Processing method of cubilose
By combining ohmic heating and steam pasteurization, the problems of nutrient loss and low-temperature sterilization efficiency caused by high-temperature heating in traditional bird's nest processing are solved, and the effects of efficient sterilization and nutritional retention are achieved.
Patent Information
- Application Number
- CN202510582925.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2025-06-06
AI Technical Summary
In traditional bird's nest processing methods, high-temperature heating leads to loss of nutrients, a loss of taste, and low-temperature sterilization cannot effectively kill spores, and the treatment efficiency is low.
The bird's nest was heated within 60 to 120 seconds by combining ohmic heating and steam pasteurization by electric field treatment, and then treated in steam pasteurization at 100 to 110°C for 3 to 5 minutes.
On the premise of ensuring the nutritional value and crispness of bird's nest, good sterilization effect is achieved, significantly reducing the total processing time and energy consumption, and improving the thoroughness of sterilization and food quality retention.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of food processing, and in particular relates to a bird's nest processing method. Background Art
[0002] As people's health awareness continues to improve, more and more consumers, especially those who pay attention to health preservation, both men and women, tend to choose natural and healthy health preservation methods. Bird's nest, as a precious food, is rich in protein, sialic acid and minerals, and has high nutritional and medicinal value, making it an ideal choice to meet the needs of these consumers.
[0003] In the traditional bird's nest processing, bird's nests are usually processed by heating methods such as stewing and steaming. These heating methods often require a long period of high-temperature heating. For example, long-term exposure to high temperatures above 110°C will cause the loss of nutrients in the bird's nest, reduce the flavor, and even affect the taste of the bird's nest. Low-temperature sterilization, such as pasteurization, usually processes bird's nests between 60 and 85°C. Although this method has relatively little effect on the taste of the bird's nest and can maintain the original taste structure of the bird's nest to a certain extent, low-temperature sterilization may not effectively kill the spores in the bird's nest, and the processing efficiency is low.
[0004] With the development of science and technology, electric heating and ohmic heating technologies are gradually being used in the field of food processing. Ohmic heating directly acts on food materials through electric current, and uses the resistance effect to generate uniform heat to heat the materials. It has the advantages of high heating efficiency, uniform heating, short time, and energy saving. In addition, the non-thermal action mechanism of ohmic heating is mainly manifested in several aspects: the cell membrane electroporation phenomenon induced by the electric field can enhance the mass transfer efficiency and promote the selective extraction of functional components; the direct destructive effect of electric current on the microbial cell membrane and the thermal synergistic effect jointly improve the sterilization effect; in addition, the electric field can also affect the secondary and tertiary structures of proteins, change enzyme activity and the conformation of biological macromolecules, thereby regulating the texture characteristics of food. However, the sterilization effect of bird's nest sterilization using simple ohmic heating is not ideal. This is mainly due to several key factors: first, the thermophilic spore bacteria in food have extremely strong heat resistance and it is difficult to completely inactivate them simply by relying on conventional ohmic heating temperature; second, bird's nests have a complex network structure, and many microorganisms are embedded in the microenvironment constructed by the gel network and cannot be fully exposed to the electric field environment to form a "protective barrier"; in addition, the difference in electrical conductivity of bird's nests leads to uneven distribution of the electric field, resulting in a "cold spot" area.
[0005] In addition, steam pasteurization can effectively inactivate heat-resistant spores and highly resistant microorganisms in food by using pressurized saturated steam as a heat transfer medium. In a closed pressurized system, steam can reach a high temperature while maintaining good heat penetration and uniformity. This high-temperature steam treatment is suitable for foods with high pH or high viscosity, such as canned products, seasoning sauces, thick fruit and vegetable purees, etc. Compared with UHT ultra-high temperature instantaneous sterilization, steam pasteurization can better maintain the texture of bird's nest while extending the shelf life of the product and reduce the destructive effect of excessive high temperature on the gel. However, the rich protein, sialic acid and other substances in bird's nest give it a high nutritional value, and inappropriate sterilization methods during the processing of bird's nest will lead to the loss of its nutritional value. In order to ensure the sterilization effect, the existing pasteurization method usually uses a higher temperature and a longer time for sterilization (such as stewing at 121°C for about 19 minutes), which will lead to the loss of nutrients such as protein and sialic acid in the bird's nest, as well as the decrease in the crispness of the bird's nest, affecting the taste. Summary of the invention
[0006] In order to solve all or part of the above technical problems, the present invention provides the following technical solutions: One of the purposes of the present invention is to provide a method for processing bird's nests, comprising: The bird's nest is placed in an electric field capable of generating Joule heating effect, the excitation voltage of the electric field is set to 3200-4800 V, the frequency is set to 20-60 kHz, and the bird's nest is allowed to stay in the electric field for 60-120 seconds for electric field treatment; Then, the bird's nest treated by the electric field is subjected to steam pasteurization, wherein the steam pasteurization temperature is 100-10° C. and the time is 3-5 minutes.
[0007] The method provided by the present invention combines ohmic heating with steam pasteurization (100-110°C), which can achieve a good sterilization effect under the important premise of maintaining the nutritional value and crispness of the bird's nest. Specifically, the electric field is first used to cause electroporation and structural damage to the microbial cell membrane, promote the dissolution of the bacteria from the protective matrix, and then a suitable high temperature is applied to complete the inactivation process. This synergistic mechanism significantly reduces the total processing time and total processing energy consumption, while improving the thoroughness of sterilization and the retention of food quality, and allowing the product to maintain a better taste.
[0008] In addition, the time of electric field treatment and pasteurization stage has an important influence on the quality improvement and sterilization effect of bird's nest. If the time is too long, it may cause the crispness to decrease and affect the taste; if the time is too short, the sterilization effect is not significant. The electric field treatment of 60~120s combined with steam pasteurization of 3~5min has a good comprehensive effect. In addition, the sterilization method in the prior art usually requires 15~25 minutes of long-term high-temperature treatment. The method provided by the present invention requires a short time, high efficiency, and is conducive to the production of high-quality bird's nests.
[0009] In some embodiments, the method specifically includes: mixing dry bird's nest with water to form wet bird's nest, and keeping the wet bird's nest in a flowing state in the electric field.
[0010] In some embodiments, the bird's nest is made to flow through the electric field at a constant speed.
[0011] In some preferred embodiments, the wet bird's nest is made to flow uniformly in the electric field at a speed of 10 L / h to 15 L / h to ensure that the bird's nest can be evenly and effectively treated when passing through the electric field.
[0012] In some embodiments, the method specifically includes: An electric field generating device is provided, the electric field generating device comprising an electrode, an excitation power source, a storage mechanism and an insulating pipeline, the excitation power source is connected to the electrode, the excitation power source is applied to the electrode to generate the electric field, the storage mechanism is used to store bird's nests and is connected to the insulating pipeline, at least part of the insulating pipeline is arranged in the electric field; The excitation power supply is turned on to generate the electric field, so that the bird's nest in the storage mechanism flows into the insulating pipeline and keeps flowing in the insulating pipeline.
[0013] In some embodiments, the strength of the electric field is 80 V / cm-120 V / cm.
[0014] In some embodiments, the peak temperature of the bird's nest in the electric field is maintained at 70°C to 95°C. Within this temperature range, the electric field treatment will not cause too much negative impact on the sensory quality of the bird's nest, and can effectively maintain the taste and nutritional components of the bird's nest. Considering sufficient sterilization and maintaining the taste and nutritional components, the preferred temperature is 90°C to 95°C. The temperature of the bird's nest before the electric field treatment is 25°C to 30°C.
[0015] The method provided by the present invention is applicable to any variety of bird's nests, such as white bird's nests, yellow bird's nests, red bird's nests, etc., but is not limited thereto.
[0016] The second object of the present invention is to provide a sterilization method for maintaining the crispness of bird's nest, comprising: The bird's nest is placed in an electric field capable of generating Joule heating effect for ohmic heating sterilization, the excitation voltage of the electric field is set to 3200-4800 V, the frequency is set to 20-60 kHz, and the bird's nest is allowed to stay in the electric field for 60-120 seconds; Then, the bird's nest treated by the electric field is subjected to steam pasteurization, wherein the steam pasteurization temperature is 100-110° C. and the time is 3-5 minutes.
[0017] The method provided by the invention can maintain the crispness and taste of the bird's nest while fully sterilizing it.
[0018] The third object of the present invention is to provide a sterilization method for maintaining the protein and sialic acid content in bird's nests, comprising: The bird's nest is placed in an electric field capable of generating Joule heating effect for ohmic heating sterilization, the excitation voltage of the electric field is set to 3200-4800 V, the frequency is set to 20-60 kHz, and the bird's nest is allowed to stay in the electric field for 60-120 seconds; Then, the bird's nest treated by the electric field is subjected to steam pasteurization, wherein the steam pasteurization temperature is 100-110° C. and the time is 3-5 minutes.
[0019] The method provided by the present invention can fully sterilize while ensuring that protein and sialic acid in the bird's nest are not lost, thereby maintaining its good nutritional quality.
[0020] The sterilization method for maintaining the crispness of the bird's nest and the further scheme of the sterilization method for maintaining the protein and sialic acid content in the bird's nest described in the present invention have been described in detail in the first purpose of the present invention, namely "a bird's nest processing method", and will not be repeated here.
[0021] Compared with the prior art, the present invention has at least the following beneficial effects: the present invention regulates electric field treatment, steam pasteurization and precisely regulates the parameters of the two stages to ensure the sterilization effect while retaining important nutrients such as protein and sialic acid of the bird's nest to the greatest extent, maintaining the crispness of the bird's nest, and obtaining a bird's nest with good quality. In addition, the method requires a short time, has high processing efficiency and low energy consumption. DETAILED DESCRIPTION
[0022] The technical solution of the present invention is described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand and implement the technical solution of the present invention. The specific functional details disclosed herein should not be interpreted as limiting, but only as the basis for the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in different ways in any appropriate detailed embodiment.
[0023] In addition, unless otherwise specified, the various raw materials used in the following examples can be purchased from the market and other channels, the various production and testing equipment used are also equipment known in the art, and the testing methods used are also methods known in the art.
[0024] The electric field generating device used in the following embodiments and comparative examples includes electrodes, an excitation power supply, a storage tank and an insulating pipeline. The excitation power supply is connected to the electrodes, and the excitation power supply is applied to the electrodes to generate an electric field. The storage tank is used to store bird's nests and is connected to the insulating pipeline, and at least a portion of the insulating pipeline is arranged in the electric field.
[0025] Example 1 Embodiment 1 provides a method for sterilizing white bird's nest, which specifically comprises the following steps: (1) Raw material pretreatment: Take 500 g of dry white bird's nest and 13 L of purified water, put the dry white bird's nest and water into a storage tank to form a wet bird's nest, and then seal the storage tank.
[0026] (2) The wet white bird's nest in the storage tank was passed into the pipeline and allowed to flow continuously at a flow rate of 11 L / h in the pipeline; the excitation voltage of the excitation power supply was set to 3200 V, the frequency was set to 20 kHz, the distance between the two poles was set to 40 cm, and the electric field strength was set to 80 V / cm. The white bird's nest was allowed to flow in the electric field for 60 s, and the peak temperature of the white bird's nest when flowing in the electric field was controlled to be 70°C for ohmic heating sterilization.
[0027] (3) The white bird's nest sterilized by ohmic heating is quickly canned and placed in a steam sterilizer for pasteurization at a temperature of 105°C for 5 minutes.
[0028] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the mean was finally calculated. The sialic acid content of the white bird's nest in Example 1 after two-stage sterilization treatment was measured to be 3.54 g / kg.
[0029] The protein content in the bird's nest was detected using GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the mean was finally calculated. The protein content of the white bird's nest of Example 1 after two-stage sterilization treatment was measured to be 2.24 g / 100 g.
[0030] The texture of the treated bird's nest was tested by the method of Li Can. Effects of bird's nest pretreatment and addition methods on sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest after two-stage pasteurization in Example 1 was measured to be 56.25 gf.
[0031] The total number of colonies in the treated bird's nest was detected, and the detection method adopted "GB 4789.2-2016 National Food Safety Standard Food Microbiology Inspection Determination of Total Colony Count". Each group of samples was tested three times. No microorganisms were detected in the white bird's nest of Example 1 after sterilization.
[0032] Example 2 Embodiment 2 provides a method for sterilizing yellow bird's nest, which specifically comprises the following steps: (1) Raw material pretreatment: Take 500 g of dry yellow bird's nest and 13 L of purified water, put the dry yellow bird's nest and water into a storage tank to form a wet bird's nest, and then seal the storage tank.
[0033] (2) The wet yellow bird's nest in the storage tank was passed into the pipeline and allowed to flow continuously at a flow rate of 13 L / h in the pipeline; the excitation voltage of the excitation power supply was set to 3600 V, the frequency was set to 50 kHz, the distance between the two poles was set to 40 cm, and the electric field strength of the formed electric field was set to 90 V / cm. The yellow bird's nest was allowed to flow in the electric field for 100 s, and the peak temperature of the yellow bird's nest when flowing in the electric field was controlled to be 90°C for ohmic heating sterilization.
[0034] (3) The yellow bird's nest sterilized by ohmic heating is quickly canned and placed in a steam sterilizer for pasteurization at a temperature of 110°C for 3 minutes.
[0035] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the mean was finally calculated. The sialic acid content of the yellow bird's nest in Example 2 after two-stage sterilization treatment was measured to be 3.58 g / kg.
[0036] The protein content in the bird's nest was detected using GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the mean was finally calculated. The protein content of the yellow bird's nest of Example 2 after two-stage sterilization treatment was measured to be 2.29 g / 100 g.
[0037] The texture of the treated bird's nest was tested by the method of Li Can. Effects of bird's nest pretreatment and addition methods on sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest after two-stage pasteurization in Example 2 was measured to be 58.57 gf.
[0038] The total number of colonies in the processed bird's nest was tested, and the detection method adopted "GB 4789.2-2016 National Food Safety Standard Food Microbiology Inspection Determination of Total Colony Count". Each group of samples was tested three times. No microorganisms were detected in the yellow bird's nest of Example 2 after two-stage pasteurization.
[0039] Example 3 Embodiment 3 provides a method for sterilizing red bird's nest, which specifically comprises the following steps: (1) Raw material pretreatment: Take 500 g of dry red bird's nest and 13 L of purified water, put the dry red bird's nest and water into a storage tank to form a wet bird's nest, and then seal the storage tank.
[0040] (2) The wet red bird's nest in the storage tank was passed into the pipeline and allowed to flow continuously at a flow rate of 15 L / h in the pipeline; the excitation voltage of the excitation power supply was set to 4800 V, the frequency was set to 60 kHz, the distance between the two poles was set to 40 cm, and the electric field strength of the formed electric field was set to 120 V / cm. The red bird's nest was allowed to flow in the electric field for 120 s, and the peak temperature of the red bird's nest when flowing in the electric field was controlled to be 95°C for ohmic heating sterilization.
[0041] (3) The red bird's nest sterilized by ohmic heating is quickly canned and placed in a steam sterilizer for pasteurization. The pasteurization temperature is 107°C and the time is retained for 5 minutes.
[0042] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the mean was finally calculated. The sialic acid content of the red bird's nest in Example 3 after two-stage sterilization treatment was measured to be 3.55 g / kg.
[0043] The protein content in the bird's nest was detected using GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the mean was finally calculated. The protein content of the red bird's nest of Example 3 after two-stage sterilization was measured to be 2.26 g / 100 g.
[0044] The texture of the treated bird's nest was tested by the method of Li Can. Effects of bird's nest pretreatment and addition methods on sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest after two-stage pasteurization in Example 3 was measured to be 57.10 gf.
[0045] The total number of colonies in the bird's nest was detected, and the detection method adopted "GB 4789.2-2016 National Food Safety Standard Food Microbiology Examination Determination of Total Colony Count". Each group of samples was tested three times. No microorganisms were detected in the red bird's nest of Example 3 after sterilization.
[0046] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the white bird's nest is not subjected to ohmic heating treatment, and in order to achieve a sufficient sterilization effect, the parameters of steam pasteurization are: temperature is 121°C, and time is 15 min.
[0047] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the average was finally calculated. The sialic acid content of the white bird's nest of comparative example 1 after sterilization was measured to be 2.54 g / kg.
[0048] The protein content in the bird's nest was detected using GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the average was finally calculated. The protein content of the white bird's nest of Comparative Example 1 after two-stage sterilization was measured to be 1.35 g / 100 g.
[0049] The texture of the bird's nest was tested using the method of Li Can. Effects of bird's nest pretreatment and addition methods on the sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest treated by the method of comparative example 1 after sterilization was measured to be 50.19 gf.
[0050] The total colony count in the bird's nest was tested using the GB 4789.2-2016 National Food Safety Standard - Determination of the Total Colony Count in Food Microbiological Examination. Each group of samples was tested three times. No microorganisms were detected in the white bird's nest of Example 1 after sterilization.
[0051] The sialic acid and protein content of the white bird's nest of Comparative Example 1 is lower than that of Example 1, indicating that the electric field effect generated by ohmic heating, such as polarization and electrolysis, may change the structure of certain proteins and polysaccharides, making the binding of sialic acid to the protein in the bird's nest more stable, thereby improving its ability to resist degradation during subsequent steam sterilization. At the same time, it reduces the adverse effects of high temperature treatment on the nutritional components of the bird's nest.
[0052] The bird's nest of Comparative Example 1 has a lower crispness than that of Example 1, indicating that excessively high temperature and excessively long time of pasteurization treatment will change the crispness of the bird's nest, thereby affecting the taste. However, if the temperature and time of pasteurization treatment are only reduced in order to maintain the taste of the bird's nest, sufficient sterilization cannot be guaranteed.
[0053] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that the yellow bird's nest is not subjected to steam pasteurization, and the rest is the same as Example 2.
[0054] After the ohmic heating treatment, the canned product is obtained. After the temperature stabilizes at room temperature, the lid is opened for observation and an obvious white core is found, indicating that the heating time is too short and there may not be enough time for the outside and inside of the bird's nest to be heated evenly, resulting in the outside being stewed but the inside (white core part) is still not completely softened or cooked.
[0055] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the mean was finally calculated. The sialic acid content of the yellow bird's nest in comparative example 2 after sterilization was measured to be 2.51 g / kg.
[0056] The protein content in the bird's nest was tested using the GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the mean was finally calculated. The protein content of the sterilized yellow bird's nest in Example 2 was measured to be 1.39 g / 100 g.
[0057] The texture of the bird's nest was tested using the method of Li Can. Effects of bird's nest pretreatment and addition methods on the sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest of comparative example 2 after sterilization was measured to be 58.12 gf.
[0058] The total colony count in the bird's nest was tested using the GB 4789.2-2016 National Food Safety Standard Food Microbiology Inspection - Determination of the Total Colony Count. Each group of samples was tested three times. The yellow bird's nest in Comparative Example 2 had significant microbial growth after sterilization, with a total colony count of 87 CFU / g.
[0059] The protein content of the yellow bird's nest in Comparative Example 2 is lower than that in Example 2, which means that if a relatively high heating temperature and a certain heating time are not reached, the soluble protein content will be reduced, which is not conducive to human absorption.
[0060] The bird's nest of comparative example 2 has a slightly lower crispness than that of example 2, with a small change. The total number of colonies detected in the bird's nest treated by the method of comparative example 2 exceeds 10 CFU / g, indicating that only ohmic heating sterilization treatment without steam sterilization step leads to incomplete sterilization.
[0061] Comparative Example 3 The only difference between Comparative Example 3 and Example 2 is that the yellow bird's nest is not subjected to ohmic heating sterilization treatment, and the rest is implemented in the same way as Example 2, which will not be repeated here.
[0062] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the average was finally calculated. The sialic acid content of the yellow bird's nest in comparative example 3 after sterilization was measured to be 2.42 g / kg.
[0063] The protein content in the bird's nest was detected using the detection method of GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the average was finally calculated. The protein content of the yellow bird's nest of Comparative Example 3 after two-stage sterilization treatment was measured to be 1.32 g / 100 g.
[0064] The texture of the processed bird's nest was tested by the method of Li Can. Effects of bird's nest pretreatment and addition methods on sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest of comparative example 3 after two-stage pasteurization was measured to be 56.82 gf.
[0065] The total colony count in the processed bird's nest was tested using the GB 4789.2-2016 National Food Safety Standard Food Microbiology Inspection - Determination of the Total Colony Count. Each group of samples was tested three times. The total colony count of the yellow bird's nest in Comparative Example 3 after two-stage pasteurization was 43 CFU / g.
[0066] The sialic acid and protein content of the yellow bird's nest in Comparative Example 3 is lower than that in Example 2. This is because the uniform heating characteristics of ohmic heating first subject the bird's nest to mild heat treatment. This pretreatment creates sialic acid and protein retention conditions that are conducive to the subsequent pasteurization process. The pasteurization treatment alone lacks this gradual heat treatment process. The bird's nest will experience uneven heat conduction from the surface to the inside. The surface tissue often bears excessive heat load to ensure that the interior reaches the sterilization temperature. This sudden "heat shock" will cause protein denaturation and aggregation and sialic acid thermal degradation, reducing the retention rate of the effective ingredients. The bird's nest in Comparative Example 3 has a slightly lower crispness than Example 2, with a small change. The total number of colonies detected in the bird's nest treated by the method of Comparative Example 3 exceeds 10 CFU / g, indicating that only steam sterilization treatment without the ohmic heating treatment step leads to incomplete sterilization.
[0067] Comparative Example 4 The difference between Comparative Example 4 and Example 3 is that the excitation voltage is set to 3000 V, the frequency is set to 15 kHz, and the induced electric field strength is generated to 75 V / cm. The rest is implemented in the same way as Example 3.
[0068] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the average was finally calculated. The sialic acid content of the red bird's nest of comparative example 4 after sterilization was measured to be 2.62 g / kg.
[0069] The protein content in the bird's nest was detected using the detection method GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the average was finally calculated. The protein content of the red bird's nest of Comparative Example 4 after two-stage sterilization treatment was measured to be 1.43 g / 100 g.
[0070] The total colony count in the bird's nest was tested using the GB 4789.2-2016 National Food Safety Standard Food Microbiology Inspection - Determination of the Total Colony Count. Each group of samples was tested three times. The red bird's nest in Comparative Example 4 had microbial growth after sterilization, and the total colony count was 18 CFU / g.
[0071] The texture of the bird's nest was tested using the method of Li Can. Effects of bird's nest pretreatment and addition methods on the sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest of comparative example 4 after sterilization was measured to be 57.25 gf.
[0072] Comparative Example 3 and Comparative Example 4 show that Comparative Example 4 uses a voltage and frequency with lower parameters to process red bird's nest, and the obtained protein and sialic acid content are lower. This is because under a lower electric field strength, the conformational change of the protein is limited, and its hydrophobic group cannot be fully exposed, resulting in the interaction between the protein and the surrounding matrix remaining in a strong state, which is not conducive to the migration and dissolution of the protein into the aqueous phase. Secondly, after the ohmic heating parameter is reduced, its synergistic thermo-electric effect is weakened, affecting the hydrolysis and release process of sialic acid from glycoproteins. Although subsequent steam pasteurization provides thermal energy, the "pretreatment" effect of the ohmic electric field on the bird's nest matrix is lacking, resulting in the difficulty of efficient transfer of thermal energy to the molecular level, so that the sialic acid molecules are still firmly bound to the glycoprotein skeleton. Comparative Example 4 failed to completely kill microorganisms, which may be due to the weakening of the electric field strength applied in the liquid medium, the reduced heating rate, and the slow temperature rise, resulting in the microorganisms inside and on the surface of the bird's nest may not be effectively killed. If ohmic heating fails to sufficiently reduce the colony count, then the high-load microorganisms may not be completely killed under steam pasteurization conditions at 105°C for 5 minutes, resulting in viable bacteria still present in the final product. Alternatively, in order to fully kill the viable bacteria, the processing temperature and / or time of the pasteurization stage must be increased, which in turn will reduce the crispness of the bird's nest and affect the overall taste.
[0073] Comparative Example 5 The difference between Comparative Example 5 and Example 3 is that the excitation voltage is set to 5200 V, the frequency is set to 80 kHz, and the induced electric field strength is generated to 130 V / cm. The rest is implemented in the same way as Example 3 and will not be repeated here.
[0074] After the treatment, the sialic acid content in the bird's nest was detected, and the detection method adopted GB31614.1-2023 "Determination of sialic acid in food, national food safety standard". Each group of samples was tested three times, and the average was finally calculated. The sialic acid content of the red bird's nest in comparative example 5 after two-stage sterilization treatment was measured to be 2.67 g / kg.
[0075] The protein content in the bird's nest was detected using the detection method of GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food". Each group of samples was tested three times, and the average was finally calculated. The protein content of the red bird's nest of Comparative Example 5 after two-stage sterilization treatment was measured to be 1.41 g / 100 g.
[0076] The texture of the processed bird's nest was tested by the method of Li Can. Effects of bird's nest pretreatment and addition methods on sensory and physicochemical properties of ice cream [D]. [Master's degree thesis]. Wuxi: Jiangnan University, 2017. Each group of samples was tested six times, and the average was finally calculated. The brittleness of the bird's nest of comparative example 5 after treatment was measured to be 52.10 gf.
[0077] The total colony count in the bird's nest was tested using the GB 4789.2-2016 National Food Safety Standard - Determination of the Total Colony Count in Food Microbiological Examination. Each group of samples was tested three times. No microorganisms were detected in the red bird's nest of Example 5 after sterilization.
[0078] Comparison of Example 3 and Comparative Example 5 shows that Comparative Example 5 uses a higher voltage and frequency parameter to treat the red bird's nest, and the obtained protein and sialic acid content is lower. When the ohmic heating parameters exceed the optimal range, a large number of hydrophobic groups inside the protein molecules are exposed, and strong intermolecular interactions occur between these hydrophobic groups, forming dense protein aggregates, which reduce solubility; excessively strong electric fields can cause local overheating in the bird's nest tissue (hot spot effect), resulting in the destruction of the heat-sensitive sialic acid molecular structure. Sialic acid is a derivative of neuraminic acid, and the glycosidic bonds in its molecules are easily broken at too high a temperature to generate degradation products, which significantly reduce the detectable sialic acid content.
[0079] The brittleness of the bird's nest obtained in Comparative Example 5 is reduced, indicating that moderate ohmic heating can form an ideal protein gel network structure. Excessively high parameter treatment destroys the colloid balance, resulting in a softening of the texture. The microstructure formed by mild treatment can better maintain the texture during the subsequent steam pasteurization process.
[0080] Table 1 shows the crispness, sialic acid and protein content and colony count of the bird's nests treated by the above examples and comparative examples.
[0081] Table 1 The brittleness, sialic acid, protein content and colony count of the bird's nests treated in the examples and comparative examples
[0082] The “blank control” in Table 1 refers to the control group that has not undergone any sterilization treatment.
[0083] Comparison Table 1 shows that the brittleness of the bird's nest treated by the method of the present invention is relatively stable. Comparative Example 1 (high temperature, long-term steam pasteurization treatment) and Comparative Example 5 (high parameter voltage and frequency treatment) have good sterilization effects, but will cause the brittleness of the bird's nest to decrease. Comparative Example 2 (simple ohmic heating treatment), Comparative Example 3 (simple steam pasteurization treatment), and Comparative Example 4 (low parameter voltage and frequency treatment) have no significant effect on the brittleness quality, but the sterilization effect is poor.
[0084] In summary, the two-stage sterilization method combining ohmic heating and steam pasteurization, and under the condition of controlling the appropriate time, can improve the sterilization efficiency, significantly reduce the microorganisms in the bird's nest, and better retain the nutrients of the bird's nest while maintaining a certain crispness. However, only one of the two-stage sterilization methods or low excitation voltage treatment of bird's nests is significantly poor in nutrient retention and microbial control effects, and the expected sterilization effect cannot be achieved. This shows that in order to achieve the expected effect of the present invention, the parameter range of ohmic heating and steam pasteurization is more important, so as to retain the nutrients and microbial safety of the bird's nest to the greatest extent.
[0085] Through the above-mentioned measurements, detailed parameter settings and experimental verification, the present invention provides a more accurate and effective method for sterilizing bird's nests, which aims to improve processing efficiency, reduce energy consumption, and retain important nutrients such as protein and sialic acid of the bird's nest to the greatest extent while ensuring the sterilization effect.
[0086] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.
[0087] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.
[0088] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present invention and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, it is not intended herein to limit the present invention to the disclosed specific embodiments for performing the present invention, but it is intended that the present invention will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another element.
Claims
1. A method for processing bird's nest, characterized in that: include: The bird's nest is placed in an electric field capable of generating Joule heating effect, the excitation voltage of the electric field is set to 3200-4800 V, the frequency is set to 20-60 kHz, and the bird's nest is allowed to stay in the electric field for 60-120 seconds for electric field treatment; Then, the bird's nest treated by the electric field is subjected to steam pasteurization, wherein the steam pasteurization temperature is 100-110° C. and the time is 3-5 minutes.
2. The method according to claim 1, characterized in that Specifically include: The dry bird's nest is mixed with water to form a wet bird's nest, and the wet bird's nest is kept in a flowing state in the electric field.
3. The method according to claim 2, characterized in that: The wet bird's nest is made to flow uniformly in the electric field at a speed of 10 L / h to 15 L / h.
4. The method according to claim 2 or 3, characterized in that: Specifically include: An electric field generating device is provided, the electric field generating device comprising an electrode, an excitation power source, a storage mechanism and an insulating pipeline, the excitation power source is connected to the electrode, the excitation power source is applied to the electrode to generate the electric field, the storage mechanism is used to store bird's nests and is connected to the insulating pipeline, at least part of the insulating pipeline is arranged in the electric field; The excitation power supply is turned on to generate the electric field, so that the bird's nest in the storage mechanism flows into the insulating pipeline and keeps flowing in the insulating pipeline.
5. The method according to claim 1, characterized in that: The intensity of the electric field is 80 V / cm~120 V / cm.
6. The method according to claim 1, characterized in that: The peak temperature of the bird's nest in the electric field is maintained at 70° C. to 95° C.
7. The method according to claim 6, characterized in that: The peak temperature of the bird's nest in the electric field is maintained at 90° C. to 95° C.
8. The method according to claim 1, characterized in that: The bird's nest comprises one or more of white bird's nest, yellow bird's nest and red bird's nest.
9. A sterilization method for maintaining the crispness of bird's nest, characterized in that: include: The bird's nest is placed in an electric field capable of generating Joule heating effect, the excitation voltage of the electric field is set to 3200-4800 V, the frequency is set to 20-60 kHz, and the bird's nest is allowed to stay in the electric field for 60-120 seconds; Then, the bird's nest treated by the electric field is subjected to steam pasteurization, wherein the steam pasteurization temperature is 100-110° C. and the time is 3-5 minutes.
10. A sterilization method for maintaining the protein and sialic acid content in bird's nests, characterized in that: include: The bird's nest is placed in an electric field capable of generating Joule heating effect, the excitation voltage of the electric field is set to 3200-4800 V, the frequency is set to 20-60 kHz, and the bird's nest is allowed to stay in the electric field for 60-120 seconds; Then, the bird's nest treated by the electric field is subjected to steam pasteurization, wherein the steam pasteurization temperature is 100-110° C. and the time is 3-5 minutes.