, glutinous corn, etc.

[0061] (Preprocessing)

[0062] The pretreatment of the present invention mainly processes the above corn raw material into corn that can be subjected to subsequent temperature-changing treatment.

[0063] In principle, there is no particular limitation on such pretreatment, which may generally include sorting / grading, peeling, beard removal, cutting / segmenting, cleaning, etc.

[0064] For sorting / grading, existing equipment can be used to select corn raw materials that meet the requirements in terms of appearance, quality, size, etc. or to grade these raw materials.

[0065] For the dehusking and desilking process, it is preferred that the corn husk and corn silk are substantially completely removed.

[0066] For the cutting / segmenting process, the parts that may affect the taste can be removed as needed, such as the head and tail. In addition, the whole corn can be cut into segments to obtain the required length as needed. Therefore, for the corn of the present invention, it can be a whole corn or a corn after cutting. In some specific embodiments, the length of these corns in the axial direction of the corncob can usually be more than 3 cm, such as 3 to 8 cm, 10 to 30 cm, 15 to 25 cm, etc.

[0067] For the cleaning process, in order to remove the debris remaining on the surface of the corn particles from the raw materials or during the processing, there is no particular restriction on the cleaning method in principle, for example, spray cleaning, water immersion cleaning, bubble cleaning, etc. can be used.

[0068] The pretreated corn can be stored briefly at room temperature for subsequent processing.

[0069] (First Heat Treatment)

[0070] The pretreated corn is further processed by a first heat treatment. The first heat treatment of the present invention is achieved by steam heating.

[0071] Steam heating usually has better processing efficiency than boiling, and it is also easier to achieve more complete heating.

[0072] Steam heating can be carried out in a device with steam inlet. The temperature of the steam itself is usually not more than 115°C to avoid overheating the corn surface. Preferably, the steam temperature can be between 102 and 112°C. By adding steam at this temperature, the temperature inside the steam heating device can usually be maintained between 100 and 115°C.

[0073] In addition, the degree of heating of corn during heat treatment is important. Due to the particularity of corn structure, when heating, it is easy to cause insufficient internal heating or excessive external heating, which deteriorates the surface morphology of corn and reduces the packability of the final product. Therefore, the present invention has found in practice that the above problems can be solved by monitoring and controlling the temperature at the "detection position".

[0074] The "detection position" of the present invention is determined in the following way: there are two axial cross-sections of the corn, and there is an equivalent circle at each of the two interfaces. The cross-section with the larger area of ​​the equivalent circle is taken as the reference, and the "detection position" of the present invention is determined 1.5 cm ± 2 mm inward in the axial direction of the corn cob from the center of the equivalent circle of the cross-section.

[0075] By controlling the temperature of the detection position to be above 90°C, the corn as a whole can be fully heated to avoid insufficient cooking of the inner layer or overheating of the skin, so as to ensure the uniformity of the final taste and external shape. In some specific embodiments, the temperature of the detection position can be 91-100°C, preferably 92-97°C. It should be noted that for the "detection position" of the present invention, if multiple corns are processed at one time, it is necessary to ensure that the temperature of the "detection position" of each heated corn reaches the above setting.

[0076] Furthermore, in principle, there is no particular restriction on the steam pressure, heating time, etc. during water vapor heating. In some specific embodiments, from the perspective of easier operation or easier achievement of the above-mentioned temperature conditions, the water vapor pressure can be below 0.6 bar, preferably above 0.2 bar; the heating time can be above 10 min, preferably 12 to 20 min.

[0077] (Freezing treatment steps)

[0078] In the freezing treatment step of the present invention, the corn heated by steam in the first heat treatment is frozen. In some preferred embodiments, the corn heated by steam is adjusted to room temperature (or the temperature at the measured position is lower than 40° C.) before the freezing treatment step of the present invention is performed. There is no particular limitation on the method of such temperature adjustment, for example, water spraying can be used to assist in adjusting the temperature of the corn.

[0079] Further, for the conditions of the freezing treatment, the corn can be cooled to a temperature of -20°C or below at the detection position under the condition of a cooling rate of 1°C / min or above. In some preferred embodiments, the cooling rate can be 1.0-1.5°C / min. If the cooling rate is too slow, the change in the internal structure of the corn kernels by freezing is not obvious; in addition, if the cooling rate is too fast, it is easy to cause a large temperature difference between the surface of the corn and the inside of the corn cob, which causes inconvenience to temperature control. In some other preferred embodiments, the temperature is lowered so that the temperature of the detection position is -22 to -27°C, for example, -25°C, -26°C, etc. If the temperature is too high, the change in the internal structure of the corn kernels by freezing is not obvious, and if the temperature is too low, it is easy to cause frostbite on the surface of the corn.

[0080] Similarly, regarding the above-mentioned "detection position" setting, if multiple corns are processed at one time, it is necessary to ensure that the temperature of the "detection position" of each frozen corn reaches the above setting.

[0081] (Second Heat Treatment)

[0082] In the second heat treatment of the present invention, the frozen corn is boiled in water. It should be noted that the boiling process of the present invention is carried out under relatively mild conditions in order to suppress the loss of nutrients or damage to the surface of the corn.

[0083] In some preferred embodiments, the boiling treatment of the present invention can be directly carried out after the freezing treatment, that is, the corn that has been frozen and has a relatively low temperature is directly boiled.

[0084] For the boiling treatment, the temperature at the detection position of the corn is mainly restored to above 35°C, preferably, it can be restored to 36-42°C, for example, to 38°C or 40°C. Similarly, for the setting of the above-mentioned "detection position", if multiple corns are processed at one time, it is necessary to ensure that the temperature of the "detection position" of each boiled corn reaches the above setting.

[0085] The temperature of the hot water used in boiling water can usually be controlled within the range of 97°C, preferably within the range of 87-95°C, so that the corn is heated in a relatively gentle manner. In some specific embodiments, although there is no particular requirement for the heating rate of the corn, in this process, the heating rate of the corn in the boiling water can be controlled within the range of 5-10°C / min.

[0086] In addition, there is no particular limitation on the boiling time in principle as long as the above conditions are met, and it can usually be 4 to 10 minutes.

[0087] The boiled corn may be cooled (eg, cooled to room temperature) to facilitate subsequent processing.

[0088] (Seasoning steps)

[0089] The seasoning step of the present invention can add seasoning to the surface of the corn after the second heat treatment.

[0090] For the step of imparting seasoning, the corn can be directly coated on the surface of the boiled corn. In some preferred embodiments, the imparting seasoning can be performed in conjunction with the step of vacuum packaging. For example, the seasoning can be added before the corn is placed in the package and not yet vacuum sealed.

[0091] In principle, there is no particular limitation on such seasoning, which can be in powder, granular or semi-solid form. In some preferred embodiments, the seasoning can be various sauces, such as barbecue sauce, spicy sauce, mustard sauce, cheese sauce, meat sauce and other flavor sauces, etc. In a more preferred embodiment of the present invention, the seasoning is barbecue sauce.

[0092] (Other steps)

[0093] After the seasoning step, other optional steps may be performed, such as a vacuum packaging step, a heat sterilization step, etc.

[0094] In principle, there is no particular limitation on the vacuum packaging step, and the vacuum packaging machine can be used after the seasoning is applied. After vacuum packaging, the seasoning can be substantially evenly attached to the surface of the corn (under pressure), and preferably, it can be stored for a certain period of time (e.g., 0.5 to 3 hours) to allow the seasoning to better penetrate into the corn kernels. Such a treatment can achieve an effect similar to pickling.

[0095] For the step of heat sterilization, the packaged corn can be heated after vacuum packaging, and the sterilization temperature can be, for example, 110-125° C., and the time can be controlled to be more than 20 minutes, for example, 20-40 minutes. Heat sterilization after vacuum packaging can not only sterilize, but also promote the high-temperature flavoring of corn and prevent the loss of flavor of seasoning. Therefore, in the present invention, the sterilization and heating flavoring of the product are combined into one process to reduce costs, which is also different from the process of existing flavor products.

[0096] Afterwards, the final packaged product can be stored at room temperature or frozen. Moreover, even under the condition of storage at room temperature, the shelf life of the corn of the present invention can be no less than 6 months.

[0097] (List of typical solutions)

[0098] In some typical embodiments of the present invention, the processing process may be as follows:

[0099] The corn raw materials are harvested, peeled, selected, cut into sections, cleaned with bubbles, heated with steam once, frozen, cleaned with high-pressure rollers, heated with water twice, cooled, beaten, made with vacuum back-pressure sauce, sealed and marinated, sterilized at high temperature, cooled and stored;

[0100] During the harvesting of corn raw materials, the corn kernels are inspected and graded according to the harvesting standards in terms of fullness, cob size, color, maturity, and foreign matter.

[0101] Peeling: Use corn peeling machine to peel the corn raw materials that have passed the acceptance inspection to remove the corn husk and corn silk;

[0102] Cutting: Use a corn cutter to place the corn into the cutter groove according to the length requirements in the production process execution document, and cut it. After cutting, remove unqualified samples;

[0103] Bubble cleaning: Soak corn cobs in water, spray water from the upper sprinkler head, and use bubbles at the bottom of the cleaning pool to clean impurities in the corn gaps. Foreign objects such as corn silk floating on the water surface are removed through a circulating filtration system;

[0104] Primary steam heating: Place the cleaned corn in a steam cabinet and heat the fresh corn at high temperature for the first time to change the permeability of the epidermis. The cabinet test constant temperature is 100-115°C, the heating time is >10min, the steam pressure is <0.6bar, and the heating rate is 3.75-6°C / min.

[0105] Freezing treatment: After one heating, the corn is sprayed to cool, and the temperature at the detection position reaches <40℃. The corn is treated by low-temperature freezing to change its structure. The corn is transported to the quick-freezing tunnel, and the tunnel temperature is ≤-27℃. This temperature can reduce nutrient loss and change the corn structure. The quick-freezing time is 37 to 55 minutes, and the freezing rate is 1 to 1.2℃ / min.

[0106] Secondary boiling and heating: The quick-frozen corn passes through a conveyor belt and enters a heating pool. The water temperature is 87-97°C and the heating time is ≥4 minutes. At this time, the corn kernels are soft and the sauce is easy to absorb. The heating rate is 6-9°C / min.

[0107] Cooling: The heated corn is transported to a cooling pool with a water temperature of ≤20°C and cooled to a temperature of 15-50°C at the detection location.

[0108] Material beating: The material beating head is a self-made filling head. The sauce is extracted by a vacuum pump. The pumping time is 3 to 9 seconds. When beating, the two discharge pipes are rotated at a speed of 95-145 rpm.

[0109] Vacuum back pressure sauce: Under the action of vacuum pressure, the vacuum pressure is <0.2MPa, which can push the sauce to be evenly distributed on the surface of the corn.

[0110] Sealed marinating: Vacuum back pressure will evenly distribute the sauce on the surface of the corn, and then heat seal it. The marinating time is ≥ 1 hour.

[0111] High temperature sterilization: After the sample is pickled, it is heated at 121℃ for ≥20min, and then cooled quickly until the temperature at the detection position is less than 20℃. The resulting corn product can be stored at room temperature for 6 months.

[0112] Example

[0113] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0114] Example 1

[0115] Raw material harvesting - peeling - sorting - cutting - air bubble cleaning - primary steam heating - quick freezing - high pressure roller cleaning - secondary boiling and heating - cooling - beating - sealed marinating - vacuum back pressure sauce - high temperature heating - storage;

[0116] Raw material harvesting: Inspect and grade the corn kernels based on harvesting standards, such as their fullness, cob size, color, maturity, and foreign matter.

[0117] Peeling: Use corn peeling machine to peel the corn raw materials that have passed the acceptance inspection to remove the corn husk and silk;

[0118] Cutting: Use a corn cutter to cut the corn into 8cm pieces according to the production process requirements. Place the corn into the cutter groove and cut it. Remove unqualified samples after cutting.

[0119] Bubble cleaning: Soak corn cobs in water, spray water from the upper sprinkler head, and use bubbles at the bottom of the cleaning pool to clean impurities in the corn gaps. Foreign objects such as corn silk floating on the water surface are removed through a circulating filtration system;

[0120] Steam heating: Place the cleaned corn in a steam cabinet and heat the fresh corn for the first time at high temperature to change the permeability of the epidermis. The cabinet test constant temperature is 111°C, the heating time is 18 minutes, the steam pressure is 0.42 bar, and the heating rate is about 4.7°C / min. The temperature change at the detection position is shown in the attached figure. Figure 1 Changes:

[0121] Freezing: After heating once, the corn is sprayed and cooled, and the temperature at the detection position reaches 28°C. The corn is processed by low-temperature freezing to change its structure. The corn is transported to the quick-freezing tunnel, and the tunnel temperature is -28°C. This temperature can reduce nutrient loss and change the structure of corn. The quick-freezing time is 37 minutes, and the freezing rate is about 1.08°C / min. The time and temperature of the detection position during the freezing process are shown in the attached figure. Figure 2 ;

[0122] Secondary boiling and heating: The quick-frozen corn passes through the conveyor belt and enters the heating pool. The water temperature is 97°C and the heating time is 4 minutes. At this time, the corn kernels are soft and the sauce is easy to taste. The heating rate is about 8.4°C / min. The time and temperature of the detection position during boiling and heating are shown in the attached figure. Figure 3 ;

[0123] Cooling: The heated corn is transported to the cooling pool with a water temperature of 18°C ​​and cooled to a temperature of 46°C at the detection location.

[0124] Filling: The filling head is a homemade filling head, and the sauce is extracted by a vacuum pump, and the pumping time is 9s.

[0125] Vacuum back pressure sauce: Under the action of vacuum pressure, the vacuum pressure is 0.13MPa, which can push the sauce to be evenly distributed on the surface of the corn.

[0126] Sealed marination: Vacuum back pressure will evenly distribute the sauce on the surface of the corn, and then heat seal it. The marination time is 1.5 hours.

[0127] High temperature heating: After the sample is sealed, heat it at 121℃ for 20 minutes, then cool it down quickly to 18℃ at the detection position. The product can be stored at room temperature for 6 months.

[0128] Example 2

[0129] Same as Example 1, except:

[0130] Primary steam heating: Place the cleaned corn in a steam cabinet and heat the fresh corn at high temperature for the first time to change the permeability of the epidermis. The cabinet test constant temperature is 115°C, the heating time is 18 minutes, the steam pressure is 0.39 bar, and the heating rate is about 5.9°C / min.

[0131] Freezing: After heating once, the corn is sprayed and cooled. The temperature at the detection position reaches 31°C. The corn is processed by low-temperature freezing to change its structure. The corn is transported to the quick-freezing tunnel. The tunnel temperature is -29°C. This temperature can reduce nutrient loss and change the structure of corn. The quick-freezing time is 51 minutes, and the freezing rate is about 1.18°C / min.

[0132] Secondary boiling and heating: The quick-frozen corn passes through the conveyor belt and enters the heating pool. The water temperature is 89°C and the heating time is 8 minutes. At this time, the corn kernels are soft and the sauce is easy to absorb. The heating rate is about 8°C / min

[0133] Filling: The filling head is a homemade filling head, and the sauce is extracted by a vacuum pump with a pumping time of 3s.

[0134] Vacuum back pressure sauce: Under the action of vacuum pressure, the vacuum pressure is 0.11MPa, which can push the sauce to be evenly distributed on the surface of the corn.

[0135] Example 3

[0136] Same as Example 1, except:

[0137] One-time steam heating: Place the cleaned corn in a steam cabinet and heat the fresh corn at high temperature for the first time to change the permeability of the epidermis. The cabinet is set at a constant temperature of 100°C, a heating time of 13 minutes, a steam pressure of 0.44 bar, and a heating rate of about 4.17°C / min.

[0138] Freezing: After heating once, the corn is sprayed and cooled. The temperature at the detection position reaches 35°C. The corn is processed by low-temperature freezing to change its structure. The corn is transported to the quick-freezing tunnel. The tunnel temperature is -27°C. This temperature can reduce nutrient loss and change the structure of corn. The quick-freezing time is 55 minutes, and the freezing rate is about 1.05°C / min.

[0139] Secondary water bath heating: The quick-frozen corn passes through the conveyor belt and enters the heating pool. The water temperature is 87°C and the heating time is 9 minutes. At this time, the corn kernels are soft and the sauce is easy to absorb. The heating rate is about 6.3°C / min

[0140] Filling: The filling head is a homemade filling head, and the sauce is extracted by a vacuum pump with a pumping time of 8s.

[0141] Vacuum back pressure sauce: Under the action of vacuum pressure, the vacuum pressure is 0.15MPa, which can push the sauce to be evenly distributed on the surface of the corn.

[0142] Example 4

[0143] Same as Example 1, except:

[0144] Primary steam heating: Place the cleaned corn in a steam cabinet and heat the fresh corn at high temperature for the first time to change the permeability of the epidermis. The cabinet test constant temperature is 115°C, the heating time is 18 minutes, the steam pressure is 0.46 bar, and the heating rate is about 5.9°C / min.

[0145] Filling: The filling head is a homemade filling head, and the sauce is extracted by a vacuum pump, and the pumping time is 9s.

[0146] Vacuum back pressure sauce: Under the action of vacuum pressure, the vacuum pressure is 0.12MPa, which can push the sauce to be evenly distributed on the surface of the corn.

[0147] Comparative Example 1

[0148] Compared with Example 1, Comparative Example 1 removes the secondary boiling heating and adopts a heating-freezing process. Since the surface temperature of the corn is relatively low, the sauce solidifies after being beaten in and cannot be evenly distributed on the surface of the corn.

[0149] Comparative Example 2

[0150] Compared with Example 1, Comparative Example 2 removed the first steam heating and adopted the freezing-boiling heating process. The sensory evaluation of the product was not the best and the flavor was poor. This may be because the first steam heating not only changed the texture, but also killed the enzyme substances in the fresh corn that can improve the flavor of corn.

[0151] Comparative Example 3

[0152] The existing boiling process is simulated to replace the boiling-heating-freezing-boiling-heating process to determine the impact on corn nutrients.

[0153] Boiling: The water temperature in the heating pool rises to 100°C and is in a boiling state. Fresh corn is placed in the heating pool and boiled for 40 minutes.

[0154] Comparative Example 4

[0155] Compared with Example 1, the difference is that the fresh corn is frozen without being heated twice and then returned to room temperature, and the distribution of the sauce after being added is observed.

[0156] Comparative Example 5

[0157] Compared with Example 1, the temperature of the corn detection position during the primary steam heating was controlled at 103°C. As a result, bubbles appeared at a part of the corn surface after the primary steam treatment, and the experiment was stopped.

[0158] Product quality evaluation and comparison

[0159] The products were evaluated according to the following scoring method as shown in Table 1.

[0160] Table 1 Sensory evaluation standards

[0161]

[0162] The comparison of corn structures before the beating step of Example 1 and each comparative example is shown in Table 2 below:

[0163] Table 2 Corn structure status table

[0164]

[0165] The comparison of the nutrient content of the product of Example 1 and the untreated fresh corn (raw material) is shown in Table 3 below:

[0166] Table 3 Nutrient determination table

[0167] sample Fresh corn samples Example 1 Protein (g / 100g) 4.9 4.8 Fat (g / 100g) 1.6 1.5

[0168] The sensory evaluation comparison of the embodiment and the comparative example is shown in Table 4 below:

[0169] Table 4 Comparison of sensory evaluation

[0170]

[0171] Product packability evaluation :

[0172] The vacuum packaging conditions in Example 1, Comparative Example 1 and Comparative Example 4 were investigated. The conditions after vacuum packaging are respectively shown in Figure 5 a, b and c in .

[0173] Among them, the packaging result of Example 1 shows that the sauce is evenly distributed. Figure 5 a; in Comparative Example 1, since no secondary heating was performed after freezing, the surface temperature of the corn was unevenly distributed, which in turn caused uneven distribution of the sauce, see Figure 5 b; the corn in Comparative Example 4 was only frozen, so the surface was rough, and there was a blank part on the surface, which was not covered by the sauce, see Figure 5 c.

[0174] It should be noted that, although the technical solution of the present invention is introduced with specific examples, those skilled in the art will appreciate that the present invention should not be limited thereto.

[0175] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for processing seasoned corn, characterized in that: The method comprises: A pretreatment step, wherein the pretreatment step includes peeling the corn; The first heat treatment step is to heat the pretreated corn with water vapor so that the temperature at the corn detection position reaches 90° C. to 100° C.; A freezing treatment step, cooling and freezing the corn obtained by the first heating treatment so that the temperature at the corn detection position reaches below -20°C, and the cooling rate is above 1°C / min; A second heat treatment step of boiling the frozen corn in water to heat the corn so that the temperature at the detection position of the corn reaches above 35° C.; The step of seasoning and packaging is to season the corn after the second heat treatment step and then package it. Among them, the detection position of the corn is determined in the following way: there are two cross-sections in the axial direction of the corn, and there is an equivalent circle at each of the two interfaces. The cross-section with the larger area of ​​the equivalent circle is taken as the reference, and the detection position is 1.5cm±2mm inward in the axial direction of the corn cob from the center of the equivalent circle where the cross-section is located.

2. The method according to claim 1, characterized in that The corn is a whole corn or corn cut into segments, and the length of the corn in the axial direction of the corn cob is more than 3 cm.

3. The method according to claim 1 or 2, characterized in that: In the first heat treatment step, the pressure of the water vapor is below 0.6 bar.

4. The method according to any one of claims 1 to 3, characterized in that: The cooling rate is 1-2°C / min; the temperature at the corn detection position is above -27°C.

5. The method according to any one of claims 1 to 4, characterized in that: Before the freezing treatment step, the temperature at the corn detection position is adjusted to 20-35°C.

6. The method according to any one of claims 1 to 5, characterized in that: In the second heat treatment step, the water temperature is 87-97°C; the temperature at the corn detection position is 35-42°C.

7. The method according to any one of claims 1 to 6, characterized in that: The second heat treatment step is directly performed after the freezing treatment step.

8. The method according to any one of claims 1 to 7, characterized in that: The packaging is vacuum packaging.

9. The method according to claim 8, characterized in that The vacuum-packed corn is subjected to heat sterilization treatment.

10. A vacuum-packed corn product with sauce, characterized in that: The corn product is prepared by the method according to any one of claims 1 to 9, and the sauce includes one or more of barbecue sauce, spicy sauce, and cheese sauce.

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