A method for preparing a high-nutrition and high-absorption rate bird's nest product by using supercritical fluid technology

Abstract

The application provides a preparation method of a supercritical bird's nest product, comprising the following steps: using a segmented advanced supercritical fluid technology, taking supercritical carbon dioxide as a drying medium, replacing water in the soaked bird's nest, and preparing a supercritical bird's nest. Carbon dioxide is used as a drying medium, and in a supercritical state, water molecules are directly replaced and dried by directly acting on pure bird's nest raw materials. The whole process does not need to add any auxiliary components, is safe, controllable and healthy; the segmented advanced molecular replacement is beneficial to the more relaxed bird's nest protein structure, the formation of a nano-porous structure in the bird's nest tissue, the removal of part of calcium and magnesium ions in the bird's nest, the improvement of the solubility of bird's nest protein, and the increase of the swelling multiple of the bird's nest after soaking. The bird's nest product prepared by the technology has higher protein digestibility, better conversion ability of sialic acid in the body, better utilization efficiency in blood plasma, high absorption rate and better nutrient utilization rate.

Description

Technical Field

[0001] This application relates to the field of food processing technology, and in particular to a bird's nest product and its preparation method. Background Technology

[0002] With the development of the health and wellness trend, bird's nest, as a traditional and precious nourishing ingredient, is increasingly accepted and recognized by consumers. Currently, the main bird's nest products on the market are dried bird's nest, ready-to-eat bird's nest, and freshly brewed bird's nest. Freshly brewed bird's nest is a convenient bird's nest product that can be brewed with boiling water and enjoyed immediately. It is portable and lightweight, and is loved by young people, especially white-collar workers.

[0003] In related technologies, freeze-drying is often used to prepare freshly soaked bird's nest. Although freeze-drying can better preserve the nutritional value and structure of bird's nest, the taste, nutrition, and absorption of freshly soaked bird's nest differ from those of dried bird's nest after stewing. The fullness and smoothness of the bird's nest are also inferior, and its expansion ratio is generally between 25 and 35 times. Summary of the Invention

[0004] Based on this, this application provides a bird's nest product with a smooth and full texture, a high expansion ratio, high nutrition and high absorption rate, and a method for preparing the same.

[0005] The first aspect of this application provides a method for preparing supercritical bird's nest products, comprising the following steps:

[0006] The supercritical bird's nest product is prepared by using segmented, progressive supercritical fluid technology and supercritical carbon dioxide as the drying medium to replace the moisture in the soaked bird's nest.

[0007] In some embodiments, the preparation method includes the following steps:

[0008] Mix the bird's nest with water and perform a water absorption and swelling treatment;

[0009] The bird's nest, after undergoing a water absorption and swelling treatment, will undergo a dehydration treatment.

[0010] The bird's nest, after undergoing a dehydration process, is replaced with supercritical carbon dioxide.

[0011] The bird's nest, after undergoing a first replacement treatment, is mixed with water and then subjected to a second water absorption and swelling treatment.

[0012] The bird's nest, after undergoing a second water absorption and swelling treatment, will undergo a second dehydration treatment.

[0013] The bird's nest, after undergoing a secondary dehydration treatment, is subjected to a secondary replacement treatment using supercritical carbon dioxide to prepare the supercritical bird's nest product.

[0014] In some embodiments, the mass ratio of bird's nest to water during the first water absorption and swelling treatment is 1:(25-35); and / or

[0015] The soaking temperature for the first water absorption and swelling treatment is 28℃-38℃, and the soaking time is 2h-4h.

[0016] In some embodiments, the primary displacement process includes at least one of the following features:

[0017] (1) The temperature of the first replacement treatment is 15℃-45℃;

[0018] (2) The pressure of the first replacement treatment is 15MPa-25MPa;

[0019] (3) The time for one replacement treatment is 20 min to 60 min;

[0020] (4) The flow rate of the supercritical carbon dioxide is 60L / h-100L / h.

[0021] In some embodiments, during the secondary water absorption and swelling treatment, the mass ratio of the bird's nest to water after the first replacement treatment is 1:(20-40); and / or

[0022] The soaking temperature for the secondary water absorption and swelling treatment is 10℃-30℃, and the soaking time is 1h-4h.

[0023] In some embodiments, mechanical wave assistance is used to perform the secondary water absorption and swelling treatment;

[0024] Optionally, the frequency of the mechanical wave is 40KHz-50KHz.

[0025] In some embodiments, the secondary displacement process includes at least one of the following features:

[0026] (1) The temperature of the secondary replacement treatment is 45℃-60℃;

[0027] (2) The pressure of the secondary replacement treatment is 35MPa-40MPa;

[0028] (3) The time for the secondary replacement treatment is 120 min-180 min;

[0029] (4) The flow rate of the supercritical carbon dioxide is 60L / h-100L / h.

[0030] In some embodiments, the primary dehydration process includes spin drying;

[0031] Optionally, the spin-drying time is 8-15 minutes.

[0032] In some embodiments, the secondary dehydration treatment includes spin drying;

[0033] Optionally, the spin-drying time is 5-8 minutes.

[0034] The second aspect of this application provides a freshly brewed bird's nest, which is prepared using the preparation method of the first aspect of this application.

[0035] The above-mentioned method for preparing bird's nest products uses carbon dioxide as a drying medium. Under supercritical conditions, it directly reacts with pure bird's nest raw materials to perform water molecule replacement drying. The entire process requires no auxiliary ingredients, making it safe, controllable, and healthy. The segmented and progressive molecular replacement method helps the bird's nest protein structure to expand more fully. At the same time, it can replace and remove some of the modified and magnesium ions in the bird's nest, improve the solubility of the bird's nest protein, and increase the expansion ratio of the bird's nest after soaking. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 These are actual photos of the supercritical bird's nest product prepared in Example 1 before and after brewing;

[0038] Figure 2 SEM images of the cross-section of the supercritical bird's nest product prepared in Example 1 and the cross-section of freshly soaked bird's nest prepared using FD technology;

[0039] Figure 3 Electrophoretic analysis of proteins in the digestion supernatant;

[0040] Figure 4 The concentration of free sialic acid in plasma for each intervention group;

[0041] Figure 5 The conversion index of sialic acid in plasma free sialic acid for each intervention group;

[0042] Figure 6 The conversion index of sialic acid in plasma-bound sialic acid for each intervention group. Detailed Implementation

[0043] To facilitate understanding of this application, a more complete description of the application will be provided below with reference to relevant embodiments. Preferred embodiments of the application are given below. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0045] As used herein, the terms "and / or," "or / and," and "and / or" encompass any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that, in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR."

[0046] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0047] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0048] This document only specifically discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0049] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows temperature fluctuations within the precision range controlled by the instrument, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0050] In this document, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0051] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0052] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0053] In the description of the application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0055] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, but sequentially is preferred.

[0056] In related technologies, when using freeze-drying technology to prepare fresh bird's nest, there are certain differences in taste, nutrition, and absorption between freshly brewed bird's nest and dried bird's nest after brewing and rehydration. The bird's nest has poor fullness and smoothness, and its expansion ratio is generally between 25 and 35 times.

[0057] Supercritical drying technology is commonly used in aerogel drying, medical material preparation, catalyst preparation, and ultrafine material preparation. When using supercritical drying to prepare aerogels, organic solvents are typically added during the drying process to reduce the surface tension of the drying medium and ensure the prepared aerogel has a dense, porous structure. This process is complex and can lead to solvent residues. While supercritical drying technology has been applied to prepare bird's nest gel products, it requires the addition of ingredients such as agar, konjac flour, and sodium alginate to form a bird's nest gel mixture. During supercritical drying, this mixture forms a dense, porous structure, thereby increasing the swelling rate of the gel product. Therefore, although supercritical drying technology can improve the swelling rate of gel products, it necessitates the addition of other gel compounding ingredients.

[0058] Based on the above problems, this application provides a method for preparing green and additive-free bird's nest products. It utilizes the high diffusivity and high solubility of carbon dioxide in the supercritical state to quickly penetrate into the interior of the material being dried, thereby rapidly replacing water molecules inside the material and achieving rapid drying.

[0059] The first aspect of this application provides a method for preparing supercritical bird's nest products, comprising the following steps: using segmented progressive supercritical fluid technology, supercritical carbon dioxide as the drying medium, replacing the water in the soaked bird's nest while forming a nanoporous structure inside the bird's nest tissue, thereby preparing supercritical bird's nest products. The bird's nest products have better sialic acid conversion ability in the body, better utilization efficiency in blood plasma, and better absorption rate.

[0060] Supercritical fluid technology utilizes a drying medium that forms a supercritical fluid under critical temperature and pressure conditions. This supercritical fluid enters the material being dried and replaces water molecules, thus achieving the drying effect. Based on the low surface tension and high diffusion coefficient of supercritical fluids, this molecular replacement drying technique can maintain the original structure of bird's nest, preventing agglomeration and shrinkage during drying. Furthermore, it can create a nanoporous structure within the bird's nest, which plays a significant role in improving the product's swelling rate, consistency, and taste after brewing.

[0061] Carbon dioxide is a non-toxic, odorless, and colorless natural gas. Using carbon dioxide as a drying medium will not have an adverse effect on the materials being dried. Carbon dioxide itself is non-flammable and non-explosive, ensuring that the production process is safe. Furthermore, carbon dioxide has a low critical temperature (31.26℃), close to room temperature, and a critical pressure of 7.4MPa, making the production process easy to achieve and control.

[0062] Understandably, this application uses carbon dioxide as a drying medium when preparing bird's nest products. Under supercritical conditions, it directly interacts with pure bird's nest raw materials to perform water molecule replacement drying. No auxiliary ingredients need to be added throughout the process, making it safe, controllable, and healthy. The segmented and progressive molecular replacement method is beneficial for the bird's nest protein structure to be more open. At the same time, it can replace and remove some calcium and magnesium ions in the bird's nest, improve the solubility of bird's nest protein, and increase the expansion ratio of bird's nest after soaking.

[0063] This application applies segmented, progressive supercritical fluid technology to bird's nest. The drying process requires no organic solvents or other gelling ingredients, allowing direct drying of pure bird's nest materials and achieving an expansion effect of up to 80 times or more. The preparation process is simple to operate, additive-free, and safer and more controllable.

[0064] In some embodiments, the preparation method includes the following steps: mixing bird's nest with water and performing a first water absorption and swelling treatment; performing a first dehydration treatment on the bird's nest after the first water absorption and swelling treatment; performing a first displacement treatment on the bird's nest after the first dehydration treatment using supercritical carbon dioxide; mixing the bird's nest after the first displacement treatment with water and performing a second water absorption and swelling treatment; performing a second dehydration treatment on the bird's nest after the second water absorption and swelling treatment; and performing a second displacement treatment on the bird's nest after the second dehydration treatment using supercritical carbon dioxide to prepare a supercritical bird's nest product.

[0065] In some embodiments, the mass ratio of bird's nest to water during a single water absorption and swelling treatment is 1:(25-35); for example, it can be, but is not limited to, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, or any range between two of the above ratios. Thus, the bird's nest can be fully submerged in water, and the water gradually penetrates into the bird's nest to achieve the effect of water absorption and swelling.

[0066] In some embodiments, the soaking temperature for a single water absorption and swelling treatment is 28℃-38℃; for example, it can be, but is not limited to, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, or any range between two of the above temperatures. When the soaking temperature during the single water absorption and swelling treatment is within the above range, it can promote faster water absorption by the bird's nest, while reducing the probability of deformation of the bird's nest protein and loss of water-soluble protein nutrients during the soaking process.

[0067] The soaking time for a single water absorption and swelling treatment is 2h-4h; for example, it can be, but is not limited to, 2h, 2.2h, 2.5h, 2.8h, 3h, 3.3h, 3.5h, 3.8h, 4h, or any range between two of the above times.

[0068] It should be noted that when performing a water absorption and swelling treatment, the soaking temperature and soaking time can be combined in any suitable way, and both can be selected from any soaking temperature and soaking time described in this article.

[0069] In some implementations, the primary dehydration process includes spin-drying. Spin-drying removes some of the residual moisture from the surface of the bird's nest after the initial water absorption and swelling process. Furthermore, spin-drying results in a looser structure of the bird's nest, which facilitates the full interaction between carbon dioxide and the bird's nest during the replacement process.

[0070] In some optional embodiments, the spin-drying time during a single dehydration process is 8-15 minutes; for example, it can be, but is not limited to, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, or any two of the above time ranges. Thus, by controlling the spin-drying time, some residual moisture can be removed while better preserving the bird's nest strips, avoiding breakage of the bird's nest strips under high-speed rotation caused by excessive spin-drying.

[0071] In some implementations, the temperature for a single replacement treatment is between 15°C and 45°C. For example, it can be, but is not limited to, 15°C, 18°C, 20°C, 23°C, 25°C, 28°C, 30°C, 33°C, 35°C, 38°C, 40°C, 43°C, 45°C, or any two of the above temperatures. Thus, the temperature is controlled with reference to the critical temperature of carbon dioxide, while the lower temperature reduces the loss of nutrients from the bird's nest during the treatment process.

[0072] In some embodiments, the pressure for a single displacement treatment is 15MPa-25MPa; for example, it can be, but is not limited to, 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, 20MPa, 21MPa, 22MPa, 23MPa, 24MPa, 25MPa, or any two of the above pressures. Thus, by controlling the pressure to be above the critical pressure of carbon dioxide (7.4MPa), it is possible to ensure that the carbon dioxide reaches a supercritical fluid state while simultaneously displacing some of the moisture in the bird's nest and forming a preliminary dense porous structure.

[0073] As one possible implementation, the replacement treatment time is 20-60 minutes; for example, it can be, but is not limited to, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, or any range between two of the above times. This removes some of the moisture from the bird's nest and initially forms a dense, porous structure, preparing it for secondary soaking and swelling.

[0074] In some embodiments, during a single replacement treatment, the flow rate of supercritical carbon dioxide is 60 L / h to 100 L / h; for example, it can be, but is not limited to, 60 L / h, 65 L / h, 70 L / h, 75 L / h, 80 L / h, 85 L / h, 90 L / h, 95 L / h, 100 L / h, or any range between two of the above flow rates. This allows the carbon dioxide fluid to fully soak and contact with the bird's nest, achieving an effective effect.

[0075] After a displacement treatment, the carbon dioxide fluid, due to its low surface tension and high diffusion coefficient, can quickly and fully interact with the bird's nest, penetrating into the bird's nest protein gel network structure and displacing and removing some water molecules; at the same time, the bird's nest protein structure slowly unfolds, and in this process, a partially dense porous structure is formed inside the bird's nest.

[0076] In some embodiments, during the secondary water absorption and swelling treatment, the mass ratio of bird's nest to water after the first replacement treatment is 1:(20-40); for example, it can be, but is not limited to, 1:20, 1:23, 1:25, 1:28, 1:30, 1:33, 1:35, 1:40, or any range between two of the above ratios. This allows the bird's nest to be fully soaked in water, undergoing a secondary water absorption and swelling process.

[0077] In some embodiments, during the secondary water absorption and swelling treatment, the soaking temperature is 10℃-30℃; for example, it can be, but is not limited to, 10℃, 13℃, 15℃, 18℃, 20℃, 23℃, 25℃, 27℃, 30℃, or any two of the above temperatures. After the first replacement treatment, the structure of the bird's nest is relatively loose. Controlling the soaking temperature within the above range during the secondary water absorption and swelling treatment can reduce the loss of water-soluble proteins in the bird's nest during the soaking process.

[0078] The soaking time for the secondary water absorption and swelling treatment is 1h-4h; for example, it can be, but is not limited to, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h or any range between two of the above times.

[0079] It should be noted that the soaking temperature and soaking time during the secondary water absorption and swelling treatment can be combined in any suitable way, and both can be selected from any soaking temperature and soaking time described in this article for the secondary water absorption and swelling treatment.

[0080] As one possible implementation method, a secondary water absorption and swelling treatment is performed with mechanical wave assistance. This secondary water absorption and swelling treatment, through the cavitation effect generated, increases the transport rate of water molecules into the bird's nest, accelerates the penetration and diffusion within the bird's nest protein, and allows the dense, porous structure of the bird's nest to be fully filled with water molecules.

[0081] In some optional implementations, the frequency of the mechanical wave is 40kHz-50kHz; for example, it can be, but is not limited to, 40kHz, 41kHz, 42kHz, 43kHz, 44kHz, 45kHz, 46kHz, 47kHz, 48kHz, 49kHz, 50kHz, or any two of the above frequencies. When the frequency of the mechanical wave is within the above range, the resulting mechanical wave acts on the bird's nest, putting it in a dynamic water absorption and permeation state, accelerating the permeation of water molecules. This is because when the frequency is below 40kHz, the penetrating power of the mechanical wave is poor, and cavitation produces larger bubbles. Due to the large amount of energy released, the damage to the bird's nest strips is also greater. When the frequency is above 50kHz, although the penetrating power is stronger, the energy released by cavitation bubbles is smaller, resulting in a poor dynamic vibration effect. Therefore, controlling the frequency between 40-50kHz not only achieves a better dynamic cavitation effect, promoting the entry of water molecules into the bird's nest tissue, but also maintains the structure of the bird's nest strips from damage.

[0082] In some implementations, the secondary dehydration process includes spin drying.

[0083] In some embodiments, the spin-drying time is 5-8 minutes; for example, it can be, but is not limited to, 5 minutes, 5.5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes, 8 minutes, or any range between two of the above times. After the secondary water absorption and swelling treatment, the internal water content of the bird's nest is significantly increased, and the wall thickness of the internal porous structure becomes thinner. By controlling the spin-drying time during the secondary dehydration treatment within the above range, damage to the internal porous structure of the bird's nest due to prolonged spin-drying can be avoided.

[0084] In some optional embodiments, the temperature for the secondary replacement treatment is 45℃-60℃. For example, it can be, but is not limited to, 45℃, 47℃, 50℃, 53℃, 55℃, 58℃, 60℃, or any range between two of the above temperatures. Therefore, by increasing the temperature of the secondary replacement treatment, the replacement efficiency between the carbon dioxide fluid and the water molecules inside the bird's nest can be accelerated, increasing the drying speed. Simultaneously, during this process, the carbon dioxide fluid not only removes water molecules from the bird's nest but also replaces some calcium and magnesium ions, exposing more hydrophilic groups in the bird's nest protein and improving its solubility. Therefore, through the secondary replacement treatment, not only are water molecules removed from the bird's nest, achieving drying and the formation of a dense, porous structure, but the solubility of the bird's nest protein is also further improved.

[0085] In some optional embodiments, the pressure of the secondary replacement treatment is 35MPa-40MPa; for example, it can be, but is not limited to, 35MPa, 36MPa, 37MPa, 38MPa, 39MPa, 40MPa, or any two of the above pressures. Controlling the pressure of the secondary replacement treatment within the above range can accelerate the replacement efficiency of carbon dioxide fluid with water molecules inside the bird's nest, increasing the drying speed. Simultaneously, during this process, the carbon dioxide fluid not only removes water molecules from the bird's nest but also replaces some calcium and magnesium ions, exposing more hydrophilic groups in the bird's nest protein and improving its solubility. Therefore, through the secondary replacement treatment, not only are water molecules removed from the bird's nest, achieving drying and the formation of a dense porous structure, but the solubility of the bird's nest protein is also further improved.

[0086] As one possible implementation, the time for the secondary replacement process is 120 min to 180 min; for example, it can be, but is not limited to, 120 min, 130 min, 140 min, 150 min, 160 min, 170 min, 180 min, or any range between any two of the above times.

[0087] In some exemplary embodiments, during the secondary replacement process, the flow rate of supercritical carbon dioxide is 60 L / h to 100 L / h; for example, it can be, but is not limited to, 60 L / h, 65 L / h, 70 L / h, 75 L / h, 80 L / h, 85 L / h, 90 L / h, 95 L / h, 100 L / h, or any range between two of the above flow rates. Thus, the carbon dioxide can fill the entire cavity, ensuring sufficient contact between the bird's nest and the carbon dioxide fluid for secondary replacement and drying.

[0088] In some implementations, a supercritical apparatus can be used for the displacement treatment. The supercritical apparatus includes a cooling unit, an extraction vessel, an extraction vessel water tank, a separation vessel, a carbon dioxide cylinder, a carbon dioxide heater, and a control panel.

[0089] In some embodiments, the preparation method of bird's nest products includes the following steps:

[0090] Soak the bird's nest in water at a mass ratio of 1:(25-35) and perform a one-time water absorption and swelling treatment. The soaking temperature is 28℃-38℃ and the soaking time is 2h-4h.

[0091] After soaking and undergoing a water absorption and swelling treatment, the bird's nests are sorted to remove impurities, washed, and then spun dry in a spin dryer for 8-15 minutes to remove water.

[0092] Turn on the cooling pump switch of the supercritical equipment to cool it to about 8°C. Turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment. Open the valve of the carbon dioxide cylinder to allow gas to enter.

[0093] After the bird's nest has undergone one dehydration treatment, place it in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading vessel, put it into the extraction vessel, and seal it.

[0094] The temperature and pressure of the extraction vessel are increased to 15℃-45℃ and 15MPa-25MPa for a single displacement treatment. The supercritical carbon dioxide flow rate is 60L / h-100L / h and the displacement treatment time is 20min-60min.

[0095] After the first replacement treatment is completed, the pressure inside the container is released to 0MPa, and the bird's nest is taken out. The bird's nest is then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water is added and the high-frequency mechanical wave is set to a power of 40KHz-50KHz for assisted soaking for 1-4 hours to carry out a second water absorption and swelling treatment.

[0096] After the second water absorption and swelling treatment, the bird's nest is spun dry in a spin dryer for 5-8 minutes to perform a second water removal treatment.

[0097] The bird's nest, after secondary dehydration, is placed in an extraction vessel and subjected to a second heating and pressurization process. The temperature of the extraction vessel is increased to 45℃-60℃, and the pressure to 35MPa-40MPa for a second displacement treatment. The supercritical carbon dioxide flow rate is 60L / h-100L / h, and the second displacement treatment time is 120min-180min. After the second displacement treatment is completed, the pressure is released, and supercritical bird's nest is obtained.

[0098] The second aspect of this application provides a supercritical bird's nest, which is prepared using the preparation method of the first aspect of this application.

[0099] The supercritical bird's nest prepared using the method described in the first aspect of this application can produce effects more efficiently than conventional ready-to-cook bird's nest at a lower dosage. In other words, a lower intake can exert a greater beneficial effect. The concentration of free sialic acid in plasma is more than three times that of ready-to-cook bird's nest, and the corresponding conversion index can reach more than four times. Furthermore, it has better protein digestibility than ordinary stewed bird's nest and is more easily digested and absorbed by the human body.

[0100] The technical solutions of this application will be described in detail below with reference to specific embodiments. It should be understood that these embodiments are only for illustrating this application and are not intended to limit the scope of this application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application first, or follow experimental manuals or conventional conditions in the field, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the field.

[0101] In the specific embodiments described below, the measurement parameters involving raw material components may have slight deviations within the weighing accuracy range unless otherwise specified. For temperature and time parameters, acceptable deviations due to instrument testing accuracy or operational precision are permissible.

[0102] I. Preparation of Freshly Brewed Bird's Nest

[0103] Example 1

[0104] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 15MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 30 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 35 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 180 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0105] Example 2

[0106] The difference between Example 2 and Example 1 is that the pressure during a single replacement treatment is 25 MPa; all other aspects are the same. Details are as follows:

[0107] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 25MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 30 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 35 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 180 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0108] Example 3

[0109] The difference between Example 3 and Example 1 is that the pressure during a single replacement treatment is 20 MPa, while all other aspects are the same.

[0110] Example 4

[0111] The difference between Example 4 and Example 1 is that the pressure during a single replacement treatment is 10 MPa, while all other aspects are the same.

[0112] Example 5

[0113] The difference between Example 5 and Example 1 is that the pressure during a single replacement treatment is 30 MPa, while all other aspects are the same.

[0114] Example 6

[0115] The difference between Example 6 and Example 2 is that the pressure during the secondary replacement treatment is 40 MPa; all other aspects are the same. Details are as follows:

[0116] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 25MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 30 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 40 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 180 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0117] Example 7

[0118] The difference between Example 7 and Example 2 is that the pressure during the secondary replacement treatment is 37 MPa, while all other aspects are the same.

[0119] Example 8

[0120] The difference between Example 8 and Example 2 is that the pressure during the secondary replacement treatment is 32 MPa, while all other aspects are the same.

[0121] Example 9

[0122] The difference between Example 9 and Example 2 is that the pressure during the secondary replacement treatment is 43 MPa, while all other aspects are the same.

[0123] Example 10

[0124] The difference between Example 10 and Example 6 is that the pressure during a single replacement treatment is 20 MPa; all other aspects are the same. Details are as follows:

[0125] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 20MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 60 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 40 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 180 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0126] Example 11

[0127] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 20MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 60 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The bird's nest after the second dehydration treatment was placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 35 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 240 minutes. After the second displacement treatment, the pressure was released, and supercritical bird's nest was obtained.

[0128] Example 12

[0129] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 25MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 60 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 25 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 180 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0130] Example 13

[0131] Soak bird's nest in water at a mass ratio of 1:35 for a first water absorption and swelling treatment at 33℃ for 4 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 8 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 20MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 100L / h for 20 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 40 kHz power for assisted soaking for 4 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 5 minutes for a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 40 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 100 L / h, and the second displacement treatment time was 120 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0132] Example 14

[0133] Soak bird's nest in water at a mass ratio of 1:30 for one water absorption and swelling treatment at 38℃ for 2 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 12 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 25MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 80L / h for 60 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 45 kHz power for assisted soaking for 1 hour to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 7 minutes to perform a second dehydration treatment. The bird's nest after the second dehydration treatment was placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 38 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 80 L / h, and the second displacement treatment time was 150 minutes. After the second displacement treatment, the pressure was released, and supercritical bird's nest was obtained.

[0134] Comparative Example 1

[0135] The difference between Comparative Example 1 and Example 1 is that only a single water absorption swelling treatment and a single replacement treatment were performed; the details are as follows:

[0136] Bird's nest was soaked in water at a mass ratio of 1:30 at 28℃ for 3 hours to absorb water and swell. After soaking, the bird's nest was sorted to remove impurities, washed, and then spun dry for 15 minutes to remove water. The cooling pump of the supercritical equipment was turned on and cooled to approximately 8℃. The main switch on the control panel was turned on, and the heating switches for the extraction vessel, circulation pump, and separation vessel were also turned on to preheat the equipment. The carbon dioxide cylinder valve was opened to allow gas to enter. The dehydrated bird's nest was placed in a filter bag. The loading device in the extraction vessel was removed, and the bird's nest was placed on the layered partition and placed into the extraction vessel, which was then sealed. The temperature and pressure in the extraction vessel were increased to 35℃ and 15MPa for displacement treatment. The supercritical carbon dioxide flow rate was 60L / h, and the displacement treatment time was 240 minutes. After the displacement treatment, the pressure was released to 0MPa, and the bird's nest was removed, yielding supercritical bird's nest.

[0137] Comparative Example 2

[0138] The difference between Comparative Example 2 and Example 1 is that only a single water absorption swelling treatment and a single replacement treatment were performed; the details are as follows:

[0139] The bird's nest was soaked in water at a mass ratio of 1:30 at 28℃ for 3 hours to absorb water and swell. After soaking, the bird's nest was sorted to remove impurities, washed, and then spun dry for 15 minutes to remove water. The cooling pump of the supercritical equipment was turned on and cooled to approximately 8℃. The main switch on the control panel was turned on, and the heating switches for the extraction vessel, circulation pump, and separation vessel were also turned on to preheat the equipment. The carbon dioxide cylinder valve was opened to allow gas to enter. The dehydrated bird's nest was placed in a filter bag. The loading device in the extraction vessel was removed, and the bird's nest was placed on the layered partition and placed into the extraction vessel, which was then sealed. The temperature and pressure in the extraction vessel were increased to 45℃ and 35MPa for displacement treatment. The supercritical carbon dioxide flow rate was 60L / h, and the displacement treatment time was 180 minutes. After the displacement treatment, the pressure was released to 0MPa, and the bird's nest was removed, yielding supercritical bird's nest.

[0140] II. Sensory evaluation and expansion ratio test of bird's nest after brewing

[0141] 1. Weigh 1g of the supercritical bird's nest prepared in each of the above examples and comparative examples into a thermos flask, add 150g of boiled purified water to fully submerge the bird's nest, cover and steep for 5 minutes, then pour it into a bowl, observe its color and consistency, and calculate the expansion ratio. The expansion ratio test method is as follows:

[0142] *Method for testing the expansion ratio of bird's nest: After soaking, pour the bird's nest into a clean 20-mesh blank filter, tilt it at a 45° angle and filter for 2 minutes. Weigh the total weight of the filter and the solids in the bird's nest, m2, where the weight of the filter is m1. Formula for calculating the expansion ratio of bird's nest:

[0143] Rehydration ratio = (m2-m1) / dry weight of bird's nest (m).

[0144] The actual images of the supercritical bird's nest prepared in Example 1 before and after brewing are shown below. Figure 1 As shown, where Figure 1 Image a shows the actual supercritical bird's nest before brewing. Figure 1 Image b shows the actual product of supercritical bird's nest after brewing. Figure 1 It is evident that the supercritical bird's nest prepared in this application has a high water absorption and swelling rate and a good soaking effect.

[0145] 2. The sensory evaluation criteria for bird's nest after brewing are shown in Table 1.

[0146] Table 1

[0147]

[0148] The sensory evaluation and expansion ratio of the supercritical bird's nest after brewing in the above embodiments and comparative examples are shown in Table 2.

[0149] Table 2

[0150]

[0151] As can be seen from the results of Examples 1-14 and Comparative Examples 1-2, the supercritical bird's nest prepared using the segmented, progressive supercritical fluid technology in this application can be fully rehydrated after 5 minutes of steeping in a thermos. After brewing, the bird's nest has a good consistency, a full texture, and a suitable firmness, and its expansion ratio is increased. In contrast, bird's nest that only undergoes a single stage of supercritical carbon dioxide displacement treatment has a smaller expansion ratio.

[0152] In Example 11, the increase in the expansion ratio of the bird's nest was relatively small, around 40. This may be because the secondary replacement treatment took too long, potentially leading to excessive drying of the bird's nest surface, causing a certain degree of shrinkage in the surface structure and affecting its water absorption and swelling. This indicates that adjusting the time of the secondary replacement treatment can further improve the expansion ratio of the bird's nest.

[0153] In Example 12, the expansion ratio of the bird's nest was relatively small, around 45. This may be because the secondary replacement treatment used higher pressure and temperature compared to the first replacement treatment. While promoting rapid drying, the pressure allowed the bird's nest protein structure to expand more fully, and the supercritical carbon dioxide fluid displaced and carried away some metal ions. This process ensured the formation of a dense, porous structure within the bird's nest while simultaneously improving the solubility of the bird's nest protein, ultimately achieving a high expansion rate. Therefore, adjusting the relative relationship between temperature and pressure used in the first and second replacement treatments can further improve the expansion ratio and the texture of the bird's nest after soaking.

[0154] The comparison of the results of Examples 1-5 shows that when using the segmented progressive molecular replacement technology to prepare fresh bird's nest, controlling the pressure of each replacement treatment to 15MPa-25MPa is more conducive to further increasing the expansion ratio of bird's nest.

[0155] A comparison of the results from Examples 2 and 6-9 shows that when using a segmented, progressive molecular replacement technique to prepare fresh bird's nest, controlling the pressure of the secondary replacement treatment to 35MPa-40MPa is more conducive to further increasing the expansion ratio of the bird's nest.

[0156] 3. Cross-sectional images of the supercritical bird's nest prepared in Example 1 and the freshly soaked bird's nest prepared using FD technology in related techniques were observed using scanning electron microscopy; the results are as follows: Figure 2 As shown, Figure 2 In the image, 'a' represents a SEM image of a cross-section of freshly soaked bird's nest obtained using FD technology. Figure 2 In Figure 'b', the cross-sectional SEM image of the supercritical bird's nest prepared in Example 1 is shown. Figure 2 It is known that the supercritical bird's nest prepared in this application has a more regular and dense porous structure with clear pore walls and a more complete pore structure, which is more conducive to water absorption and swelling.

[0157] III. Evaluation of Application Products

[0158] Soak bird's nest in water at a mass ratio of 1:25 for a first water absorption and swelling treatment at 28℃ for 3 hours. After the first water absorption and swelling treatment, sort out impurities, wash, and then spin-dry for 15 minutes to remove water. Turn on the cooling pump of the supercritical equipment to cool to about 8℃, turn on the main switch of the control panel, and turn on the heating switches of the extraction vessel, circulation pump, and separation vessel to preheat the equipment; open the carbon dioxide cylinder valve to allow gas to enter. Place the dehydrated bird's nest in a filter bag, remove the loading device from the extraction vessel, place the bird's nest on the layered partition of the loading container, put it into the extraction vessel, and seal. Perform a first heat and pressure increase to the extraction vessel temperature of 35℃ and pressure of 20MPa for a first displacement treatment at a supercritical carbon dioxide flow rate of 60L / h for 40 minutes. After the first displacement treatment, the pressure inside the container was released to 0 MPa, and the bird's nest was removed. The bird's nest was then removed from the filter bag and placed in a high-frequency mechanical wave soaking device. Pure water was added, and the high-frequency mechanical wave was set to 50 kHz power for assisted soaking for 2 hours to perform a second water absorption and swelling treatment. The bird's nest after the second water absorption and swelling treatment was then spun dry for 8 minutes to perform a second dehydration treatment. The dehydrated bird's nest was then placed in an extraction vessel, and a second heating and pressurization process was performed until the extraction vessel temperature reached 45℃ and the pressure reached 40 MPa for a second displacement treatment. The supercritical carbon dioxide flow rate was 60 L / h, and the second displacement treatment time was 150 minutes. After the second displacement treatment, the pressure was released, yielding supercritical bird's nest.

[0159] 1. Product digestibility evaluation

[0160] To compare the protein digestibility of supercritical bird's nest prepared by supercritical fluid technology with that of ordinary white bird's nest, the following sample preparation was performed: the supercritical product was stewed in a water bath at a ratio of 1:100 for 5 minutes; the white bird's nest product was stewed in a water bath at a ratio of 1:100 for 25 minutes. After stewing, the samples were homogenized, and 1.00g (±0.1g) of the homogenized bird's nest was taken and the volume was adjusted to 5.0mL.

[0161] 1) Preparation of digestion products from supercritical fluid and white bird's nest products:

[0162] a. Simulated digestion: Before digestion, all digestive fluids are warmed to 37°C.

[0163] b. Oral digestion

[0164] Weigh 30g of sample, mix it with 30g of saliva digestion electrolyte and 0.15mL of CaCl2(H2O)2, and incubate at 37℃ for 2min.

[0165] c. Stomach digestion

[0166] Add 50 mL of gastric digestion electrolyte to the oral digests, adjust the pH of the digestion solution to 3 with 1 M HCl solution, add 0.03 mL of CaCl2(H2O)2 and mix, dissolve pepsin in 10 mL of gastric digestion electrolyte solution to prepare a final concentration of pepsin 1800 U / mL, adjust the pH to 3, and incubate at 37℃ for 2 h.

[0167] d. Intestinal digestion

[0168] Add 110 mL of intestinal digestion electrolyte to the gastric digest, add 1 M NaOH solution to adjust the pH of the digestion solution to 7, add 0.24 mL of CaCl2(H2O)2 and mix, dissolve trypsin in 10 mL of intestinal digestion electrolyte to prepare a concentration of 90 U / mL, adjust the pH to 7, and incubate at 37°C for 2 h.

[0169] Centrifuge the digestion solution, collect the supernatant, take 30 μL of the above sample and mix it with 10 μL of 4× protein loading buffer (containing DTT), heat at 100℃ for denaturation for 8 min, centrifuge for 2 min, and take 20 μL of the supernatant into the lane for electrophoresis.

[0170] 2) Electrophoresis conditions

[0171] Use an electrophoresis system with a 4% stacking gel and a 10% separating gel. Voltage settings: 80V for 20 min, 120V for 50 min. Stop electrophoresis when the bromophenol blue reaches the bottom of the separating gel. Remove the gel to a petri dish, rinse with pure water to reduce background, then add Coomassie Brilliant Blue rapid staining solution and stain for 20 min, followed by destaining with pure water overnight.

[0172] 3) Results

[0173] SDS-PAGE gel electrophoresis analysis showed that the protein concentration in the supernatant after digestion was significantly higher in the supercritical product than in the white bird's nest product. Figure 3As shown, the electrophoretic bands of the supercritical product are significantly darker than those of the white bird's nest product, indicating that the protein digestibility of the supercritical product is higher than that of ordinary white bird's nest when stewed. This is because supercritical processing of bird's nest can change its texture, forming a nanoporous structure inside the bird's nest, making the protein structure more open, accelerating the water absorption and swelling process during stewing, and making it easier to digest.

[0174] 2. Evaluation of the utilization rate of sialic acid in blood from supercritical products

[0175] Animal experiments were conducted to compare and evaluate the differences in sialic acid utilization efficiency between the supercritical bird's nest product prepared above and ordinary ready-to-cook dried bird's nest product. The specific methods are as follows:

[0176] 1) Sample preparation:

[0177] The bird's nest products were processed, and the total sialic acid content of supercritical bird's nest and ready-to-cook bird's nest was tested separately. An appropriate amount of bird's nest product was placed in a beaker and homogenized at 10000 rpm for 3 minutes. The mixture was allowed to stand until the foam disappeared, and at least 15g was reserved for nitrogen determination analysis. The remaining portion was accurately weighed (to a precision of 0.01g) into a colorimetric tube, and an equal volume of glacial acetic acid was added to make the acetic acid concentration in the hydrolysate 50%. The colorimetric tube was sealed with a glass stopper and hydrolyzed in a 100℃ water bath for 10 minutes. The colorimetric tube was then removed and cooled to room temperature. The hydrolysate was filtered through filter paper and transferred to a 100mL volumetric flask. The volume was adjusted to the mark with the mobile phase, mixed well, and the supernatant was filtered through a 0.45μm syringe filter for analysis. The method for determining sialic acid content refers to the People's Republic of China National Standard (GB / T30636—2014) "Determination of sialic acid in bird's nest and its products - Liquid chromatography", and high performance liquid chromatography is used to determine the sialic acid content in the sample.

[0178] 2) Animal grouping and intervention

[0179] Twenty-four adult male SD rats, approximately 60-70 days old and weighing 300-400g, were provided by the Experimental Animal Center of Xiamen University (ethics review number: XMULAC20210010). Each group was treated with sialic acid standard, ready-to-cook bird's nest, supercritical bird's nest, or sterilized ultrapure water, respectively. See Table 3 for details.

[0180] Table 3. Animal grouping and intervention

[0181]

[0182] Animal feeding and grouping: Twenty-four 9-week-old male SD rats were acclimatized for one week and then randomly divided into four groups: a supercritical bird's nest group (35.46 mg / kg), a ready-to-cook bird's nest group (43.80 mg / kg), a sialic acid control group (41.71 mg / kg), and a blank control group (sterilized ultrapure water), with six rats in each group. The experiment was divided into three phases (nitrogen-free and sialic acid-free feeding phase, nitrogen-free and sialic acid-containing feeding phase, and nitrogen-containing and sialic acid-containing feeding phase). Each rat was fed individually in a metabolic cage, and its feed consumption and body weight were measured daily during the formal experiment.

[0183] Sample Collection and Testing: During the intervention period, rat urine and feces were collected daily at regular intervals. After the feces and urine were collected at each stage, the sialic acid content in the samples was detected by high-performance liquid chromatography (HPLC), and the nitrogen content in the samples was detected by the Kjeldahl method. After the metabolic cage stage, the test substance was continuously administered by gavage for 15 days. Blood samples were collected before and after the intervention. After centrifugation, plasma was collected, plasma proteins were precipitated, and erythrocyte membranes were extracted. The concentrations of free serum sialic acid (FSSA), erythrocyte surfaceialic acid (ESSA), and protein-bound sialic acid (PBSA) in rat plasma before and after the intervention were detected by HPLC.

[0184] 3) Plasma free sialic acid concentration and conversion index are shown in Table 4 and Figure 4-5 As shown.

[0185] Table 4. Plasma free sialic acid concentration and conversion index (x±S) in each intervention group

[0186] Grouping N 0 day (mg / L) 15 days (mg / L) Conversion Index Blank control 3 O±0a <![CDATA[O±0 6 ]]> -＝ Standard products 3 <![CDATA[O±0 3 ]]> 4.23±2.39b 0.64±0.366 Stewed bird's nest 3 <![CDATA[O±0 8 ]]> 2.81±2.79b 0.41±0.4b Supercritical bird's nest <![CDATA[O±0 8 ]]> 10.54±2.74 1.89±0.49a

[0187] Note: In Table 4, there are significant differences between values ​​with completely different superscript letters in the same column (P < 0.05). (Bonferroni correction used)

[0188] like Figure 4As shown, free sialic acid was not detected in plasma before intervention. After 15 days of continuous intervention with the test substance, free sialic acid was detected in plasma in all intervention groups except the blank group. The supercritical bird's nest group had the highest concentration of free sialic acid in rat plasma (10.54±2.74 mg / L), while the standard group (4.23±2.39 mg / L) and the ready-to-cook bird's nest group (2.81±2.79 mg / L) had lower concentrations, and the differences between the groups were statistically significant (F=7.888, P=0.009). The results showed that the concentration of free sialic acid in plasma in the supercritical bird's nest group was higher than that in the other three groups. Since the total amount of sialic acid ingested by different groups also differed, after adjusting for this factor, the conversion capacity of exogenous sialic acid in plasma for the same intake was obtained as follows: Figure 5 As shown, statistical analysis revealed significant differences in the free sialic acid conversion index among the groups (F = 10.601, P = 0.011). Pairwise comparisons showed differences between the supercritical bird's nest group and the instant bird's nest group, as well as the sialic acid group (P = 0.011, P = 0.005). The sialic acid conversion index of the supercritical bird's nest group was higher than that of the other two groups, indicating that the sialic acid in supercritical bird's nest has a better conversion capacity in the body and is more efficiently utilized in plasma.

[0189] 4) Plasma protein-bound sialic acid content and conversion index are shown in Table 5 and Figure 6 As shown.

[0190] Table 5. Plasma protein-bound sialic acid content and conversion index (x±S) in each intervention group

[0191] Grouping N 0 day (mg / g) 15 days (mg / g) Conversion Index Blank control 3 34.65±19.59a 16.17±19.54 Standard products 3 5.29±4.82a 19.72±5.46 2.2±1.45 Stewed bird's nest 3 35.09±23.04ǎ 304.09±7.01a 39.01±2.365 Supercritical bird's nest 3 9.00±10.37a 273.25±41.71 47.33±5.650

[0192] Note: In Table 5, there are significant differences between values ​​with completely different superscript letters in the same column (P < 0.05). (Bonferroni correction used)

[0193] like Figure 6 As shown, the sialic acid conversion index of supercritical bird's nest (47.33±5.65) was the highest among all groups, followed by the stewed bird's nest group (39.01±2.36), while the standard group (2.2±1.45) was significantly lower. Analysis of variance revealed statistically significant differences in the sialic acid conversion index among the groups (F=131.182, P=0.0001). Pairwise comparisons showed that the saliva segment of the supercritical bird's nest group had the highest conversion index.

[0194] In terms of blood parameters, the plasma free sialic acid concentration and conversion index, as well as the protein-bound sialic acid conversion index, of the supercritical bird's nest group were significantly higher than those of the ready-to-cook bird's nest group (P < 0.05), the sialic acid group (P < 0.005), and the blank group (P < 0.005). These differences were statistically significant, indicating that the utilization efficiency of sialic acid in the blood of the supercritical group was superior to the other three groups. After 15 days of continuous intervention, the plasma free sialic acid concentration in the supercritical bird's nest group was more than three times that of the ready-to-cook bird's nest group, and the corresponding conversion index was more than four times higher. This demonstrates that freshly brewed bird's nest processed using supercritical carbon dioxide molecular displacement technology can produce a more efficient effect than ready-to-cook bird's nest at lower doses.

[0195] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0196] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a bird's nest product, characterized in that, Includes the following steps: The bird's nest product is prepared by using segmented, progressive supercritical fluid technology and supercritical carbon dioxide as a drying medium to replace the moisture in the soaked bird's nest. The preparation method includes the following steps: Mix the bird's nest with water and perform a water absorption and swelling treatment; The bird's nest, after undergoing a water absorption and swelling treatment, will undergo a dehydration treatment. The bird's nest, after undergoing a dehydration process, is replaced with supercritical carbon dioxide. The bird's nest, after undergoing a first replacement treatment, is mixed with water and then subjected to a second water absorption and swelling treatment. The bird's nest, after undergoing a second water absorption and swelling treatment, will then undergo a second dehydration treatment. The bird's nest product is prepared by using supercritical carbon dioxide to perform a secondary replacement treatment on the bird's nest after secondary dehydration. The temperature of the first replacement treatment is 15℃-45℃, the pressure of the first replacement treatment is 15MPa-25MPa, the time of the first replacement treatment is 20min-60min, and the flow rate of the supercritical carbon dioxide is 60L / h-100L / h. The temperature of the secondary replacement treatment is 45℃-60℃, the pressure of the secondary replacement treatment is 35MPa-40MPa, the time of the secondary replacement treatment is 120min-180min, and the flow rate of the supercritical carbon dioxide is 60L / h-100L / h.

2. The preparation method according to claim 1, characterized in that, During the first water absorption and swelling treatment, the mass ratio of bird's nest to water is 1:(25-35); and / or The soaking temperature for the first water absorption and swelling treatment is 28℃-38℃, and the soaking time is 2h-4h.

3. The preparation method according to claim 1, characterized in that, During the secondary water absorption and swelling treatment, the mass ratio of the bird's nest to water after the first replacement treatment is 1:(20-40); and / or The soaking temperature for the secondary water absorption and swelling treatment is 10℃-30℃, and the soaking time is 1h-4h.

4. The preparation method according to claim 1, characterized in that, The secondary water absorption and swelling treatment is carried out with the assistance of mechanical waves.

5. The preparation method according to claim 4, characterized in that, The frequency of the mechanical wave is 40KHz-50KHz.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The primary dehydration process includes spin drying.

7. The preparation method according to claim 6, characterized in that, The spin-drying time is 8-15 minutes.

8. The preparation method according to any one of claims 1 to 5, characterized in that, The secondary dehydration process includes spin drying.

9. The preparation method according to claim 8, characterized in that, The spin-drying time is 5-8 minutes.

10. A bird's nest product, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 9.

Images