Normal-temperature instant baked sea cucumber and preparation method thereof

Abstract

The invention discloses a normal-temperature instant baked sea cucumber and a preparation method thereof, and belongs to the technical field of deep processing of aquatic products and instant snack food. Fresh sea cucumbers are used as main raw materials, and are sequentially subjected to cleaning treatment, pre-cooking shaping, slicing, vacuum rolling and pickling, hot air drying, high-temperature short-time baking, vacuum packaging and sterilization treatment. The obtained instant sea cucumber baked at normal temperature is in a sheet shape, has stable baking fragrance, good sticky and soft elasticity and complete appearance, can be stored for 9-12 months at 25 DEG C, has a sensory comprehensive score of not less than 7.0 points after being stored for 12 months, and overcomes the problems that the existing instant sea cucumber depends on refrigeration, has single flavor type, is easy to age in texture, is limited in shelf life at normal temperature and the like. The method is suitable for various consumption scenes such as family catering, travel carrying and leisure snacks, and has good industrial application prospect and economic value.

Description

Technical Field

[0001] This invention relates to the field of deep processing of aquatic products and ready-to-eat snack foods, specifically to a room-temperature ready-to-eat roasted sea cucumber and its preparation method. Background Technology

[0002] Sea cucumbers are rich in collagen, active peptides, polysaccharides, and other nutrients, possessing high nutritional and health benefits. However, traditional sea cucumber products are mostly dried or salted, requiring prolonged soaking and cooking before consumption, which is cumbersome and raises the barrier to entry for consumers. To meet the demand for convenience and ready-to-eat options, various ready-to-eat sea cucumber products have emerged, such as frozen ready-to-eat sea cucumbers and room-temperature ready-to-eat sea cucumbers in braising liquid. Currently, frozen ready-to-eat sea cucumbers are heavily reliant on cold chain conditions, resulting in high transportation and sales costs, and are inconvenient for consumers to carry and consume at any time. While room-temperature ready-to-eat sea cucumbers in braising liquid can be stored at room temperature, their flavor is primarily braising, and they are often sold whole or in large slices. Their texture tends to age and harden during room-temperature storage, and their flavor profile is relatively limited, making it difficult to balance the demands for long shelf life and roasted flavor. Furthermore, most roasted sea cucumber products still rely on refrigeration or short-term storage, with relatively little research and publicly available technology for long shelf life at room temperature. For sea cucumber raw materials, which are relatively expensive and have a distinct seasonal and regional supply, it is difficult to achieve cross-seasonal and cross-regional supply and regular terminal sales if they cannot obtain a sufficiently long shelf life at room temperature. This greatly limits the promotion and application of ready-to-eat sea cucumber products.

[0003] Meanwhile, in the existing aquatic product preservation and ready-to-eat products, vacuum packaging or simple nitrogen-filled packaging has been used to delay oxidation and some microbial growth. However, there is still a lack of targeted technical solutions on how to effectively combine roasting process, formula water retention, anti-corrosion system and vacuum packaging to obtain ready-to-eat sea cucumbers that are suitable for family meals, snacks and travel, and can be stored at room temperature for a long time, under the premise of achieving commercial sterility.

[0004] Therefore, this invention proposes a method for preparing ready-to-eat sea cucumbers at room temperature with roasting, which achieves a comprehensive balance between shelf life at room temperature, flavor and texture, packaging cost and formula compliance. This method allows the product to be stably stored at room temperature (approximately 25°C) for 9-12 months without refrigeration, while also possessing a unique roasted flavor and a soft, elastic texture. The product is packaged in a lightweight, small package, is affordable, and convenient to consume, making it suitable for large-scale industrial production and widespread market promotion. Summary of the Invention

[0005] Therefore, this invention proposes a method for preparing ready-to-eat roasted sea cucumbers at room temperature that achieves a comprehensive balance between shelf life at room temperature, flavor and texture, packaging costs, and formula compliance. By rationally controlling the thickness and moisture content of the sea cucumber slices, selecting a composite preservative system that complies with GB 2760, combining vacuum nitrogen-filled soft packaging, and synergistic final sterilization by heat sterilization and irradiation, this invention enables the product to be stably stored at approximately 25°C for 9-12 months without refrigeration, which is significantly superior to traditional refrigerated or short-shelf-life roasted sea cucumber products.

[0006] Long shelf life at room temperature is particularly important for sea cucumber products. On the one hand, consumers can easily access them at home, in the office, while traveling, or outdoors, without the need for thawing or complicated cooking, thus lowering the barrier to consumption. On the other hand, businesses no longer rely on end-to-end cold chain transportation and refrigerated display cases, and can use lightweight small packaging, facilitating e-commerce and cross-regional distribution, which helps reduce overall distribution costs and expand sales reach. Therefore, this invention, while ensuring the nutritional and flavor characteristics of sea cucumbers, focuses on solving the key technical problem of long-term storage of roasted ready-to-eat sea cucumber products at room temperature, making it suitable for industrial-scale production and widespread market promotion.

[0007] This invention provides a method for preparing ready-to-eat roasted sea cucumber at room temperature, comprising the following steps: (1) Raw material processing: Fresh sea cucumbers are selected as raw materials. After cleaning, the internal organs and impurities are removed to obtain processed sea cucumbers; (2) Pre-cooking and shaping: The treated sea cucumbers are pre-cooked at 80-100 ℃ for 5-15 min, cooled and drained to obtain pre-cooked and shaped sea cucumbers; (3) Slicing: The pre-cooked and shaped sea cucumber is sliced ​​horizontally along its longitudinal axis into several basically uniform slices, so that each slice retains the arrangement of the tubercles and longitudinal texture on the body surface. The thickness of the sea cucumber slice is preferably 2-5 mm, the length is preferably 2-5 cm, and the width is preferably 1-3 cm, all of which are within the range suitable for consumption. (4) Vacuum tumbling and marinating: The sea cucumber slices and seasoning liquid are placed together in a vacuum tumbling machine and tumbled and marinated under vacuum conditions; the seasoning liquid includes: salt, soy sauce, sugar, edible vegetable oil, compound spices, water-retaining agent, and preservative, wherein the sugar is selected from one or more of white sugar, glucose, and maltose; (5) Pre-drying and roasting: Spread the vacuum-tumbled and marinated sea cucumber slices flat on a baking tray and pre-dry them for 30-90 min under hot air circulation drying conditions at 60-80 ℃ to reduce their moisture content to 65-70%. Then roast them for 6-15 min under hot air conditions at 120-180 ℃ to bring the core temperature of the product to 75-85 ℃ and control the moisture content at 55-65%. (6) Bagging and vacuum packaging: The roasted sea cucumber slices cooled to no higher than 30°C are packaged into food-grade high-temperature resistant vacuum bags. First, food-grade nitrogen is filled into the vacuum bag to replace the original air. Then, vacuuming or repeated nitrogen filling-vacuuming operations are performed to ensure that the residual oxygen volume fraction in the packaging bag is no higher than 1%, and the bag is sealed. (7) Sterilization and cooling: The packaging bag obtained in step (6) is heated to sterilize until it meets the commercial sterility requirements, and then cooled to below 35 °C; (8) Irradiation treatment: The sealed packaged roasted sea cucumber products that have been heat-sterilized in step (7) and cooled to room temperature are placed in a food irradiation device for irradiation treatment. The irradiation process and dose measurement comply with the requirements of relevant national standards and specifications for food irradiation. Under the premise of not inducing radioactive residues in the product, the cold point absorbed dose of the product reaches the minimum absorbed dose D determined by the process verification. min To further reduce the microbial load and extend the shelf life, ready-to-eat roasted sea cucumber products that can be stored at room temperature are obtained.

[0008] In one embodiment of the present invention, in step (4), the water-retaining agent is a compound phosphate, preferably a combination of sodium tripolyphosphate and sodium hexametaphosphate in a mass ratio of 1:1 to 1:2, and its total addition amount in the seasoning liquid is 0.2-0.5% of the mass of the sea cucumber slices.

[0009] In one embodiment of the present invention, in step (4), the preservative is selected from one or more of the preservatives permitted for use in cooked aquatic products under the national food safety standard GB2760, including sorbic acid and its potassium salt, and nisin; the actual amount used in the finished product does not exceed the corresponding maximum amount, and when preservatives of the same function are used in combination, the sum of the ratios of the actual amount of each preservative to its maximum amount does not exceed 1.

[0010] In one embodiment of the present invention, in step (4), the vacuum tumbling and marinating is carried out under a vacuum degree of not less than -0.06MPa, the tumbling time is 30-90 min, the total marinating time is 4-12 h, and the marinating temperature is 0-4 ℃.

[0011] In one embodiment of the present invention, in step (5), the pre-drying is carried out under hot air conditions of 60-80 ℃ for 30-90 min, and then baked in a hot air circulating oven of 150-170 ℃ for 8-12 min, so that the surface of the sea cucumber slices forms a brownish-brown baked color, while the inside remains sticky and elastic, and the moisture content of the finished product is 55-65%.

[0012] In one embodiment of the present invention, in step (6), a nitrogen-vacuum combined packaging process is adopted, the gas filled is food-grade nitrogen, the nitrogen gas integral is ≥99%, and after nitrogen filling and vacuuming, the residual oxygen volume fraction in the packaging bag is not higher than 1.0%.

[0013] In one embodiment of the present invention, in step (7), the sterilization conditions are to maintain at 121 °C for 8-10 min, and combine the heat treatment of heating and cooling stages to make the F0 value of the cold point of the product inside the packaging not less than 6.0 min, so that the core temperature of the product can be fully raised and meet the commercial sterility requirements.

[0014] In one embodiment of the present invention, in step (8), the irradiation treatment uses 60Co γ-ray irradiation, and the minimum absorbed dose D at the product cold point is... min The irradiation dose is 1-5 kGy, preferably 2-4 kGy, and the irradiation dose range is within the dose limits allowed by relevant national standards and regulations for food irradiation, so as to improve sterilization reliability and extend shelf life while basically maintaining the sensory quality of the product. This invention provides ready-to-eat roasted sea cucumbers prepared by the method described above.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) Using sea cucumber as the main raw material, the process includes the following steps in sequence: raw material processing, pre-cooking and shaping, slicing, vacuum tumbling and marinating, pre-drying and roasting, bagging and vacuum nitrogen-filled packaging, and sterilization and cooling. In the vacuum tumbling and marinating step, the seasoning liquid includes salt, soy sauce, sugars, edible vegetable oil, compound spices, a water-retaining agent, and a preservative. The sugars are selected from one or more of white sugar, glucose, and maltose. The water-retaining agent is preferably a compound phosphate formed by the combination of sodium tripolyphosphate and sodium hexametaphosphate. The preservative is a variety permitted for use in cooked aquatic products according to the national food safety standard GB 2760. Vacuum tumbling and low-temperature marinating improve the permeability of the seasoning in the sea cucumber tissue and the bound water content.

[0016] (2) The pre-drying and roasting steps combine hot air pre-drying with high-temperature short-time roasting to ensure that the moisture content of the sea cucumber slices is ultimately stabilized within the range of 55-65%, which inhibits microbial growth and maintains the product's softness, elasticity, and good chewiness. In the bagging and vacuum nitrogen-filling packaging steps, high-temperature resistant, high-barrier soft packaging bags are used, and a nitrogen-filling-vacuum combination process is employed to ensure that the residual oxygen volume fraction inside the packaging bag is not higher than 1.0%, thereby significantly slowing down the oxidation reaction and the growth of some aerobic microorganisms. Heat sterilization and subsequent irradiation together constitute the final sterilization step of this invention, and their synergistic effect enables the product to meet commercial sterility requirements.

[0017] (3) The ready-to-eat roasted sea cucumber product prepared by the present invention has a comprehensive sensory score of more than 7.0 when stored at (25±2)℃ for 12 months, and a shelf life of 9-12 months. (4) Long shelf life at room temperature: Through “roasting and water control, composite anti-corrosion system, vacuum packaging, heat sterilization and irradiation treatment”, the moisture content of roasted sea cucumber is controlled within the range of 55-65% and can be stably stored at 25℃ for 9-12 months without refrigeration or freezing, which reduces the distribution and terminal sales costs.

[0018] (5) Flavor and texture are both taken into account: The sea cucumber slices are seasoned with compound spices, pre-dried and roasted at high temperature for a short time, giving them a unique roasted aroma and compound flavor; the product’s softness, elasticity and chewiness are improved by using compound phosphate water-retaining agent and vacuum tumbling process, and the texture changes little during storage.

[0019] (6) Lightweight and low-cost packaging: The flexible vacuum packaging process does not rely on traditional metal can containers and the entire cold chain. Medium-sized sea cucumber raw materials can be selected, which helps to control the cost of raw materials and packaging, making the product price more acceptable to the public.

[0020] (7) Wide range of applicable consumption scenarios: The product is in sheet form and can be eaten directly after opening the bag, or it can be simply heated and paired with staple food. It is suitable for various scenarios such as family meals, travel, and outdoor leisure, and is suitable for consumers of different ages.

[0021] (8) Compliance of formulation and additive use: The phosphates, preservatives, antioxidants and other additives used in this invention are all within the permitted range of the category of cooked aquatic products in GB2760, and follow the principles of necessity and minimum usage, which is conducive to product registration and market access. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process flow for preparing ready-to-eat sea cucumbers at room temperature according to the present invention.

[0023] Figure 2 The images show the sensory evaluation results of the Examples (1, 2) and Comparative Samples (1, 2, 3) at different storage times (0, 9, 12 months).

[0024] Figure 3 The changes in volatile basic nitrogen in all examples (1, 2) and comparative samples (1, 2, 3) during different storage times (0, 9, 12 months) during the storage period. Detailed Implementation

[0025] Example 1 1. Experimental Methods 1.1 Raw materials: Fresh sea cucumber: weight (110±20)g, body length (10±2)cm; compound spices include ginger, scallion, garlic, Sichuan pepper, star anise, cinnamon, fennel, bay leaves, etc., forming a five-spice flavor; water-retaining agent is sodium tripolyphosphate and sodium hexametaphosphate compounded in a mass ratio of 1:1; preservatives are potassium sorbate and nisin; optional colloidal thickeners such as carrageenan.

[0026] 1.2 Processing Technology (1) Raw material pretreatment Remove the internal organs and sand mouth of the fresh sea cucumber, and clean it thoroughly for later use.

[0027] (2) Pre-cooking and shaping The processed sea cucumbers are pre-cooked in 90℃ hot water for 10 minutes to cook them thoroughly, set their shape, and remove any fishy smell. Then they are taken out and cooled to room temperature.

[0028] (3) Slicing The pre-cooked sea cucumbers are transversely sliced ​​along their longitudinal axis into several arc-shaped thin slices, each approximately 3 mm thick, 3 cm long, and 2 cm wide, preserving the surface of the sea cucumbers and longitudinal striations to facilitate subsequent dehydration and flavor absorption, while ensuring that consumers can easily identify them as sea cucumbers by appearance. Based on 100 kg of sea cucumber slices, the following ingredients may be used: salt: 1.5 kg; white sugar: 2.0 kg; soy sauce: 8 kg; cooking wine: 2 kg; edible vegetable oil: 1.0 kg; scallions, ginger, and garlic combined: 1.0 kg; five-spice compound: 0.2 kg; compound phosphate: 0.3 kg (approximately 0.3% of the sea cucumber slice weight); preservatives are a combination of potassium sorbate and nisin, with potassium sorbate at 96.60 g and nisin (1100 IU / mg) at 32.77 g; carrageenan: 0.2 kg. Weigh out each seasoning ingredient according to the formula and mix with 28 kg of water. Heat to about 80°C to cook until fragrant, then cool to <30°C. Place the sea cucumber slices and seasoning liquid into a vacuum tumbler, vacuum to ≤-0.06 MPa, tumble for 30 min, and continue to marinate at 0-4°C for a total of 8 h, turning 1-2 times during the process.

[0029] (4) Pre-drying: After marinating, drain the surface liquid from the sea cucumber slices and spread them evenly on a baking tray; pre-dry them under hot air at 70℃ for about 60 minutes; after pre-drying, the moisture content was measured to be about 65-70%.

[0030] (5) Baking: The pre-dried sea cucumber slices are placed in an oven and roasted at 160℃ for 8 minutes to give the surface a slightly browned appearance and a roasted aroma. The interior is heated to about 80℃. After roasting, the product has a moisture content of about 55-65%.

[0031] (6) Cooling and Packaging: After cooling, the sea cucumber slices are packaged into food-grade high-temperature resistant vacuum bags. Food-grade nitrogen is first introduced into the vacuum bags in the packaging machine to ensure that the nitrogen content in the packaging is ≥99%, and air is removed as much as possible through nitrogen replacement. Then, a vacuum is drawn to ensure that the residual oxygen volume fraction is ≤1.0%. If necessary, the "nitrogen filling-vacuuming" process can be repeated 1-2 times to further reduce the oxygen content in the packaging and complete the sealing.

[0032] (7) Sterilization and cooling: After sealing, the packaging bag is placed in a sterilizer at 121℃ for 8 minutes for heat sterilization. After sterilization, it is quickly cooled to below 35℃, then cooled to room temperature, the packaging surface is wiped dry, and after passing the inspection, it can be stored and sold at room temperature.

[0033] (8) Irradiation treatment: After heat sterilization and cooling to room temperature, the sealed packaged products are subjected to 3 kGy of ^60Co γ-ray irradiation. The irradiation process and dose measurement comply with the requirements of relevant national standards and regulations for food irradiation, in order to further reduce microbial load and extend shelf life.

[0034] Example 2 2. Experimental Methods 2.1 Raw materials Fresh sea cucumber: weight (110±20)g, body length (10±2)cm; compound spices include ginger, scallion, garlic, Sichuan pepper, star anise, dried red chili, fennel, etc., to form a spicy flavor; water-retaining agent is sodium tripolyphosphate and sodium hexametaphosphate in a mass ratio of 1:1; preservatives are potassium sorbate and nisin.

[0035] 2.2 Processing Technology (1) Raw material pretreatment Remove the internal organs and sand mouth of the fresh sea cucumber, and clean it thoroughly for later use.

[0036] (2) Pre-cooking and shaping The processed sea cucumbers are pre-cooked in 90℃ hot water for 10 minutes to cook them thoroughly, set their shape, and remove any fishy smell. Then they are taken out and cooled to room temperature.

[0037] (3) Slicing The pre-cooked sea cucumbers are sliced ​​transversely along their longitudinal axis into several arc-shaped thin slices, each approximately 3 mm thick, 3 cm long, and 2 cm wide, preserving the surface of the sea cucumbers and longitudinal striations to facilitate subsequent dehydration and flavor absorption, while ensuring that consumers can easily identify them as sea cucumbers by appearance. Based on 100 kg of sea cucumber slices, the following ingredients can be used: salt: 1.6 kg; white sugar: 1.5 kg; soy sauce: 7 kg; cooking wine: 2 kg; edible vegetable oil: 1.5 kg; scallions, ginger, and garlic combined: 1.2 kg; spicy compound spices: 0.5 kg; compound phosphates: 0.3 kg (approximately 0.3% of the sea cucumber slice weight); the preservative is a combination of potassium sorbate and nisin, with potassium sorbate at 97.53 g and nisin (1100 IU / mg) at 33.09 g. Weigh out each seasoning ingredient according to the formula and mix with 30kg of water. Heat to about 80℃ to cook until fragrant, then cool to <30℃. Place the sea cucumber slices and seasoning liquid into a vacuum tumbler, vacuum to ≤-0.06 MPa, tumble for 30 minutes, and continue to marinate at 0-4℃ for a total of 8 hours, turning 1-2 times in between.

[0038] (4) Pre-drying: After marinating, drain the surface free liquid from the sea cucumber slices and spread them evenly on a baking tray; pre-dry them under hot air at 60℃ for about 60 minutes; after pre-drying, the moisture content was measured to be about 65-75%.

[0039] (5) Baking: The pre-dried sea cucumber slices are placed in an oven and roasted at 170℃ for 7 minutes, until the surface turns a slightly dark reddish-brown and the aroma becomes more intense. The internal temperature is then heated to approximately 80℃, resulting in a product with a moisture content of approximately 55-65% after roasting.

[0040] (6) Cooling and Packaging: After cooling, the sea cucumber slices are packaged into food-grade high-temperature resistant vacuum bags. Food-grade nitrogen is first introduced into the vacuum bags in the packaging machine to ensure that the nitrogen content in the packaging is ≥99%, and air is removed as much as possible through nitrogen replacement. Then, a vacuum is drawn to ensure that the residual oxygen volume fraction is ≤1.0%. If necessary, the "nitrogen filling-vacuuming" process can be repeated 1-2 times to further reduce the oxygen content in the packaging and complete the sealing.

[0041] (7) Sterilization and cooling: After sealing, the packaging bag is placed in a sterilizer at 121℃ for 10 minutes for heat sterilization to fully raise the core temperature of the product and meet the requirements for commercial sterility. After sterilization, it is quickly cooled to below 35℃, then cooled to room temperature, the packaging surface is wiped dry, and after passing the inspection, it can be stored and sold at room temperature.

[0042] (8) Irradiation treatment: After heat sterilization and cooling to room temperature, the sealed packaged products are subjected to 3 kGy of ^60Co γ-ray irradiation. The irradiation process and dose measurement comply with the requirements of relevant national standards and regulations for food irradiation, in order to further reduce microbial load and extend shelf life.

[0043] Comparative Example 1 3. Experimental Methods 3.1 Raw materials Fresh sea cucumber: weight (110±20)g, body length (10±2)cm; compound spices include ginger, scallion, garlic, Sichuan pepper, star anise, dried red chili, fennel, etc., to form a spicy flavor; water-retaining agent is sodium tripolyphosphate and sodium hexametaphosphate in a mass ratio of 1:1; preservatives are potassium sorbate and nisin.

[0044] 3.2 Processing Technology (1) Raw material pretreatment Remove the internal organs and sand mouth of the fresh sea cucumber, and clean it thoroughly for later use.

[0045] (2) Pre-cooking and shaping The processed sea cucumbers are pre-cooked in 90℃ hot water for 10 minutes to cook them thoroughly, set their shape, and remove any fishy smell. Then they are taken out and cooled to room temperature.

[0046] (3) Slicing The pre-cooked sea cucumbers are transversely sliced ​​along their longitudinal axis into several arc-shaped thin slices, each approximately 3 mm thick, 3 cm long, and 2 cm wide, maintaining the surface of the sea cucumbers with their warts and longitudinal stripes largely intact. This facilitates subsequent dehydration and flavor absorption, while ensuring that consumers can easily identify them as sea cucumbers by their appearance. Based on 100 kg of sea cucumber slices, the following ingredients may be used: salt: 1.6 kg; white sugar: 1.5 kg; soy sauce: 7 kg; cooking wine: 2 kg; edible vegetable oil: 1.5 kg; scallions, ginger, and garlic combined: 1.2 kg; spicy compound spices: 0.5 kg; compound phosphates: 0.3 kg (approximately 0.3% of the sea cucumber slice weight); potassium sorbate + nisin: added at 50% of the maximum usage specified in GB 2760, with potassium sorbate at 97.53 g and nisin (1100 IU / mg) at 33.09 g. Weigh out each seasoning ingredient according to the formula and mix with 30 kg of water. Heat to about 80°C to cook until fragrant, then cool to <30°C. Place the sea cucumber slices and seasoning liquid into a vacuum tumbler, vacuum to ≤-0.06 MPa, tumble for 30 min, and continue to marinate at 0-4°C for a total of 8 h, turning 1-2 times during the process.

[0047] (4) Pre-drying: After marinating, drain the surface free liquid from the sea cucumber slices and spread them evenly on a baking tray; pre-dry them under hot air at 70℃ for about 60 minutes; after pre-drying, the moisture content was measured to be about 65-72%.

[0048] (5) Baking: The pre-dried sea cucumber slices are placed in an oven and roasted at 170℃ for 7 minutes, until the surface turns a slightly dark reddish-brown and the aroma becomes more intense. The internal temperature is then heated to approximately 80℃, resulting in a product with a moisture content of approximately 55-65% after roasting.

[0049] (6) Cooling and Packaging: After cooling, the sea cucumber slices are packaged into food-grade high-temperature resistant vacuum bags. Food-grade nitrogen is first introduced into the vacuum bags in the packaging machine to ensure that the nitrogen content in the packaging is ≥99%, and air is removed as much as possible through nitrogen replacement. Then, a vacuum is drawn to ensure that the residual oxygen volume fraction is ≤1.0%. If necessary, the "nitrogen filling-vacuuming" process can be repeated 1-2 times to further reduce the oxygen content in the packaging and complete the sealing.

[0050] (7) Sterilization and cooling: After sealing, the packaging bag is placed in a sterilizer at 121℃ for 8 minutes for heat sterilization to fully raise the core temperature of the product and meet commercial sterility requirements. After sterilization, it is rapidly cooled to below 35℃ and then cooled to room temperature. Comparative Example 2 4. Experimental Methods 4.1 Raw Materials Fresh sea cucumber: weight (110±20)g, body length (10±2)cm; compound spices include ginger, scallion, garlic, Sichuan pepper, star anise, dried red chili, fennel, etc., to form a spicy flavor; water-retaining agent is sodium tripolyphosphate and sodium hexametaphosphate in a mass ratio of 1:1; preservatives are potassium sorbate and nisin.

[0051] 4.2 Processing Technology (1) Raw material pretreatment Remove the internal organs and sand mouth of the fresh sea cucumber, and clean it thoroughly for later use.

[0052] (2) Pre-cooking and shaping The processed sea cucumbers are pre-cooked in 90℃ hot water for 10 minutes to cook them thoroughly, set their shape, and remove any fishy smell. Then they are taken out and cooled to room temperature.

[0053] (3) Slicing The pre-cooked sea cucumbers are sliced ​​transversely along their longitudinal axis into several arc-shaped thin slices, each approximately 3 mm thick, 3 cm long, and 2 cm wide, preserving the surface of the sea cucumbers and longitudinal striations to facilitate subsequent dehydration and flavor absorption, while ensuring that consumers can easily identify them as sea cucumbers by appearance. Based on 100 kg of sea cucumber slices, the following ingredients can be used: salt: 1.6 kg; white sugar: 1.5 kg; soy sauce: 7 kg; cooking wine: 2 kg; edible vegetable oil: 1.5 kg; scallions, ginger, and garlic combined: 1.2 kg; spicy compound spices: 0.5 kg; compound phosphates: 0.3 kg (approximately 0.3% of the sea cucumber slice weight); the preservative is a combination of potassium sorbate and nisin, with potassium sorbate at 97.53 g and nisin (1100 IU / mg) at 33.09 g. Weigh out each seasoning ingredient according to the formula and mix with 30kg of water. Heat to about 80℃ to cook until fragrant, then cool to <30℃. Place the sea cucumber slices and seasoning liquid into a vacuum tumbler, vacuum to ≤-0.06 MPa, tumble for 30 minutes, and continue to marinate at 0-4℃ for a total of 8 hours, turning 1-2 times in between.

[0054] (4) Pre-drying: After marinating, drain the surface free liquid from the sea cucumber slices and spread them evenly on a baking tray; pre-dry them under hot air at 60℃ for about 60 minutes; after pre-drying, the moisture content was measured to be about 65-75%.

[0055] (5) Baking: The pre-dried sea cucumber slices are placed in an oven and roasted at 170℃ for 7 minutes. The surface turns slightly dark brownish-red and the aroma becomes more intense. The internal temperature is heated to about 80℃. After roasting, the product has a moisture content of about 55-65%.

[0056] (6) Cooling and Packaging: After cooling, the sea cucumber slices are packaged into high-temperature resistant vacuum bags for food use; the vacuum bags are then vacuumed in a packaging machine to ensure that the residual oxygen volume fraction is ≤2.0%, and then sealed.

[0057] (7) Sterilization and cooling: After sealing, the packaging bag is placed in a sterilizer at 121℃ for 10 minutes for heat sterilization to fully raise the core temperature of the product and meet the requirements for commercial sterility. After sterilization, it is quickly cooled to below 35℃, then cooled to room temperature, the packaging surface is wiped dry, and after passing the inspection, it can be stored and sold at room temperature.

[0058] (8) Irradiation treatment: After heat sterilization and cooling to room temperature, the sealed packaged products are subjected to 3 kGy of ^60Co γ-ray irradiation. The irradiation process and dose measurement comply with the requirements of relevant national standards and regulations for food irradiation, in order to further reduce microbial load and extend shelf life.

[0059] Comparative Example 3 5. Experimental Methods 5.1 Raw Materials Fresh sea cucumber: weight (110±20)g, body length (10±2)cm; compound spices include ginger, scallion, garlic, Sichuan pepper, star anise, dried red chili, fennel, etc., to form a spicy flavor; water-retaining agent is sodium tripolyphosphate and sodium hexametaphosphate in a mass ratio of 1:1; preservatives are potassium sorbate and nisin.

[0060] 5.2 Processing Technology (1) Raw material pretreatment Remove the internal organs and sand mouth of the fresh sea cucumber, and clean it thoroughly for later use.

[0061] (2) Pre-cooking and shaping The processed sea cucumbers are pre-cooked in 90℃ hot water for 10 minutes to cook them thoroughly, set their shape, and remove any fishy smell. Then they are taken out and cooled to room temperature.

[0062] (3) Slicing The pre-cooked sea cucumbers are sliced ​​transversely along their longitudinal axis into several arc-shaped thin slices, each approximately 3 mm thick, 3 cm long, and 2 cm wide, preserving the surface of the sea cucumbers and longitudinal striations to facilitate subsequent dehydration and flavor absorption, while ensuring that consumers can easily identify them as sea cucumbers by appearance. Based on 100 kg of sea cucumber slices, the following ingredients can be used: salt: 1.6 kg; white sugar: 1.5 kg; soy sauce: 7 kg; cooking wine: 2 kg; edible vegetable oil: 1.5 kg; scallions, ginger, and garlic combined: 1.2 kg; spicy compound spices: 0.5 kg; compound phosphates: 0.3 kg (approximately 0.3% of the sea cucumber slice weight); the preservative is a combination of potassium sorbate and nisin, with potassium sorbate at 97.53 g and nisin (1100 IU / mg) at 33.09 g. Weigh out each seasoning ingredient according to the recipe and mix with 30kg of water. Heat to about 80℃ to cook until fragrant, then cool to <30℃. Soak the sea cucumber slices in the seasoning and marinate at 0-4℃ for a total of 8 hours, turning them 1-2 times during the process.

[0063] (4) Pre-drying: After marinating, drain the surface free liquid from the sea cucumber slices and spread them evenly on a baking tray; pre-dry them under hot air at 60℃ for about 90 minutes; after pre-drying, the moisture content was measured to be about 65-75%.

[0064] (5) Baking: The pre-dried sea cucumber slices were placed in an oven and roasted at 170°C for 15 minutes. The surface turned a slightly dark brownish-red, and the roasting aroma became more intense. The internal temperature was heated to approximately 80°C. After roasting, the water activity of the product was significantly reduced to 0.83–0.88, and the water content of the product was significantly lower than the target range of this invention. The water content was approximately 40-50%.

[0065] (6) Cooling and Packaging: After cooling, the sea cucumber slices are packaged into high-temperature resistant vacuum bags for food use; the vacuum bags are then vacuumed in a packaging machine to ensure that the residual oxygen volume fraction is ≤2.0%, and then sealed.

[0066] (7) Sterilization and cooling: After sealing, the packaging bag is placed in a sterilizer at 121℃ for 8 minutes for heat sterilization. After sterilization, it is quickly cooled to below 35℃, then cooled to room temperature, the packaging surface is wiped dry, and after passing the inspection, it can be stored and sold at room temperature.

[0067] Storage tests and sensory evaluation: The roasted sea cucumber products obtained in Examples 1 and 2 and Comparative Examples 1, 2, and 3 were stored at (25±2)℃, relative humidity ≤75%, and in the dark. Sensory evaluations were conducted at 0 months, 9 months, and 12 months of storage, according to the methods described in Table 1. Ten evaluators scored the color, odor, taste, texture, and overall acceptability on a 9-point scale. The scores for each indicator were calculated by weighting the individual scores according to preset criteria. The results are as follows: Figure 2 As shown.

[0068] Table 1 Sensory Evaluation Form

[0069] Depend on Figure 2 As can be seen, the product of Example 1 maintained a comprehensive sensory score of no less than 7.0 after 9 months of storage, with all individual indicators at a good level and no obvious off-odors from oil oxidation or textural aging. After 12 months of storage, the color darkened slightly, and the aroma and taste decreased slightly, but the comprehensive score remained above 7.0, indicating that the roasted sea cucumber prepared by the process of this invention has good sensory stability under room temperature conditions. The spicy roasted sea cucumber product prepared by Example 2 also maintained a comprehensive sensory score of over 7.0 after 9 months of storage, with good color, spicy aroma, and taste. After 12 months of storage, the comprehensive score remained above 7.0, indicating that the spicy spices masked the slight oxidized odor, resulting in a better flavor retention in the later storage stages compared to the ordinary five-spice flavor sample.

[0070] The roasted sea cucumber products from Comparative Examples 1 and 2, which underwent only heat sterilization and vacuum treatment, also achieved a comprehensive sensory score higher than 7.0 at the end of the 9-month storage period. However, compared to the sample from Example 2, their scores for odor and texture dropped below 7 in the later storage period (12 months). This indicates that nitrogen-filled vacuum packaging and irradiation treatment are beneficial in delaying quality deterioration caused by some microorganisms, creating a synergistic preservation effect with heat sterilization and moisture control. Meanwhile, Comparative Example 3 significantly reduced the water activity of its product by extending dehydration and roasting time before vacuum packaging and heat sterilization. Although its comprehensive sensory score was higher than 7.0 after 12 months of storage, the product was too dry, had a tough texture, and an unbalanced roasted flavor. Therefore, its initial sensory score was low.

[0071] Changes in volatile basic nitrogen in samples during storage The roasted sea cucumber products obtained in Examples 1 and 2 and Comparative Examples 1, 2 and 3 were tested according to Method III of GB 5009.228-2016 "Determination of Volatile Basic Nitrogen in Food" after 0 months, 9 months and 12 months of storage.

[0072] Depend on Figure 2 It is evident that during the storage period, the volatile basic nitrogen of all roasted sea cucumber products showed an increasing trend with increasing storage time, but did not exceed the national standard requirements. However, the TVB-N growth rate of Examples 1 and 2 was significantly lower than that of Comparative Examples 1, 2, and 3, indicating that the present invention, through the synergistic effect of water control, low residual oxygen packaging, heat sterilization, and irradiation, can more effectively inhibit the accumulation of volatile alkaline substances caused by microbial reproduction and protein decomposition during room temperature storage, thereby slowing down quality deterioration and extending shelf life.

[0073] In summary, only when the moisture content is 55-65%, nitrogen-filled vacuum packaging, heat sterilization, and low-dose irradiation are combined can sensory and textural stability be maintained for a shelf life of 9-12 months.

[0074] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing ready-to-eat roasted sea cucumber at room temperature, characterized in that, Includes the following steps: (1) Raw material processing: Fresh sea cucumbers are selected as raw materials. After cleaning, the internal organs and impurities are removed to obtain processed sea cucumbers; (2) Pre-cooking and shaping: The treated sea cucumbers are pre-cooked at 80-100 ℃ for 5-15 min, cooled and drained to obtain pre-cooked and shaped sea cucumbers; (3) Slicing: Cut the pre-cooked and shaped sea cucumber into basically uniform slices; (4) Vacuum tumbling and marinating: The sea cucumber slices and seasoning liquid are placed together in a vacuum tumbling machine and tumbled and marinated under vacuum conditions; (5) Pre-drying and roasting: Spread the vacuum-tumbled and marinated sea cucumber slices flat on a baking tray and pre-dry them for 30-90 min under hot air circulation drying conditions at 60-80 ℃ to reduce their moisture content to 65-75%. Then roast them for 6-15 min under hot air conditions at 120-180 ℃ to bring the core temperature of the product to 75-85 ℃ and control the moisture content at 55-65%. (6) Packaging and vacuum packaging: The roasted sea cucumber slices from step (5) are packaged into food-grade high-temperature resistant vacuum bags. First, food-grade nitrogen is filled into the vacuum bags to replace the original air. Then, vacuuming or repeated nitrogen filling-vacuuming operations are performed to ensure that the residual oxygen volume fraction in the packaging bags is not higher than 1%, and the bags are sealed. (7) Sterilization and cooling: The packaging bag obtained in step (6) is sterilized by heating and then cooled to below 35°C; (8) Irradiation treatment: The roasted sea cucumber product that has been heat sterilized and cooled in step (7) is placed in a food irradiation device and irradiated.

2. The preparation method according to claim 1, characterized in that, In step (4), the seasoning liquid includes: salt, soy sauce, sugar, edible vegetable oil, compound spices, water-retaining agent, and preservative.

3. The preparation method according to claim 2, characterized in that, The sugars are selected from one or more of white sugar, glucose, and maltose; the water-retaining agent is a compound phosphate, which is a combination of sodium tripolyphosphate and sodium hexametaphosphate in a mass ratio of 1:1 to 1:2, and its total addition amount in the seasoning liquid is 0.2-0.5% of the mass of the sea cucumber slices.

4. The preparation method according to claim 2, characterized in that, The preservatives are one or more of sorbic acid and its potassium salt, and nisin.

5. The preparation method according to claim 1, characterized in that, In step (4), the vacuum tumbling and marinating is carried out under a vacuum degree of not less than -0.06 MPa, the tumbling time is 30-90 min, the total marinating time is 4-12 h, and the marinating temperature is 0-4 ℃.

6. The preparation method according to claim 1, characterized in that, In step (5), the pre-drying is carried out under hot air conditions of 60-80 ℃ for 30-90 min, and then baked in a hot air circulating oven of 150-170 ℃ for 8-12 min, so that the surface of the sea cucumber slices forms a brown baking color, while the inside remains sticky and elastic, and the moisture content of the finished product is 55-65%.

7. The preparation method according to claim 1, characterized in that, In step (6), a nitrogen-vacuum combined packaging process is adopted. The gas filled in is food-grade nitrogen with a nitrogen gas fraction of ≥99%. After nitrogen filling and vacuuming, the residual oxygen volume fraction in the packaging bag is not higher than 1.0%.

8. The preparation method according to claim 1, characterized in that, In step (7), the sterilization conditions are to maintain the product at 121 °C for 8-10 min, and combine the heat treatment with the heating and cooling stages to ensure that the F0 value of the cold point of the product inside the packaging is not less than 6.0 min, so that the core temperature of the product can be fully raised and meet the commercial sterility requirements.

9. The preparation method according to claim 1, characterized in that, In step (8), the irradiation treatment uses 60Co γ-ray irradiation, and the minimum absorbed dose D at the product's cold point is... min It ranges from 1 to 5 kGy.

10. Ready-to-eat roasted sea cucumber prepared by any one of the methods described in claims 1-9.

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