CN106281048B - A kind of preparation method of low fishlike smell dog salmon fishskin gelatin - Google Patents

Abstract

The present invention provides a kind of preparation method of low fishlike smell dog salmon fishskin gelatin, including dog salmon fish-skin is taken to add in liquid detergent aqueous degreaser；Add in sodium hydroxide solution alkali process；Add in aqueous hydrogen peroxide solution decoloration；Add in citric acid solution decalcification；Add in phosphoric acid solution acid treatment fish-skin；Rosmarinus officinalis extract is added, with hot water extraction, cools down, supernatant is collected by centrifugation, is gelatin solution；Gelatin solution is freeze-dried, obtains low fishlike smell dog salmon fishskin gelatin.The present invention provides a kind of preparation method of dog salmon fishskin gelatin, improves the utilization rate of by-product fish-skin in discarded dog salmon process, reduce environmental pollution using dog salmon fish-skin as raw material；The method of the present invention is easy to operate, reduces the operation difficulty of worker, and processing cost is low, production efficiency is high.

Description

A preparation method of salmon skin gelatin with low fishy smell

technical field

The invention relates to the field of making fish skin food, in particular to a method for making salmon skin gelatin with low fishy smell.

Background technique

Gelatin is a hydrolyzed product of collagen, that is, a natural polymer mixture formed by breaking and degrading collagen molecules under the action of heat, which has high safety. The skin and bones of mammals such as pigs and cattle have always been the main source of gelatin. However, due to the outbreak of animal diseases such as mad cow disease, foot-and-mouth disease, and bird flu, people have questioned mammalian gelatin. The European Union has even banned the use of bovine gelatin in food. Products, and religious beliefs also hinder the application of pig-derived gelatin to a certain extent. The worldwide market demand for gelatin is increasing year by year, and the supply is in short supply. Therefore, it is an inevitable development trend of the gelatin industry to find new resources to develop gelatin products and replace pig and cattle source gelatin. The collagen content in fish skin reaches about 30%, which is a high-quality potential gelatin resource. Fish skin gelatin has good biodegradability and biocompatibility, as well as low allergenicity. Using fish skin to develop gelatin products can not only relieve the pressure on the gelatin industry, but also reduce environmental pollution and resource waste, and increase the economic value of by-products of aquatic product processing.

Salmon belongs to the family Salmonidae and is a well-known cold-water anadromous fish that spawns and migrates. my country is a big salmon processing country, resulting in a large amount of discarded fish skin. Salmon is a rare cold-water fish. Compared with other fish, its skin gelatin has its own characteristics and is easier to be absorbed and utilized. It is considered to be a good resource for developing functional products such as collagen peptides, and has broad market development value. At present, there is no report on the extraction of salmon skin gelatin in China, and there are few reports on the extraction of salmon skin gelatin abroad.

The gelatin production process usually includes three parts: raw material pretreatment, extraction and drying. The pretreatment and extraction steps are the key steps to convert collagen into gelatin. The pretreatment process is directly related to the yield and quality of gelatin. At present, hot water extraction is mostly used for gelatin extraction, that is, raw materials are directly extracted with hot water at a certain temperature after pretreatment such as fat removal and protein removal.

The traditional fish skin gelatin extraction process has the following disadvantages:

1. Using organic solvents such as n-hexane, petroleum ether, diethyl ether and n-butanol for degreasing affects the safety of gelatin products, while the cost of reagents is high and pollutes the environment;

2. Soak raw materials with high concentration of lye and hydrochloric acid, it is not easy to remove melanin and other substances in fish skin, affect the appearance of gelatin products, and there are hidden dangers in operation safety;

3. Fish skin is decalcified with strong acid, which destroys the integrity of gelatin and affects its functional properties;

4. Fish skin gelatin has a strong fishy smell.

Contents of the invention

The purpose of the present invention is to develop a safe and environmentally friendly process for high-value processing of salmon skin, fully develop and utilize collagen peptides in fish skin, improve the utilization rate of by-products in the processing of salmon, and avoid resources Waste and environmental pollution; at the same time enrich the food types of salmon.

In order to achieve the above object, the invention provides a method for preparing salmon skin gelatin with low fishy smell, comprising the steps of:

S1. Raw material pretreatment: take the salmon skin, wash it, and set it aside;

There is no need to shave the skin of salmon, only need to remove impurities such as minced meat and silt.

S2. Add an aqueous solution of detergent to the spare fish skin obtained in step S1, soak at 18-25°C for 3-5 hours, rinse, and collect the fish skin, which is defatted fish skin;

The mass-to-volume ratio of the standby fish skin to the aqueous detergent solution is 1g:5-15ml;

The detergent aqueous solution is obtained by diluting common household detergent with water, and the detergent is high-efficiency, fast in degreasing, easy to rinse and leaves no residue.

S3, adding sodium hydroxide solution to the defatted fish skin obtained in step S2, soaking at 18-25°C for 3-8 hours, washing with water until the pH value is 7-9, collecting the fish skin to obtain the alkali-treated fish skin;

The concentration of the sodium hydroxide solution is 0.01～0.1mol/L, and the mass volume ratio of the defatted fish skin to the sodium hydroxide solution is 1g:3～15ml;

S4. Add aqueous hydrogen peroxide solution to the alkali-treated fish skin prepared in step S3, soak at 18-25°C for 1-4 hours, collect the fish skin, and obtain decolorized fish skin;

The volume concentration of the aqueous hydrogen peroxide solution is 0.5 to 2%, and the mass volume ratio of the alkali-treated fish skin to the aqueous hydrogen peroxide solution is 1g:3 to 15ml;

S5, adding citric acid solution to the decolorized fish skin prepared in step S4, soaking at 18-25° C. for 1-3 hours, washing with water 3 times, collecting the fish skin to obtain decalcified fish skin;

The concentration of the citric acid solution is 0.1～0.8mol/L, and the mass volume ratio of the decolorized fish skin and the citric acid solution is 1g:8～25ml;

S6, adding phosphoric acid solution to the decalcified fish skin prepared in step S5, soaking at 18-25°C for 2-5 hours, washing with water until the pH value is 6-7, collecting the fish skin to obtain acid-treated fish skin;

The concentration of the phosphoric acid solution is 0.05～0.1mol/L, and the mass volume ratio of the decalcified fish skin to the phosphoric acid solution is 1g:4ml～10ml;

S7. Add rosemary extract to the acid-treated fish skin prepared in step S6, add water for extraction at 40-80°C for 8-18 hours, cool to 18-25°C, and centrifuge to collect the supernatant, that is For gelatin solution;

The mass volume ratio of the acid-treated fish skin to the water added is 1g:2-12ml; the mass ratio of the fish skin to the rosemary extract is 1g:0.0005-0.005g;

The rosemary extract of the present invention is the crude extract of rosemary purchased from Henan Yuzhong Biotechnology Co., Ltd.

S8. Freeze-dry the gelatin solution prepared in step S7 for 24-36 hours to obtain salmon skin gelatin with low fishy smell.

In a preferred manner, the mass volume ratio of the spare fish skin described in step S2 to the aqueous detergent solution is 1g:5-8ml;

The mass-to-volume ratio of the degreased fish skin to the sodium hydroxide solution in step S3 is 1g:5-8ml;

The mass volume ratio of the alkali-treated fish skin to the hydrogen peroxide aqueous solution in step S4 is 1g:5-8ml;

The mass volume ratio of the decolorized fish skin described in step S5 to the citric acid solution is 1g:8ml;

The mass volume ratio of the decalcified fish skin to the phosphoric acid solution in step S6 is 1g:4-8ml;

The mass volume ratio of the acid-treated fish skin to the water added in step S7 is 1g:5ml; the mass ratio of the fish skin to the rosemary extract is 1g:0.002-0.003g.

In a preferred manner, the soaking process described in steps S2, S3, S4, S5, and S6 is changed every 60 to 80 minutes.

In a preferred manner, the centrifugation conditions in step S7 are: centrifugal force 4000-10000g, ambient temperature 18-25°C, and centrifugation time 10-30min.

In a preferred manner, the freeze-drying method in step S7 is: vacuum freeze-drying, and the gelatin solution prepared in step S7 is pre-frozen at -80° C. for 2 to 4 hours before drying.

Compared with previous techniques and similar products, the present invention has the following innovations and advantages:

1. The present invention provides a preparation method of salmon skin gelatin using salmon skin as a raw material, which improves the utilization rate of by-product fish skin in the discarded salmon processing process and reduces environmental pollution.

2. The salmon skin in the present invention does not need to be scaled, which is easy to operate, reduces the difficulty of operation for workers, has low processing cost and high production efficiency.

3, adopt liquid detergent solution to replace the organic solvent in the traditional method to remove the fat in the fish skin among the present invention, consumption is few, cost is low, pollution-free; Reaching no residue, making the prepared gelatin product safer, and reducing the fishy smell of the fish skin gelatin product to a certain extent.

4. The concentration of sodium hydroxide lye used in the present invention is lower than that of the prior art, and can achieve a better effect of removing foreign proteins.

5. The present invention uses hydrogen peroxide solution to soak fish skin for a short time, so that the extraction rate of fish skin gelatin is significantly increased, and at the same time, the decolorization effect of fish skin is achieved, and the color properties of the obtained gelatin are better; hydrogen peroxide itself is easy to decompose , and the concentration of the solution is low, after repeated washing, no residue can be achieved.

6. The present invention uses citric acid to decalcify fish skin, and the obtained fish skin gelatin solution is more clear and transparent, and the color property of gelatin is significantly improved.

7. The present invention adds a small amount of rosemary extract in the extraction process, which can inhibit fat oxidation in the extraction process and effectively reduce the fishy smell of fish skin gelatin products.

8. The present invention uses different temperatures to extract gelatin to obtain fish skin gelatin with different properties. During production, specific processing conditions and extraction temperatures can be selected according to needs to obtain gelatin products with required properties.

In summary, the method of the present invention uses detergent degreasing, hydrogen peroxide decolorization, citric acid decalcification and other processes to pretreat the fish skin, and uses hot water at different temperatures to add a small amount of rosemary extract at the same time to obtain a series of emulsification. High-quality fish skin gelatin with good properties, foamability and gel strength and low fishy smell. The invention improves the properties of the fish skin gelatin and expands the application range.

Detailed ways

The following examples further illustrate the technical solutions of the present invention, which help to understand the patent, but the embodiments of the present invention are not limited by the examples, and the protection scope of the present invention is determined by the claims.

Example 1

The method for preparing salmon skin gelatin comprises the following steps:

(1) Take salmon skin, remove scales without shaving, remove impurities such as minced meat and silt, chop, wash, and set aside;

(2) Soak the cleaned fish skin with a volume fraction of 1% detergent solution, the soaking time is 3h, change the solution every 1h, the mass volume ratio of salmon skin and detergent solution is 1g:5ml, Rinse 3 times with tap water after soaking to collect fish skin;

(3) Add 0.05mol/L sodium hydroxide solution to the fish skin obtained in (2) step and soak for 4h, change the solution once every 80min, the mass volume ratio of fish skin and sodium hydroxide solution is 1g:5ml, after alkali treatment , washed with water until neutral, and the fish skin was collected;

(4) adding volume concentration to the fish skin obtained in (3) step is 1% hydrogen peroxide solution soaking, soaking time is 2h, every 1h changes solution, the mass volume ratio of fish skin and hydrogen peroxide solution is 1g:5ml , after soaking, rinse with tap water 3 times to collect the fish skin;

(5) Add 0.1mol/L citric acid solution to the fish skin obtained in step (4) and soak for 2 hours, change the solution every 1 hour, the mass volume ratio of fish skin and citric acid solution is 1g: 8ml; after soaking, tap water Rinse 3 times to collect fish skin;

(6) Add 0.05mol/L phosphoric acid to the fish skin obtained in step (5) and soak for 3 hours, change the solution every 1.5 hours, the mass volume ratio of fish skin and phosphoric acid solution is 1g:4ml, after acid treatment, wash with water to neutral, to collect the fish skin;

(7) Extract the fish skin in step (6) with deionized water for 10 h at 45° C., the amount of rosemary extract added is 2‰ of the fish skin quality, and the mass volume ratio of fish skin to deionized water is 1g: 5ml; after cooling to room temperature, centrifuge (1000g, 10min, 18°C), and collect the supernatant;

(8) Put the gelatin solution obtained in (7) at -80° C. for 2 hours, and then conduct vacuum freeze-drying for 24 hours to obtain the gelatin product.

The specific properties of the fish skin gelatin prepared in this embodiment are shown in Tables 1-6.

In addition, a gelatin product without adding H ₂ O ₂ was made as a comparative example, that is, the other processes were the same as in Example 1 except that it was not processed in step (4).

Example 2

The method for preparing salmon skin gelatin comprises the following steps:

(1) Take salmon skin, remove scales without shaving, remove impurities such as minced meat and silt, chop, wash, and set aside;

(2) Soak the cleaned fish skin with a volume fraction of 0.5% detergent solution, the soaking time is 4h, change the solution every 1h, the mass volume ratio of salmon skin and detergent solution is 1g:8ml, Rinse 3 times with tap water after soaking to collect fish skin;

(3) Add 0.08mol/L sodium hydroxide solution to the fish skin obtained in (2) step and soak for 4h, change the solution once every 80min, the mass volume ratio of fish skin and sodium hydroxide solution is 1g:8ml, after alkali treatment , washed with water until neutral, and the fish skin was collected;

(4) adding volume concentration to the fish skin obtained in (3) step is 1% hydrogen peroxide solution soaking, soaking time is 2h, every 1h changes solution, the mass volume ratio of fish skin and hydrogen peroxide solution is 1g:8ml , after soaking, rinse with tap water 3 times to collect the fish skin;

(5) Add 0.2mol/L citric acid solution to the fish skin obtained in step (4) and soak for 2 hours, change the solution every 1 hour, the mass volume ratio of fish skin and citric acid solution is 1g: 8ml; after soaking, tap water Rinse 3 times to collect fish skin;

(6) Add 0.08mol/L phosphoric acid to the fish skin obtained in step (5) and soak for 3 hours, change the solution every 1.5 hours, the mass volume ratio of fish skin and phosphoric acid solution is 1g:8ml, after acid treatment, wash with water to neutral, to collect the fish skin;

(7) Extract the fish skin in step (6) with deionized water at 55°C for 10 hours, the amount of rosemary extract is 3‰, and the mass volume ratio of fish skin to deionized water is 1g:5ml ; After cooling to room temperature, centrifuge (1000g, 20min, 18°C) to collect the supernatant;

(8) Put the gelatin solution obtained in (7) at -80° C. for 2 hours, and then conduct vacuum freeze-drying for 24 hours to obtain the gelatin product.

The specific properties of the fish skin gelatin prepared in this embodiment are shown in Tables 1-6.

In addition, a gelatin product without adding H ₂ O ₂ was made as a comparative example, that is, the other processes were the same as in Example 2 except that it was not processed in step (4).

Example 3

The method for preparing salmon skin gelatin comprises the following steps:

(1) Take salmon skin, remove scales without shaving, remove impurities such as minced meat and silt, chop, wash, and set aside;

(2) Soak the cleaned fish skin with a volume fraction of 2% detergent aqueous solution, the soaking time is 4h, and change the solution every 1h, the mass volume ratio of salmon skin and detergent aqueous solution is 1g:10ml, Rinse 3 times with tap water after soaking to collect fish skin;

(3) Add 0.1mol/L sodium hydroxide solution to the fish skin obtained in (2) step and soak for 3h, change the solution every 1h, the mass volume ratio of fish skin and sodium hydroxide solution is 1g:10ml, after alkali treatment , washed with water until neutral, and the fish skin was collected;

(4) adding volume concentration to the fish skin obtained in (3) step is 1% hydrogen peroxide solution soaking, soaking time is 2h, every 1h changes solution, the mass volume ratio of fish skin and hydrogen peroxide solution is 1g:10ml , after soaking, rinse with tap water 3 times to collect the fish skin;

(5) Add 0.3mol/L citric acid solution to the fish skin obtained in step (4) and soak for 2 hours, change the solution every 1 hour, the mass volume ratio of fish skin and citric acid solution is 1g: 10ml; after soaking, tap water Rinse 3 times to collect fish skin;

(6) Add 0.1mol/L phosphoric acid to the fish skin obtained in step (5) and soak for 3 hours, change the solution every 1.5 hours, the mass volume ratio of fish skin and phosphoric acid solution is 1g:10ml, after acid treatment, wash with water to neutral, to collect the fish skin;

(7) Extract the fish skin in step (6) with deionized water at 65° C. for 10 h, the amount of rosemary extract added is 4‰, and the mass volume ratio of fish skin to deionized water is 1 g: 5 ml; After cooling to room temperature, centrifuge (1000g, 10min, 18°C), and collect the supernatant;

(8) Put the gelatin solution obtained in (7) at -80° C. for 2 hours, and then conduct vacuum freeze-drying for 24 hours to obtain the gelatin product.

The specific properties of the fish skin gelatin prepared in this embodiment are shown in Tables 1-6.

In addition, a gelatin product without adding H ₂ O ₂ was made as a comparative example, that is, the other processes were the same as in Example 3 except that it was not processed in step (4).

Example 4

The method for preparing salmon skin gelatin comprises the following steps:

(1) Take salmon skin, remove scales without shaving, remove impurities such as minced meat and silt, chop, wash, and set aside;

(2) Soak the cleaned fish skin with a volume fraction of 1% detergent aqueous solution, the soaking time is 4h, and change the solution every 1h, the mass volume ratio of salmon skin and detergent aqueous solution is 1g:7ml, Rinse 3 times with tap water after soaking to collect fish skin;

(3) add 0.05mol/L sodium hydroxide solution to the fish skin obtained in (2) step and soak for 3h, change the solution every 1h, the mass volume ratio of fish skin and sodium hydroxide solution is 1g:7ml, after alkali treatment , wash with water until neutral, and collect the fish skin;

(4) adding volume concentration to the fish skin obtained in (3) step is 2% hydrogen peroxide solution soaking, soaking time is 2h, every 1h changes solution, the mass volume ratio of fish skin and hydrogen peroxide solution is 1g:7ml , after soaking, rinse with tap water 3 times to collect the fish skin;

(5) Add 0.5mol/L citric acid solution to the fish skin obtained in step (4) and soak for 2 hours, change the solution every 1 hour, the mass volume ratio of fish skin and citric acid solution is 1g: 15ml; after soaking, tap water Rinse 3 times to collect fish skin;

(6) Add 0.05mol/L phosphoric acid to soak in the fish skin obtained in (5) step for 3h, change the solution every 1.5h, the mass volume ratio of fish skin and phosphoric acid solution is 1g:7ml, after acid treatment, wash with water to neutral, to collect fish skin;

(7) Extract the fish skin in step (6) with deionized water at 75° C. for 10 h, the amount of rosemary extract added is 5 ‰, and the mass volume ratio of fish skin to deionized water is 1 g: 5 ml; After cooling to room temperature, centrifuge (1000g, 10min, 18°C), and collect the supernatant;

(8) Put the gelatin solution obtained in (7) at -80° C. for 2 hours, and then conduct vacuum freeze-drying for 24 hours to obtain the gelatin product.

In addition, a gelatin product without adding H ₂ O ₂ was made as a comparative example, that is, the other processes were the same as in Example 4 except that it was not processed in step (4).

The specific properties of the fish skin gelatin prepared in this embodiment are shown in Tables 1-6.

The concrete character of the fish skin gelatin that each embodiment of the present invention makes is as shown in Table 1～6; Wherein, table 1 is the fish skin gelatin extraction rate of each embodiment, and table 2 is the fish skin gelatin that each embodiment makes and The color comparison of commercial gelatin, table 3 is the gel strength comparison of fish skin gelatin and commercial gelatin that each embodiment makes, and table 4 is the foamability comparison of fish skin gelatin and commercial gelatin that each embodiment makes, table 5 For the comparison of the emulsifying properties of the fish skin gelatin prepared in each embodiment and commercial gelatin, Table 6 is a comparison of the volatile matter content of the fish skin gelatin prepared in each embodiment and commercial gelatin.

Table 1

As can be clearly seen from the data in Table 1, the addition of hydrogen peroxide in the present invention has obviously improved the extraction rate of gelatin.

The present invention uses a colorimeter to measure the color of the fish skin gelatin freeze-dried powder and commercial gelatin prepared in each embodiment, and the results are shown in Table 2.

Table 2

In gelatin products, the influence of calcium content on gelatin is mainly reflected in the transparency, which will affect the brightness of gelatin, which can be seen from the L* value measured by the colorimeter. As shown in table 2 data, the gelatin L* (black-white) value that the present invention extracts is higher than commercial gelatin, and a* (red-green), b* (yellow-blue) and △ E value are obviously lower than commercial gelatin Gelatin, shows that the color of the gelatin extracted by the present invention is better, indirectly shows that the decalcification effect is better.

The present invention adopts texture analyzer to measure the gel strength of fish skin gelatin and commercial gelatin that each embodiment makes, and measuring method is as follows:

Lyophilized collagen was dissolved in deionized water at 60°C to a final concentration of 6.67% (w/v)

Stir magnetically until the collagen is completely dissolved, and place in a refrigerator at 10°C for 16-18 hours to form a gel. The size of the glue: 3cm in diameter, 2.5cm in height. Measure its gel properties with a texture analyzer. Conditions of the texture analyzer: load 5kN, P/5 probe, the speed before the test is 5.00mm/s, and the test speed is 1.00mm/s , the speed after the test is 5.00mm/s, and the probe penetration distance is 10mm. Each sample was repeated three times and the average value was taken.

The results are shown in Table 3.

table 3

As can be seen from the data in Table 3: the gel strength of gelatin in Example 1 is closer to that of commercial gelatin. The commercial gelatin in the present invention is cowhide gelatin. Generally speaking, the gel strength of fish skin gelatin is far lower than that of mammalian gelatin. Similar results have been found in many fish skin gelatin studies. This is because fish skin gelatin cannot completely replace breastfeeding at present. An important reason for animal gelatin. Compared with commercial gelatin, the gel strength of the gelatin extracted by the present invention is very close to that of commercial gelatin, and can completely replace mammalian gelatin and be used in frozen and refrigerated products to realize reasonable popularization and application.

The present invention freeze-dries and redissolves the fish skin gelatin prepared in each embodiment, that is, calculates the required freeze-dried samples according to different concentrations (g/ml), then dissolves them in water at 60°C, and magnetically stirs until completely dissolved to obtain Gelatin solutions with protein concentrations of 1, 2, and 3 g/ml, respectively.

Table 4 is the test result of the foamability of the fish skin gelatin and commercial gelatin that each embodiment makes; , homogenate for 1min, 13400rpm; samples stand for 0-30min;

FE(%)=(VT/V0)×100

FS(%)=(Vt/V0)×100

VT: total volume after homogenization; V0: total volume before homogenization; Vt: total volume at room temperature for 30 minutes.

Table 4

As can be seen from the data in Table 4: the foamability in Example 4 of the present invention is the best, which is very close to commercial gelatin. The gelatin extracted by the present invention can replace commercial gelatin, ie mammalian gelatin, in this application.

The present invention adopts the scenery photometer method to measure the emulsifying property of fish skin gelatin and commercial gelatin that each embodiment makes, and concrete test method is as follows:

(1) Prepare at least 3ml of collagen solutions of different concentrations with freeze-dried samples;

(2) Homogenize 1ml soybean oil with 3ml collagen solutions of different concentrations: 20000rpm, 1min;

(3) Aspirate the latex after 0 min and 10 min after homogenization, dilute 100 times with 0.1% SDS, and vortex mix for 10 s;

(4) Measure the absorbance value at 500nm with a spectrophotometer, and use 0.1% SDS as a blank control;

EAI(m ² /g)＝(2×2.303×A×DF)/L∮C

A: absorbance value at 500nm; DF: dilution factor; L: path length of cuvette (0.01m)∮: ratio of oil phase in emulsion (0.25) oil volume fraction; C: protein concentration in water phase (g/m ³ )

ESI(min)＝A ₀ /(A ₀ -A ₁₀ )×△t

Δt=10min; A ₀ and A ₁₀ are the absorbance values at 500nm at 0min and 10min respectively.

The results are shown in Table 5.

table 5

As can be seen from the data in Table 5: the gelatin emulsifying property extracted in the present invention is all very good, and the gelatin in embodiment 1 and embodiment 2 is obviously higher than commercial gelatin, and the gelatin in embodiment 3 and embodiment 4 and commercial gelatin near.

The present invention detects the volatile substance content of the fish skin gelatin prepared in each embodiment and the fish skin gelatin of the control group by GC-MS, and the results are shown in Table 6. Wherein, the fish skin gelatin of the control group is fish skin gelatin prepared without adding rosemary extract, and the specific preparation steps are the same as in Example 1.

Table 6

Note: ND means not detected.

As can be clearly seen from the data in Table 6: the gelatin extracted by the present invention has significantly reduced volatile matter content and improved fishy smell.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (5)

1. a kind of preparation method of low fishlike smell dog salmon fishskin gelatin, which is characterized in that include the following steps：

S1, pretreatment of raw material：Dog salmon fish-skin is taken, is cleaned, it is spare；

S2, liquid detergent aqueous solution is added in into the spare fish-skin that step S1 is obtained, 18~25 DEG C of 3~5h of immersion rinse, collect fish Skin is degreasing fish-skin；

The mass volume ratio of the spare fish-skin and the liquid detergent aqueous solution is 1g:5~15ml；

S3, the degreasing fish-skin obtained into step S2 add in sodium hydroxide solution, and 18~25 DEG C of 3~8h of immersion are washed to pH value For 7~9, fish-skin is collected, obtains alkali process fish-skin；

The concentration of sodium hydroxide solution is the quality of 0.01~0.1mol/L, the degreasing fish-skin and the sodium hydroxide solution Volume ratio is 1g:5~8ml；

S4, aqueous hydrogen peroxide solution is added in into alkali process fish-skin made from step S3,18~25 DEG C of 1~4h of immersion collect fish Skin obtains decoloration fish-skin；

The aqueous hydrogen peroxide solution volumetric concentration is 0.5~2%, the alkali process fish-skin and the aqueous hydrogen peroxide solution Mass volume ratio is 1g:3~15ml；

S5, citric acid solution is added in into the fish-skin that decolourizes made from step S4,18~25 DEG C of 1~3h of immersion are washed with water 3 times, receive Collect fish-skin, obtain decalcification fish-skin；

The concentration of the citric acid solution is 0.1~0.8mol/L, the mass body of the decoloration fish-skin and the citric acid solution Product is than being 1g:8ml；

S6, add in phosphoric acid solution into decalcification fish-skin made from step S5,18~25 DEG C of 2~5h of immersion, be washed to pH value for 6~ 7, fish-skin is collected, obtains acid treatment fish-skin；

The concentration of the phosphoric acid solution is the mass volume ratio of 0.05~0.1mol/L, the decalcification fish-skin and the phosphoric acid solution For 1g:4~8ml；

S7, Rosmarinus officinalis extract is added into acid treatment fish-skin made from step S6, under 40~80 DEG C of environment, adds flooding 8 After being cooled to 18~25 DEG C, supernatant is collected by centrifugation in~18h, is gelatin solution；

The acid treatment fish-skin is 1g with the mass volume ratio for adding in water:2~12ml；The fish-skin and the Rosmarinus officinalis extract Mass ratio be 1g:0.0005~0.005g；

S8, gelatin solution made from step S7 is freeze-dried 24~36h, obtains low fishlike smell dog salmon fishskin gelatin.

2. the preparation method of low fishlike smell dog salmon fishskin gelatin according to claim 1, which is characterized in that described in step S2 The mass volume ratio of spare fish-skin and the liquid detergent aqueous solution is 1g:5~8ml；

The mass volume ratio of alkali process fish-skin described in step S4 and the aqueous hydrogen peroxide solution is 1g:5~8ml；

Acid treatment fish-skin described in step S7 is 1g with the mass volume ratio for adding in water:5ml；The fish-skin is extracted with the rosemary The mass ratio of object is 1g:0.002~0.003g.

3. the preparation method of low fishlike smell dog salmon fishskin gelatin according to claim 1, which is characterized in that step S2, walk Rapid S3, step S4, step S5, soaking process changes a soaking solution in every 60~80 minutes described in step S6.

4. the preparation method of low fishlike smell dog salmon fishskin gelatin according to claim 1, which is characterized in that described in step S7 The condition of centrifugation is：4000~10000g of centrifugal force, 18~25 DEG C of environment temperature, 10~30min of centrifugation time.

5. the preparation method of low fishlike smell dog salmon fishskin gelatin according to claim 1, which is characterized in that described in step S7 The mode of freeze-drying is：Gelatin solution made from step S7 is placed in -80 DEG C of 2~4h of pre-freeze by vacuum freeze drying before drying.