Deodorization method for increasing nutrition of fish maw by utilizing snakegourd fruit protein emulsion

Abstract

The invention provides a fishy smell removal method for increasing nutrition of fish maw by utilizing a trichosanthes kirilowii Maxim protein emulsion, and belongs to the technical field of food processing. The deodorization method comprises the following steps: (1) adding trichosanthes kirilowii maxim protein and glucose into water, mixing, stirring, adjusting the pH value, and heating in a water bath to obtain modified trichosanthes kirilowii maxim protein; (2) mixing the modified trichosanthes kirilowii maxim protein with water and trichosanthes kirilowii maxim oil to obtain a modified trichosanthes kirilowii maxim protein emulsion; (3) adding dried fish maw into the ginger juice, boiling, fishing out the fish maw, washing, draining and cooling to obtain cold fish maw; and (4) soaking the cold fish maw with the modified snakegourd fruit protein emulsion, fishing out, cleaning and draining, soaking the fish maw with ice water for the second time, washing and draining to obtain the fishy smell removed dry fish maw. The snakegourd fruit protein emulsion has better compatibility with fat, so that grease on the surface of the fish maw can be effectively cleaned, and the problem of fishy smell of the fish maw is solved from the source. Besides, the snakegourd fruit protein emulsion can effectively avoid loss of water-soluble nutrient substances in the fish maw in the cleaning process, and on the basis of effective deodorization, the nutrition of the fish maw can be increased.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to a method for removing fishy smell by increasing the nutrition of fish maw by using trichosanthes protein emulsion. Background Art

[0002] Fish maw, also known as fish maw, is a dried fish bladder product obtained by cleaning and pre-processing the fresh fish bladders of various fish and then dehydrating them. It is named for its rich gelatin. It is as famous as bird's nest and shark fin, is one of the "Eight Treasures", and is known as the "marine ginseng". It is one of the traditional tonics.

[0003] With the rapid economic growth and people's pursuit of a healthy and well-maintained lifestyle, the market demand for fish maw products is increasing day by day. However, the fish maw products on the market currently have many defects, especially the serious residual fishy smell.

[0004] The grease on the surface of fish maw is one of the main sources of the fishy smell. This layer of grease comes from the fat inside the fish and is rich in unsaturated fatty acids. Unsaturated fatty acids can undergo oxidation reactions to produce volatile substances with fishy smell. In addition, some alcohols and aldehydes inside and on the surface of the fish body are also the cause of the fishy smell. Cleaning this layer of grease is an effective way to remove the fishy smell from fish maw.

[0005] In fish maw production, fish maw is usually removed from the fish by rinsing or soaking it in ginger juice. The volatile oils and spicy ingredients contained in ginger juice, such as gingerol, have high aroma intensity and penetration. This may cause these ingredients in ginger juice to be adsorbed on the surface of the fish maw during the washing process, thus affecting its original flavor characteristics. The strong flavor of ginger may significantly mask the delicious taste of the fish maw itself.

[0006] Trichosanthes kirilowii is a plant that can be used as both medicine and food with rich nutritional value. Trichosanthes kirilowii seeds contain 17 kinds of amino acids, including 7 essential amino acids for the human body, accounting for 28.19% of the total amino acids. It is rich in arginine and contains rich protein, triterpenoid saponins, multiple vitamins and 16 trace elements such as calcium, iron, zinc and selenium.

[0007] Few people use Trichosanthes to remove the fishy smell of fish maw. Summary of the invention

[0008] The invention provides a method for removing fish smell by utilizing trichosanthes protein emulsion to increase the nutrition of fish maw. The method has a significant effect on removing fish smell of fish maw, does not leave a strong odor compared with ginger juice deodorization, and can increase the nutritional value of fish maw, thus providing a new idea for fish maw processing.

[0009] The present invention provides a method for removing fishy smell by using trichosanthes protein emulsion to increase the nutrition of fish maw, comprising the following steps: (1) adding trichosanthes protein and glucose into water, mixing, adjusting the pH after stirring, and heating in a water bath to obtain modified trichosanthes protein; (2) mixing the modified Trichosanthes protein with water to obtain a modified Trichosanthes protein solution, and homogenizing the modified Trichosanthes protein solution with Trichosanthes oil to obtain a modified Trichosanthes protein emulsion; (3) Mix water and ground ginger to make ginger juice, add dried fish maw to the ginger juice and cook, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; (4) Soaking the cooled fish maw in the modified Trichosanthes protein emulsion, taking it out, washing it and draining it, soaking the fish maw twice in ice water, washing it and draining it, and obtaining dry fish maw after removing the fishy smell.

[0010] Furthermore, in step (1), the concentration of Trichosanthes protein in the system is 1-5 g / mL, and the concentration of glucose in the system is 1-5 g / mL; Preferably, in step (1), the concentration of Trichosanthes protein in the system is 3 g / mL, and the concentration of glucose in the system is 3 g / mL. Furthermore, in step (2), the concentration of the Trichosanthes protein solution is 1-3 g / mL.

[0011] Furthermore, in step (2), the volume ratio of the modified Trichosanthes protein solution to the Trichosanthes oil is 2-4:1; Preferably, in step (2), the volume ratio of the modified Trichosanthes protein solution to the Trichosanthes oil is 3:1. Furthermore, in step (3), the cooking time is 5 to 15 min; Preferably, in step (3), the cooking time is 10 min. Furthermore, in step (3), the mass volume ratio of the ground ginger to the water is 1 g: (15 ~ 25) mL; Preferably, in step (3), the mass volume ratio of the minced ginger to water is 1 g: 25 mL.

[0012] Furthermore, in step (4), the mass ratio of the cooled fish maw to the dry fish maw is calculated according to the mass of the corresponding dry fish maw, and the mass ratio of the modified Trichosanthes protein emulsion to the dry fish maw is 100 ~ 300 mL: 1g.

[0013] Furthermore, in step (4), the amount of the cooled fish maw is calculated according to the corresponding mass of the dry fish maw, and the ratio of the dry fish maw to the ice water is 1 g: 100 mL.

[0014] Furthermore, in step (4), the soaking time is 1 to 5 hours.

[0015] Preferably, in step (4), the soaking time is 3 h.

[0016] Furthermore, in step (4), the soaking time for the secondary expansion is 1 h.

[0017] The present invention has the following advantages: The method for removing fishy smell by increasing the nutrition of fish maw by using trichosanthes protein emulsion provided by the present invention comprises the following steps: firstly preparing modified trichosanthes protein, then mixing it with trichosanthes oil to obtain modified trichosanthes protein emulsion, cooling the dried fish maw after boiling it with ginger juice, and then taking out the cooled fish maw after soaking it with modified trichosanthes protein emulsion, and controlling the soaking time so that the fish maw can achieve the best fishy smell removal effect, and then soaking the fish maw twice with ice water to obtain the dried fish maw after fishy smell removal. In the present invention, trichosanthes protein emulsion has better compatibility with fat, so it can effectively wash away the grease on the surface of the fish maw, and solve the fishy smell problem of the fish maw at the source. In addition, trichosanthes protein emulsion can effectively avoid the loss of water-soluble nutrients of the fish maw during the cleaning process, and on the basis of effective fishy smell removal, it can also increase the nutrition of the fish maw. Moreover, the increased amino acids can further capture formaldehyde as a formaldehyde capture agent, thereby improving the formaldehyde removal rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative labor.

[0019] Figure 1 The figure is a graph showing the change of trimethylamine content in fish maw after deodorization treatment in Example 2 of the present invention and Comparative Examples 1 to 2; wherein different letters indicate significant differences between the samples ( p <0.05).

[0020] Figure 2 The formaldehyde content in fish maw after deodorization treatment in Example 2 of the present invention and Comparative Examples 1 to 2 is shown in Table 2; different letters indicate significant differences between samples ( p <0.05).

[0021] Figure 3 The radar chart of the odor induction intensity of fish maw after deodorization treatment of Example 2 of the present invention and Comparative Examples 1 to 3 is shown. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0023] The embodiment of the present invention provides a method for removing fishy smell by using Trichosanthes protein emulsion to increase the nutrition of fish maw, comprising the following steps: (1) adding trichosanthes protein and glucose into water, mixing, adjusting the pH after stirring, and heating in a water bath to obtain modified trichosanthes protein; (2) mixing the modified Trichosanthes protein with water to obtain a modified Trichosanthes protein solution, and homogenizing the modified Trichosanthes protein solution with Trichosanthes oil to obtain a modified Trichosanthes protein emulsion; (3) Mix water and ground ginger to make ginger juice, add dried fish maw to the ginger juice and cook, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; (4) Soaking the cooled fish maw in the modified Trichosanthes protein emulsion, taking it out, washing it and draining it, soaking the fish maw twice in ice water, washing it and draining it, and obtaining dry fish maw after removing the fishy smell.

[0024] The inventor of the present application found that the emulsion has better compatibility with oil, and the emulsifier in the emulsion can promote better mixing of oil and water, so that the oil is dispersed in water, thereby making it easier to remove the oil. Therefore, it is proposed to use the trichosanthes protein emulsion for fish maw deodorization, first prepare modified trichosanthes protein, and then mix it with trichosanthes oil to obtain the modified trichosanthes protein emulsion, boil the dry fish maw with ginger juice and cool it, soak the cooled fish maw with the modified trichosanthes protein emulsion and then take it out, and by controlling the soaking time, the fish maw can achieve the best deodorization effect, and then the fish maw is soaked twice with ice water to obtain the deodorized dry fish maw.

[0025] Among them, the trichosanthes protein emulsion has good compatibility with fat, so it can effectively clean the grease on the surface of fish maw, solving the problem of fishy smell at the source. In addition, when the trichosanthes protein emulsion is used to remove the fishy smell of fish maw, the protein will form an adsorption layer at the oil-water interface, which helps the components in the emulsion to disperse on the surface of the fish maw and penetrate into the inside of the fish maw, thereby enhancing the nutrition of the fish maw. Compared with ginger juice deodorization, the trichosanthes protein emulsion has a smaller odor and will not have a strong residual odor to cover up the umami taste of the fish maw itself. And the increased amino acids can further capture formaldehyde as a formaldehyde scavenger, thereby increasing the formaldehyde removal rate.

[0026] In steps (1) and (2) of the embodiment of the present invention, the modified Trichosanthes protein is first prepared, and then mixed with water and Trichosanthes oil to obtain the modified Trichosanthes protein emulsion.

[0027] In one embodiment of the present invention, in step (1), the concentration of Trichosanthes protein in the system is 1-5 g / mL, and the concentration of glucose in the system is 1-5 g / mL. Preferably, in step (1), the concentration of Trichosanthes protein in the system is 3 g / mL, and the concentration of glucose in the system is 3 g / mL. In one embodiment of the present invention, in step (1), the stirring temperature is 25° C., the stirring time is 2 h, and the pH is adjusted to 11.

[0028] In one embodiment of the present invention, in step (1), the water bath heating is specifically carried out at 90° C. for 2 h.

[0029] In one embodiment of the present invention, in step (2), the concentration of the Trichosanthes protein solution is 1-3 g / mL.

[0030] In one embodiment of the present invention, in step (2), the volume ratio of the modified Trichosanthes protein solution to the Trichosanthes oil is 2 to 4: 1. Preferably, the volume ratio of the modified Trichosanthes protein solution to the Trichosanthes oil is 3: 1. In one embodiment of the present invention, in step (2), the speed of the homogenization is 11000-13000 rpm, and the time is 1-3 min. Preferably, the speed of the homogenization is 12000 rpm, and the time is 2 min.

[0031] In step (3) of the embodiment of the present invention, the dried fish maw is boiled with ginger juice and then cooled. Boiling with ginger juice can, on the one hand, shorten the soaking time and avoid nutrient loss caused by too long soaking time of the fish maw; on the other hand, boiling can soften the dried fish maw and improve the soaking rate.

[0032] In one embodiment of the present invention, in step (3), the cooking time is 5 to 15 min; preferably, the cooking time is 10 min. In one embodiment of the present invention, in step (3), the mass volume ratio of the ground ginger to the clean water is 1 g: (15 ~ 25) mL. Preferably, the mass volume ratio of the ground ginger to the clean water is 1 g: 25 mL. The use of a lower concentration of ginger juice for cooking reduces the influence of the ginger juice in the pre-cooking, and the taste of the subsequent Trichosanthes protein emulsion can cover up the spicy taste of ginger remaining in the ginger juice cooking. In step (4) of the embodiment of the present invention, the cooled fish maw is soaked in the modified Trichosanthes protein emulsion and then taken out. By controlling the soaking time, the fish maw can achieve the best deodorizing effect. The fish maw is then soaked again in ice water to obtain the deodorized dry fish maw.

[0033] In one embodiment of the present invention, in step (4), the mass ratio of the cooled fish maw to the corresponding dry fish maw is 100-300 mL: 1 g.

[0034] In one embodiment of the present invention, in step (4), the soaking time is 1 to 5 h. In the embodiment of the present invention, the soaking time of the modified Trichosanthes protein emulsion on the dried fish maw is too short, and the emulsion cannot be deeply combined with the fishy substances on the surface and inside of the fish maw, and the deodorizing effect cannot be achieved. If the soaking time is too long, the emulsion structure becomes unstable and the droplets are destroyed, which fails to increase the nutrition of the fish maw and causes the loss of nutrition of the fish maw, and the deodorizing effect is not good. Preferably, the soaking time is 3 h. In one embodiment of the present invention, in step (4), the soaking time for the secondary expansion is 1 h.

[0035] In one embodiment of the present invention, in step (4), the amount of the cooled fish maw is calculated according to the corresponding mass of the dry fish maw, and the amount ratio of the dry fish maw to the ice water is 1 g: 100 mL.

[0036] In one embodiment of the present invention, in step (4), the temperature of the ice water is 0°C. The present invention will be described in detail below with reference to embodiments.

[0037] Example 1 Method for removing fishy smell by increasing nutrition of fish maw using Trichosanthes protein emulsion Trichosanthes protein (3 g / mL) and glucose (3 g / mL) were added into water and mixed, the pH was adjusted to 11 after stirring, and heated in a water bath at 90 °C for 2 h to obtain modified Trichosanthes protein; The modified Trichosanthes protein (2 g / mL) was mixed with water to obtain a modified Trichosanthes protein solution, and the modified Trichosanthes protein solution was mixed with Trichosanthes oil at a volume ratio of 3:1, and homogenized at a speed of 12000 rpm for 2 min to obtain a modified Trichosanthes protein emulsion; Mix ginger powder and water to make ginger juice (the mass volume ratio of ginger powder to water is 1g: 25mL), add dried fish maw and cook for 10 minutes, remove the fish maw, rinse it, drain and cool it to obtain cooled fish maw; The cooled fish maw is soaked in the modified Trichosanthes kirilowii protein emulsion at a mass volume ratio of 1:200 for 1 h, then taken out, washed and drained. Finally, the soaked fish maw is soaked again in 0°C ice water at a mass volume ratio of 1 g:100 mL for 1 h, rinsed and drained to obtain the deodorized dry fish maw. Example 2 Method for removing fishy smell by increasing nutrition of fish maw using Trichosanthes protein emulsion Trichosanthes protein (3 g / mL) and glucose (3 g / mL) were added into water and mixed, the pH was adjusted to 11 after stirring, and heated in a water bath at 90 °C for 2 h to obtain modified Trichosanthes protein; The modified Trichosanthes protein (2 g / mL) was mixed with water to obtain a modified Trichosanthes protein solution, and the modified Trichosanthes protein solution was mixed with Trichosanthes oil at a volume ratio of 3:1, and homogenized at a speed of 12000 rpm for 2 min to obtain a modified Trichosanthes protein emulsion; Mix ginger powder and water into ginger juice (the mass volume ratio of ginger powder to water is 1g: 25 mL), add dried fish maw and cook for 10 min, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; The cooled fish maw was soaked in the modified Trichosanthes kirilowii protein emulsion at a mass volume ratio of 1:200 for 3 hours, then taken out, washed and drained. Finally, the soaked fish maw was soaked again in 0°C ice water at a mass volume ratio of 1 g:100 mL for 1 hour, rinsed and drained to obtain the deodorized dry fish maw. Example 3 Method for removing fishy smell by increasing nutrition of fish maw using Trichosanthes protein emulsion Trichosanthes protein (3 g / mL) and glucose (3 g / mL) were added into water and mixed, the pH was adjusted to 11 after stirring, and heated in a water bath at 90 °C for 2 h to obtain modified Trichosanthes protein; The modified Trichosanthes protein (2 g / mL) was mixed with water to obtain a modified Trichosanthes protein solution, and the modified Trichosanthes protein solution was mixed with Trichosanthes oil at a volume ratio of 3:1, and homogenized at a speed of 12000 rpm for 2 min to obtain a modified Trichosanthes protein emulsion; Mix ginger powder and water into ginger juice (the mass volume ratio of ginger powder to water is 1g: 25 mL), add dried fish maw and cook for 10 min, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; The cooled fish maw was soaked in the modified Trichosanthes kirilowii protein emulsion at a mass volume ratio of 1:200 for 5 h, then taken out, washed and drained. Finally, the soaked fish maw was soaked again in 0°C ice water at a mass volume ratio of 1 g:100 mL for 1 h, rinsed and drained to obtain the deodorized dry fish maw.

[0038] Comparative Example 1 Dried fish maw, without any deodorization treatment. Comparative Example 2 Mix ginger powder and water into ginger juice (the mass volume ratio of ginger powder to water is 1g: 25 mL), add dried fish maw and cook for 10 min, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; Soak the above-mentioned cold fish maw in lemon ginger juice (mixed with 1 g: 1 g: 25 mL) of ground ginger, lemon slices, and water. Soak the fish maw in 1 g: 200 mL of lemon ginger juice for 3 h, then wash and drain. Finally, soak the fish maw again in 1 g: 100 mL of 0 ℃ ice water for 1 h, rinse and drain to obtain dry fish maw after deodorization.

[0039] Comparative Example 3 Mix ginger powder and water into ginger juice (the mass volume ratio of ginger powder to water is 1g: 25 mL), add dried fish maw and cook for 10 min, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; The above-mentioned cold fish maw was soaked in clean water at a mass volume ratio of 1 g: 200 mL, then taken out for 3 h, washed and drained. Finally, the soaked fish maw was soaked again in 0 ℃ ice water at a mass volume ratio of 1 g: 100 mL for 1 h, washed and drained to obtain the dry fish maw after deodorization. Test Example 1 In order to further verify the technical effect of the present invention, the fish maws obtained from the above-mentioned embodiments and comparative examples were subjected to the following tests.

[0040] 1. Sensory evaluation The sensory evaluation team consists of 20 sensory evaluators who have received professional sensory evaluation training and can accurately and objectively evaluate the fishy smell, spicy or irritating taste and color of fish maw. For the sensory evaluation of fishy smell, spicy taste and irritating taste, pure water is used as a control sample, and according to the standards in Table 1, examples 1 to 3 and comparative examples 1 to 3 are scored, and the results are averaged. The evaluation results are shown in Table 2.

[0041] Table 1 Sensory evaluation of fish maw

[0042] Table 2 Sensory evaluation results

[0043] 2. Amino acid content determination, composition and nutritional evaluation (1) Determination of amino acid content in fish maw The determination of amino acid content refers to the determination method in GB5009.124-2016 "National Food Safety Standard Determination of Amino Acids in Foods".

[0044] (2) Amino acid composition and nutritional evaluation The nutritional value is assessed based on the optimal ratio model of the Food and Agriculture Organization of the United Nations (FAO) / World Health Organization (WHO). Since egg protein is considered to be the substance with the most comprehensive nutritional value, it is used as a scoring standard for assessing food protein.

[0045] Amino acid score (AAS), chemical score (CS) and essential amino acid index (EAAI) were used to evaluate the nutritional value of fish maw amino acids.

[0046] Among them, the calculation formula of amino acid evaluation parameters is:

[0047]

[0048]

[0049]

[0050] (3) Measurement results To further illustrate that the method for removing fish smell from fish maw using the Trichosanthes protein emulsion provided by the present invention can increase nutrition, the changes in amino acids after deodorization of Example 2 and Comparative Examples 1 and 2 are compared and illustrated.

[0051] Table 3 Amino acid content

[0052] Note: The results are expressed as mean ± standard deviation. Compared with comparative example 1, * p <0.05, indicating significant difference, * p <0.01, indicating that the difference is extremely significant.

[0053] As shown in Table 3, the total amino acid content (TAA) and essential amino acid content (EAA) of the fish maw after deodorization in Example 2 increased significantly, among which arginine, glutamic acid, methionine and the total amino acid content increased significantly compared with Comparative Example 1. Table 4 Functional amino acid content

[0054] Note: The results are expressed as mean ± standard deviation. Compared with comparative example 1, * indicates significant difference. p <0.05, ** indicates extremely significant difference, p <0.01.

[0055] Medicinal amino acids (MAA) refer to amino acids with pharmacological effects, which can enhance immunity, assist in the treatment of heart disease, improve liver function, etc., including arginine, glutamic acid, glycine, tyrosine, aspartic acid, leucine, lysine, methionine, and phenylalanine. Arginine and histidine are essential amino acids for children (CEAA), which are particularly important for children's growth and can promote the development of children's nervous system and body.

[0056] As shown in Table 4, the medicinal amino acids and essential amino acids for children contained in the fish maw after deodorization in Example 2 are significantly increased, among which the contents of arginine, glutamic acid and methionine are significantly increased compared with those in Comparative Example 1. This indicates that deodorizing fish maw with Trichosanthes protein emulsion can increase its nutrition.

[0057] Table 5 Essential Amino Acid Index (EAAI)

[0058] Table 6 Amino Acid Score (AAS)

[0059] Note: The results are expressed as mean ± standard deviation. Different letters after the data in the same row indicate significant differences. p <0.05.

[0060] Table 7 Amino Acid Chemical Score (CS)

[0061] Note: The results are expressed as mean ± standard deviation. Different letters after the data in the same row indicate significant differences. p <0.05.

[0062] Generally, the EAAI value in fish maw is between 32.65 and 37.74. As shown in Tables 5 to 7, the EAAI of fish maw after deodorization in Example 2 reached 40.64, and the EAAI of Comparative Example 2 after deodorization was reduced to 32.81. At the same time, the AAS and CS values ​​of fish maw after deodorization in Example 2 were significantly increased compared with those in Comparative Example 1. This shows that the amino acid nutrition of fish maw after deodorization with the Trichosanthes protein emulsion is increased.

[0063] 3. Determination of key substances in fish maw odor In order to further illustrate the significant removal effect of the deodorization method provided by the present invention on the key substances of the fishy smell of fish maw, an electronic nose and a gas chromatography-mass spectrometer (GC-MS) were used to determine and analyze the components of the fishy smell substances in fish maw after different deodorization treatments, and the odor activity value (OAV) and trimethylamine content were further used to compare the changes in the key substances of the fishy smell of fish maw after treatment with different deodorization methods in the embodiment and the comparative example.

[0064] (1) Solid phase microextraction conditions Accurately weigh 5.00 g of sample, 1 mL of saturated salt water, and 5 μL of 0.816 μg / μL 2-methyl-3-heptanone methanol solution as internal standard and place them in a 20 mL headspace sample bottle. Use the CAR / PDMS extraction head for adsorption for 5 min, then inject the sample and desorb for 5 min.

[0065] (2) Chromatographic conditions HP-5MS capillary column (30 m × 0.25 mm × 0.25 μm); injection port temperature 250 °C; carrier gas (He) flow rate 1.0 mL / min; injection in splitless mode; programmed temperature: column temperature 40 °C, hold for 2 min, increase to 120 °C at 5 °C / min, hold for 2 min, then increase to 250 °C at 10 °C / min, hold for 5 min.

[0066] (3) Mass spectrometry conditions GC-MS transfer line temperature was 250 °C; ion source temperature was 250 °C; quadrupole temperature was 150 °C; ionization mode: electron ionization; electron energy was 70 eV; mass scanning range was m / z 30 ~ 550.

[0067] (4) Calculate the OAV value using the following formula:

[0068]

[0069] The results are shown in Tables 8~9. Table 8 Odor activity values ​​of key fishy smell substances in fish maw after deodorization in Examples 1 to 3 and Comparative Example 1

[0070] Note: The results are expressed as mean ± standard deviation. Different letters after the data in the same row indicate significant differences. p <0.05.

[0071] Table 9 Odor activity values ​​of key fishy smell substances in fish maw after deodorization in Example 2 and Control Groups 1 to 3

[0072] Note: The results are expressed as mean ± standard deviation. Different letters after the data in the same row indicate significant differences. p <0.05.

[0073] As shown in Table 8, the deodorizing effect of Example 2 on fish maw is better than that of Example 1 and Example 3, indicating that the most preferred soaking time for deodorizing fish maw with the Trichosanthes protein emulsion is 3 h.

[0074] As can be seen from Table 9, the method for deodorizing fish maw using the Trichosanthes protein emulsion provided by the present invention has a deodorizing effect that is significantly better than that of ginger juice and water.

[0075] (5) Determination of trimethylamine content The determination of trimethylamine content refers to the headspace gas chromatography-mass spectrometry method in GB5009.179-2016 "National Food Safety Standard Determination of Trimethylamine in Food".

[0076] Calculate the trimethylamine content, the formula is as follows:

[0077]

[0078] The results of the test are shown in Figure 1 .

[0079] 4. Determination of formaldehyde content In recent years, formaldehyde has been frequently detected in food, especially in aquatic fish. The source of high-content formaldehyde is partly due to artificial addition of formaldehyde for its antiseptic and bactericidal effects, and partly due to endogenous formaldehyde produced by the decomposition of trimethylamine oxidase in aquatic products. Endogenous formaldehyde is the main source of formaldehyde in aquatic products. Therefore, it is necessary to explore the formaldehyde content of fish products such as fish maw.

[0080] The formaldehyde content was determined by high performance liquid chromatography. Formaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH) in a water bath at 60°C to generate 2,4-dinitrophenylhydrazone, which was separated by an ODS-C18 column and detected by an ultraviolet detector at a wavelength of 355 nm. The retention time was used for qualitative analysis and the peak area was used for quantitative analysis to indirectly measure the formaldehyde content.

[0081] (1) Prepare buffer solution: weigh 2.64 g sodium acetate, dissolve it in an appropriate amount of water, add 1.0 mL glacial acetic acid, and dilute to 500 mL with water. Prepare derivatization solution: Take equal volumes of buffer solution and 2,4-dinitrophenylhydrazine solution and mix them for later use.

[0082] (2) Prepare formaldehyde standard solution: Take 1 mL of 1000 mg / L formaldehyde standard solution and dilute it to 10 mL with water to prepare a 100 mg / L standard stock solution. Prepare a series of standard solutions of 0.02, 0.05, 0.10, 1.00, 2.00, 5.00 and 10.0 mL from the standard stock solution. Perform derivatization according to the sample pretreatment method.

[0083] (3) Sample pretreatment: Accurately weigh 2.0 g of sample and place it in a 50 mL centrifuge tube. Add 20 mL of derivatization solution, vortex mix, place in a 60 ℃ constant temperature oscillator, 180 r / min, shake for 1 h, then take out and cool to room temperature. Centrifuge the derivatized sample at 10,000 rmin for 5 min, then filter the supernatant with a 0.22 μm organic filter membrane and pour into a sample injection vial for testing.

[0084] (4) Chromatographic conditions: C18 column; monitoring wavelength 365 nm; injection volume: 10 μL; flow rate: 0.5 mL / min; column temperature: 40 ℃; mobile phase: methanol: water (70:30) isocratic elution.

[0085] (5) Sample determination: 1.0 mL of the prepared sample solution was injected into the liquid chromatograph to obtain the corresponding peak area. The formaldehyde concentration in the test solution was obtained based on the calibration curve and measured three times in parallel.

[0086] (6) Calculation of formaldehyde content

[0087] The results of the test are shown in Figure 2 .

[0088] Depend on Figure 1 and Figure 2 It can be seen that the trimethylamine content and formaldehyde content of the fish maw after the deodorization treatment in Example 2 are significantly lower than those in the fish maws deodorized in Comparative Examples 1 and 2, indicating that the method for deodorizing fish maw using Trichosanthes protein emulsion provided by the present invention has obvious deodorization effect.

[0089] At room temperature, the amino groups in amino acids can react with formaldehyde to generate hydroxymethyl derivatives, thereby removing formaldehyde. The amino group content on arginine is higher than that on other amino acids. The more amino groups there are, the more advantageous it is for the reaction between formaldehyde and amino acids. Other amino acids, such as glutamic acid and glycine, also have a certain capture rate for formaldehyde. After the fish maw is deodorized with modified Trichosanthes protein emulsion, the amino acid content increases, especially the arginine content increases significantly, which can achieve efficient and rapid formaldehyde removal. 5. Electronic Nose Fish Maw Odor Determination (1) Electronic nose conditions: Electronic nose measurement time 100 s; headspace temperature 25 °C; internal flow rate 300 mL / min; injection flow rate 300 mL / min. Each sample was measured three times.

[0090] (2) Electronic nose sample preparation: Accurately weigh 3.00 g of fish maw sample and place it in a 20 mL headspace bottle for testing.

[0091] The electronic nose sensor performance description is shown in Table 10, and the measurement results are shown in Figure 3 .

[0092] Table 10 Electronic nose sensor performance description

[0093] Depend on Figure 3It can be seen that there is a significant difference in the odor profile of the fish maw treated with deodorization in Example 2 and that treated with deodorization in Comparative Example 1. The sensors with more obvious response values ​​are R(6), R(7), R(8), and R(9), respectively, indicating that the alkanes, inorganic sulfides, ethanols, and organic sulfides in the fish maw treated with deodorization in Example 2 are reduced, indicating that Example 2 has a significant deodorization effect on the fish maw. When ginger juice was used for deodorization in Comparative Example 2, it may be that the strong smell of ginger juice masked the smell of the fish maw, so the fish maw sample treated with ginger juice had the largest response value to the sensor.

[0094] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for removing fishy smell by using Trichosanthes protein emulsion to increase the nutrition of fish maw, characterized in that: The steps include: (1) adding trichosanthes protein and glucose into water, mixing, adjusting the pH after stirring, and heating in a water bath to obtain modified trichosanthes protein; (2) mixing the modified Trichosanthes protein with water to obtain a modified Trichosanthes protein solution, and homogenizing the modified Trichosanthes protein solution with Trichosanthes oil to obtain a modified Trichosanthes protein emulsion; (3) Mix water and ground ginger to make ginger juice, add dried fish maw to the ginger juice and cook, remove the fish maw, rinse, drain and cool to obtain cooled fish maw; (4) Soaking the cooled fish maw in the modified Trichosanthes protein emulsion, taking it out, washing it and draining it, soaking the fish maw twice in ice water, washing it and draining it, and obtaining dry fish maw after removing the fishy smell.

2. The method for removing fishy smell according to claim 1, characterized in that: In step (1), the concentration of Trichosanthes protein in the system is 1-5 g / mL, and the concentration of glucose in the system is 1-5 g / mL; Preferably, in step (1), the concentration of Trichosanthes protein in the system is 3 g / mL, and the concentration of glucose in the system is 3 g / mL.

3. The method for removing fishy smell according to claim 1, characterized in that: In step (2), the concentration of the Trichosanthes protein solution is 1-3 g / mL.

4. The method for removing fishy smell according to claim 3, characterized in that: In step (2), the volume ratio of the modified Trichosanthes protein solution to the Trichosanthes oil is 2-4:1; Preferably, in step (2), the volume ratio of the modified Trichosanthes protein solution to the Trichosanthes oil is 3:

1.

5. The method for removing fishy smell according to claim 1, characterized in that: In step (3), the cooking time is 5 to 15 minutes; Preferably, in step (3), the cooking time is 10 min.

6. The method for removing fishy smell according to claim 1, characterized in that: In step (3), the mass volume ratio of the ground ginger to the water is 1 g: (15-25) mL; Preferably, in step (3), the mass volume ratio of the minced ginger to water is 1 g: 25 mL.

7. The method for removing fishy smell according to claim 1, characterized in that: In step (4), the mass ratio of the cooled fish maw to the dry fish maw is calculated according to the mass of the corresponding dry fish maw, and the mass ratio of the modified Trichosanthes kirilowii protein emulsion to the dry fish maw is 100 ~ 300 mL: 1g.

8. The method for removing fishy smell according to claim 1, characterized in that: In step (4), the amount of cooled fish maw is calculated according to the corresponding mass of dry fish maw, and the ratio of dry fish maw to ice water is 1 g: 100 mL.

9. The method for removing fishy smell according to claim 1, characterized in that: In step (4), the soaking time is 1 to 5 hours; Preferably, in step (4), the soaking time is 3 h.

10. The method for removing fishy smell according to claim 1, characterized in that: In step (4), the soaking time for the secondary expansion is 1 h.

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