A kind of preparation method of freeze-dried frog oil

Abstract

The invention discloses a preparation method of freeze-dried frog oil, comprising: foaming frog oil; compounding the foamed frog oil with a quality improver; loading the compounded frog oil into a mold for freeze molding and freeze drying; and subjecting the freeze-dried frog oil to pulse sterilization. The preparation method of freeze-dried frog oil provided by the invention has no heat treatment throughout the process, and the nutrients are less damaged due to processing; the water is changed in the front process to reduce the loss of water-soluble active substances; through pre-porosity and quality improver treatment, the rehydration time is reduced by more than 70%, so that the freeze-dried frog oil truly becomes a convenient, ready-to-eat food.

Description

Technical Field

[0001] The invention belongs to the technical field of food, and in particular relates to a preparation method of freeze-dried frog oil. Background Art

[0002] Rana oil refers to the oviduct of mature female Rana, which contains a lot of protein, fat, carbohydrates, vitamins and natural sex hormone estradiol, etc. According to the theory of traditional Chinese medicine, Rana oil has the special effect of "tonifying the kidney and essence, moistening the lungs and nourishing yin", which has a certain effect on helping weak body and low immunity, and is a tonic product with extremely high nutritional value.

[0003] Rana affine oil has excellent health functions, but its functional ingredients are difficult to preserve and easily lose their activity during processing, making it inconvenient to eat and difficult to carry and store.

[0004] The existing technology for the preparation method of Rana sylvatica oil has many limitations, mainly including the strong fishy smell of the product, the denaturation of the product protein, and the extremely poor rehydration effect. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] One of the purposes of the present invention is to provide a preparation method of freeze-dried frog oil, which ensures that the nutritional components of the frog oil are not destroyed through a pre-soaking and deodorizing process and a non-thermal sterilization technology, and the product has good sensory properties and a good rehydration effect.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a preparation method of freeze-dried Rana sylvatica oil, comprising:

[0009] Soak the frog oil;

[0010] Compounding the soaked frog oil with a quality improver;

[0011] The compounded Rana sylvatica oil is placed in a mold for freezing molding and freeze drying;

[0012] The freeze-dried Rana sylvatica oil was sterilized by pulse sterilization.

[0013] As a preferred embodiment of the method for preparing freeze-dried Rana sylvatica oil of the present invention, the quality improver is composed of hydroxypropyl distarch phosphate, white sugar and sorbitol;

[0014] The compounding with the quality improver comprises, by weight, 30 to 100 parts of forest frog oil, 0 to 10 parts of hydroxypropyl distarch phosphate, 1 to 10 parts of white sugar and 0 to 10 parts of sorbitol, and the mixture is stirred evenly.

[0015] As a preferred solution of the method for preparing freeze-dried Rana sylvatica oil of the present invention, the pulse sterilization has an electric field strength of 10 to 50 Kv / cm and a time of 10 to 30 microseconds.

[0016] As a preferred embodiment of the preparation method of freeze-dried Rana sylvatica oil of the present invention, the Rana sylvatica oil is soaked by mixing the Rana sylvatica oil with water at a mass volume ratio of 1:50 to 1:260 at room temperature and soaking for 1 to 40 hours.

[0017] As a preferred embodiment of the method for preparing freeze-dried Rana sylvatica oil of the present invention, the freeze molding comprises freezing the Rana sylvatica oil loaded into the mold at a freezing temperature of -8 to -80°C for 1 to 80 hours.

[0018] As a preferred embodiment of the preparation method of freeze-dried frog oil of the present invention, the freeze-drying comprises sending the frozen frog oil into a vacuum freeze dryer at a temperature of -3 to -40°C, a vacuum degree of 500 to 2 Pa, and a time of 10 to 80 hours.

[0019] As a preferred embodiment of the method for preparing freeze-dried Rana affine oil of the present invention, before the Rana affine oil is soaked, the method further comprises pre-soaking the Rana affine oil in an alcohol solution.

[0020] As a preferred embodiment of the method for preparing freeze-dried Rana sylvatica oil of the present invention, the alcohol concentration of the alcohol solution is 0-85%.

[0021] As a preferred embodiment of the method for preparing freeze-dried Rana sylvatica oil of the present invention, the mass volume ratio of the Rana sylvatica oil to the alcohol solution is 1:10 to 1:100.

[0022] As a preferred embodiment of the method for preparing freeze-dried Rana sylvatica oil of the present invention, the pre-soaking time is 0.2 to 15 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The freeze-dried frog oil product provided by the present invention has no heat treatment in the whole process, and the nutrients are less damaged due to processing; the water is changed in the front process to reduce the loss of water-soluble active substances; through pre-porosity and quality improver treatment, the rehydration time is reduced by more than 70%, so that the freeze-dried frog oil can truly become a convenient and ready-to-eat food. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0026] Figure 1 This is the SEM image of the surface of raw material frog oil.

[0027] Figure 2 This is the SEM image of the internal structure of the raw material frog oil.

[0028] Figure 3 This is a SEM image of the freeze-dried frog oil obtained in Example 2 of the present invention.

[0029] Figure 4 This is a SEM image of the freeze-dried Rana sylvatica oil obtained in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Example 1

[0034] (1) Removal of impurities from frog oil: artificially removing frog eggs, internal organs and other impurities attached to frog oil;

[0035] (2) Pre-soaking: at room temperature, the Rana sylvatica oil cleaned in step (1) and a 25% alcohol aqueous solution are placed in a container and soaked for 8 hours in a ratio of 1:80;

[0036] (3) cleaning and removing impurities: taking out the Rana sylvatica oil pre-soaked in step (2), and manually removing impurities such as fascia and white thread-like substances attached to the Rana sylvatica oil;

[0037] (4) Soaking: Soak for 10 hours at room temperature at a ratio of 1:160;

[0038] (5) Preparation: Weigh 100 parts of the Rana sylvatica oil after the foaming in step (4) and a quality improver according to their mass parts, wherein the specific type and amount of the quality improver are shown in Table 1; and stir evenly;

[0039] (6) Molding: The mixed Rana sylvatica oil in step (5) is evenly loaded into a 1.5 cm*1.5 cm*1 cm mold;

[0040] (7) Freezing molding: sending the molded frog oil in step (6) into a freezing chamber at a freezing temperature of -20°C for 20 hours;

[0041] (8) Freeze drying: The frozen Rana sylvatica oil block in step (7) was placed in a vacuum freeze dryer, the temperature was adjusted to -18°C, the vacuum degree was adjusted to 80 Pa, and the drying time was 30 hours;

[0042] (9) Flexible sterilization: The freeze-dried Rana sylvatica oil in step (8) is placed in a high-voltage pulse sterilizer with an electric field strength of 22 kv / cm and a time of 20 microseconds to obtain freeze-dried Rana sylvatica oil.

[0043] The freeze-dried Rana oil obtained in Example 1 was tested for rehydration performance, and the test method was: after the freeze-dried Rana oil was put into water, the timing was started, and when the Rana oil was no longer obviously core-shaped after foaming, the Rana oil was taken out, the time was recorded, and the quality of the Rana oil before and after foaming was measured. 20 groups of parallel experiments were carried out under each condition, and the results were averaged and recorded in Table 1.

[0044] Table 1

[0045]

[0046]

[0047] It can be seen from the data in Table 1 that when white sugar or sorbitol is used as a quality improver, the rehydration time gradually decreases with the increase of the amount of white sugar or sorbitol added. When hydroxypropyl distarch phosphate is used as a quality improver, the rehydration time first decreases and then increases with the increase of the amount of hydroxypropyl distarch phosphate added.

[0048] Example 2

[0049] (1) Removal of impurities from frog oil: artificially removing frog eggs, internal organs and other impurities attached to frog oil;

[0050] (2) Pre-soaking: at room temperature, the Rana sylvatica oil cleaned in step (1) and a 25% alcohol aqueous solution are placed in a container and soaked for 8 hours in a ratio of 1:80;

[0051] (3) cleaning and removing impurities: taking out the Rana sylvatica oil pre-soaked in step (2), and manually removing impurities such as fascia and white thread-like substances attached to the Rana sylvatica oil;

[0052] (4) Soaking: Soak for 10 hours at room temperature at a ratio of 1:160;

[0053] (5) Preparation: Weigh 100 parts of the Rana sylvatica oil soaked in step (4), 0.8 parts of hydroxypropyl distarch phosphate, 1 part of white sugar, and 1 part of sorbitol according to the weight ratio; stir evenly;

[0054] (6) Molding: The mixed Rana sylvatica oil in step (5) is evenly loaded into a 1.5 cm*1.5 cm*1 cm mold;

[0055] (7) Freezing molding: sending the molded frog oil in step (6) into a freezing chamber at a freezing temperature of -20°C for 20 hours;

[0056] (8) Freeze drying: The frozen Rana sylvatica oil block in step (7) was placed in a vacuum freeze dryer, the temperature was adjusted to -18°C, the vacuum degree was adjusted to 80 Pa, and the drying time was 30 hours;

[0057] (9) Flexible sterilization: The freeze-dried Rana sylvatica oil in step (8) is placed in a high-voltage pulse sterilizer with an electric field strength of 22 kv / cm and a time of 20 microseconds to obtain freeze-dried Rana sylvatica oil.

[0058] The freeze-dried Rana oil obtained in Example 2 was subjected to a rehydration performance test, and the test method was referred to Example 1. 20 groups of parallel experiments were performed, and the results were averaged. The test results showed that the rehydration time was 8 minutes, and the mass of the Rana oil after the rehydration test was 100 times the mass of the Rana oil before the rehydration test.

[0059] The SEM image of the surface of the raw material frog oil is as follows Figure 1 The SEM image of the internal structure is shown in Figure 2 The SEM image of the freeze-dried Rana sylvatica oil obtained in Example 2 is shown in Figure 3 As shown,

[0060] Depend on Figure 1 , 2It can be seen that the surface of the product has a dense structure without cracks or gaps, making it difficult for water to enter; the interior of the product is lumpy and spherical. During rehydration, the water diffusion path is the minimum radius of the sphere, the path is longer, and the rehydration time is longer.

[0061] Depend on Figure 3 It can be seen that the product presents a uniform network structure, and water can be directly and evenly dispersed into the interior of the product, greatly reducing the path of water diffusion. It is the support of the quality improver for the structure of the forest frog, improving the phenomenon of freeze-dried samples becoming flaky after soaking, and greatly improving the structural state of the product.

[0062] Comparative Example 1

[0063] The frog oil is soaked and freeze-dried, and the specific steps are as follows:

[0064] (1) Removal of impurities from frog oil: artificially removing frog eggs, internal organs and other impurities attached to frog oil;

[0065] (2) Cleaning and removing impurities: Manually remove impurities such as fascia and white thread-like substances attached to the frog oil;

[0066] (3) Soaking: Soak for 10 hours at room temperature at a ratio of 1:160;

[0067] (4) Molding: The Rana sylvatica oil after foaming in step (3) is evenly loaded into a 1.5 cm*1.5 cm*1 cm mold;

[0068] (5) Freezing molding: sending the molded frog oil in step (4) into a freezing chamber at a freezing temperature of -20°C for 20 hours;

[0069] (6) Freeze drying: The Rana sylvatica oil block frozen in step (5) is sent to a vacuum freeze dryer, the temperature is adjusted to -18°C, the vacuum degree is adjusted to 80 Pa, and the drying time is 30 hours to obtain freeze-dried Rana sylvatica oil.

[0070] The freeze-dried Rana oil obtained in Comparative Example 1 was subjected to a rehydration performance test, and the test method was referred to Example 1. 20 groups of parallel experiments were performed, and the results were averaged. The test results showed that the rehydration time was 20.5 min, and the mass of the Rana oil after the rehydration test was 100 times the mass of the Rana oil before the rehydration test.

[0071] The SEM image of the surface of the freeze-dried Rana sylvatica oil obtained in Comparative Example 1 is as follows: Figure 4 As shown in the figure, it can be seen that the organizational structure is flaky, and there are certain gaps between the structures, which makes it easy for water to enter. The water diffusion path is half of the thickness of the flaky layer. During rehydration, the water diffusion path is reduced, which increases the speed of rehydration.

[0072] Comparative Example 2

[0073] On the basis of Example 2, no quality improver was added in step (5), 100 parts of the foamed frog oil were weighed and directly put into the high-pressure pulse sterilizer, and the other steps were the same as in Example 2.

[0074] The freeze-dried Rana sylvatica oil obtained in Comparative Example 2 was subjected to a rehydration performance test, and the test method was referred to Example 1. 20 groups of parallel experiments were performed, and the results were averaged. The test results showed that the rehydration time was 30 min, and the mass of the Rana sylvatica oil after the rehydration test was 90 times the mass of the Rana sylvatica oil before the rehydration test.

[0075] Comparative Example 3

[0076] On the basis of Example 2, a commercially available quality improver was added in step (5). The quality improver was purchased from Angel (frozen raw embryo improver) and was a protein quality improver. The added amount was 3 parts. The other steps were the same as in Example 2.

[0077] The freeze-dried Rana sylvatica oil obtained in Comparative Example 3 was subjected to a rehydration performance test, and the test method was referred to Example 1. 20 groups of parallel experiments were performed, and the results were averaged. The test results showed that the rehydration time was 24 minutes, and the mass of the Rana sylvatica oil after the rehydration test was 93 times the mass of the Rana sylvatica oil before the rehydration test.

[0078] Comparative Example 4

[0079] Based on Example 2, step (9) is omitted and the other steps are the same as Example 2.

[0080] The freeze-dried Rana oil obtained in Comparative Example 5 was subjected to a rehydration performance test, and the test method was referred to Example 1. 20 groups of parallel experiments were performed, and the results were averaged. The test results showed that the rehydration time was 13 minutes, and the mass of the Rana oil after the rehydration test was 95 times the mass of the Rana oil before the rehydration test.

[0081] Example 3

[0082] (1) Removal of impurities from frog oil: artificially removing frog eggs, internal organs and other impurities attached to frog oil;

[0083] (2) Pre-soaking: at room temperature, the Rana sylvatica oil washed in step (1) was soaked in different concentrations of alcohol aqueous solutions at a ratio of 1:80 for 8 hours, the specific alcohol concentrations being as shown in Table 2;

[0084] (3) cleaning and removing impurities: taking out the Rana sylvatica oil pre-soaked in step (2), and manually removing impurities such as fascia and white thread-like substances attached to the Rana sylvatica oil;

[0085] (4) Soaking: Soak for 10 hours at room temperature at a ratio of 1:160;

[0086] (5) Preparation: Weigh 100 parts of the Rana sylvatica oil soaked in step (4), 0.8 parts of hydroxypropyl distarch phosphate, 1 part of white sugar, and 1 part of sorbitol according to the weight ratio; stir evenly;

[0087] (6) Molding: The mixed Rana sylvatica oil in step (5) is evenly loaded into a 1.5 cm*1.5 cm*1 cm mold;

[0088] (7) Freezing molding: sending the molded frog oil in step (6) into a freezing chamber at a freezing temperature of -20°C for 20 hours;

[0089] (8) Freeze drying: The frozen Rana sylvatica oil block in step (7) was placed in a vacuum freeze dryer, the temperature was adjusted to -18°C, the vacuum degree was adjusted to 80 Pa, and the drying time was 30 hours;

[0090] (9) Flexible sterilization: The freeze-dried Rana sylvatica oil in step (8) is placed in a high-voltage pulse sterilizer with an electric field strength of 22 kv / cm and a time of 20 microseconds to obtain freeze-dried Rana sylvatica oil.

[0091] The freeze-dried Rana sylvatica oils obtained in Example 3 were tested for rehydration performance, and the test method was referred to Example 1.

[0092] Each freeze-dried frog oil obtained in Example 3 was subjected to sensory evaluation, and the evaluation criteria were: 20 sensory assessors aged 20 to 30 years old who were engaged in food flavor research were selected, and the sensory assessors were trained according to ISO8586-1:1993 (E) standard; appropriate amount of sample was placed in a clean white porcelain dish, and the color and state were observed under natural light, and its odor was smelled, and after being soaked in 60°C warm water, its flavor was tasted, and the fishy smell of the frog oil was scored within the range of 1 to 10 (0 to 2 means that it is almost there, 3 to 4 is weak, 5 to 6 is medium, 7 to 8 is strong, and 9 to 10 is strong). 20 groups of parallel experiments were carried out under each condition, and the results were averaged and recorded in Table 2.

[0093] Table 2

[0094] Alcohol concentration (%) Rehydration times Fishy smell evaluation 0 100 10 10 100 7 20 100 6 30 100 6 40 98 4 50 98 2 60 90 1 70 83 1 80 56 1 90 43 1

[0095] It can be seen from the data in Table 2 that the fishy smell of Rana oil gradually decreases with the increase of alcohol concentration. Within the alcohol concentration range of 10-30%, alcohol will not affect the quality of freeze-dried Rana oil after rehydration, but after the concentration exceeds 30%, as the alcohol concentration increases, the quality of freeze-dried Rana oil after rehydration gradually decreases. Considering the above factors, 50% alcohol concentration is the best.

[0096] The preparation method of freeze-dried frog oil provided by the present invention has no heat treatment in the whole process, and the nutrients are less damaged due to processing; the water is changed in the front process to reduce the loss of water-soluble active substances; and the rehydration time is reduced by more than 70% through pre-porosity and quality improver treatment, so that the freeze-dried frog oil can truly become a convenient and ready-to-eat food.

[0097] The invention aims to improve the problems of protein denaturation, low rehydration rate and low water holding capacity of existing products, which are mainly reflected in non-thermal sterilization and flexible processing to maintain the structure of protein; a pre-soaking process is added to maintain the integrity of the product, which is convenient for removing impurities from the product and removes the fishy smell of the product; the fishy smell removal process is pre-placed, and the soaking liquid is only replaced in the pre-soaking process of the frog oil, and the water is not replaced subsequently, thereby minimizing the loss of dry matter and the loss of soluble nutrients in the product; and a new type of compound quality improver is used as an auxiliary to protect the protein structure of the frog oil and the integrity of the product structure during the freezing process, thereby ensuring the rehydration rate and water holding capacity of the product.

[0098] Compared with the prior art, the processing method of the forest frog oil proposed by the invention has good product sensory properties, rehydration properties and water holding properties.

[0099] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing freeze-dried Rana sylvatica oil, characterized in that: include, Soak the frog oil; Compounding the soaked frog oil with a quality improver; The compounded Rana sylvatica oil is placed in a mold for freezing molding and freeze drying; The freeze-dried Rana sylvatica oil was sterilized by pulse sterilization; The frog oil is compounded with a quality improver, and 100 parts of frog oil, 0.8 parts of hydroxypropyl distarch phosphate, 1 part of white sugar and 1 part of sorbitol are mixed uniformly by weight; The pulse sterilization has an electric field strength of 10-50 Kv / cm and a time of 10-30 microseconds.

2. The method for preparing freeze-dried Rana sylvatica oil according to claim 1, wherein: The method comprises the following steps: soaking the forest frog oil, mixing the forest frog oil with water at a mass volume ratio of 1:50 to 1:260 at room temperature, and soaking the mixture for 1 to 40 hours.

3. The method for preparing freeze-dried Rana sylvatica oil as claimed in claim 1, wherein: The freezing molding comprises freezing the wood frog oil in the mold at a freezing temperature of -8 to -80°C for 1 to 80 hours.

4. The method for preparing freeze-dried Rana sylvatica oil according to claim 1, wherein: The freeze drying process includes sending the frozen Rana sylvatica oil into a vacuum freeze dryer at a temperature of -3 to -40°C, a vacuum degree of 500 to 2 Pa, and a time period of 10 to 80 hours.

5. The method for preparing the freeze-dried Rana sylvatica oil as claimed in any one of claims 1 to 4, wherein: Before soaking the frog oil, the method also includes pre-soaking the frog oil in an alcohol solution.

6. The method for preparing freeze-dried Rana sylvatica oil as claimed in claim 5, wherein: The alcohol concentration of the alcohol solution is 25-85%.

7. The method for preparing freeze-dried Rana sylvatica oil according to claim 5, wherein: The mass volume ratio of the forest frog oil to the alcohol solution is 1:10-1:

100.

8. The method for preparing freeze-dried Rana sylvatica oil as claimed in claim 5, wherein: The pre-soaking time is 0.2 to 15 hours.

Images