Method for producing low-salt high-quality fish sauce by fermenting yellow-fin tuna dark meat

Abstract

The invention belongs to the field of food processing, and discloses a method for rapidly preparing fish sauce by using yellow-fin tuna dark meat. The method comprises the following steps: mincing dark meat of the yellow-fin tuna by using a meat mincer; adding water and enzyme into the meat paste for enzymolysis; adding the activated lactobacillus fermentum into the sterilized fish meat enzymatic hydrolysate mixture; fermenting in an incubator; and sterilizing and canning. The fermentation time is greatly shortened, the fermented fish sauce meets the national standard requirement, and the fermentation product has good flavor.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and relates to a method for producing low-salt high-quality fish sauce by fermenting dark meat of yellowfin tuna. Background Art

[0002] Yellowfin tuna (Thunnus albacares) is a fish with a breastplate in the family Scombridae, order Pereifornes, class Osteichthyes. More than 50% of waste and by-products (fish scales, heads, viscera, etc.) are generated during the processing of yellowfin tuna, which are usually discarded or used to produce low value-added products such as fishmeal, fish feed, etc. However, these wastes still contain molecules necessary for human diet, such as essential metals, vitamins, omega-3 fatty acids, amino acids and proteins with high nutritional value.

[0003] Fish sauce, also known as fish sauce or shrimp sauce, is a brown-red condiment with a salty and fresh taste. It is usually made from fish and shrimp, using proteases and other enzymes in the fish body, and fermented by a variety of different microorganisms to decompose the protein, fat and other components of the fish. It is a common aquatic condiment in Southeast Asia, and is more consumed in Fujian and Guangdong in my country. Fish sauce has rich nutritional value, containing more than 18 kinds of amino acids and essential trace elements for the human body, rich vitamins, organic acids, etc. It can maintain the body's acid-base balance, participate in the body's metabolic activities, and supplement the nutrients needed by the human body.

[0004] The traditional fish sauce has a long fermentation cycle and a strong fishy smell during the fermentation process. To address this problem, a rapid fermentation method can be used, including enzymatic fermentation, heat preservation fermentation, fermentation with koji, and compound fermentation. Compared with traditional natural fermentation, the fermentation cycle of fish sauce can be shortened to a certain extent.

[0005] Lactic acid bacteria are widely used in the food industry, and they can improve food quality and nutritional properties, extend food storage period, and improve food safety. In the production process of fish sauce, lactic acid bacteria are an important type of microorganisms, which can produce organic acids, active peptides and other substances, which are closely related to the flavor and quality of fish sauce. Summary of the invention

[0006] In view of the shortcomings of the prior art and in order to solve the problems of long fermentation period and strong fishy smell of traditional fish sauce, the object of the present invention is to provide a method for quickly fermenting low-salt fish sauce using dark meat of yellowfin tuna.

[0007] A method for rapidly fermenting low-salt fish sauce using dark-colored meat of yellowfin tuna, the method comprising the following steps: (1) Steaming and boiling the minced dark meat of yellowfin tuna; (2) mixing the steamed minced meat obtained in step (1) with water, and adding trypsin and alkaline protease for enzymatic hydrolysis to obtain a fish meat enzymatic hydrolysis mixture; (3) Adding Lactobacillus fermentum to the fish enzymatic hydrolysis mixture obtained in step (2) Lactobacillus fermentum The starter is fermented, filtered and sterilized to obtain the fish sauce.

[0008] Furthermore, in step (1), the yellowfin tuna dark meat mince is obtained by mincing the yellowfin tuna dark meat.

[0009] Furthermore, in step (1), the cooking temperature is 121° C. and the cooking time is 15 min. After cooking, the protein structure of the yellowfin tuna is destroyed.

[0010] Furthermore, in step (2), the ratio of the minced meat to water is 1:4.

[0011] Furthermore, in step (2), the added amount of trypsin and alkaline protease is 3.2%, and the ratio of trypsin to alkaline protease is 2:1.

[0012] Furthermore, in step (2), the pH value of the system needs to be adjusted to 8.3 before the enzymatic hydrolysis; the temperature of the enzymatic hydrolysis is 53.34°C and the time is 4 h.

[0013] Furthermore, in step (2), the enzymatic hydrolysis needs to be followed by enzyme inactivation and sterilization.

[0014] Furthermore, after the enzymatic hydrolysis, 1.02% glucose is added to the enzymatic hydrolysis product, and sterilized at 115° C. for 15 min to obtain a fish meat enzymatic hydrolysis mixture.

[0015] Furthermore, the enzyme inactivation temperature is 95° C. and the time is 15 min.

[0016] Furthermore, in step (3), the preparation method of the lactobacillus fermentation agent adopts the following steps: centrifuging the lactobacillus culture solution, mixing the bacteria with 0.85% (w / v) physiological saline to prepare a bacterial suspension, and obtaining the lactobacillus fermentation agent.

[0017] Furthermore, the centrifugation is carried out at 4°C, with a rotation speed of 6000 r / min and a time of 5 min; and washing is required after the centrifugation.

[0018] Furthermore, the reagent used for flushing is 0.85% (w / v) physiological saline.

[0019] Furthermore, in step (3), the Lactobacillus is deposited with a number of BNCC194173, a deposit date of September 30, 2022, a depository of Henan Microbial Culture Resource Collection Center, a deposit address of Henan Industrial Microbial Culture Engineering Technology Research Center, and a classification name of Lactobacillus ( Lactobacillus ) Furthermore, in step (3), the concentration of the fermented Lactobacillus starter added to the fish enzymatic hydrolysis mixture is 5.99%; the concentration of the fermented Lactobacillus inoculated is 10 7 CFU / mL Furthermore, in step (3), the fermentation is carried out at 37° C. and the fermentation time is 4.68 days.

[0020] Furthermore, in step (3), the sterilization temperature is 115° C. and the sterilization time is 15 min.

[0021] Beneficial effects: The present invention adopts enzymolysis followed by fermentation, uses trypsin and alkaline protease for simultaneous enzymolysis, and optimizes the degree of hydrolysis to reach the highest level, thereby solving the problems of long fermentation cycle and strong fishy smell of traditional fish sauce. The salt content of the fish sauce prepared by the present invention is 10.8%. Compared with the traditional fermentation technology, the present invention greatly shortens the fermentation time by enzymolysis followed by fermentation, and greatly reduces the fishy smell of fish meat. The present invention is conducive to improving the production efficiency and product quality of fish sauce. The present invention has the characteristics of simple operation, low cost and good product flavor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a sample picture of the dark meat stock solution of yellowfin tuna; Figure 2 This is a sample picture of the enzymatic hydrolysate mixture of yellowfin tuna dark meat; Figure 3 A sample picture of the fish sauce prepared in Example 1; Figure 4 The three-dimensional spectra and HS-GC-IMS two-dimensional spectra of yellowfin tuna dark meat liquid, enzymatic hydrolysate, and fish sauce; Figure 5 The Gallery Plot fingerprints of yellowfin tuna dark meat stock solution, yellowfin tuna dark meat enzymatic hydrolysate, and yellowfin tuna dark meat fish sauce. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described clearly and completely below in conjunction with specific implementation cases. The described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Materials and Methods Yellowfin tuna was caught in the South China Sea; alkaline protease (200,000 u / g) was purchased from Henan Yangshao Biotechnology Co., Ltd.; trypsin (2000 u / g) was purchased from Shandong Longkote Enzyme Preparation Co., Ltd.; Lactobacillus fermentum ( Lactobacillus fermentum ), the accession number is BNCC194173, Henan Microbial Culture Resource Collection Center.

[0025] Example 1 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.02% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 5.99% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented Lactobacillus, and the Lactobacillus culture solution is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 4.68 days to obtain a crude fish sauce; (6) Filtration: Filtering the crude fish sauce obtained in step (5) using a suction filter; (7) Sterilization: The filtered fish sauce obtained in step (6) is sterilized at 115° C. for 15 min, and canned and sealed under sterile conditions to obtain a finished fish sauce.

[0026] Example 2 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.02% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 5.99% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented lactobacillus, and the lactobacillus culture liquid is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4° C., at a speed of 6000 r / min, for 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37° C. for 2.5 d to obtain a crude fish sauce; (6) Filtration: Filtering the crude fish sauce obtained in step (5) using a suction filter; (7) Sterilization: The filtered fish sauce obtained in step (6) is sterilized at 115° C. for 15 min, and canned and sealed under sterile conditions to obtain a finished fish sauce.

[0027] Comparative Example 1 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented Lactobacillus, and the Lactobacillus culture solution is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 1 day to obtain a crude fish sauce; (6) Filtration: Filtering the crude fish sauce obtained in step (5) using a suction filter; (7) Sterilization: The fish sauce obtained in step (6) is sterilized at 115° C. for 15 min, and canned and sealed under sterile conditions to obtain a finished fish sauce.

[0028] Comparative Example 2 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder;

[0029] (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented lactobacillus, and the lactobacillus culture liquid is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 2 days to obtain a crude fish sauce; (6) Filtration: Filtering the crude fish sauce obtained in step (5) using a suction filter; (7) Sterilization: The filtered fish sauce obtained in step (6) is sterilized at 115° C. for 15 min, and canned and sealed under sterile conditions to obtain a finished fish sauce.

[0030] Comparative Example 3 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented lactobacillus, and the lactobacillus culture liquid is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 3 days to obtain a crude fish sauce; (6) Filtration: Filtering the crude fish sauce obtained in step (5) using a suction filter; (7) Sterilization: The filtered fish sauce obtained in step (6) is sterilized at 115° C. for 15 min, and canned and sealed under sterile conditions to obtain a finished fish sauce.

[0031] Comparative Example 4 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent used is an activated fermented Lactobacillus, and the Lactobacillus culture solution is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 4 days to obtain a crude fish sauce; (6) Filtration: Filtering the crude fish sauce obtained in step (5) using a suction filter; (7) Sterilization: The filtered fish sauce obtained in step (6) is sterilized at 115° C. for 15 min, and canned and sealed under sterile conditions to obtain a finished fish sauce.

[0032] Comparative Example 5 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented lactobacillus, and the lactobacillus culture liquid is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 5 days to obtain a crude fish sauce; (6) Filtration: The crude fish sauce obtained in step (5) is subjected to suction filtration by a suction filter to obtain fish sauce.

[0033] Comparative Example 6 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent is activated fermented Lactobacillus, and the Lactobacillus culture solution is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 6 days to obtain a crude fish sauce; (6) Filtration: The crude fish sauce obtained in step (5) is subjected to suction filtration by a suction filter to obtain fish sauce.

[0034] Comparative Example 7 A method for producing low-salt high-quality fish sauce by fermenting dark-colored meat of yellowfin tuna, the specific steps are as follows: (1) Raw material processing: Select the dark meat part of yellowfin tuna and grind it into minced meat using a meat grinder; (2) high temperature cooking: cooking the minced meat obtained in step (1) at 121° C. for 15 min to destroy the protein structure, which is beneficial to the next enzymatic hydrolysis process, and obtaining the minced meat after high temperature treatment; (3) Enzymatic hydrolysis: the high temperature treated minced meat obtained in step (2) was mixed with water in a ratio of 1:4, trypsin and alkaline protease were added in a ratio of 2:1, and the amount of the two enzymes added was 3.2%, the pH value of the mixture was adjusted to 8.3, and the mixture was enzymatically hydrolyzed in a constant temperature shaking water bath at a temperature of 53.34°C for 4 h, and then placed at 95°C for 15 min to inactivate the enzyme, thereby obtaining enzymatically hydrolyzed minced meat; (4) Sterilization: adding 1.0% glucose to the enzymatically hydrolyzed minced meat obtained in step (3), and sterilizing at 115° C. for 15 min to facilitate subsequent lactic acid bacteria fermentation, thereby obtaining a fish meat enzymatic hydrolysis mixture; (5) Fermentation: 4% of a fermentation agent is added to the fish enzymatic hydrolysis mixture obtained in step (4), wherein the fermentation agent used is an activated fermented Lactobacillus, and the Lactobacillus culture liquid is transferred to a sterilized 50 mL centrifuge tube for centrifugation at 4°C, a speed of 6000 r / min, and a time of 5 min. After centrifugation, the supernatant is discarded, the bacteria are rinsed twice with 0.85% (w / v) sterile saline, and the rinsed bacteria are suspended in 0.85% (w / v) saline to prepare a bacterial suspension, which is added to the enzymatic hydrolysis mixture obtained in step (4) and fermented at 37°C for 7 days to obtain a crude fish sauce; (6) Filtration: The crude fish sauce obtained in step (5) is subjected to suction filtration by a suction filter to obtain fish sauce.

[0035] Indicator testing (1) Testing of physical and chemical indicators of fish sauce The amino acid nitrogen content was evaluated by the acidometer method in GB5009.235-2016; the total nitrogen content was evaluated by the Kjeldahl nitrogen method in GB5009.5; the volatile basic nitrogen content was evaluated by the microdiffusion method in GB5009.228-2016. The results are shown in Table 1.

[0036] Table 1 Test results of fish sauce physical and chemical indicators (2) Microbial index evaluation The method for evaluating microbial indicators refers to GB 10133-2014, and the results are shown in Table 2.

[0037] Table 2 Microbiological indicators of fish sauce (3) Analysis of aroma compounds in fish sauce at different fermentation stages based on GC-IMS Flavour Spec1H1-00053 GC-IMS coupling instrument, GAS, Germany. Weigh 2 g of fish extract sample, put it in a 20 mL headspace bottle, incubate at 60°C for 15 min and then inject the sample.

[0038] Yellowfin tuna dark meat stock solution: The ratio of fish meat to water is 1:4. After mixing, centrifuge at 8000 r / min for 15 min and take the supernatant, which is the yellowfin tuna dark meat stock solution.

[0039] Figure 4The three-dimensional spectra and HS-GC-IMS two-dimensional spectra of the yellowfin tuna dark meat stock solution, the enzymatic hydrolyzate prepared in Example 1, and the fish sauce prepared in Example 1 are shown. Figure 4 A, each sample from left to right is fish stock solution (Control), fish enzymatic hydrolysate (FH), fish sauce (FS). Figure 4 The background color of Figure A (GC-IMS three-dimensional spectrum) is blue, the red vertical line on the X-axis is the RIP peak, the X-axis is the drift time of the volatiles for the reactive ion peak during IMS separation, the Y-axis is the retention time of the volatiles during GC separation, and the Z-axis is the ion peak intensity of the volatiles in IMS. After normalization, each point on both sides of the RIP peak represents a volatile organic compound, and the color represents the concentration of the substance. White indicates a low concentration of the substance, and red indicates a high concentration of the substance. Qualitative analysis of each component is performed through ion drift time and ion peak intensity. Figure 4 The circled area A shows the differences in volatile compounds among fish stock solution (Control), fish enzymatic hydrolysate (FH), and fish sauce (FS).

[0040] Figure 4 B is a top view of the three-dimensional spectrum of the volatile substances in the sample. The red points in the figure represent compounds with higher concentrations, while the blue points represent compounds with lower concentrations. The circled positions in the figure show differences in the volatile compounds in the fish stock solution (Control), fish enzymatic hydrolysate (FH), and fish sauce (FS).

[0041] Figure 4 C is a comparative difference diagram of sample volatile substances. The difference in volatile substances is determined by comparing the color of the reference sample and other sample spectra. The darker the red, the higher the concentration of volatile substances corresponding to the sample is than the reference sample, and the darker the blue, the lower the concentration is than the reference sample.

[0042] The statistical results of volatile organic compounds in yellowfin tuna meat liquid, fish meat enzymatic hydrolysate, and fish sauce samples are shown in Table 3.

[0043] Table 3 Statistical results of volatile organic compounds in yellowfin tuna meat liquid, fish meat enzymatic hydrolysate, and fish sauce samples As can be seen from Table 3, a total of 122 volatile flavor substances were detected, including aldehydes (30), esters (15), alcohols (15), ketones (15), acids (6), alkenes (5), others (9), and unknown substances (22). It can be seen that the changes in the content of aldehydes and esters may be the main reason for the flavor differences. Aldehydes mainly come from lipid oxidation, usually accompanied by low-threshold grassy, ​​malty and meaty flavors, and make an important contribution to the formation of fish sauce flavor. Esters are mainly produced through the esterification process of alcohols and organic acids. Most of them have fruity and floral aromas, which can reduce the spiciness of fatty acids and the bitterness of amino acids. Aldehyde volatile compounds have a low olfactory threshold and can be smelled even at very low concentrations. After fermentation, aldehyde substances are significantly reduced, and esters, alcohols, acids, etc. are produced at the same time.

[0044] Figure 5 The Gallery Plot fingerprints of yellowfin tuna dark meat stock solution, yellowfin tuna dark meat enzymatic hydrolysate, and yellowfin tuna dark meat fish sauce. The substances marked in area A were detected in all three fish meat extract samples, among which butyraldehyde had a pungent and irritating odor, and ethyl acetate had a fruity aroma.

[0045] The substances marked in area B are aroma compounds with higher content in the fish stock solution and fish enzymatic hydrolysate samples, among which 1-pentanol (monomer) has bready, wine and fruity aromas, 2-pentanone has sweet fruity, wine and woody aromas, 2-hexenal (monomer), 2-hexenal (monomer) has sweet almond flavor, α-phellandrene has black pepper flavor, trans-2-pentenal (monomer) has spicy taste, heptanal (monomer) has fruity aroma, 1,4-cineole has minty camphor flavor, and propionaldehyde (dimer) has earthy and nutty flavor. The content of the above volatile substances is significantly reduced after fermentation.

[0046] The substances marked in area C are aroma compounds with higher content in the fish stock solution samples, including diethyl succinate, methyl nonyl ketone, propionaldehyde (dimer), heptaldehyde, 2-methyl-2-pentenal, methyl heptenone, which have fruity aroma, dipentene has lemon aroma, ethyl hexanoate has pineapple aroma, trans, cis-2,6-nonadienal, damascus ketone, nonanal (monomer), and rose oxide have floral aroma, 2-acetylfuran has sweet aroma, hydroxyacetone has caramel aroma, (E,E)-2,4-heptadienal (monomer) and (E,E)-2,4-heptadienal (dimer) have fatty aldehyde smell, trans-2-octenal (monomer) and trans-2-octenal (dimer) have fat and meat aroma, (Z)-4-heptenal has grass and oil aroma, hexanal has fat, green and fruity aroma, 2-nonadienal has a strong aroma, and hydroxyacetone has a strong aroma. Ketones have an oily and herbal aroma, n-octanal (monomer) and n-octanal (dimer) have a waxy aroma; (E)-2-heptenal and (E)-2-heptenal (dimer) have a grassy smell, sec-octanone has a woody herbal aroma, 1-octen-3-one has a fish and vegetable aroma, 1-pentanol has a bready, wine and fruity aroma, and 2-n-pentylfuran has a fruity and beany smell; 2-hexenal has a sweet almond smell, valeraldehyde has a fermented bread and berry smell, 3-carene has a medicinal woody aroma, hexanol has a wine smell, (E)-2-heptenal (dimer) has a spicy taste, 1-penten-3-one and acrolein have a pungent smell, and dipropyl disulfide has a sulfur-like pungent smell. The above volatile substances are significantly reduced in the fish stock solution after enzymatic hydrolysis, and the content of these volatile substances does not change significantly after fermentation.

[0047] The substances marked in area D are those that exist in the fish enzymatic hydrolysate samples and have high content. (2E,4E)-2,4-octadienal has a pear peel smell, ethyl heptanoate has an aromatic smell, benzaldehyde (monomer) and benzaldehyde (dimer) have a bitter almond smell, 4-methyl-2-pentanol has a pungent smell, isopentanol-(monomer) has a spicy taste; n-butanol-(monomer) has an alcohol oil smell, 2-methyl-3-(methylthio)pyrazine has a green pepper aroma, isopropyl acetate has a fruity aroma, linalyl acetate has a sweet aroma, ethyl heptanoate has a meaty and fishy aroma, and methyl 2-octynoate has an unpleasant odor. The contents of the above volatile substances generally show an increasing trend after enzymatic hydrolysis, and the content decreases after fermentation.

[0048] The substances marked in area E are those that are commonly contained in the fish enzymatic hydrolysate and fish fermentation liquid samples and are present in relatively high levels. 2-Butanone has fruity and green aromas, 3-hydroxy-2-butanone has a creamy aroma, cyclohexanone has a minty aroma, myrcene has a sweet orange and balsamic flavor, propionaldehyde-(monomer) has a pungent odor, and 4-hydroxy-4-methyl-2-pentanone has a pleasant odor. The above volatile substances increase significantly in the fish stock solution after enzymatic hydrolysis, and the contents of 4-hydroxy-4-methyl-2-pentanone, myrcene, and cyclohexanone increase after fermentation.

[0049] The substances marked in area F are those that exist in the fish fermentation broth sample and have a high content. 2-ethylhexanol (dimer) and 2-ethylhexanol (monomer) have sweet and floral aromas, phenylacetaldehyde and phenylethyl acetate have floral aromas, isobutyl acetate, propyl acetate, ethyl propionate, ethyl butyrate, ethyl propionate and ethyl heptanoate have fruity aromas, isobutyl acetate has a banana aroma, methyl butyrate has an apple and cheese aroma, n-hexanol has a green fruity aroma and a fat aroma, n-hexanol (monomer) has a green fruity aroma and a fat aroma, 1-dodecene has a mild odor, and eucalyptol has a camphor aroma. and herbal taste; dimethyl disulfide has a foul smell; 4-methyl-2-pentanol has a camphor smell; 2-n-butylfuran has a sweet and spicy taste; triethylamine has an ammonia smell; n-pentanoic acid (dimer) and n-pentanoic acid (monomer) have a rotten smell; 3-methylthiopropionaldehyde has a musty and earthy smell; acetic acid (monomer), propionic acid, acetic acid (dimer), and isobutyric acid have a pungent smell; isopentanol (dimer) and isobutanol have a special smell; n-butanol (dimer) has an alcohol oil smell. The above volatile substances do not change significantly after enzymatic hydrolysis, and the content of volatile substances increases significantly after fermentation.

[0050] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For technicians in this field, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for rapidly fermenting low-salt fish sauce using dark-colored meat of yellowfin tuna, characterized in that: The method comprises the following steps: (1) Steaming and boiling the minced dark meat of yellowfin tuna; (2) mixing the steamed minced meat obtained in step (1) with water, and adding trypsin and alkaline protease for enzymatic hydrolysis to obtain a fish meat enzymatic hydrolysis mixture; (3) adding a Lactobacillus fermentation agent to the fish meat enzymatic hydrolysis mixture obtained in step (2) for fermentation, and then filtering and sterilizing to obtain the fish sauce; In step (3), the Lactobacillus has a preservation number of BNCC194173, a preservation date of September 30, 2022, a preservation unit of Henan Microbial Culture Resource Collection Center, a preservation address of Henan Industrial Microbial Culture Engineering Technology Research Center, and a classification name of Lactobacillus .

2. The method according to claim 1, characterized in that In step (1), the yellowfin tuna dark meat mince is obtained by mincing the yellowfin tuna dark meat; The cooking temperature is 121° C. and the cooking time is 15 min.

3. The method according to claim 1, characterized in that: In step (2), the ratio of the minced meat to water is 1:4; The added amount of the trypsin and alkaline protease is 3.2%, and the ratio of the trypsin and alkaline protease is 2:

1.

4. The method according to claim 3, characterized in that The pH value of the system needs to be adjusted to 8.3 before the enzymatic hydrolysis; the temperature of the enzymatic hydrolysis is 53.34°C and the time is 4 hours; After the enzymolysis, enzyme inactivation and sterilization are required.

5. The method according to claim 4, characterized in that After the enzymolysis, the enzymolysis product is placed at 95° C. for 15 minutes, 1.02% glucose is added, and sterilized at 115° C. for 15 minutes to obtain a fish meat enzymolysis mixture.

6. The method according to claim 1, characterized in that In step (3), the method for preparing the lactobacillus fermentation agent comprises the following steps: centrifuging the lactobacillus culture solution, mixing the bacteria with 0.85% (w / v) physiological saline to prepare a bacterial suspension, and obtaining the lactobacillus fermentation agent.

7. The method according to claim 6, characterized in that The centrifugation is performed at 4°C, with a rotation speed of 6000 r / min and a time of 5 min; washing is also required after the centrifugation; The reagent used for the flushing is 0.85% (w / v) physiological saline.

8. The method according to claim 1, characterized in that In step (3), the amount of the Lactobacillus fermentation agent added is 5.99%; The fermentation was carried out at 37°C for 4.68 days.

9. The method according to claim 1, characterized in that: In step (3), the sterilization temperature is 115°C and the sterilization time is 15 min.

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