Method for preparing fish sauce through temperature-control and light-control coupling photosensitive microbial fermentation

Abstract

The invention discloses a method for preparing fish sauce through temperature-control and light-control coupling photosensitive microbial fermentation, and belongs to the technical field of microbial fermentation. According to the method, temperature control and illumination adjustment are combined, the fermentation process is optimized by utilizing the special properties of photosensitive microorganisms, and an optimal growth and metabolism environment is provided for the photosensitive microorganisms, so that the fermentation efficiency and the product quality are improved, and the defect that traditional fish sauce depends on solarization and night dew is overcome; fish sauce fermentation is not limited by factors of illumination, seasons and regions, large-scale production can be achieved, industrial application is easy, and the industrial problem that the fish sauce fermentation depends on the day to eat is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial fermentation, and in particular relates to a method for preparing fish sauce by utilizing temperature-controlled light-controlled coupled photosensitive microbial fermentation. Background Art

[0002] Fish sauce, also known as fish soy sauce, is a common aquatic seasoning in Fujian cuisine, Cantonese cuisine and Southeast Asian cuisine. Traditional fish sauce production relies on the sun-drying and night-dew fermentation process, that is, the sauce is exposed to the sun during the day and naturally absorbs dew at night, which can produce fish sauce with excellent flavor, color and taste. However, why the sun-drying and night-dew fermentation process can produce fish sauce with excellent flavor, color and taste is also a difficult problem that technicians in this field have been exploring; in addition, the sun-drying and night-dew fermentation process is greatly affected by factors such as season and region, and there are problems such as difficulty in controlling the fermentation process and significant quality differences between batches.

[0003] At present, rapid fermentation methods for fish sauce have been developed, including heat preservation fermentation, external enzyme fermentation and inoculation fermentation. The main purpose is to clarify the relationship between the succession and metabolism of microbial flora and the flavor of fish sauce during the fermentation process. However, the color, aroma and taste of the product are still different from those of fish sauce fermented under traditional sun and night dew conditions. Summary of the invention

[0004] [Technical issues]

[0005] The technical problem to be solved by the present invention is that the process of sun-drying and night-dew fermentation of fish sauce is easily affected by seasons and regions, the fermentation process is difficult to control, the quality difference between batches is significant, and the methods for preparing fish sauce by heat preservation fermentation method, external enzyme fermentation method and inoculation fermentation method have problems such as poor color, aroma and taste of products.

[0006] [Technical solution]

[0007] In order to solve the above problems, the present invention provides a method for preparing fish sauce by temperature-controlled and light-controlled coupled photosensitive microbial fermentation, which optimizes the growth and metabolic environment of photosensitive microorganisms by precisely controlling the temperature and light conditions of the secondary fermentation of the fish sauce, improves the flavor and nutritional value of the fish sauce, and stabilizes the production quality of the fish sauce.

[0008] The present invention provides a method for preparing fish sauce by temperature-controlling and light-controlling coupled photosensitive microbial fermentation, comprising the following steps:

[0009] (1) Wash and mince fresh fish meat, add edible salt and mix well to obtain pre-treated meat paste;

[0010] (2) inoculating activated microorganisms into the pretreated meat paste and fermenting at 40 to 45° C. for 5 to 10 days to complete a primary fermentation;

[0011] (3) After the primary fermentation is completed, the salt content of the fermented material is supplemented to 20-25%, w / w, mixed, and stirred and mixed using temperature and light control facilities, and fermented for more than 30 days to complete the secondary fermentation;

[0012] (4) After the secondary fermentation, the fish sauce is filtered to remove insoluble matter and then sterilized and bottled.

[0013] In one embodiment of the present invention, in step (1), the amount of edible salt added is 8-10% of the mass of the meat paste.

[0014] In one embodiment of the present invention, in step (2), the inoculation amount of the activated microorganisms is 5-10% of the mass of the meat paste.

[0015] In one embodiment of the present invention, in step (2), the method for preparing activated microorganisms comprises: soaking soybeans, steaming, cooling, mixing with microbial strains and flour, spreading, covering with wet gauze, and incubating in a constant temperature and humidity incubator for 72 to 75 hours.

[0016] In one embodiment of the present invention, in step (2), the microbial strains are mixed bacteria; the amount of microbial strains added is 2-3‰ of the mass of soybeans; and the amount of flour added is 10-12% of the mass of soybeans.

[0017] In one embodiment of the present invention, in step (2), the temperature of the constant temperature and humidity incubator is 30-35°C, and the humidity is 80-90RH.

[0018] In one embodiment of the present invention, in step (3), the temperature control facility is a heating jacket.

[0019] In one embodiment of the present invention, in step (3), the secondary fermentation temperature is 25-45°C.

[0020] In one embodiment of the present invention, in step (3), the light control facility is an LED lamp, the wavelength of the light is 280 to 800 nm, 100 to 120 W, and the irradiation time is 4 to 24 hours per day.

[0021] The invention provides fish sauce prepared by the method described above.

[0022] In one embodiment of the present invention, the fish sauce contains photosensitive microorganisms, which are one or more of Aspergillus oryzae, Aspergillus niger, Rhizopus arrhizus and Mucor piriformis.

[0023] [Beneficial Effects]

[0024] (1) Why the sun-exposure and night-dew fermentation process can be used to prepare fish sauce with excellent flavor, color and taste is also a difficult problem that has been explored by those skilled in the art. However, the present invention explores the importance of light in the preparation of fish sauce through dark simulation and light comparison experiments. The present invention produces fish sauce through temperature-controlled light-controlled coupled photosensitive microbial fermentation technology. The amino acid nitrogen content, free amino acid content and overall flavor of the produced fish sauce are comparable to those of the fish sauce produced by sun-exposure and night-dew fermentation, reaching the first-level level of the national fish sauce industry standard, solving the disadvantage that traditional fish sauce fermentation relies on sun-exposure and night-dew fermentation, breaking through the geographical location and seasonal restrictions of fish sauce production, and realizing year-round production, thereby improving economic benefits;

[0025] (2) The present invention has low cost, is easy to operate, can be produced on a large scale, and is easy to apply industrially;

[0026] (3) Compared with the traditional sun-dried overnight fish sauce fermentation, the fermentation conditions of the present invention are easier to control and the product quality is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the GC-MS total ion current diagram of the fish sauce after the secondary fermentation of Examples 1 to 3 and Comparative Examples 1 to 2;

[0028] Figure 2 It is a bar chart of absolute quantitative microorganisms at the end of secondary fermentation of fish sauces of Examples 1 to 3 and Comparative Examples 1 to 2. DETAILED DESCRIPTION

[0029] In order to make the technical advantages and purposes of the present invention more clearly understood, the present invention is further described in detail in conjunction with the following examples. The specific examples are only used to explain the present invention and are not used to limit the present invention.

[0030] The microbial strains used in the following examples and comparative examples were purchased from Yishui Jinrun Biotechnology Co., Ltd., model 3.042, mixed bacteria.

[0031] Determine the amino acid nitrogen content in fish sauce samples according to the provisions of GB5009.235.

[0032] The free amino acid content in the fish sauce sample was determined with reference to the provisions of GB5009.124-2016. The determined free amino acid content can be divided into sweet, bitter and umami amino acids according to the taste classification.

[0033] The volatile and / or semi-volatile flavor substances in fish sauce were determined by gas chromatography-mass spectrometry, as follows:

[0034] Extraction conditions: Weigh 5g of fish sauce sample, dilute to 12mL with ultrapure water, and place in a 20mL headspace sample bottle. Insert the DMU-SPME extraction head fiber into the headspace sample bottle, keep the upper coating above the liquid surface, and immerse the lower coating in the sample to be tested. The extraction temperature is 60℃, the stirring speed is 500rpm, and the extraction time is 30min. The volatile and semi-volatile compounds are extracted in an integrated manner.

[0035] Gas phase parameters: Agilent7890B, non-polar HP-5ms ultra-inert 30m×0.25mm×0.25μmAgilent chromatographic column was used for analysis; the initial temperature of the gas chromatography column oven was 35℃, maintained for 3min, then increased to 250℃ at a rate of 5℃ / min and maintained for 10min; the injection method was splitless injection, and the injection port temperature was 250℃; helium was used as the carrier gas, and the flow rate was 1mL / min.

[0036] Mass spectrometry parameters: The instrument used was Agilent 5977A, which was detected in scanning mode with a scanning range of 35-500 m / z. The ion source was an electron impact ion source (70 eV) at 230°C.

[0037] Microbial profiling of fish sauce using metagenomic absolute quantitative sequencing.

[0038] Example 1

[0039] A method for preparing fish sauce by temperature-controlling and light-controlling coupled photosensitive microbial fermentation, specifically comprising the following steps:

[0040] (1) Raw material pretreatment: fresh yellow croaker meat is washed, minced with a meat chopper, 10% (w / w) edible salt is added, and mixed for later use to obtain pretreated meat paste;

[0041] (2) Preparation of activated microorganisms: Soybeans were soaked overnight, steamed for 2 h, cooled to 30°C, mixed with 2‰ (w / w) microbial strains and 10% (w / w) flour, spread on a tray with a thickness of 1 cm, covered with a double layer of wet gauze, and placed in a constant temperature and humidity incubator at 30°C and 80-90 RH for 72 h, turning over once a day to prevent caking;

[0042] (3) Primary fermentation: 8% (w / w) activated microorganisms were inoculated into the pretreated meat paste and fermented at 45°C for 6 days;

[0043] (4) Secondary fermentation: The fermented material that has completed the primary fermentation is supplemented with salt to 25% (w / w), mixed, and irradiated with a 100 W LED lamp with a wavelength range of 600-760 nm for 24 h per day. The fermentation temperature is maintained at 30° C. using a heating jacket, and stirred at a fixed point every day for 30 days.

[0044] (5) Filtration and sterilization: After the secondary fermentation, the supernatant of the fish sauce is filtered through multi-layer gauze and centrifuged, then sterilized at 100°C for 30 min and filled under aseptic conditions.

[0045] Example 2

[0046] A method for preparing fish sauce by temperature-controlling and light-controlling coupled photosensitive microbial fermentation, specifically comprising the following steps:

[0047] (1) Raw material pretreatment: fresh yellow croaker meat is washed, minced with a meat chopper, 8% (w / w) edible salt is added, mixed and set aside to obtain pretreated meat paste;

[0048] (2) Preparation of activated microorganisms: Soybeans were soaked overnight, steamed for 2 h, cooled to 30°C, mixed with 2‰ (w / w) microbial strains and 10% (w / w) flour, spread on a tray with a thickness of 1 cm, covered with a double layer of wet gauze, and placed in a constant temperature and humidity incubator at 30°C and 80-90 RH for 72 h, turning over once a day to prevent caking;

[0049] (3) Primary fermentation: inoculate 10% (w / w) activated microorganisms into the pretreated meat paste and ferment at 40°C for 10 days;

[0050] (4) Secondary fermentation: The fermented material that has completed the primary fermentation is supplemented with salt to 20% (w / w), mixed, and irradiated with a 100 W LED lamp with a wavelength range of 510-537 nm for 12 h per day. A heating jacket is used to maintain the fermentation temperature at 45°C. The material is stirred at a fixed point every day and fermented for 30 days.

[0051] (5) Filtration and sterilization: After the secondary fermentation, the supernatant of the fish sauce is filtered through multi-layer gauze and centrifuged, then sterilized at 100°C for 30 min and filled under aseptic conditions.

[0052] Example 3

[0053] A method for preparing fish sauce by temperature-controlling and light-controlling coupled photosensitive microbial fermentation, specifically comprising the following steps:

[0054] (1) Raw material pretreatment: fresh yellow croaker meat is washed, minced with a meat chopper, 9% (w / w) edible salt is added, and mixed for later use to obtain pretreated meat paste;

[0055] (2) Preparation of activated microorganisms: Soybeans were soaked overnight, steamed for 2 h, cooled to 30°C, mixed with 2‰ (w / w) microbial strains and 10% (w / w) flour, spread on a tray with a thickness of 1 cm, covered with a double layer of wet gauze, and placed in a constant temperature and humidity incubator at 30°C and 80-90 RH for 72 h, turning over once a day to prevent caking;

[0056] (3) Primary fermentation: 5% (w / w) activated microorganisms were inoculated into the pretreated meat paste and fermented at 43°C for 8 days;

[0057] (4) Secondary fermentation: The fermented material that has completed the primary fermentation is supplemented with salt to 23% (w / w), mixed, and irradiated with a 100 W LED lamp with a wavelength range of 476-463 nm for 8 h per day. The fermentation temperature is maintained at 35° C. using a heating jacket, and stirred at a fixed point every day for 30 days.

[0058] (5) Filtration and sterilization: After the secondary fermentation, the supernatant of the fish sauce is filtered through multi-layer gauze and centrifuged, then sterilized at 100°C for 30 min and filled under aseptic conditions.

[0059] Comparative Example 1

[0060] A method for preparing fish sauce specifically comprises the following steps:

[0061] (1) Raw material pretreatment: Wash fresh small yellow croaker, mince with a meat chopper, add 10% (w / w) edible salt, mix well and set aside;

[0062] (2) Preparation of activated microorganisms: Soybeans were soaked overnight, steamed for 2 h, cooled to 30°C, mixed with 2‰ (w / w) microbial strains and 10% (w / w) flour, spread on a tray with a thickness of 1 cm, covered with a double layer of wet gauze, and placed in a constant temperature and humidity incubator at 30°C and 80-90 RH for 72 h, turning over once a day to prevent caking;

[0063] (3) Primary fermentation: 8% (w / w) activated microorganisms were inoculated into the pretreated meat paste and fermented at 45°C for 6 days;

[0064] (4) Secondary fermentation: The fermented material that has completed the primary fermentation is supplemented with salt to 25% (w / w), mixed, and fermented using the traditional sun-drying and night-dew fermentation method, i.e., the sauce is exposed to the sun during the day and naturally absorbs dew at night, and is stirred at a fixed point every day for 30 days;

[0065] (5) Filtration and sterilization: After the secondary fermentation, the supernatant of the fish sauce is filtered through multi-layer gauze and centrifuged, then sterilized at 100°C for 30 min and filled under aseptic conditions.

[0066] Comparative Example 2

[0067] A method for preparing fish sauce specifically comprises the following steps:

[0068] (1) Raw material pretreatment: Wash fresh yellow croaker meat, mince it with a meat chopper, add 10% (w / w) pickling salt, mix well and set aside;

[0069] (2) Preparation of activated microorganisms: 300 g soybeans were soaked overnight, steamed for 2 h, cooled to 30°C, mixed with 2‰ (w / w) microbial strains and 10% (w / w) flour, spread on a tray with a thickness of 1 cm, covered with a double layer of wet gauze, and placed in a constant temperature and humidity incubator at 30°C and 80-90 RH for 72 h, turning the soybeans once a day to prevent agglomeration;

[0070] (3) Primary fermentation: 8% (w / w) activated microorganisms were inoculated into the pretreated meat paste and fermented at 45°C for 6 days;

[0071] (4) Secondary fermentation: The fermented product that has completed the primary fermentation is supplemented with salt to 25% (w / w), mixed, and covered with an opaque black cloth. The fermentation temperature is maintained at 30° C. using a heating jacket, and stirred at a fixed point every day for 30 days.

[0072] (5) Filtration and sterilization: After the secondary fermentation, the supernatant of the fish sauce is filtered through multi-layer gauze and centrifuged, then sterilized at 100°C for 30 min and filled under aseptic conditions.

[0073] Amino acid nitrogen is an important indicator for measuring the fermentation degree and quality grade of fish sauce, which can reflect its taste characteristics. The higher the content, the better the quality of fish sauce. As can be seen from Table 1, after 30 days of secondary fermentation, the amino acid nitrogen content of Examples 1 to 3 and Comparative Example 1 all reached the requirement of "the amino acid nitrogen content of first-grade fish sauce should not be less than 0.9g / 100mL" of the industry standard SB / T 10324-1999 "Industry Standard Fish Sauce of the People's Republic of my country", which is significantly higher than the amino acid nitrogen content of Comparative Example 2 of 0.86g / 100mL. The umami amino acid content and sweet amino acid content in Examples 1 to 3 and Comparative Example 1 are both higher than those in Comparative Example 2, and the bitter amino acid content in Examples 1 to 3 is lower than that in Comparative Example 1 and Comparative Example 2, which shows that temperature and light control are beneficial to promoting the formation of umami and sweet amino acids and can reduce the formation of bitter amino acids in fish sauce.

[0074] Table 1 Physical and chemical indicators of fish sauces of Examples 1 to 3 and Comparative Examples 1 to 2

[0075]

[0076]

[0077] There are 66 flavor substances in Examples 1 to 3 at most, among which benzaldehyde, hexanal and 3,5-octadien-2-one were detected in Examples 1 to 3 and Comparative Example 1, but not detected in Comparative Example 2. Among them, high concentration of benzaldehyde helps to form pleasant almond and nut flavors in fish sauce; hexanal has raw oil, grass and apple aroma; 3,5-octadien-2-one tastes fruity, fat and mushroom, which can give the product a unique aroma and flavor and improve the sensory quality of the product.

[0078] like Figure 2 As shown, the photosensitive microorganisms Aspergillus oryzae, Aspergillus niger, Rhizopus arrhizus and Mucorpiriformis in Examples 1 to 3 and Comparative Example 1 are more than those in Comparative Example 2, indicating that the technology of the present invention is conducive to the growth of photosensitive microorganisms.

[0079] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing fish sauce, characterized in that: The following steps are involved: (1) Wash and mince fresh fish meat, add edible salt and mix well to obtain pre-treated meat paste; (2) inoculating activated microorganisms into the pretreated meat paste to perform a primary fermentation; (3) After the primary fermentation is completed, edible salt is added, and a secondary fermentation is performed using temperature and light control facilities, and then insoluble matter is filtered out and sterilized to obtain fish sauce.

2. The method for preparing fish sauce according to claim 1, characterized in that: In step (1), the amount of edible salt added is 8-10% of the mass of the meat paste.

3. The method for preparing fish sauce according to claim 1, characterized in that: In step (2), the inoculation amount of the activated microorganisms is 5 to 10% of the mass of the meat paste.

4. The method for preparing fish sauce according to claim 1, characterized in that: In step (2), the primary fermentation condition is 40-45° C. for 5-10 days.

5. The method for preparing fish sauce according to claim 1, characterized in that: In step (2), the preparation method of the activated microorganisms comprises: soaking, steaming, cooling the soybeans, and then mixing them with the microbial strains and flour, spreading them flat, covering them with wet gauze, and incubating them in a constant temperature and humidity incubator for 72 to 75 hours.

6. The method for preparing fish sauce according to claim 5, characterized in that: The microbial strains are mixed bacteria; the addition amount of the microbial strains is 2-3‰ of the mass of soybeans; the addition amount of flour is 10-12% of the mass of soybeans; the temperature of the constant temperature and humidity incubator is 30-35°C, and the humidity is 80-90RH.

7. The method for preparing fish sauce according to claim 1, characterized in that: In step (3), salt is added continuously until the salt content of the fermented product obtained after one fermentation is 20-25%, w / w.

8. The method for preparing fish sauce according to claim 1, characterized in that: In step (3), the temperature control facility is a heating jacket; the light control facility is an LED lamp, the wavelength of the light is 280-800nm, 100-120W, and the irradiation time is 4-24h per day; the secondary fermentation temperature is 25-45°C.

9. The fish sauce prepared by the method according to any one of claims 1 to 9.

10. The fish sauce according to claim 9, characterized in that Fish sauce contains photosensitive microorganisms, which are one or more of Aspergillus oryzae, Aspergillus niger, Rhizopus arrhizus, and Mucor piriformis.

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