Freeze-dried instant frog oil and preparation method thereof

Abstract

The invention discloses a freeze-dried instant frog oil and a preparation method thereof, comprising soaking the frog oil in a 0-95% alcohol solution and then rinsing it; removing the impurities attached to the frog oil and then putting the frog oil into a mold for freezing and freeze drying. The invention uses alcohol rinsing technology to remove fishy smell, brighten color, sterilize and freeze-dry, thereby ensuring that the nutritional components of the frog oil are not destroyed and improving the phenomenon of poor sensory properties of the product; the frog oil product obtained by the invention has good product sensory properties, rehydration properties, water retention properties and aesthetics.

Description

Technical Field

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

[0002] Rana oil contains a variety of biologically active substances that are beneficial to the human body, including estradiol content of 25.03μg / g, chorionic gonadotropin (HCG) of 107.5μg / g, vitamin E of 100.5mg / g, and crude protein content of more than 50%.

[0003] The oviduct of a mature female frog contains a large amount of protein, fat, carbohydrates, vitamins and natural sex hormone estradiol. According to the theory of traditional Chinese medicine, frog oil has the special effects of "tonifying the kidney and essence, moistening the lungs and nourishing yin". It has a certain effect on helping weak body and low immunity, and is a nourishing product with extremely high nutritional value.

[0004] Rana affine oil is mostly consumed in the form of dried products. In daily production and processing, the whole frog is mainly processed into dry products by direct sun drying and hot air drying, and then the oil is mainly extracted manually through slow drying. The production process is complicated and mostly manual operations. Product hygiene is difficult to guarantee and the original bacterial count is high.

[0005] There are many limitations in the processing methods of forest frog oil in the existing technology, mainly including the fat oxidation caused by the drying process of the product, the browning of the product surface, the dark color and the unsightly appearance; there is a fishy smell due to the lack of fishy removal process, and the general acceptance of the product is low; drying causes the direct pores of the protein molecules in the product to be smaller, and the product rehydrates slowly; the existing slaughtering of forest frogs is mostly done by piercing the trunk of the forest frog with an iron stick, and then drying it in the sun or with hot air. The forest frogs suffer great pain during slaughter, which is not in line with the spirit of humanitarianism, arouses the disgust of some consumers, and loses a large number of target consumer groups. Summary of the invention

[0006] 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.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] One of the purposes of the present invention is to provide a preparation method of freeze-dried instant frog oil, which ensures that the nutritional components of the frog oil are not destroyed and improves the poor sensory experience of the product through alcohol rinsing process to remove fishy smell, brighten color, sterilize and freeze-dry technology.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for preparing freeze-dried instant frog oil, comprising:

[0010] Soak the Rana oil in 0-95% alcohol solution and rinse it clean;

[0011] After removing impurities from the frog oil, the frog oil is put into a mold for freezing and freeze drying.

[0012] As a preferred solution of the preparation method of the freeze-dried instant frog oil of the present invention, wherein: the mass ratio of the frog oil to the alcohol solution is 1:0.1-200, and the soaking time is 0-24 hours.

[0013] As a preferred solution of the preparation method of freeze-dried instant frog oil of the present invention, the concentration of the alcohol solution is 70%, the mass ratio of frog oil to alcohol solution is 1:200, and the soaking time is 1 hour.

[0014] As a preferred embodiment of the method for preparing freeze-dried instant frog oil of the present invention, the freeze molding comprises freezing the frog oil in the mold at a freezing temperature of -8 to -80°C for 1 to 80 hours.

[0015] As a preferred embodiment of the preparation method of freeze-dried instant 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 2 to 60 hours.

[0016] As a preferred solution of the preparation method of the freeze-dried instant frog oil of the present invention, the frog oil is loaded into a mold, the frog oil after impurities are removed is placed in its original form, fixed in the mold, and quantitatively 1 to 300 g.

[0017] As a preferred embodiment of the method for preparing freeze-dried instant frog oil of the present invention, the frog oil is obtained by slaughtering and peeling living frogs.

[0018] As a preferred embodiment of the method for preparing freeze-dried instant frog oil of the present invention, the method comprises: slaughtering the frogs by directly destroying the spine of the frogs.

[0019] Another object of the present invention is to provide freeze-dried instant frog oil obtained by any of the preparation methods described above.

[0020] As a preferred embodiment of the freeze-dried instant frog oil of the present invention, the frog oil has the following characteristics:

[0021] (i) The mass after expansion is 72 to 100 times the mass before expansion;

[0022] (ii) The time required for sufficient expansion is 0.5 to 3 hours.

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

[0024] The invention provides a preparation method of freeze-dried instant frog oil. The method uses an alcohol rinsing process to remove fishy smell, brighten color, sterilize and freeze-dry, thereby ensuring that the nutritional components of the frog oil are not destroyed and improving the phenomenon that the product has poor sensory properties. The frog oil product obtained by the invention has good product sensory properties, rehydration properties, water retention properties and aesthetics. 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 The surface SEM morphology comparison diagram of the frog oil product prepared in Example 3 of the present invention and Comparative Examples 1 and 2 is shown. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Example 1

[0031] This embodiment provides three different live slaughtering methods, and prepares freeze-dried frog oil products based on these methods. The specific steps are:

[0032] (1) Cleaning the frog: Use clean water to wash away dust, weeds and other impurities on the surface of the frog;

[0033] (2) Slaughtering: The cleaned frogs in step (1) were slaughtered by three methods: "piercing the trunk of the frog with an iron skewer", "cutting off the head" and "cutting the spine".

[0034] The lethal time of three different live slaughtering methods was statistically analyzed, and the lactic acid content of the slaughtered forest frog carcasses was measured. The test method was thiobarbituric acid (TBA) colorimetric method, referring to the test method in the reference (Qiu Hongqiang. Study on the changes in the lactic acid content of pork by colorimetric method). 20 groups of parallel experiments were carried out for the three different live slaughtering methods, and the average value of the test results was recorded in Table 1.

[0035] Table 1

[0036] Slaughter method Deadly time Lactic acid content Piercing the trunk of a wood frog with an iron skewer 15.8min 89mmol / kg Cut off the head 5.1min 65mmol / kg Cut the spine 5.2min 53mmol / kg

[0037] From the data in Table 1, it can be seen that the traditional method of slaughtering frogs with oil, "piercing the trunk of the frog with an iron stick", takes a long time to kill, the frog suffers great pain, and the lactic acid content of the frog carcass reaches 89mmol / kg.

[0038] The slaughtering methods of "cutting off the head" and "cutting the spine" can significantly shorten the lethal time. Among them, the slaughtering method of "cutting the spine" obtained the lowest lactic acid content in the frog carcass, only 53mmol / kg. Therefore, subsequent experiments used the slaughtering method of "cutting the spine" to extract frog oil alive.

[0039] Example 2

[0040] This embodiment provides a method for preparing freeze-dried instant frog oil, the specific steps are:

[0041] (1) Cleaning the frog: Use clean water to wash away dust, weeds and other impurities on the surface of the frog;

[0042] (2) Slaughtering: The cleaned forest frog in step (1) is slaughtered by cutting the spine;

[0043] (3) removing oil and impurities: removing the oil from the forest frog slaughtered in step (2) and removing the accompanying tissue fragments, blood and other impurities;

[0044] (4) rinsing: at a temperature of 20° C., the Rana sylvatica oil removed in step (3) is respectively placed in a container with a 0-90% alcohol solution in a mass volume ratio of Rana sylvatica oil to alcohol solution of 1:200, and then soaked for 1 hour and rinsed clean;

[0045] (5) removing impurities: removing impurities such as fascia and black lines attached to the Rana sylvatica oil from the Rana sylvatica rinsed in step (4);

[0046] (6) Shaping: placing the Rana sylvatica oil after removing impurities in step (5) according to the original shape of the Rana sylvatica and fixing it in a mold;

[0047] (7) molding: evenly loading the Rana sylvatica oil shaped in step (6) into a mold;

[0048] (8) Freezing molding: sending the molded frog oil in step (7) into a freezing chamber at a freezing temperature of -10°C for 40 hours;

[0049] (9) Freeze drying: The Rana sylvatica oil block frozen in step (8) is placed in a vacuum freeze dryer, the temperature is adjusted to -25°C, the vacuum degree is adjusted to 300 Pa, and the drying time is 30 hours.

[0050] The total colony count, fishy smell evaluation, and rehydration multiple test were performed on the freeze-dried frog oil obtained under different alcohol concentrations. Twenty groups of parallel experiments were performed under each alcohol concentration, and the average value of the test results was recorded in Table 2.

[0051] The test method for total colony count refers to "National Food Safety Standard Food Microbiological Inspection-Determination of Total Colony Count" GB4789.2-2022.

[0052] The evaluation standard for the degree of fishy smell is as follows: 20 sensory evaluators aged 20 to 30 who are engaged in food flavor research were selected, and they were trained according to ISO8586-1:1993 (E) standard; an appropriate amount of sample was placed in a clean white porcelain plate, and the color and state were observed under natural light, and its odor was smelled. After soaking it in 60°C warm water, its flavor was tasted, and the fishy smell of the forest frog oil was scored in the range of 1 to 10 (0 to 2 means it is almost present, 3 to 4 is weak, 5 to 6 is medium, 7 to 8 is strong, and 9 to 10 is rich).

[0053] The rehydration multiple test method is: put the freeze-dried frog oil into water and start timing. When the frog oil has no obvious core after swelling (sufficient swelling), take it out, record the time, and measure the quality of the frog oil before and after swelling.

[0054] Table 2

[0055] Alcohol concentration Total colony count (cfu / g) Odor level (1-10) Rehydration times 0％ <![CDATA[6.3*10 4 ]]> 10 100 30％ <![CDATA[6.1*10 4 ]]> 7 100 50％ <![CDATA[2.4*10 4 ]]> 5 93 70％ <![CDATA[8.3*10 3 ]]> 3 85 90％ <![CDATA[3.6*10 4 ]]> 3 72

[0056] From the data in Table 2, it can be seen that with the increase of alcohol concentration, the smell of Rana oil gradually decreases, and the total number of colonies, within the alcohol concentration of 10-30%, alcohol will not affect the quality of freeze-dried Rana oil after rehydration, but after the concentration exceeds 30%, with the increase of alcohol concentration, the quality of freeze-dried Rana oil after rehydration gradually decreases. Taking the above factors into consideration, the best alcohol concentration is 50%.

[0057] Example 3

[0058] This embodiment provides a method for preparing freeze-dried instant frog oil, the specific steps of which are:

[0059] (1) Cleaning the frog: Use clean water to wash away dust, weeds and other impurities on the surface of the frog;

[0060] (2) Slaughtering: The cleaned frogs in step (1) are slaughtered by cutting the spine;

[0061] (3) removing oil and impurities: removing the oil from the forest frog slaughtered in step (2) and removing the accompanying tissue fragments, blood and other impurities;

[0062] (4) rinsing: at a temperature of 20° C., the Rana sylvatica oil removed in step (3) is placed in a container with a 70% alcohol solution in a mass volume ratio of Rana sylvatica oil to alcohol solution of 1:200, and then soaked for 1 hour and rinsed clean;

[0063] (5) removing impurities: removing impurities such as fascia and black lines attached to the Rana sylvatica oil from the Rana sylvatica rinsed in step (4);

[0064] (6) Shaping: placing the Rana sylvatica oil after removing impurities in step (5) according to the original shape of the Rana sylvatica and fixing it in a mold;

[0065] (7) molding: evenly loading the Rana sylvatica oil shaped in step (6) into a mold;

[0066] (8) Freezing molding: sending the molded frog oil in step (7) into a freezing chamber at a freezing temperature of -10°C for 40 hours;

[0067] (9) Freeze drying: The Rana sylvatica oil block frozen in step (8) is placed in a vacuum freeze dryer, the temperature is adjusted to -25°C, the vacuum degree is adjusted to 300 Pa, and the drying time is 30 hours.

[0068] The product obtained in Example 3 is light yellow in color.

[0069] Comparative Example 1

[0070] On the basis of Example 1, step (2) adopts the slaughtering method of "cutting the spine", the alcohol concentration in step (4) is adjusted to 70%, and the drying method of the forest frog oil is changed. The specific steps are:

[0071] (1) Cleaning the frog: Use clean water to wash away dust, weeds and other impurities on the surface of the frog;

[0072] (2) Slaughtering: The cleaned frogs in step (1) are slaughtered by cutting the spine;

[0073] (3) removing oil and impurities: removing the oil from the forest frog slaughtered in step (2) and removing the accompanying tissue fragments, blood and other impurities;

[0074] (4) rinsing: at a temperature of 20° C., the Rana sylvatica oil removed in step (3) is placed in a container with a 70% alcohol solution in a mass volume ratio of Rana sylvatica oil to alcohol solution of 1:200, and then soaked for 1 hour and rinsed clean;

[0075] (5) removing impurities: removing impurities such as fascia and black lines attached to the Rana sylvatica oil from the Rana sylvatica rinsed in step (4);

[0076] (6) Shaping: placing the Rana sylvatica oil after removing impurities in step (5) according to the original shape of the Rana sylvatica and fixing it in a mold;

[0077] (7) Air drying: Place the shaped frog oil outdoors to dry for 2 to 3 days until the product is dry.

[0078] The product obtained in Comparative Example 1 is dark yellow in color and contains impurities.

[0079] Comparative Example 2

[0080] On the basis of Comparative Example 1, the drying method of step (7) was changed, and the other steps were the same as those of Comparative Example 1; the specific steps of step (7) were:

[0081] (7) Hot air drying: Place the shaped Rana sylvatica oil in a hot air drying oven and dry at 75°C for 24 hours until the product is dry.

[0082] The product obtained in Comparative Example 2 is dark yellow in color and free of impurities.

[0083] The prepared forest frog oil products of Example 3 and Comparative Examples 1 and 2 were tested for total bacterial count and rehydration performance. The rehydration performance test method was as follows: the forest frog oil product was put into water and the timing was started. When the forest frog oil was not obviously core-shaped after foaming, it was taken out, the time was recorded, and the quality of the forest frog 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 3.

[0084] Table 3

[0085] Rehydration time (25℃) Product color Total colony count (cfu / g) Comparative Example 1 36.5h Dark yellow, with impurities <![CDATA[1.2*10 5 ]]> Comparative Example 2 36.2h Dark yellow <![CDATA[8.9*10 4 ]]> Example 3 2.1h Light yellow <![CDATA[8.3*10 3 ]]>

[0086] The surface SEM morphology of the obtained frog oil products in Example 3 and Comparative Examples 1 and 2 is as follows: Figure 1 As shown. Figure 1 AIt can be seen that the tissue structure of the direct freeze-dried product is a flaky structure, and water can be evenly dispersed into the interior of the product, which reduces the water diffusion path and greatly shortens the rehydration time.

[0087] Depend on Figure 1As can be seen from B and C, the surfaces of air-dried products and hot-air-dried products present a dense structure without cracks or gaps, making it difficult for water to enter, resulting in a longer rehydration time.

[0088] The forest frog oil product prepared by the present invention is not heated or aired, but rinsed with alcohol. The surface of the product is light yellow to white with good color. There is no light exposure, no "ha" smell is generated, and the sensory experience of the product is greatly improved.

[0089] The freeze-drying technology combined with alcohol rinsing can remove the fishy smell of the product to the greatest extent, and protect the various nutrients, estrogen and other active substances of the product; freeze-forming quickly fixes the structure of the product molecules, avoids the dehydration and polymerization of the protein structure during the drying process, and is not easy to form a dense hydrophobic structure, which can be quickly soaked and easy to eat. Alcohol rinsing, sterilization, rinsing makes the color whiter and removes the fishy smell;

[0090] The present invention adopts live body oil extraction, which can remove impurities such as black lines and glandular membranes attached to the fallopian tubes, which are product pain points, in the previous process, can simplify the product consumption process, and increase the aesthetic attributes of the product.

[0091] The current method of killing the frogs by stringing them alive and then drying them in the sun takes a long time to kill (more than 2 hours), causing them to suffer great pain, which is not in line with the spirit of humanitarianism. The new method uses the method of cutting the spine while alive to kill the frogs, which greatly reduces their pain, complies with the relevant requirements of the World Animal Protection Association on humane slaughter, and avoids consumer disgust caused by inhumane slaughter.

[0092] 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 instant frog oil, characterized in that: include, Soak the Rana oil in 50% to 70% alcohol solution and rinse it clean; After removing the impurities attached to the frog oil, the frog oil is put into a mold for freezing and freeze drying; The forest frog oil is obtained by slaughtering and peeling living forest frogs, wherein the slaughtering is carried out by cutting the spine of the forest frogs; The soaking in the alcohol solution, the mass volume ratio of the forest frog oil to the alcohol solution is 1:200, and the soaking time is 1 hour; The freezing molding comprises freezing the wood frog oil in the mold at a freezing temperature of -10°C for 40 hours; The freeze drying process is to send the frozen Rana sylvatica oil into a vacuum freeze dryer at a temperature of -25°C and a vacuum degree of 300 Pa for 30 hours.

2. The method for preparing freeze-dried instant frog oil according to claim 1, wherein: The method comprises: putting the forest frog oil into a mold, placing the forest frog oil after removing impurities in an original form, fixing the oil in the mold, and quantitatively measuring 1 to 300 g.

3. The freeze-dried instant frog oil obtained by the preparation method according to any one of claims 1 to 2, characterized in that: The frog oil has the following characteristics: (i) The mass after expansion is 85 to 93 times the mass before expansion; (ii) The soaking time is 0.5~3h.

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