Vegetable crispening agent, preparation method and application thereof

Abstract

The present invention discloses a vegetable crispening agent, a preparation method, and an application thereof. The vegetable crispening agent is made from the following raw materials in the following mass percentages: 40% to 50% sodium hexametaphosphate, 30% to 38% calcium chloride, 12% to 19% sodium tripolyphosphate, 1% to 4% sodium alginate, and 1% to 5% calcium ascorbate, with the sum of the mass percentages of the raw materials being 100%. The components of the crispening agent prepared in the present invention fully exert a synergistic effect in their specific proportions, exhibiting a significant crispening effect, maximally maintaining the texture of vegetables, and having important value for crispening vegetables in the field of pre-prepared dishes.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and in particular relates to a vegetable crispening agent and a preparation method and application thereof. Background Art

[0002] Currently, pre-prepared vegetable dishes sold on the market fall into four main categories: ready-to-eat vegetables (such as light salads and dried vegetables), ready-to-heat vegetables (such as frozen fresh vegetables), ready-to-cook vegetables (such as dumplings and wonton fillings), and ready-to-serve vegetables (such as fresh-cut vegetables). Pre-prepared and semi-finished vegetables can reduce the loss of fresh agricultural products during multi-level circulation and transportation, providing consumers with more diverse and convenient food solutions. Therefore, research on the quality control of pre-prepared vegetable dishes is of great significance to the high-quality development of the entire pre-prepared meal industry.

[0003] Food texture is a crucial factor influencing consumer sensory perception, encompassing both the touch of food with the hands or fingers and the overall sensation after ingestion, including the softness, firmness, consistency, crispness, and smoothness experienced during chewing. Changes in vegetable texture are associated with alterations in the intercellular material that makes up the cell wall, such as the degradation of hemicellulose and the decomposition and dissolution of pectin, which results in a decrease in firmness. Pectin degradation is particularly prone to occur and has a more significant impact on firmness. Pectin degradation is a complex, enzyme-catalyzed process influenced by factors such as temperature, pH, and metal ions. Similar to the ripening and aging of fruit, damaged and ruptured vegetable cells during cutting or heating release enzymes such as PME and PG. Under the action of enzymes, acids, alkalis, or high temperatures, water-insoluble PP (proto-pectin) degrades into soluble pectin or pectic acid, which is further broken down into small molecules such as D-Gal-A. This degrades the binding function that maintains the texture, resulting in a softening of the vegetable and a decrease in firmness.

[0004] Related technologies disclose some vegetable crispening agents. For example, the document "Study on Optimization of Pretreatment Conditions for Preserving the Crispness and Greenness of Shanghai Greens" discloses that treating Shanghai greens with 0.6% (w / v) calcium chloride results in moderate crispness after blanching. The document "Optimization of Color Preservation and Crispness Preservation of Mustard Greens in Pre-prepared Dishes" discloses the optimal crispness-preserving process: soaking mustard greens at 0.24% (m / m) calcium chloride for 30 minutes, effectively maintaining their crisp and tender texture.

[0005] With the rapid development of the pre-prepared food industry, it is particularly important to develop a crispening agent with safe ingredients and significant crispening effect. Summary of the Invention

[0006] The purpose of the present invention is to provide a vegetable crispening agent with significant crispening effect and its preparation method and application, which can be applied to various fields of pre-prepared dishes (frozen cooking packages, refrigerated delivery of vegetables), etc.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The invention provides a vegetable crispening agent, which is prepared from the following raw materials in percentage by mass: 40% to 50% of sodium hexametaphosphate, 30% to 38% of calcium chloride, 12% to 19% of sodium tripolyphosphate, 1% to 4% of sodium alginate, and 1% to 5% of calcium ascorbate, wherein the total percentage by mass of the raw materials is 100%.

[0009] Preferably, the raw materials and their mass percentages are: sodium hexametaphosphate 43% to 47%, calcium chloride 33% to 38%, sodium tripolyphosphate 13% to 17%, sodium alginate 2% to 4%, and calcium ascorbate 1% to 3%, and the sum of the mass percentages of the raw materials is 100%.

[0010] More preferably, the raw materials and their mass percentages are: 45% sodium hexametaphosphate, 35% calcium chloride, 15% sodium tripolyphosphate, 3% sodium alginate, and 2% calcium ascorbate.

[0011] The present invention also provides a preparation method of the vegetable crispening agent, comprising the following steps: uniformly mixing sodium hexametaphosphate, calcium chloride, sodium tripolyphosphate, sodium alginate and calcium ascorbate according to mass percentage to prepare the vegetable crispening agent.

[0012] The present invention also provides the use of the above-mentioned vegetable crispening agent in crispening pre-prepared vegetables. The vegetable crispening agent is added to water in an amount of 0.1-0.2wt% to prepare a crispening liquid. The washed and cut vegetables are immersed in the crispening liquid for crispening treatment, and then blanched. After processing according to conventional processes, the vegetables are stored and preserved.

[0013] Furthermore, the embrittlement treatment is carried out at a temperature of 4° C. and for a time of 15 minutes.

[0014] Furthermore, the material-liquid ratio of the vegetables to the crispening liquid is 1:5.

[0015] Furthermore, when the desired vegetables need to be crispened and color protected, the method also includes the step of placing the vegetables in a color protection liquid to protect the color after blanching; the color protection liquid is prepared by adding a color protection agent into water at an addition amount of 0.2-0.3wt%; the soaking treatment temperature is 4°C, the time is 15 minutes, and the material-liquid ratio is 1:5.

[0016] Furthermore, the color protection agent is 50% to 60% green tea extract, 6% to 12% calcium ascorbate, 16% to 28% sodium citrate, 7% to 15% sodium D-isoascorbate, and 0.5% to 3% sodium chloride, with the sum of the mass percentages of the raw materials being 100%. Preferably, the color protection agent is composed of 60% green tea extract, 8% calcium ascorbate, 20% sodium citrate, 10% sodium D-isoascorbate, and 2% sodium chloride.

[0017] Furthermore, the crispening agent is recycled, and the steps are as follows: the washed and cut vegetables are soaked in the crispening liquid for crispening treatment, and the crispening liquid can be repeatedly soaked in two rounds of vegetables; then 0.02% of the crispening agent is added to the crispening liquid after soaking the vegetables twice (the supplementary amount is 0.02% of the weight of the entire aqueous solution) and the water weight is replenished (equivalent to the weight of the water before soaking); the material is replenished every two rounds of soaking, and the total number of soaking times does not exceed 6 rounds.

[0018] The present invention has the following advantages and beneficial effects:

[0019] (1) The components of the crispening agent prepared in the present invention fully exert their synergistic effect at their specific proportions, have a significant crispening effect, and can maintain the texture of vegetables to the maximum extent, which is of great value to the crispening of vegetables in the field of pre-prepared dishes.

[0020] (2) The sodium hexametaphosphate, calcium chloride, sodium tripolyphosphate, sodium alginate and calcium ascorbate used in the present invention are safe and non-toxic, and can ensure the safety of the pre-prepared dish products.

[0021] (3) The sodium hexametaphosphate, calcium chloride, sodium tripolyphosphate, sodium alginate and calcium ascorbate used in the present invention do not contain chemical and irritating odors and will not mask the unique aroma of the vegetables themselves. In addition, they also have a certain preservation function. After the vegetables have been crispened, they can be stored in hot, cold and frozen storage for a period of time without losing the fragrance of the vegetables themselves.

[0022] (4) The preparation method and application method of the present invention are simple and easy to implement, and are conducive to industrial production and use. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0024] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0025] Unless otherwise defined, scientific and technical terms used herein have the same meanings as commonly understood by those skilled in the art.

[0026] The following are specific embodiments and comparative examples of the present invention. It should be further explained that the following comparative examples are not prior art and are only provided for comparison with the embodiments and are not intended to limit the present invention.

[0027] Example 1

[0028] A method for preparing a vegetable crispening agent comprises the following steps:

[0029] 480 g of sodium hexametaphosphate, 310 g of calcium chloride, 180 g of sodium tripolyphosphate, 15 g of sodium alginate, and 15 g of calcium ascorbate were mixed uniformly to prepare a composite embrittlement agent.

[0030] Example 2

[0031] A method for preparing a vegetable crispening agent comprises the following steps:

[0032] 450 g of sodium hexametaphosphate, 350 g of calcium chloride, 150 g of sodium tripolyphosphate, 30 g of sodium alginate, and 20 g of calcium ascorbate were mixed uniformly to prepare a composite embrittlement agent.

[0033] Example 3

[0034] A method for preparing a vegetable crispening agent comprises the following steps:

[0035] 420 g of sodium hexametaphosphate, 370 g of calcium chloride, 120 g of sodium tripolyphosphate, 40 g of sodium alginate, and 50 g of calcium ascorbate were mixed uniformly to prepare a composite embrittlement agent.

[0036] Comparative Example 1

[0037] 415 g of sodium hexametaphosphate, 500 g of calcium chloride, 80 g of sodium tripolyphosphate and 5 g of sodium alginate were mixed uniformly to prepare a vegetable crispening agent.

[0038] Comparative Example 2

[0039] 380 g of sodium hexametaphosphate, 520 g of calcium chloride, 60 g of sodium tripolyphosphate and 40 g of calcium ascorbate were mixed uniformly to prepare a vegetable crispening agent.

[0040] Comparative Example 3

[0041] Mix 450 g of sodium hexametaphosphate, 450 g of calcium chloride and 100 g of sodium tripolyphosphate to obtain a vegetable crispening agent.

[0042] Comparative Example 4

[0043] 420 g of sodium hexametaphosphate, 480 g of calcium chloride and 100 g of sodium alginate were mixed evenly to prepare a vegetable crispening agent.

[0044] Comparative Example 5

[0045] 120 g of sodium hexametaphosphate, 150 g of calcium chloride, 670 g of sodium tripolyphosphate, 10 g of sodium alginate and 50 g of calcium ascorbate were mixed uniformly to prepare a vegetable crispening agent.

[0046] Comparative Example 6:

[0047] 100 g of sodium hexametaphosphate, 130 g of calcium chloride, 630 g of sodium tripolyphosphate, 25 g of sodium alginate and 115 g of calcium ascorbate were mixed uniformly to prepare a vegetable crispening agent.

[0048] Comparative Example 7:

[0049] 480 g of sodium hexametaphosphate, 310 g of calcium chloride, 180 g of sodium tripolyphosphate, 15 g of trehalose and 15 g of calcium ascorbate were mixed uniformly to prepare a composite embrittlement agent.

[0050] Comparative Example 8

[0051] 480 g of sodium hexametaphosphate, 310 g of calcium gluconate, 180 g of sodium tripolyphosphate, 15 g of sodium alginate, and 15 g of calcium ascorbate were mixed uniformly to prepare a composite embrittlement agent.

[0052] Comparative Example 9

[0053] Mix 480 g of sodium hexametaphosphate, 310 g of calcium chloride, 180 g of sodium tripolyphosphate, 15 g of sodium alginate, and 15 g of calcium citrate to obtain a composite embrittlement agent.

[0054] Comparative Example 10

[0055] Mix 480 g of sodium hexametaphosphate, 310 g of calcium gluconate, 180 g of sodium tripolyphosphate, 15 g of trehalose, and 15 g of calcium citrate to obtain a composite embrittlement agent.

[0056] Comparative Example 11: Sodium Hexametaphosphate

[0057] Comparative Example 12: Calcium Chloride

[0058] Comparative Example 13: Sodium tripolyphosphate

[0059] Comparative Example 14: Sodium Alginate

[0060] Comparative Example 15: Calcium Ascorbate

[0061] Comparative Example 16: Blank Group

[0062] Comparative Example 17: Freshly Stir-fried Dishes

[0063] Application Experiment 1

[0064] Green peppers, which are frequently used in pre-prepared meal packages, were selected as the vegetable raw materials for the experiment.

[0065] The embrittlement agent was added into water at an addition amount of 0.1 wt% to prepare an embrittlement liquid;

[0066] The pre-prepared food package is prepared by washing and cutting the green peppers → soaking them in a crispening agent to make them crispy → blanching → removing them from the water and draining them → frying them according to the process → packaging and storing them. The specific application steps of the embodiment of the present invention and the comparative example are as follows:

[0067] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0068] S2: Immediately pour the cleaned and cut green pepper pieces into the prepared 4°C crispening liquid to make them crisp; the soaking time is 15 minutes, and the material-liquid ratio is (vegetable: water = 1:5);

[0069] S3: Prepare water in a pot and boil until the water temperature reaches 90°C, then add the green pepper pieces and blanch them for 15 seconds before removing them;

[0070] S4: Remove and drain for later use;

[0071] S5: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0072] S6: The fished-out dishes are stored and preserved under different conditions.

[0073] New stir-fry dishes: The specific steps are:

[0074] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0075] S2: Prepare water in a pot and boil until the water temperature reaches 90°C. Add the green pepper pieces and blanch them for 15 seconds before removing them from the pot.

[0076] S3: Drain and set aside;

[0077] S4: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0078] S5: Place the fished-out dishes on a plate.

[0079] The finished product of stir-fried green pepper and meat was stored at 60°C for 4 hours, frozen at -18°C for 60 days, and refrigerated at 4°C for 14 days (the three storage methods were independently tested and evaluated). The crispening effect of the examples and comparative examples on the green peppers in the cooking package was tested respectively, and the examples and comparative examples were subjected to sensory evaluation according to the evaluation criteria of Table 1. The results are shown in Tables 2-1, 2-2 and 2-3.

[0080] Table 1 Sensory evaluation standards for brittleness effect

[0081]

[0082] Table 2 - Brittleness enhancement effect of each embodiment and comparative example after hot storage at 160℃ for 4h

[0083]

[0084]

[0085] Table 2 - Brittleness enhancement effect of each embodiment and comparative example after refrigeration at 24°C for 14 days

[0086]

[0087]

[0088] Table 2-3-18℃ frozen for 60 days after each embodiment and comparative example embrittlement effect

[0089]

[0090] As shown in Tables 2-1, 2-2, and 2-3, the composite crispening agent prepared in Examples 1-3 showed a good crispening effect after being treated with green peppers after being stored hot, refrigerated, and frozen for a period of time, and the vegetable crispness scores in the sensory evaluation were all above 80 points. Compared with Comparative Examples 1, 2, 3, 4, 5, and 6, the sensory scores of vegetable crispness under the component conditions of Examples 1-3 were significantly better than those of the above comparative examples. Comparative Examples 7, 8, 9, and 10 were partially replaced with raw materials with similar functions. The results showed that only under the conditions of the said crispening agent components could the sensory scores of vegetable crispness be significantly better than those of the other comparative examples. The crispness of green peppers treated with other single crispening agents was also alleviated to a certain extent. However, the green peppers treated with the composite crispening agent had a higher sensory score of crispness after being stored hot at 60°C for 4h, refrigerated at 4°C for 14d, and frozen at -18°C for 60d. At this time, the green peppers had no odor and their original fragrance was also maintained. In addition, comparative example 16 (blank group) shows extremely low sensory scores under three storage conditions, indicating that if no brittle agent is added, the organoleptic quality of vegetables after hot storage, refrigeration and freezing will decline significantly. Comparative example 17 is a dish made by imitating a family. It is compared with each embodiment as a standard sample. It is found that the sensory score of Example 2 is closer to comparative example 17 (standard sample). This result shows that the composite brittle agent has a good brittle effect, and there is a good synergistic effect between each effective ingredient. Only mixing several of them cannot achieve the best effect, and the effect of adding ratio on the brittle effect is also more significant. The possible reason is that the blank group causes the pectin in the cell wall to decompose into pectic acid due to the influence of factors such as temperature during storage, the connecting force between the cell walls is weakened, and the cells lose adhesion, causing the vegetables to soften and the texture to become soft and rotten. The other raw materials selected by other comparative examples or the different proportions under the same component are not significant to compensate for the decline in vegetable brittleness caused under unfavorable conditions such as temperature. The selected embrittlement agent can first penetrate into the gaps between cell tissues and form an irreversible gel with the metal ions that penetrate later, thereby strengthening the strength of the tissue gaps and playing a role in strengthening the "cytoskeleton".

[0091] Tables 3-1, 3-2 and 3-3 are the texture analyzer test data of green peppers under three different storage conditions: The measurements were made using a texture analyzer, with a P / 2E probe used to measure the upper, middle and lower parts of the inner peel of the green pepper blocks before and after hot storage, before and after refrigeration, and before and after freezing and thawing. The results were averaged, with the pre- and post-test speeds being 2.0 mm / s, the test speed being 1.0 mm / s, the puncture deformation being 75%, the trigger force being 5 g, and the inner fruit hardness being measured.

[0092] Table 3 - Brittleness enhancement effect of each embodiment and comparative example after hot storage at 160℃ for 4h (texture analyzer)

[0093]

[0094]

[0095] Table 3 - Brittleness effect of each embodiment and comparative example after refrigeration at 24°C for 14 days (texture analyzer)

[0096]

[0097]

[0098] Table 3-3 Brittleness effect of each example and comparative example after freezing at -18℃ for 60 days (texture analyzer)

[0099] Hardness (0d) Hardness (60d) Example 1 14.5N 10.4N Example 2 14.7N 11.3N Example 3 14.5N 9.9N Comparative Example 1 14.4N 6.4N Comparative Example 2 14.1N 6.2N Comparative Example 3 14.4N 7.2N Comparative Example 4 14.2N 6.8N Comparative Example 5 14.7N 5.4N Comparative Example 6 14.8N 5.7N Comparative Example 7 14.6N 7.5N Comparative Example 8 14.5N 7.8N Comparative Example 9 14.6N 7.2N Comparative Example 10 14.4N 7.1N Comparative Example 11 14.1N 3.8N Comparative Example 12 14.2N 4.7N Comparative Example 13 14.2N 4.1N Comparative Example 14 14.4N 3.7N Comparative Example 15 14.4N 4.9N Comparative Example 16 14.1N 0.8N Comparative Example 17 14.3N -

[0100] As shown in Table 3-1, Table 3-2 and Table 3-3, the composite brittleness enhancer prepared in Example 1-3 treats the green peppers and shows a good brittleness effect after hot storage, cold storage and freezing for a period of time, which is significantly better than Comparative Examples 1-15. The texture analyzer measurement results are shown in the table above. In addition, Comparative Example 16 (blank group) shows extremely low hardness values ​​under three storage conditions, indicating that if no brittleness enhancer is added, the vegetables will show a very obvious decline in brittleness after hot storage, cold storage and freezing. Comparative Example 17 is a dish made by imitating a family. It is compared with each embodiment as a standard sample. It is found that the hardness value of Example 2 is closer to Comparative Example 17 (standard sample). This result shows that the composite brittleness enhancer has a good brittleness effect, and there is a good synergistic effect between the active ingredients. Simply mixing several of them cannot achieve the most effective effect, and the influence of the addition ratio on the brittleness effect is also more significant.

[0101] Application Experiment 2

[0102] The embrittlement agent is added to water in an amount of 0.1 wt% to prepare an embrittlement liquid; the color retaining agent is added to water in an amount of 0.2 wt%;

[0103] The embrittlement agent is prepared by uniformly mixing 450 g of sodium hexametaphosphate, 350 g of calcium chloride, 150 g of sodium tripolyphosphate, 30 g of sodium alginate and 20 g of calcium ascorbate to obtain a composite embrittlement agent.

[0104] The color preservative is 600 g of green tea extract, 80 g of calcium ascorbate, 200 g of sodium citrate, 100 g of sodium D-isoascorbate, and 20 g of sodium chloride.

[0105] Solution 1: Prepare the pre-cooked meal package by washing and cutting the green peppers → soaking them in a crispening agent to make them crisp → blanching → soaking them in a color preservative to protect their color and then draining them → stir-frying them according to the process → packaging and storing them.

[0106] Option 2: Prepare the pre-cooked meal package by washing and cutting the green peppers → soaking them in crispening agents and color preservatives to enhance crispness and color preservation → blanching → removing and draining → frying the dishes according to the process → packaging and storage.

[0107] Option 3: Prepare the pre-cooked meal package by washing and cutting the green peppers → blanching → soaking them in crispening agents and color preservatives to enhance crispness and color preservation → removing and draining → frying the dishes according to the process → packaging and storing.

[0108] The specific application steps of the embodiments of the present invention and the comparative examples are as follows:

[0109] Option 1:

[0110] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0111] S2: Immediately pour the cleaned and cut green pepper pieces into the prepared 4°C crispening liquid to make them crisp; the soaking time is 15 minutes, and the material-liquid ratio is (vegetable: water = 1:5);

[0112] S3: Prepare water in a pot and boil until the water temperature reaches 90°C, then add the green pepper pieces and blanch them for 15 seconds before removing them;

[0113] S4: After removing and draining the green peppers, immediately pour them into the color-protecting solution prepared in advance at 4°C to soak them in the solution; the soaking time is 15 minutes, and the material-liquid ratio is (vegetable: water = 1:5);

[0114] S5: Remove from water and drain for later use;

[0115] S6: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0116] S7: The fished-out dishes are stored and preserved under different conditions.

[0117] Option 2:

[0118] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0119] S2: Immediately pour the cleaned and cut green pepper pieces into the prepared 4°C crispening and color protection solution (accurately weigh 0.1wt% crispening agent and 0.2wt% color protection agent, mix them and add them to water) to soak for 15 minutes, with a material-liquid ratio of (vegetable:water=1:5);

[0120] S3: Prepare water in a pot and boil until the water temperature reaches 90°C, then add the green pepper pieces and blanch them for 15 seconds before removing them;

[0121] S4: Remove and drain for later use;

[0122] S5: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0123] S6: The fished-out dishes are stored and preserved under different conditions.

[0124] Option 3:

[0125] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0126] S2: Prepare water in a pot and boil until the water temperature reaches 90°C. Add the green pepper pieces and blanch them for 15 seconds before removing them from the pot.

[0127] S3: Immediately pour the green pepper pieces into the prepared 4°C crispening and color protection solution (accurately weigh 0.1wt% crispening agent and 0.2wt% color protection agent, mix them and add them to water) to soak for 15 minutes to enhance crispness and color protection; the material-liquid ratio is (vegetable: water = 1:5);

[0128] S4: Remove and drain for later use;

[0129] S5: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0130] S6: The fished-out dishes are stored and preserved under different conditions.

[0131] New stir-fry dishes: The specific steps are:

[0132] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0133] S2: Prepare water in a pot and boil until the water temperature reaches 90°C. Add the green pepper pieces and blanch them for 15 seconds before removing them from the pot.

[0134] S3: Drain and set aside;

[0135] S4: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0136] S5: Place the fished-out dishes on a plate.

[0137] The stir-fried green peppers and meat were stored at 60°C for 4 hours, -18°C for 60 days, and 4°C for 14 days to test the crispness of the green peppers in the cooking packs. The sensory evaluation and instrumental measurement of each storage method were performed on each method, along with the blank group and the newly stir-fried dishes. The results are shown in Tables 4-1, 4-2, 4-3 and Tables 5-1, 5-2, and 5-3.

[0138] Table 4-1 Crispness enhancement effect of each solution after 4h hot storage at 60℃ (sensory evaluation)

[0139] Vegetable crispness Vegetable aroma Vegetable aroma Vegetable odor Likeability Option 1 89.1 86.2 86.1 6.5 89.9 Option 2 83.3 83.7 84.2 9.7 78.1 Option 3 80.1 82.5 83.1 11.1 77.2 Blank group 11.3 9.8 9.7 30.5 16.9 New stir-fried dishes 92.1 89.3 90.3 3.1 92.7

[0140] Table 4-2 Crispness enhancement effect of each solution after 14 days of refrigeration at 4℃ (sensory evaluation)

[0141]

[0142] Table 4-3 Crispness enhancement effect of each solution after freezing at -18℃ for 60 days (sensory evaluation)

[0143]

[0144] Table 5-1 Brittleness enhancement effect of each solution after 4h hot storage at 60℃ (texture analyzer)

[0145] Hardness (0h) Hardness (4h) Option 1 14.5N 12.3N Option 2 14.4N 11.1N Option 3 14.3N 10.2N Blank group 14.6N 1.5N New stir-fried dishes 14.5N -

[0146] Table 5-2 Brittleness enhancement effect of each solution after 14 days of refrigeration at 4℃ (texture analyzer)

[0147] Hardness (0d) Hardness (14d) Option 1 14.6N 13.1N Option 2 14.4N 12.6N Option 3 14.5N 12.4N Blank group 14.4N 3.3N New stir-fried dishes 14.7N -

[0148] Table 5-3 Brittleness enhancement effect of each solution after freezing at -18℃ for 60 days (texture analyzer)

[0149] Hardness (0d) Hardness (60d) Option 1 14.5N 12.5N Option 2 14.4N 11.8N Option 3 14.3N 11.4N Blank group 14.6N 0.9N New stir-fried dishes 14.7N -

[0150] The sensory evaluation results in Tables 4-1, 4-2, and 4-3 and the texture analyzer data in Tables 5-1, 5-2, and 5-3 show that Option 1 outperforms Options 2 and 3 in sensory indicators such as crispness and hardness. Furthermore, when color protectants and crispening agents are used simultaneously on vegetables, applying color protection and crispening before blanching is more effective for maintaining crispness than applying color protection and crispening after blanching. This may be due to the high temperatures during blanching that affect the integrity of the cell walls. Applying crispening after blanching, where the cell walls are already damaged, makes it difficult for the crispening agent to maintain the vegetable's crispness to the maximum extent possible. Therefore, Option 1, using the crispening agent and color protectant separately, maximizes their crispening properties and maintains the crispness of the vegetables.

[0151] Application Experiment 3

[0152] Green pepper was selected as the experimental raw material for application experiment;

[0153] The embrittlement agent of Example 2 was added to water in an amount of 0.1 wt % to prepare an embrittlement liquid.

[0154] The specific application steps of the cycle experiment during the application of the present invention are:

[0155] S1: Prepare a large amount of green peppers, wash them, remove the stems, and cut them into small pieces for later use; at the same time, prepare pork tenderloin, cut it into pieces for later use;

[0156] S2a: Immediately pour the cleaned and cut green pepper pieces into the prepared 4°C crispening liquid to make them crisp; soak for 15 minutes, with a material-liquid ratio of (vegetable: water = 1:5); remove from the water after 15 minutes;

[0157] S2b: In the second round, the freshly cleaned and cut green pepper pieces are repeatedly poured into the above-mentioned crispening liquid and soaked for 15 minutes (the material-liquid ratio is vegetable: water = 1:5);

[0158] S2c: In the third round, the freshly cleaned and cut green pepper pieces are repeatedly poured into the above-mentioned crispening liquid and soaked for 15 minutes (the material-liquid ratio is vegetable: water = 1:5);

[0159] S2d: In the fourth round, the freshly washed and cut green pepper pieces are repeatedly poured into the above-mentioned crispening liquid and soaked for 15 minutes (the material-liquid ratio is vegetable: water = 1:5);

[0160] S3: Prepare water in a pot, boil the green peppers with different treatments until the water temperature in the pot reaches 90°C, add the green pepper pieces and blanch them for 15 seconds before removing them;

[0161] S4: Drain and set aside;

[0162] S5: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0163] S6: The fished-out dishes are stored and preserved under different conditions.

[0164] New stir-fry dishes: The specific steps are:

[0165] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0166] S2: Prepare water in a pot and boil until the water temperature reaches 90°C. Add the green pepper pieces and blanch them for 15 seconds before removing them from the pot.

[0167] S3: Drain and set aside;

[0168] S4: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0169] S5: Place the fished-out dishes on a plate.

[0170] The stir-fried green peppers and meat were stored at 60°C for 4 hours, -18°C for 60 days, and 4°C for 14 days to test the crispness of the green peppers in the cooking packs. The sensory evaluation and instrumental measurement of each storage method were performed on each method, along with the blank group and the newly stir-fried dishes. The results are shown in Tables 6-1, 6-2, 6-3 and Tables 7-1, 7-2, and 7-3.

[0171] Table 6-1 Crispness enhancement effect of each solution after 4h hot storage at 60℃ (sensory evaluation)

[0172] Vegetable crispness Vegetable aroma Vegetable aroma Vegetable odor Likeability Use one round 89.3 86.1 86.3 6.7 89.5 Use two wheels 89.1 86.3 86.1 6.5 89.2 Use three wheels 81.3 84.7 84.2 9.8 77.4 Use four wheels 76.1 84.5 84.1 10.1 76.5 Blank group 11.8 8.5 8.4 29.1 14.3 New stir-fried dishes 92.4 89.1 89.8 3.3 92.9

[0173] Table 6-2 Crispness enhancement effect of each solution after 14 days of refrigeration at 4℃ (sensory evaluation)

[0174]

[0175] Table 6-3 Crispness enhancement effect of each solution after freezing at -18℃ for 60 days (sensory evaluation)

[0176]

[0177] Table 7-1 Brittleness enhancement effect of each solution after 4h hot storage at 60℃ (texture analyzer)

[0178] Hardness (0h) Hardness (4h) Use one round 14.5N 12.3N Use two wheels 14.3N 12.1N Use three wheels 14.4N 10.1N Use four wheels 14.4N 8.5N Blank group 14.2N 1.3N New stir-fried dishes 14.3N -

[0179] Table 7-2 Brittleness enhancement effect of each solution after 14 days of refrigeration at 4℃ (texture analyzer)

[0180]

[0181]

[0182] Table 7-3 Brittleness enhancement effect of each solution after freezing at -18℃ for 60 days (Texture analyzer)

[0183] Hardness (0d) Hardness (60d) Use one round 14.6N 12.5N Use two wheels 14.8N 12.6N Use three wheels 14.3N 9.8N Use four wheels 14.4N 8.2N Blank group 14.7N 1.1N New stir-fried dishes 14.7N -

[0184] The sensory evaluation results in Tables 6-1, 6-2, and 6-3, and the texture analyzer data in Tables 7-1, 7-2, and 7-3, show that the crispness and other sensory indicators, as well as the hardness values, of the green peppers soaked in one and two cycles were superior to those soaked in three and four cycles, significantly better than the blank control group but close to those of freshly prepared dishes. These experimental results demonstrate that a 0.1% crispening agent-based solution can be reused twice during application. Furthermore, there was no significant difference in sensory indicators, such as crispness, or hardness between the first and second soaking cycles.

[0185] In addition, the present invention screens and verifies the amount of the crispening agent added after two cycles of use. The selected experimental vegetables are still green peppers.

[0186] The specific application steps are:

[0187] S1: Prepare a large amount of green peppers, wash them, remove the stems, and cut them into small pieces for later use; at the same time, prepare pork tenderloin, cut it into pieces for later use;

[0188] S2a: Immediately pour the cleaned and cut green pepper pieces into the prepared 4°C crispening liquid to make them crisp; soak for 15 minutes, with a material-liquid ratio of (vegetable: water = 1:5); remove from the water after 15 minutes;

[0189] S2b: In the second round, the freshly cleaned and cut green pepper pieces are repeatedly poured into the above-mentioned crispening liquid and soaked for 15 minutes (the material-liquid ratio is vegetable: water = 1:5);

[0190] S2c: After adding 0.01%, 0.02%, and 0.03% of the crispening agent to the crispening liquid, freshly washed green pepper pieces were added and soaked for 15 minutes to crispen them. The material-liquid ratio was (vegetable: water = 1:5);

[0191] S3: Prepare water in a pot, boil the green peppers with different treatments until the water temperature in the pot reaches 90°C, add the green pepper pieces and blanch them for 15 seconds before removing them;

[0192] S4: Drain and set aside;

[0193] S5: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0194] S6: The fished-out dishes are stored and preserved under different conditions.

[0195] New stir-fry dishes: The specific steps are:

[0196] S1: Wash the green peppers, remove the stems and cut into small pieces for later use; meanwhile, prepare the pork tenderloin and cut into pieces for later use;

[0197] S2: Prepare water in a pot and boil until the water temperature reaches 90°C. Add the green pepper pieces and blanch them for 15 seconds before removing them from the pot.

[0198] S3: Drain and set aside;

[0199] S4: Add appropriate amount of oil (about 10ml) to the pot, add 5g of green onion and 5g of garlic and stir-fry for 10s, add pork tenderloin (about 100g) and stir-fry for 4min, add 3g of cooking wine and 3g of cooking oil, add green pepper pieces (about 150g), stir-fry for 1min and remove the dish;

[0200] S5: Place the fished-out dishes on a plate.

[0201] The stir-fried green peppers and meat were stored at 60°C for 4 hours, -18°C for 60 days, and 4°C for 14 days to test the crispness of the green peppers in the cooking packs. The sensory evaluation and instrumental measurement of each storage method were performed on each method, along with the blank group and the newly stir-fried dishes. The results are shown in Tables 8-1, 8-2, 8-3 and Tables 9-1, 9-2, and 9-3.

[0202] Table 9 - Brittleness enhancement effect of each solution after hot storage at 160℃ for 4 hours (sensory evaluation)

[0203]

[0204] Table 9 - Crispness enhancement effect of each solution after refrigeration at 24℃ for 14 days (sensory evaluation)

[0205]

[0206] Table 8-3- Crispness enhancement effect of each solution after freezing at 18℃ for 60 days (sensory evaluation)

[0207]

[0208]

[0209] Table 9 - Brittleness enhancement effect of each solution after 4h hot storage at 160℃ (Texture analyzer)

[0210]

[0211] Table 9 - Brittleness enhancement effect of each solution after 14 days of refrigeration at 24℃ (texture analyzer)

[0212]

[0213]

[0214] Table 9-3-18℃ freezing for 60 days after each solution brittle effect (texture analyzer)

[0215]

[0216] The sensory evaluation results in Tables 8-1, 8-2, and 8-3, and the texture analyzer data in Tables 9-1, 9-2, and 9-3, show that after adding 0.02% crispening agent to the crispening solution, the crispening solution can be reused twice. The crispness of the green peppers in the third cycle after adding the crispening agent is essentially the same as that in the first and second cycles. Considering both the crispening effect and customer cost, washed and cut vegetables are soaked in the crispening solution for crispening. The crispening solution can be used to soak the vegetables twice. Then, 0.02% crispening agent (the amount added is 0.02% of the total aqueous solution weight) is added to the crispening solution after the vegetables have been soaked twice, and the water weight is replenished to the original weight (equivalent to the water weight before soaking). It is recommended to replenish the vegetables after every two soaking cycles, and the total number of soaking cycles should not exceed six.

[0217] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A vegetable crispening agent, characterized in that: The invention is prepared from the following raw materials in the following mass percentages: 40% to 50% sodium hexametaphosphate, 30% to 38% calcium chloride, 12% to 19% sodium tripolyphosphate, 1% to 4% sodium alginate, and 1% to 5% calcium ascorbate, wherein the sum of the mass percentages of the raw materials is 100%.

2. A vegetable crispening agent according to claim 1, characterized in that: The raw materials and their mass percentages are: 43% to 47% sodium hexametaphosphate, 33% to 38% calcium chloride, 13% to 17% sodium tripolyphosphate, 2% to 4% sodium alginate, and 1% to 3% calcium ascorbate. The sum of the mass percentages of the raw materials is 100%.

3. A vegetable crispening agent according to claim 2, characterized in that: The raw materials and their mass percentages are: 45% sodium hexametaphosphate, 35% calcium chloride, 15% sodium tripolyphosphate, 3% sodium alginate, and 2% calcium ascorbate.

4. The method for preparing the vegetable crispening agent according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: uniformly mixing sodium hexametaphosphate, calcium chloride, sodium tripolyphosphate, sodium alginate and calcium ascorbate according to mass percentage to obtain the mixture.

5. Use of the vegetable crispening agent according to any one of claims 1 to 3 in crispening pre-made vegetables, characterized in that: The vegetable crispening agent is added to water at an addition amount of 0.1-0.2wt% to prepare a crispening liquid, and the washed and cut vegetables are immersed in the crispening liquid for crispening treatment, and then blanched, and stored after processing according to conventional processes.

6. The use according to claim 5, characterized in that The temperature of the embrittlement treatment is 4° C. and the time is 15 minutes.

7. The use according to claim 5, characterized in that The material-liquid ratio of the vegetables to the crispening liquid is 1:

5.

8. The use according to claim 5, characterized in that When the desired vegetables need to be crispened and color protected, the method also includes the step of placing the vegetables in a color protection liquid to protect the color after blanching; the color protection liquid is prepared by adding a color protection agent in water at an addition amount of 0.2-0.3wt%; the soaking temperature is 4°C, the time is 15 minutes, and the material-liquid ratio is 1:

5.

9. The use according to claim 8, characterized in that The color preservative comprises 50% to 60% green tea extract, 6% to 12% calcium ascorbate, 16% to 28% sodium citrate, 7% to 15% sodium D-isoascorbate, and 0.5% to 3% sodium chloride, and the sum of the mass percentages of the raw materials is 100%.

10. The use according to claim 9, characterized in that The color preservative comprises: 60% green tea extract, 8% calcium ascorbate, 20% sodium citrate, 10% sodium D-isoascorbate, and 2% sodium chloride.

11. The use according to claim 5, characterized in that The crispening agent is circulated and used in the following steps: the washed and cut vegetables are soaked in the crispening liquid for crispening treatment, and the crispening liquid can be repeatedly soaked in the vegetables for two rounds; 0.02% of the crispening agent is added to the crispening liquid after soaking the vegetables for two rounds, and the weight of water is replenished; the vegetables are replenished after being soaked for two rounds, and the total number of soaking times does not exceed six rounds.

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