Preparation method of high-quality high-digestibility fresh stewed bird's nest product

Abstract

The application provides a preparation method of high-quality and high-digestibility fresh stewed bird's nest products, and the method comprises the following steps: subjecting the bird's nest packed in a container to first constant-temperature sterilization treatment; after the sterilization is completed, filling the container with a sugar solution and sealing the container to obtain a fresh stewed bird's nest semi-finished product; and sequentially subjecting the fresh stewed bird's nest semi-finished product to first temperature-increasing sterilization treatment, second temperature-increasing sterilization treatment, second constant-temperature sterilization treatment, first temperature-decreasing sterilization treatment and second temperature-decreasing sterilization treatment; wherein during the first temperature-increasing sterilization treatment and the second temperature-increasing sterilization treatment, the reaction temperature continuously increases and does not contain a constant-temperature process of at least 1 min. The method can effectively improve the consistency, taste, protein digestibility and sialic acid digestibility of the fresh stewed bird's nest product, improve the nutritional value and flavor taste of the fresh stewed bird's nest product as a whole, ensure the stability of the fresh stewed bird's nest during the sterilization process and the safety of the product during the shelf life, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of food. Specifically, the present application relates to a preparation method of high-quality high-digestibility fresh stewed bird's nest product. BACKGROUND

[0002] Bird's nest is the nest built by salivary or salivary and down feather mixture of Collocalia tricolor and other Collocalia. Bird's nest has rich nutritional value and medicinal value, and is the first of eight treasures, and has been praised as a tonic since the Tang Dynasty. The main components of bird's nest are water-soluble protein (more than 50%), carbohydrates, trace elements (phosphorus, iron, sodium, potassium, etc.) and amino acids that promote human vitality.

[0003] At present, there are mainly three kinds of bird's nest products on the market, namely dry bird's nest, instant bird's nest and fresh stewed bird's nest. Fresh stewed bird's nest refers to dry bird's nest after high-temperature stewing, packaging into containers and sterilization treatment, and the obtained fresh stewed bird's nest product is distributed by cold chain. Since fresh stewed bird's nest does not contain preservatives and bird's nest is a heat-sensitive raw material, the sterilization conditions of fresh stewed bird's nest are relatively high, which requires effective sterilization while retaining as much as possible the original nutritional ingredients, and ensuring the flavor and taste, which is also a technical problem in the production of fresh stewed bird's nest and needs to be solved urgently. SUMMARY

[0004] It should be noted that the present application is based on the following findings of the inventor:

[0005] As a heat-sensitive raw material, bird's nest, during the sterilization process, the higher the sterilization temperature and the longer the sterilization time, the rising rate and aroma of bird's nest will increase and then decrease, the softening degree will gradually increase, and the consistency and solid content of the product will gradually decrease, and the quality will decrease. If the sterilization temperature is lower and the sterilization time is shorter, the product cannot guarantee the microorganism, the structure of macromolecular protein is tight, it is not easy to be opened, and the digestibility will also be affected.

[0006] Therefore, based on the temperature and time of sterilization, the inventors have found that the temperature and time of sterilization are key factors affecting the flavor and taste, microbial content, protein content, sialic acid and protein digestibility of fresh stewed bird's nest. By precisely controlling the temperature and time of each stage in the sterilization process, the bird's nest can be maximally expanded in a gradient, the flavor substances of the bird's nest can be promoted to release, the degradation and loss of nutrients such as protein can be avoided, the product consistency and taste can be improved, the sialic acid and protein in the fresh stewed bird's nest product can have a high digestibility in the intestinal tract, and thus the nutritional value of the fresh stewed bird's nest can be greatly improved. Therefore, the sterilization method of the fresh stewed bird's nest product according to the embodiments of the present application can effectively improve the consistency, taste, protein digestibility and sialic acid digestibility of the fresh stewed bird's nest product, improve the nutritional value and flavor and taste of the fresh stewed bird's nest product as a whole, ensure the stability of the fresh stewed bird's nest in the sterilization process and the safety of the product in the shelf life, and is suitable for industrial production.

[0007] Therefore, in one aspect of the present application, a sterilization method of a fresh stewed bird's nest product is provided. According to the embodiments of the present application, the method comprises: subjecting the bird's nest divided and packed in a container to a first constant-temperature sterilization treatment, filling the container with a sugar solution after the sterilization is completed, and sealing the container to obtain a fresh stewed bird's nest semi-finished product; and sequentially subjecting the fresh stewed bird's nest semi-finished product to a first temperature-increasing sterilization treatment, a second temperature-increasing sterilization treatment, a second constant-temperature sterilization treatment, a first temperature-decreasing sterilization treatment and a second temperature-decreasing sterilization treatment; wherein the reaction temperature continuously increases and does not include a constant-temperature process of at least 1 min during the first temperature-increasing sterilization treatment and the second temperature-increasing sterilization treatment.

[0008] According to the method of the embodiments of the present application, by subjecting the bird's nest to the first constant-temperature sterilization treatment, the first temperature-increasing sterilization treatment, the second temperature-increasing sterilization treatment, the second constant-temperature sterilization treatment, the first temperature-decreasing sterilization treatment and the second temperature-decreasing sterilization treatment, especially by continuously increasing the reaction temperature during the first temperature-increasing sterilization treatment and the second temperature-increasing sterilization treatment, the bird's nest can be better expanded, the flavor substances of the bird's nest can be promoted to release, and the degradation and loss of nutrients such as protein can be avoided. In addition, the inventors have surprisingly found that the sterilization method of the present application can make the sialic acid and protein in the fresh stewed bird's nest product have a high digestibility in the intestinal tract, thereby greatly improving the nutritional value of the fresh stewed bird's nest.

[0009] According to the embodiments of the present application, the sterilization method of the fresh stewed bird's nest product described above can have the following additional technical features:

[0010] According to an embodiment of the present application, the first constant temperature sterilization treatment is at a temperature of 97-100℃ for 15-25 minutes. At this temperature, the purpose of pre-sterilization can be achieved, i.e. the fresh stewed bird's nest is sterilized at a low temperature for a long time in advance so as to kill the microorganisms in the fresh stewed bird's nest and reduce the loss of nutritional ingredients, thereby reducing the degree of subsequent sterilization, i.e. the final fresh stewed bird's nest product can meet the standard of microorganism content and have high product quality under relatively low temperature and short time sterilization conditions. In addition, it is also helpful to improve the digestion rate of sialic acid and protein in the intestinal tract.

[0011] According to an embodiment of the present application, the first constant temperature sterilization treatment is performed on the divided bird's nest in the container in an environment containing liquid water and water vapor. The conventional sterilization of bird's nest is mainly steam sterilization, i.e. the bird's nest or the container containing the bird's nest is placed in a water vapor environment. The present inventors have found that, during steam sterilization, spraying liquid water into the environment so that the container is in a liquid water-water vapor two-phase steam-liquid environment can more fully improve the uniformity of the bird's nest in receiving heat and increase the swelling rate of the bird's nest. Therefore, in the present application, the "first constant temperature sterilization" is also called "two-phase steam-liquid sterilization".

[0012] It should be noted that the type of instrument used for the first constant temperature sterilization treatment according to the present application is not strictly limited, as long as it can achieve steam sterilization and apply liquid water in the sterilization environment, and can be designed by itself, for example, a water spraying port is designed in a sterilization tunnel so as to spray liquid water into the sterilization tunnel during steam sterilization.

[0013] According to an embodiment of the present application, the first temperature increasing sterilization treatment, the second temperature increasing sterilization treatment, the second constant temperature sterilization treatment, the first temperature decreasing sterilization treatment and the second temperature decreasing sterilization treatment are all performed on the fresh stewed bird's nest semi-finished product in a rotating state.

[0014] According to an embodiment of the present application, the fresh stewed bird's nest has a water content of 70-90 mass%. Thus, the bird's nest can be ensured not to soften during the sterilization process and has strong heat penetration.

[0015] According to an embodiment of the present application, the temperature of the sugar solution is not lower than 90℃. Thus, the environmental microbial contamination can be effectively controlled and the vacuum degree can be improved.

[0016] According to an embodiment of the present application, the filling is completed within 10-15 seconds. Thus, the secondary proliferation of microorganisms can be prevented.

[0017] According to an embodiment of the present application, the first temperature rising sterilization process comprises: raising the temperature of the fresh stewed bird's nest semi-finished product at a first temperature rising frequency, wherein the first temperature rising frequency is 11-13℃ / min, and the first temperature rising sterilization process lasts for 2-8min. The inventor has found that, as the temperature rises, the hydrophobic index of protein changes weakly under high moisture conditions, and when the temperature is below 95-105℃, the product thermal penetration is controlled by controlling the above first temperature rising frequency, so as to promote the bird's nest to expand fully.

[0018] According to an embodiment of the present application, the second temperature rising sterilization process comprises: raising the temperature of the first temperature rising product obtained by the first temperature rising sterilization process to 112-118℃ at a second temperature rising frequency, wherein the second temperature rising frequency is 6.5-8.8℃ / min, and the second temperature rising sterilization process lasts for 1-3min. In the second temperature rising sterilization process, the higher the temperature, the stronger the aroma of the bird's nest protein in the same heating time, and the aroma and sterilization effect are both good under the above sterilization conditions.

[0019] According to an embodiment of the present application, the second constant temperature sterilization process comprises: maintaining the second temperature rising product obtained by the second temperature rising sterilization process at 112-118℃ for 8-20min. Thus, the microorganisms in the product are killed to the maximum extent. Moreover, since the fresh stewed bird's nest has been subjected to the first constant temperature sterilization process, the temperature of the second constant temperature sterilization can be reduced under the premise of effective sterilization, so that the second constant temperature sterilization is performed under relatively low temperature conditions, the loss of nutritional ingredients is reduced, the nutritional value of the product is improved, and the safety requirement is met.

[0020] According to an embodiment of the present application, the terminal temperature of the first temperature rising sterilization process is the same as the initial temperature of the second temperature rising sterilization process, and the terminal temperature of the second temperature rising sterilization process is the same as the initial temperature of the second constant temperature sterilization process.

[0021] According to an embodiment of the present application, the first temperature rising sterilization process comprises: raising the temperature of the fresh stewed bird's nest semi-finished product at a first temperature rising frequency, wherein the first temperature rising frequency is 11-13℃ / min, and the first temperature rising sterilization process lasts for 2-8min. The inventor has found that, as the temperature rises, the hydrophobic index of protein changes weakly under high moisture conditions, and when the temperature is below 95-105℃, the product thermal penetration is controlled by controlling the above first temperature rising frequency, so as to promote the bird's nest to expand fully.

[0022] According to an embodiment of the present application, the second temperature-reducing sterilization process comprises: reducing the first temperature-reduced product obtained from the first temperature-reducing sterilization process to 35-45°C at a second temperature-reducing frequency of 12-14°C / min, and the second temperature-reducing sterilization time is 3-6 min. The inventors have found that the above high-frequency and rapid temperature-reducing condition can effectively reduce the degradation and loss of bird's nest. Moreover, the softening of bird's nest can be avoided, and the elasticity of bird's nest and the heat penetration of the product are increased.

[0023] According to an embodiment of the present application, the total time of the first temperature-increasing sterilization process, the second temperature-increasing sterilization process, the second constant-temperature sterilization process, the first temperature-reducing sterilization process and the second temperature-reducing sterilization process is 20-43 min. Thus, the microbial content of the fresh stewed bird's nest product can be better reduced to meet the edible safety, the nutritional ingredients are preserved as much as possible, and the digestion rates of sialic acid and protein in the intestinal tract are high.

[0024] According to an embodiment of the present application, the first temperature-increasing sterilization process, the second temperature-increasing sterilization process, the second constant-temperature sterilization process, the first temperature-reducing sterilization process and the second temperature-reducing sterilization process are all carried out in a rotating state of the fresh stewed bird's nest semi-finished product. Thus, the fresh stewed bird's nest can be uniformly heated and cooled, and the product uniformity is improved.

[0025] According to an embodiment of the present application, the preparation method of the bird's nest packed in a container comprises: soaking dry bird's nest in water at 15-30°C for 2-6 hours; picking impurities in the soaked bird's nest, and then packing the bird's nest in a container. The above soaking and picking can make the water content of the fresh stewed bird's nest be 70-90 mass%, so as to ensure that the bird's nest is not softened in the sterilization process and the heat penetration is strong.

[0026] In another aspect of the present application, a method for improving the protein digestion rate and / or sialic acid digestion rate of a fresh stewed bird's nest product is provided. According to an embodiment of the present application, the method comprises: treating the fresh stewed bird's nest according to the sterilization method of the fresh stewed bird's nest product described above. As described above, by using the sterilization conditions of the fresh stewed bird's nest of the present application, the digestion rates of sialic acid and protein in the intestinal tract can be effectively improved, which helps to better exert the nutritional value.

[0027] In another aspect of the present application, a fresh stewed bird's nest product is provided. According to an embodiment of the present application, the fresh stewed bird's nest product is prepared by the sterilization method of the fresh stewed bird's nest product described above. Thus, the fresh stewed bird's nest product according to the embodiment of the present application has high consistency, taste, protein digestion rate and sialic acid digestion rate, and has good overall nutritional value, flavor and taste, good safety and long shelf life.

[0028] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and the description or be learned by practice of the application. DETAILED DESCRIPTION

[0029] The scheme of the present application will be explained below with reference to examples. Those skilled in the art will understand that the following examples are only for illustrating the present application and should not be regarded as limiting the scope of the present application. If a specific technique or condition is not mentioned in the examples, it is performed according to the technique or condition described in the literature in the art or according to the product manual. If a reagent or instrument is not mentioned by the manufacturer, it is a conventional product that can be obtained by purchase in the market.

[0030] Example 1

[0031] In this example, the fresh stewed bird's nest product was prepared according to the following steps:

[0032] (1) Bird's nest soaking: dry bird's nest was soaked in purified water, the temperature was controlled at 20℃ for 4h until the bird's nest was fully expanded;

[0033] (2) Stripping and picking: the expanded bird's nest was stripped along the lines, and the impurities in the bird's nest were picked out, and the water temperature was maintained at 20℃ during the picking process;

[0034] (3) Sub-packing: after picking, the bird's nest was evenly divided and packed in product containers;

[0035] (4) Steam-liquid two-phase sterilization: the moisture content of the packed bird's nest was controlled at 80%, and the product was transported into the sterilization tunnel (containing water spray port) of the steam sterilization equipment through the conveying belt, the temperature of the hot steam was 97℃, and the product was placed in the sterilization tunnel for 18min;

[0036] (5) Liquid filling: after the product came out of the sterilization tunnel, it was filled with 90℃ sugar water, and the time from the product coming out of the tunnel to starting filling was controlled at 15s, and the center temperature of the product was 80℃;

[0037] (6) Cap sealing: cap sealing was performed under high-pressure steam jet vacuum environment;

[0038] (7) One-stage frequency temperature rising sterilization: the sealed semi-finished product was placed in a sterilization pot, the initial temperature of the product was 35℃, the temperature rising frequency was controlled at 13℃ / min during the stage of 35-94.8℃, the time was 4.6min, and the product was sterilized by rotation;

[0039] (8) Two-stage frequency temperature rising sterilization: the temperature rising frequency was controlled at 6.7℃ / min during the stage of 94.8-114.9℃, the time was 3min, and the product was sterilized by rotation;

[0040] (9) Constant temperature sterilization: the product was kept at 114.9℃ for 10min, and was sterilized by rotation;

[0041] (10) One-stage rapid cooling: in the 114.9-95.1℃ stage, control the cooling frequency of 6℃ / min, time 3.3min, and rotate the cooling;

[0042] (11) Two-stage rapid cooling: in the 95.1-44.7℃ stage, control the cooling frequency of 12℃ / min, time 4.2min, and rotate the cooling, and then the cooling is completed to obtain the fresh stewed bird's nest product.

[0043] Example 2

[0044] In this example, the fresh stewed bird's nest product is prepared according to the following steps:

[0045] (1) Bird's nest soaking: dry bird's nest is soaked in pure water, the temperature is controlled at 25℃ for 4h until the bird's nest is fully swollen;

[0046] (2) Stripping and picking: the swollen bird's nest is stripped along the lines, and the impurities in the bird's nest are picked out, and the water temperature is maintained at 25℃ during the picking process;

[0047] (3) Sub-packing: after picking, the bird's nest is evenly divided and packed in product containers;

[0048] (4) Steam-liquid two-phase sterilization: the moisture content of the packed bird's nest is controlled at 90%, and the bird's nest is transported into the sterilization tunnel (containing water spraying port) of the steam sterilization equipment through the conveying belt, the hot steam temperature is 100℃, and the product is placed in the sterilization tunnel for 25min;

[0049] (5) Liquid filling: after the product comes out of the sterilization tunnel, it is filled with sugar water with a temperature of ≥90℃, and the time from the product coming out of the tunnel to starting filling is controlled at 10s, and the center temperature of the product is 85℃;

[0050] (6) Sealing: the cap is sealed under high-pressure steam jet vacuum environment;

[0051] (7) One-stage frequency rising sterilization: the sealed semi-finished product is placed in the sterilization pot, and the initial temperature of the product is 35℃, in the 35-105.4℃ stage, the rising frequency is controlled at 11℃ / min, the time is 6.4min, and the rotation sterilization is performed;

[0052] (8) Two-stage frequency rising sterilization: in the 105.4-115.6℃ stage, the rising frequency is controlled at 8.5℃ / min, the time is 1.2min, and the rotation sterilization is performed;

[0053] (9) Constant temperature sterilization: 115.6℃ is maintained for 8min, and the rotation sterilization is performed;

[0054] (10) One-stage rapid cooling: in the 115.6-105.2℃ stage, the cooling frequency is controlled at 8℃ / min, the time is 1.3min, and the rotation cooling is performed;

[0055] (11) Two-stage rapid cooling: in the 105.2-40.8 °C stage, control the cooling frequency at 14 °C / min, time 4.6 min, rotate cooling, and then cooling out of the pot to obtain fresh stewed bird's nest products.

[0056] Example 3

[0057] In this example, the fresh stewed bird's nest product is prepared according to the following steps:

[0058] (1) Bird's nest soaking: dry bird's nest is soaked in pure water, the temperature is controlled at 20 °C for 4 h, until the bird's nest is fully swollen;

[0059] (2) Stripping and picking: the swollen bird's nest is stripped along the lines, and impurities in the bird's nest are picked out, and the water temperature is maintained at 20 °C during the picking process;

[0060] (3) Sub-packing: after picking, the bird's nest is evenly divided and packed in product containers;

[0061] (4) Steam-liquid two-phase sterilization: the moisture content of the packed bird's nest is controlled at 80%, and the bird's nest is transported into the sterilization tunnel (containing water spray port) of the steam sterilization equipment through the conveying belt, the hot steam temperature is 97 °C, and the product is placed in the sterilization tunnel for 18 min;

[0062] (5) Liquid filling: after the product comes out of the sterilization tunnel, it is filled with 90 °C sugar water, and the time from the product coming out of the tunnel to starting filling is controlled at 15 s, and the center temperature of the product is 80 °C;

[0063] (6) Sealing: sealing is carried out under high-pressure steam jet vacuum environment;

[0064] (7) One-stage frequency rising sterilization: the sealed semi-finished product is placed in the sterilization pot, and the initial temperature of the product is 35 °C, in the 35-94.8 °C stage, the rising frequency is controlled at 13 °C / min, time 4.6 min, and the product is rotated for sterilization;

[0065] (8) Two-stage frequency rising sterilization: in the 94.8-100 °C stage, the rising frequency is controlled at 6.5 °C / min, time 0.8 min, and the product is rotated for sterilization;

[0066] (9) Constant temperature sterilization: at 100 °C for 8 min, and the product is rotated for sterilization;

[0067] (10) One-stage rapid cooling: in the 100-80.2 °C stage, the cooling frequency is controlled at 6 °C / min, time 3.3 min, and the product is rotated for cooling;

[0068] (11) Two-stage rapid cooling: in the 80.2-29.8℃ stage, control the cooling frequency at 12℃ / min, time 4.2min, rotate cooling, and then cooling out of the pot to obtain fresh stewed bird's nest product.

[0069] Example 4

[0070] In this pair of examples, fresh stewed bird's nest product is prepared according to the following steps:

[0071] (1) Bird's nest soaking: dry bird's nest is soaked in pure water, the temperature is controlled at 20℃ for 4h until the bird's nest is fully swollen;

[0072] (2) Stripping and picking: the swollen bird's nest is stripped along the lines, and impurities in the bird's nest are picked out, and the water temperature is maintained at 20℃ during the picking process;

[0073] (3) Sub-packing: after picking, the bird's nest is evenly divided and packed in product containers;

[0074] (4) Steam-liquid two-phase sterilization: the moisture content of the packed bird's nest is controlled at 90%, and the product is transported into the sterilization tunnel (containing water injection port) of the steam sterilization equipment through the conveying belt, the hot steam temperature is 97℃, and the product is placed in the sterilization tunnel for 18min;

[0075] (5) Liquid filling: after the product comes out of the sterilization tunnel, it is filled with 90℃ sugar water, and the time from the product coming out of the tunnel to starting filling is controlled at 15s, and the center temperature of the product is 80℃;

[0076] (6) Cap sealing: cap sealing is performed in a high-pressure steam injection vacuum environment;

[0077] (7) One-stage frequency rising sterilization: the sealed semi-finished product is placed in a sterilization pot, the initial temperature of the product is 35℃, in the 35-94.8℃ stage, the rising frequency is controlled at 13℃ / min, the time is 4.6min, and the product is rotated for sterilization;

[0078] (8) Two-stage frequency rising sterilization: in the 94.8-120.8℃ stage, the rising frequency is controlled at 6.5℃ / min, the time is 4min, and the product is rotated for sterilization;

[0079] (9) Constant temperature sterilization: at 120.8℃, the product is kept for 8min for sterilization;

[0080] (10) One-stage rapid cooling: in the 120.8-101℃ stage, the cooling frequency is controlled at 6℃ / min, the time is 3.3min, and the product is rotated for cooling;

[0081] (11) Two-stage rapid cooling: in the 101-50.6℃ stage, the cooling frequency is controlled at 12℃ / min, the time is 4.2min, and the product is rotated for cooling, and then cooled out of the pot to obtain fresh stewed bird's nest product.

[0082] Example 5

[0083] In this example, the fresh stewed bird's nest product is prepared according to the following steps:

[0084] (1) Bird's nest soaking: Dry bird's nest is soaked in pure water, the temperature is controlled at 20°C for 4h until the bird's nest is fully swollen;

[0085] (2) Stripping and picking: The swollen bird's nest is stripped along the lines, and impurities in the bird's nest are picked out, and the water temperature is maintained at 20°C during the picking process;

[0086] (3) Sub-packing: After picking, the bird's nest is evenly divided and packed in product containers;

[0087] (4) Steam-liquid two-phase sterilization: The moisture content of the packed bird's nest is controlled at 80%, and the product is transported into the sterilization tunnel (containing a water spraying port) of the steam sterilization equipment through a conveying belt, the hot steam temperature is 97°C, and the product is placed in the sterilization tunnel for 18min;

[0088] (5) Liquid filling: After the product comes out of the sterilization tunnel, it is filled with 90°C sugar water, and the time from the product coming out of the tunnel to starting filling is controlled at 15s, and the center temperature of the product is 80°C;

[0089] (6) Cap sealing: Cap sealing is performed in a high-pressure steam jet vacuum environment;

[0090] (7) One-stage frequency rising sterilization: The sealed semi-finished product is placed in a sterilization pot, the initial temperature of the product is 35°C, the rising frequency is controlled at 13°C / min in the 35-94.8°C stage, the time is 4.6min, and the product is sterilized by rotation;

[0091] (8) Two-stage frequency rising sterilization: The rising frequency is controlled at 2°C / min in the 94.8-114.8°C stage, the time is 10min, and the product is sterilized by rotation;

[0092] (9) Constant temperature sterilization: The product is kept at 114.8°C for 10min and sterilized by rotation;

[0093] (10) One-stage rapid cooling: The cooling frequency is controlled at 6°C / min in the 114.8-95°C stage, the time is 3.3min, and the product is cooled by rotation;

[0094] (11) Two-stage rapid cooling: The cooling frequency is controlled at 12°C / min in the 95-44.6°C stage, the time is 4.2min, and the product is cooled by rotation, and then the product is taken out of the pot after cooling to obtain the fresh stewed bird's nest product.

[0095] Example 6

[0096] In this example, the fresh stewed bird's nest product is prepared according to the following steps:

[0097] (1) Soaking of bird's nest: Dry bird's nest is soaked in purified water, the temperature is controlled at 20°C for 4h until the bird's nest is fully swollen;

[0098] (2) Stripping and picking: The swollen bird's nest is stripped along the lines, and the impurities in the bird's nest are picked out, and the water temperature is maintained at 20°C during the picking process;

[0099] (3) Sub-packing: After picking, the bird's nest is evenly divided and packed in product containers;

[0100] (4) Steam-liquid two-phase sterilization: The moisture content of the packed bird's nest is controlled at 80%, and the product is transported into the sterilization tunnel (containing a water spraying port) of the steam sterilization equipment through a conveying belt, the hot steam temperature is 97°C, and the product is placed in the sterilization tunnel for 18min;

[0101] (5) Liquid filling: After the product comes out of the sterilization tunnel, it is filled with 90°C sugar water, and the time from the product coming out of the tunnel to starting filling is controlled at 15s, and the center temperature of the product is 80°C;

[0102] (6) Sealing: Sealing is performed under high-pressure steam jet vacuum environment;

[0103] (7) One-stage frequency rising sterilization: The sealed semi-finished product is placed in a sterilization pot, the initial temperature of the product is 35°C, the rising frequency is controlled at 13°C / min in the 35-94.8°C stage, the time is 4.6min, and the product is sterilized by rotation;

[0104] (8) Two-stage frequency rising sterilization: The rising frequency is controlled at 6.5°C / min in the 94.8-114.8°C stage, the time is 3min, and the product is sterilized by rotation;

[0105] (9) Constant temperature sterilization: The product is kept at 114.8°C for 10min and sterilized by rotation;

[0106] (10) One-stage rapid cooling: The cooling frequency is controlled at 2°C / min in the 114.8-94.8°C stage, the time is 10min, and the product is cooled by rotation;

[0107] (11) Two-stage rapid cooling: The cooling frequency is controlled at 12°C / min in the 94.8-44.4°C stage, the time is 4.2min, and the product is cooled by rotation, and then the product is taken out of the pot after cooling to obtain the fresh stewed bird's nest product.

[0108] Comparative Example 1

[0109] In this comparative example, the fresh stewed bird's nest product is prepared according to the following steps:

[0110] (1) Soaking of bird's nest: Dry bird's nest is soaked in purified water, the temperature is controlled at 20°C for 4h until the bird's nest is fully swollen;

[0111] (2) Sorting and picking: the bird's nest after swelling is sorted along the lines, and impurities in the bird's nest are picked out, and the water temperature is kept at 20°C during the picking process;

[0112] (3) Sub-packing: after picking, the bird's nest is evenly divided and packed in product containers;

[0113] (4) Steam-liquid two-phase sterilization: the moisture content of the packed bird's nest is controlled at 80%, and the bird's nest is transported into the sterilization tunnel (containing a water spraying port) of the steam sterilization equipment through a conveying belt, the hot steam temperature is 97°C, and the product is placed in the sterilization tunnel for 18 min;

[0114] (5) Liquid filling: after the product comes out of the sterilization tunnel, it is filled with 90°C sugar water, and the time from the product coming out of the tunnel to starting to fill the liquid is controlled at 15s, and the center temperature of the product is 80°C;

[0115] (6) Sealing: sealing is performed under high-pressure steam jet vacuum environment;

[0116] (7) Sterilization: initial temperature 35°C, time 7.6 min, temperature increased to 115°C and maintained for 10 min, and rotary sterilization;

[0117] (9) Cooling: time 15.5 min, rotary cooling to 45°C, and the fresh stewed bird's nest product can be obtained after cooling and taking out of the pot.

[0118] Comparative Example 2

[0119] In this comparative example, the fresh stewed bird's nest product is prepared according to the following steps:

[0120] (1) Bird's nest soaking: dry bird's nest is soaked in pure water, the temperature is controlled at 20°C, and the soaking time is 4h, until the bird's nest is fully swollen;

[0121] (2) Sorting and picking: the bird's nest after swelling is sorted along the lines, and impurities in the bird's nest are picked out, and the water temperature is kept at 20°C during the picking process;

[0122] (3) Sub-packing: after picking, the bird's nest is evenly divided and packed in product containers;

[0123] (4) Liquid filling: after the product comes out of the sterilization tunnel, it is filled with 90°C sugar water, and the time from the product coming out of the tunnel to starting to fill the liquid is controlled at 15s, and the center temperature of the product is 80°C;

[0124] (5) Sealing: sealing is performed under high-pressure steam jet vacuum environment;

[0125] (6) One-stage frequency increasing sterilization: the semi-finished product after sealing is placed in a sterilization pot, the initial temperature of the product is 35°C, and the frequency increasing temperature is controlled at 13°C / min during the 35-94.8°C stage, and the time is 4.6 min, and the product is rotary sterilized

[0126] (7) Two-stage frequency temperature rising sterilization: in the 94.8-114.9℃ stage, control the temperature rising frequency of 6.7℃ / min, time 3min, rotary sterilization;

[0127] (8) Constant temperature sterilization: keep at 114.9℃ for 10min, rotary sterilization;

[0128] (9) One-stage fast temperature falling: in the 114.9-95.1℃ stage, control the temperature falling frequency of 6℃ / min, time 3.3min, rotary falling;

[0129] (10) Two-stage fast temperature falling: in the 95.1-44.7℃ stage, control the temperature falling frequency of 12℃ / min, time 4.2min, rotary falling, and then falling cooling out of the pot to obtain the fresh stewed bird's nest product.

[0130] Comparative Example 3

[0131] In this comparative example, the fresh stewed bird's nest product was prepared according to the following steps:

[0132] (1) Bird's nest soaking: dry bird's nest was soaked in pure water, the temperature was controlled at 20℃ for 4h until the bird's nest was fully swollen;

[0133] (2) Stripping and picking: the swollen bird's nest was stripped along the lines, and the impurities in the bird's nest were picked out, and the water temperature was maintained at 20℃ during the picking process;

[0134] (3) Sub-packing: the picked bird's nest was evenly divided and packed in product containers;

[0135] (4) Steam-liquid two-phase sterilization: the water content of the packed bird's nest was controlled at 80%, and the product was transported into the sterilization tunnel of the steam sterilization equipment (containing a water spraying port) through a conveying belt, the hot steam temperature was 97℃, and the product was placed in the sterilization tunnel for 18min;

[0136] (5) Liquid filling: after the product came out of the sterilization tunnel, it was filled with 90℃ sugar water, and the time from the product coming out of the tunnel to starting filling was controlled at 15s, and the center temperature of the product was 80℃;

[0137] (6) Sealing: rotary cap sealing was carried out under high-pressure steam jet vacuum environment;

[0138] (7) One-stage frequency temperature rising sterilization: the sealed semi-finished product was placed in a sterilization pot, the initial temperature of the product was 35℃, in the 35-94.8℃ stage, the temperature rising frequency was controlled at 13℃ / min, the time was 4.6min, constant temperature sterilization for 2min, and rotary sterilization;

[0139] (8) Two-stage frequency temperature rising sterilization: in the 94.8-114.9℃ stage, control the temperature rising frequency of 6.7℃ / min, time 3min, rotary sterilization;

[0140] (9) Constant temperature sterilization: 114.9°C for 8 min, rotary sterilization;

[0141] (10) First-stage rapid cooling: 114.9-95.1°C, control cooling frequency 6°C / min, time 3.3 min, rotary cooling;

[0142] (11) Second-stage rapid cooling: 95.1-44.7°C, control cooling frequency 12°C / min, time 4.2 min, rotary cooling, and then cooling to obtain the fresh stewed bird's nest product.

[0143] Comparative Example 4

[0144] In this comparative example, the fresh stewed bird's nest product was prepared according to the following steps:

[0145] (1) Bird's nest soaking: dry bird's nest was soaked in pure water, the temperature was controlled at 20°C for 4 h until the bird's nest was fully swollen;

[0146] (2) Stripping and picking: the swollen bird's nest was stripped along the lines, and impurities in the bird's nest were picked out, and the water temperature was maintained at 20°C during the picking process;

[0147] (3) Sub-packing: the picked bird's nest was evenly divided and packed in product containers;

[0148] (4) Steam-liquid two-phase sterilization: the water content of the packed bird's nest was controlled at 80%, and the product was transported into the sterilization tunnel (containing a water spraying port) of the steam sterilization equipment through a conveying belt, the hot steam temperature was 97°C, and the product was placed in the sterilization tunnel for 18 min;

[0149] (5) Liquid filling: after the product came out of the sterilization tunnel, it was filled with 90°C sugar water, and the time from the product coming out of the tunnel to starting filling was controlled at 15 s, and the center temperature of the product was 80°C;

[0150] (6) Cap sealing: rotary cap sealing was performed under high-pressure steam jet vacuum environment;

[0151] (7) Sterilization by temperature rise: the initial temperature of the product was 35°C, and the temperature was raised at a frequency of 10°C / min during the stage of 35-114.9°C, and the time was 8 min, and the product was sterilized by rotation;

[0152] (9) Constant temperature sterilization: 114.9°C for 10 min, rotary sterilization;

[0153] (10) First-stage rapid cooling: 114.9-95.1°C, control cooling frequency 6°C / min, time 3.3 min, rotary cooling;

[0154] (11) Two-stage rapid cooling: in the 95.1-44.7℃ stage, the cooling frequency is controlled at 12℃ / min, the time is 4.2min, the rotation cooling is performed, and then the product is taken out of the pot after cooling to obtain the fresh stewed bird's nest product.

[0155] Comparative Example 5

[0156] In the comparative example, the fresh stewed bird's nest product is prepared according to the following steps:

[0157] (1) Bird's nest soaking: dry bird's nest is soaked in pure water, the temperature is controlled at 20℃ for 4h until the bird's nest is fully swollen;

[0158] (2) Stripping and picking: the swollen bird's nest is stripped along the lines, and impurities in the bird's nest are picked out, and the water temperature is maintained at 20℃ during the picking process;

[0159] (3) Sub-packing: after picking, the bird's nest is evenly divided and packed in product containers;

[0160] (4) Steam-liquid two-phase sterilization: the moisture content of the packed bird's nest is controlled at 80%, and the product is transported into the sterilization tunnel (containing a water spraying port) of the steam sterilization equipment through a conveying belt, the hot steam temperature is 97℃, and the product is placed in the sterilization tunnel for 18min;

[0161] (5) Liquid filling: after the product is taken out of the sterilization tunnel, the product is filled with 90℃ sugar water, and the time from the product being taken out of the tunnel to the start of filling is controlled at 15s, and the center temperature of the product is 80℃;

[0162] (6) Cap sealing: the cap is sealed in a high-pressure steam jet vacuum environment;

[0163] (7) One-stage frequency rising sterilization: the sealed semi-finished product is placed in a sterilization pot, the initial temperature of the product is 35℃, in the 35-94.8℃ stage, the rising frequency is controlled at 13℃ / min, the time is 4.6min, and the rotation sterilization is performed;

[0164] (8) Two-stage frequency rising sterilization: in the 94.8-114.9℃ stage, the rising frequency is controlled at 6.7℃ / min, the time is 3min, and the rotation sterilization is performed;

[0165] (9) Constant temperature sterilization: the temperature is maintained at 114.9℃ for 10min, and the rotation sterilization is performed;

[0166] (10) Cooling: in the 114.9-45.15℃ stage, the cooling frequency is controlled at 9.3℃ / min, the time is 7.5min, the rotation cooling is performed, and then the product is taken out of the pot after cooling to obtain the fresh stewed bird's nest product.

[0167] Effect Example

[0168] The fresh stewed bird's nest products prepared in each example and comparative example were detected for commercial sterility, total number of colonies, Escherichia coli, strip, solid, color, consistency, aroma, taste, texture, protein molecular weight, and sialic acid digestion rate, and the detection methods were as follows:

[0169] Commercial sterility: GB 4789.26 "National food safety standard Food microbiological examination Commercial sterility test".

[0170] Total number of colonies and Escherichia coli: plate colony counting.

[0171] Solid: After opening the sample, the contents were poured into a pre-weighed circular sieve m1, without stirring the product, the circular sieve was inclined at about 45°, and after draining for 2 min, the circular sieve and the drained material were weighed together m2, and the mass fraction of solid was calculated, X = (m2-m1) / m3*100%.

[0172] Color, consistency, aroma, and taste: 10 professional bird's nest sensory evaluation personnel were selected to conduct sensory evaluation of the fresh stewed bird's nest, and the four sensory characteristics were subjected to quantitative descriptive analysis, and the statistical analysis was performed using SPSS 22.0 software.

[0173] Texture: texture analyzer.

[0174] Protein molecular weight: SDS-PAGE was used to analyze the change in molecular weight of bird's nest protein during digestion.

[0175] Sialic acid digestion rate and protein digestion rate: by constructing a simulated gastrointestinal digestion model, the Standard method was used to simulate the gastrointestinal digestion. 10 g of stewed bird's nest was mixed with 10 mL of simulated gastric juice in a 50 mL centrifuge tube, and the mixture was subjected to constant temperature oscillation in a water bath at 37°C. HCl was used to adjust the pH to keep it at 2.0±0.2. The gastric phase digestion was simulated at a speed of 100 r / min, and each time point was subjected to a separate digestion tube. Every 30 min, the pH was adjusted to 8.0 with alkali to inactivate the enzyme. The supernatant was separated by centrifugation at 4500g and stored at -20°C. The digestion was analyzed. After the gastric digestion was completed, the small intestinal digestion phase was entered. 16 mL of simulated intestinal fluid was added, and NaOH was used to adjust the pH to keep it at 7.0±0.2. Water was added to make the system reach 40 mL. The intestinal phase in vitro digestion was continued at a stirring speed of 100 r / min and a temperature of 37°C. Each time point was subjected to a separate digestion tube. Every 30 min, one centrifuge tube was subjected to boiling water bath to inactivate the enzyme. The supernatant was stored at -20°C, and the centrifugal precipitate was stored by freeze-drying. The digestion was analyzed.

[0176] As shown in Table 1, the fresh stewed bird's nest products of Example 1 and Example 2 can achieve commercial sterility, strong stringiness, and high solid content.

[0177] Example 3 Due to the low constant temperature sterilization temperature in step (9), the bacteria content in the fresh stewed bird's nest product is high.

[0178] Example 4 Due to the high constant temperature sterilization temperature in step (9), the fresh stewed bird's nest product has poor properties and is not resistant to fishing.

[0179] Example 5 Due to the low frequency of the second frequency increasing temperature in step (8) and the long time, the fresh stewed bird's nest product is poor and not resistant to fishing.

[0180] Example 6 Due to the low frequency of the first rapid cooling in step (10) and the long time, the fresh stewed bird's nest product is poor and not resistant to fishing.

[0181] Comparative Example 1 Due to not using frequency increasing temperature and cooling, the solid physical and chemical indicators of the fresh stewed bird's nest product do not meet the product standard requirements (≥90%).

[0182] Comparative Example 2 Due to not sterilizing after the sub-packaging in step (3), the bacteria content in the fresh stewed bird's nest product is high.

[0183] Comparative Example 3 Due to the constant temperature phase in the first frequency increasing temperature process in step (7), the solid physical and chemical indicators of the fresh stewed bird's nest product do not meet the product standard requirements (≥90%), and the stability is poor.

[0184] Comparative Example 4 Due to not containing the frequency increasing temperature step and using the same increasing temperature frequency, the solid physical and chemical indicators of the fresh stewed bird's nest product do not meet the product standard requirements (≥90%), and the stability is poor.

[0185] Comparative Example 5 Due to not containing the frequency decreasing temperature step and using the same decreasing temperature frequency, the fresh stewed bird's nest product has weak taste, is not resistant to fishing, and the solid physical and chemical indicators do not meet the product standard requirements (≥90%).

[0186] Table 1 Comparison of physical and chemical indicators of examples and comparative examples

[0187]

[0188]

[0189] As shown in Tables 2 and 3, the color, taste, aroma, and consistency indicators of the fresh stewed bird's nest products of Example 1 and Example 2 are in the best range.

[0190] Example 3 Due to the low constant temperature sterilization temperature in step (9), the bird's nest has hard taste, strong chewing sensation, and insufficient aroma.

[0191] Example 4 Due to the high constant temperature sterilization temperature in step (9), the fresh stewed bird's nest has soft taste, deep color, and heavy aroma that is not pleasant.

[0192] Example 5 Due to the low frequency and long time of the two-stage frequency warming in step (8), the fresh stewed bird's nest has a soft taste and poor consistency.

[0193] Example 6 Due to the low frequency and long time of the one-stage rapid cooling in step (10), the fresh stewed bird's nest has a soft taste and poor consistency.

[0194] Comparative Example 1 Due to the lack of frequency warming and cooling, the fresh stewed bird's nest has a hard taste.

[0195] Comparative Example 2 Due to the lack of sterilization after the sub-packaging in step (3), the fresh stewed bird's nest has a hard taste.

[0196] Comparative Example 3 Due to the presence of a constant temperature stage in the one-stage frequency warming in step (7), the fresh stewed bird's nest has a soft taste and poor consistency.

[0197] Comparative Example 4 Due to the lack of a frequency warming step, the fresh stewed bird's nest has a soft taste and poor consistency.

[0198] Comparative Example 5 Due to the lack of a frequency cooling step, the fresh stewed bird's nest has a soft taste and poor consistency.

[0199] Table 2 Sensory evaluation of examples and comparative examples

[0200]

[0201]

[0202] Note: The same letter means no significant difference, and different letters mean significant difference

[0203] Table 3 Texture comparison of examples and comparative examples

[0204] Item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Hardness 1 / N 12.66±0.02 12.66±0.05 17.57±0.10 7.64±0.07 10.09±0.08 11.51±0.02 Adhesion / N.mm 0.28±0.02 0.30±0.03 0.27±0.02 0.36±0.03 0.32±0.02 0.36±0.03 Hardness 2 / N 9.01±0.78 9.32±0.87 12.82±0.29 6.27±0.29 6.52±0.27 7.43±0.04 Elasticity / mm 0.71±0.04 0.84±0.07 0.87±0.08 0.56±0.05 0.61±0.04 0.69±0.03 Gumminess / N 4.07±0.4 4.02±0.6 5.96±0.04 2.7±0.29 3.57±0.03 4.06±0.06 Chewiness / mj 2.86±0.2 3.04±0.32 5.04±0.05 1.51±0.28 2.01±0.05 2.3±0.06 Item Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 / Hardness 1 / N 13.56±0.02 13.01±0.10 12.78±0.06 11.58±0.02 11.42±0.08 / Adhesion / N.mm 0.26±0.02 0.23±0.02 0.31±0.03 0.30±0.03 0.28±0.01 / Hardness 2 / N 9.11±0.09 9.22±0.09 9.25±0.06 9.20±0.06 9.15±0.05 / Elasticity / mm 0.79±0.06 0.80±0.07 0.82±0.08 0.70±0.04 0.68±0.05 / Gumminess / N 4.66±0.04 4.56±0.03 4.81±0.04 3.98±0.05 3.88±0.07 / Chewiness / mj 3.10±0.03 2.96±0.02 3.01±0.02 2.80±0.02 2.77±0.01 /

[0205] As shown in Tables 4 and 5, the fresh stewed bird's nest of Example 1, Example 2 and Example 4 has a high proportion of <1 kDa at 120 min (stomach) and 240 min (intestine), while Example 3 has a relatively low proportion.

[0206] The fresh stewed bird's nest of Example 1, Example 2 and Example 4 has a high content of free sialic acid at 120 min (stomach) and 240 min (intestine), while Example 3 has a relatively low content.

[0207] Table 4 Comparison of molecular weight after protein digestion of Examples 1-4

[0208]

[0209] Table 5 Comparison of molecular weight after protein digestion of Examples 1-4

[0210]

[0211]

[0212] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A method for sterilizing a fresh stewed bird's nest product, characterized by, The method comprises: The first constant temperature sterilization treatment is carried out on the cubilose packed in the container in an environment containing liquid water and water vapor. The first temperature-increasing sterilization treatment, the second temperature-increasing sterilization treatment, the second constant temperature sterilization treatment, the first temperature-decreasing sterilization treatment and the second temperature-decreasing sterilization treatment are sequentially carried out on the fresh stewed cubilose semi-product. In the first temperature-increasing sterilization treatment and the second temperature-increasing sterilization treatment, the reaction temperature continuously increases and does not include a constant temperature process of at least 1 min. The first temperature-increasing sterilization treatment comprises increasing the temperature of the fresh stewed cubilose semi-product at a first temperature-increasing frequency, wherein the first temperature-increasing frequency is 11-13 ℃ / min, and the time of the first temperature-increasing sterilization treatment is 2-8 min. The second temperature-increasing sterilization treatment comprises increasing the temperature of the first temperature-increasing product obtained in the first temperature-increasing sterilization treatment to 112-118 ℃ at a second temperature-increasing frequency, wherein the second temperature-increasing frequency is 6.5-8.8 ℃ / min, and the time of the second temperature-increasing sterilization treatment is 1-3 min. The temperature of the first constant temperature sterilization treatment is 97-100 ℃, and the time is 15-25 min. The second constant temperature sterilization treatment comprises maintaining the second temperature-increasing product obtained in the second temperature-increasing sterilization treatment at 112-118 ℃ for 8-20 min. The terminal temperature of the first temperature-increasing sterilization treatment is the same as the initial temperature of the second temperature-increasing sterilization treatment, and the terminal temperature of the second temperature-increasing sterilization treatment is the same as the initial temperature of the second constant temperature sterilization treatment. The first temperature-decreasing sterilization treatment comprises decreasing the temperature of the product obtained in the second constant temperature sterilization treatment to 95-106 ℃ at a first temperature-decreasing frequency, wherein the first temperature-decreasing frequency is 6-8 ℃ / min, and the time of the first temperature-decreasing sterilization treatment is 1-4 min. The second temperature-decreasing sterilization treatment comprises decreasing the first temperature-decreasing product obtained in the first temperature-decreasing sterilization treatment to 35-45 ℃ at a second temperature-decreasing frequency, wherein the second temperature-decreasing frequency is 12-14 ℃ / min, and the time of the second temperature-decreasing sterilization treatment is 3-6 min. The water content of the cubilose is 70-90% by mass. The temperature of the sugar solution is not lower than 90 ℃. The filling is completed within 10-15 s.

2. The method of claim 1, wherein, The first constant temperature sterilization treatment is carried out on the cubilose packed in the container in an environment containing liquid water and water vapor.

3. The method of claim 1, wherein, The first temperature-increasing sterilization treatment, the second temperature-increasing sterilization treatment, the second constant temperature sterilization treatment, the first temperature-decreasing sterilization treatment and the second temperature-decreasing sterilization treatment are all carried out on the fresh stewed cubilose semi-product in a rotating state.

4. The method of claim 1, wherein, The preparation method of the cubilose packed in the container comprises: The dried cubilose is soaked in water at 15-30 ℃ for 2-6 hours. The impurities in the soaked cubilose are picked out and then packed in the container.

5. A method of improving protein digestibility and / or sialic acid digestibility of a fresh stewed bird's nest product, characterized in that, The method comprises: treating the fresh stewed cubilose according to the sterilization method of the fresh stewed cubilose product in any one of claims 1-4.

6. A fresh stewed bird's nest product, characterized in that, The fresh stewed cubilose product is prepared by the sterilization method of the fresh stewed cubilose product in any one of claims 1-4.

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