Production process of microbial fermentation high-salt liquid-state soy sauce

Abstract

The invention relates to the technical field of fermentation engineering, in particular to a preparation process of microbial fermentation high-salt liquid-state soy sauce. Comprising the following components in parts by weight: 10-25 parts of pure yeast extract, 200-800 parts of pure water, 12-28 parts of edible salt, 8-16 parts of xylose, 6-10 parts of edible glucose and 11-25 parts of a food additive, the food additive is prepared from sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1 and DL-methionine, and the mass ratio of the sodium hydroxide to the glycine to the L-cysteine hydrochloride monohydrate to the vitamin B1 to the DL-methionine is 1 to (1.2 to 1.5) to (2 to 3) to (1 to 2) to (1.1 to 1.9). An aspergillus oryzae and lactic acid bacteria synergistic fermentation system is introduced. The preparation process provides a technical path with economical efficiency and environmental protection property for industrial production of the soy sauce.

Description

Technical Field

[0001] The present invention relates to the technical field of fermentation engineering, and more specifically, it relates to a production process for microbial fermentation of high-salt and dilute-state soy sauce. Background Art

[0002] Yeast extract (YE), as a natural flavoring auxiliary material that is nutritious, safe, and healthy, plays an important role in improving food flavor, enhancing food quality and nutritional value. Together with monosodium glutamate (MSG), hydrolyzed protein (HVP, HAP), and inosinic acid disodium (I+G), it is known as the four major seasonings and is widely used in seasonings, meat products, and baked foods. In view of the flavor characteristics of the company's original soy sauce and other seasoning bases, this project aims to develop a series of flavor-type yeast extracts (sauce flavor, meat flavor) and achieve industrial application.

[0003] Yeast extract is a product obtained by enzymatically hydrolyzing and autolyzing (which can be further separated and extracted) food-grade yeast as the main raw material under the action of its own enzymes or externally added food-grade enzymes, and is rich in soluble components in yeast cells such as amino acids, peptides, and polypeptides. A large number of amino acids and nucleotides contained in yeast extract have a significant umami effect, can coordinate and balance flavors, enhance flavors, mask off-flavors, and even generate more umami. As an effective umami substitute, it has been widely used by seasoning production enterprises and is widely used in the production of various powdered seasonings (instant noodle seasoning packets, chicken essence, food flavorings), viscous seasonings (mushroom sauce, Lao Gan Ma, broad bean paste), and liquid flavoring sauces (soy sauce, oyster sauce, edible vinegar).

[0004] As consumers' requirements for the taste and flavor of seasonings are getting higher and higher, the use of yeast extract in seasonings will become a trend in the seasoning industry. As one of the most popular industries for developing new products and opening up differentiated markets, consumers' requirements for flavoring sauces, especially flavor, are becoming increasingly demanding. The development of flavoring sauce products with different flavors will surely be the direction and goal of flavoring sauce research and development.

[0005] Flavor-type yeast extract refers to a product that uses yeast extract as the main raw material and is formulated by adding food ingredients such as maltodextrin, glucose, sodium glutamate, disodium 5'-ribonucleotide, and edible salt as needed, or through processes such as the Maillard reaction to endow the product with a special flavor. Flavor-type yeast extract not only has the advantage of good flavor presentation of yeast extract but also has the characteristic of prominent main flavor of thermal reaction flavor, and is deeply loved by consumers.

[0006] Currently, common flavor-type yeast extracts on the market include chicken flavor, pork flavor, beef flavor, seafood flavor, sauce flavor, etc., which are respectively applied to various soups, sauces, and seasonings, and have achieved good application effects.

[0007] In the prior art, there are the following deficiencies: The fermentation environment of high-salt and dilute-state soy sauce usually has a high salt concentration, which will inhibit the growth of some microorganisms, resulting in a decrease in microbial metabolic activity, an extension of the fermentation cycle, and thus affecting the quality and flavor of soy sauce. During the fermentation process of high-salt and dilute-state soy sauce, the structure and abundance of the microbial community will change significantly, leading to a decrease in the diversity of the microbial community, and further affecting the flavor stability of soy sauce. Summary of the Invention

[0008] The present invention provides a production process for fermenting high-salt and dilute-state soy sauce with microorganisms, by introducing a co-fermentation system of Aspergillus oryzae and lactic acid bacteria. The production process in the present invention provides a technical path with both economic and environmental protection for the industrial production of soy sauce.

[0009] In the first aspect, the present invention provides a flavor-type yeast extract, comprising the following weight components: 10-25 parts of pure yeast extract, 200-800 parts of pure water, 12-28 parts of edible salt, 8-16 parts of xylose, 6-10 parts of edible glucose, 11-25 parts of food additives; the food additives include sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine, and the mass ratio of sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine is 1:1.2-1.5:2-3:1-2:1.1-1.9.

[0010] Preferably, the pure yeast extract includes a sauce-flavor yeast extract and a meat-flavor yeast extract, and the mass ratio of the sauce-flavor yeast extract to the meat-flavor yeast extract is 1-2:2-5.

[0011] Preferably, the pretreatment process of the pure yeast extract is: pouring the pure yeast extract into a reaction tank, adding water, stirring and mixing evenly, and adjusting the pH value to pH = 7.0.

[0012] In the second aspect, the present invention provides a preparation method for a flavor-type yeast extract, comprising the following steps: weighing the pretreated pure yeast extract, pure water, sodium hydroxide, edible salt, glycine, xylose, edible glucose, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine in accordance with the formula weights in sequence, pouring them into a reaction tank, stirring evenly, heating with steam to 90°C - 100°C, maintaining the temperature and stirring for 90 min - 120 min, exhausting gas by opening the air valve, and then cooling to 62°C - 65°C through a plate heat exchanger.

[0013] In the fourth aspect, the present invention provides an application of the flavor-type yeast extract in soy sauce production.

[0014] Fifth aspect, the present invention provides a fermentation method for microbial fermentation of high-salt dilute-state soy sauce, mixing koji with brine at a mass ratio of 1-3:3-5, so that the final concentration of salt content in the system ≤ 12g / 100mL -1 , adding the flavor-type yeast extract, Aspergillus oryzae K9 and lactic acid bacteria described in claim 1, or adding koji for fermentation, and then fermenting at 25-30°C for at least 30 days.

[0015] Preferably, add NaCl in a proportion of 15%-20% to the enzyme solutions of Aspergillus oryzae K9 and lactic acid bacteria, and after dissolution, place the enzyme solutions in a static water bath at 40-50°C for 30-45 min.

[0016] Sixth aspect, the present invention provides a production process for microbial fermentation of high-salt dilute-state soy sauce, including the following steps:

[0017] (1) Koji-making process: Mix defatted soybeans and water evenly, mix them evenly with wheat flour at a mass ratio of 3-5:1-2, add soy sauce koji essence accounting for 1-1.5:1 of the total mass of the mixed raw materials, mix well, and cultivate at 28°C - 30°C, turn the koji in due time, and make koji for 40h - 48h;

[0018] (2) Fermentation process: Mix the koji prepared in step (1) with brine containing NaCl at a volume ratio of 1-3:2-5, so that the final concentration of salt content in the system ≤ 12g / 100mL -1 , add the flavor-type yeast extract described in claim 1 or Aspergillus oryzae K9 and lactic acid bacteria described in claim 6, or add a fermentation agent, wheat koji, bran koji or other types of koji for fermentation, and ferment at 25°C - 30°C for 40 days, and stir in due time during fermentation.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The present invention uses yeast extract as the main raw material, plus certain other substances such as amino acids and reducing sugars, and blends them according to different ratios, and uses the Maillard reaction to produce different sauce flavors and meat flavor substances. The industrial production of this flavor-type yeast extract and its application in seasonings make the product have both realistic meaty and spicy flavors, and at the same time have a sauce flavor and a mellow and full taste, producing a balanced and rich flavor.

[0021] 2. In the process of making soy sauce, the present invention innovatively introduces yeast extract to achieve multiple effects. It not only enhances the umami of soy sauce, effectively reduces the salty and astringent taste, but also optimizes the overall taste, making it more mellow and lasting. In addition, this component helps to shorten the fermentation cycle, improve production efficiency, and at the same time ensure the stability of product quality and the uniqueness of flavor.

[0022] 3. The present invention uses thermal reaction technology to effectively kill microorganisms, ensure the hygienic quality of soy sauce, and extend the shelf life. It promotes chemical reactions to generate new flavor substances, making the flavor of soy sauce more intense, maintaining the bright color of soy sauce, and preventing fading or discoloration.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the protection scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the process flow chart of the present invention;

[0025] Figure 2 is the appearance diagram of the flavor-type yeast extract in the present invention;

[0026] Figure 3 is the growth situation diagram of the Aspergillus oryzae strain on plates with different NaCl contents in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following further elaborates on the present invention in conjunction with embodiments. It should be specifically noted that: for those not specifying specific conditions in the following embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Except for special instructions, the raw materials used in the following embodiments can all be obtained from ordinary commercial sources.

[0028] Embodiments

[0029] Embodiment 1

[0030] A flavor-type yeast extract includes the following weight components: 10 parts of pure yeast extract, 200 parts of pure water, 12 parts of edible salt, 8 parts of xylose, 6 parts of edible glucose, 11 parts of food additives; the food additives include sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine, and the mass ratio of sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine is 1:1.2:2:1:1.1.

[0031] The pure yeast extract includes sauce-flavor yeast extract and meat-flavor yeast extract, and the mass ratio of sauce-flavor yeast extract to meat-flavor yeast extract is 1:2. The pretreatment process of the pure yeast extract is: pour the pure yeast extract into a reaction tank, add water, stir and mix evenly, and adjust the pH value to pH = 7.0.

[0032] A preparation method of a flavor-type yeast extract, comprising the following steps: sequentially weighing pure-type yeast extract, pure water, sodium hydroxide, edible salt, glycine, xylose, edible glucose, L-cysteine hydrochloride monohydrate, vitamin B1, and DL-methionine after pretreatment according to the formula weight, pouring them into a reaction tank, stirring evenly, heating with steam to 90 °C, keeping warm and stirring for 90 min, exhausting air through an air valve, and then cooling to 62 °C through a plate heat exchanger.

[0033] A production process of a microbial-fermented high-salt dilute-state soy sauce, comprising the following steps:

[0034] (1) Koji-making process: Mix defatted soybeans evenly with water, mix them evenly with wheat flour at a mass ratio of 3:1, add soy sauce koji essence accounting for 1:1 of the total mass of the mixed raw materials, mix well, and culture at 28 °C, turning the koji in due time, and making koji for 40 h;

[0035] (2) Fermentation process: Mix the koji prepared in step (1) with brine containing NaCl at a volume ratio of 1:2, so that the final concentration of salt content in the system ≤ 12 g·100 mL -1 , add flavor-type yeast extract Aspergillus oryzae K9 and lactic acid bacteria, or add a fermenting agent, wheat koji, bran koji or other types of fermenting koji, and ferment at 25 °C for 40 days, stirring in due time during fermentation.

[0036] Example 2

[0037] A flavor-type yeast extract, comprising the following weight components: 15 parts of pure-type yeast extract, 500 parts of pure water, 18 parts of edible salt, 10 parts of xylose, 8 parts of edible glucose, 15 parts of food additives; the food additives include sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, and DL-methionine, and the mass ratio of sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, and DL-methionine is 1:1.3:3:1:1.5.

[0038] The pure yeast extract includes a sauce-flavor yeast extract and a meat-flavor yeast extract, and the mass ratio of the sauce-flavor yeast extract to the meat-flavor yeast extract is 2:3. The pretreatment process of the pure yeast extract is: pour the pure-type yeast extract into a reaction tank, add water, stir and mix evenly, and adjust the pH value to pH = 7.0.

[0039] A preparation method of a flavor-type yeast extract, comprising the following steps: successively weighing pure-type yeast extract, pure water, sodium hydroxide, edible salt, glycine, xylose, edible glucose, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine after pretreatment according to the formula weight, pouring them into a reaction tank, stirring well, heating with steam to 90 °C, keeping warm and stirring for 90 min, after opening the air valve to exhaust, cooling to 62 °C through a plate heat exchanger.

[0040] A production process of a microbial fermentation high-salt dilute-state soy sauce, comprising the following steps:

[0041] (1) Koji-making process: Mix defatted soybeans and water evenly, mix them with wheat flour in a mass ratio of 3:2, and then add soy sauce koji essence accounting for 1.5:1 of the total mass of the mixed raw materials. After mixing evenly, cultivate at 28 °C, turn the koji in due time, and make koji for 40 h;

[0042] (2) Fermentation process: Mix the koji prepared in step (1) with brine containing NaCl in a volume ratio of 3:2, so that the final concentration of salt content in the system ≤ 12 g·100 mL -1 , add flavor-type yeast extract or Aspergillus oryzae K9 and lactic acid bacteria, or add fermenting agent, wheat koji, bran koji or other types of fermenting koji, ferment at 30 °C for 40 days, and stir in due time during fermentation.

[0043] Example 3

[0044] A flavor-type yeast extract, comprising the following weight components: 25 parts of pure-type yeast extract, 800 parts of pure water, 28 parts of edible salt, 16 parts of xylose, 10 parts of edible glucose, 25 parts of food additives; the food additives include sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine, and the mass ratio of sodium hydroxide, glycine, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine is 1:1.5:3:2:1.9.

[0045] The pure yeast extract includes sauce-flavor yeast extract and meat-flavor yeast extract, and the mass ratio of the sauce-flavor yeast extract to the meat-flavor yeast extract is 2:5. The pretreatment process of the pure yeast extract is: pour the pure-type yeast extract into a reaction tank, add water again, stir and mix evenly, and adjust the pH value to pH = 7.0.

[0046] A preparation method of a flavor-type yeast extract, comprising the following steps: successively weighing pure-type yeast extract after pretreatment, pure water, sodium hydroxide, edible salt, glycine, xylose, edible glucose, L-cysteine hydrochloride monohydrate, vitamin B1, DL-methionine according to the formula weight, pouring them into a reaction tank, stirring evenly, heating with steam to 100 °C, keeping warm and stirring for 120 min, opening the air valve to exhaust, and then cooling to 65 °C through a plate heat exchanger.

[0047] A production process of a microbial fermentation high-salt dilute-state soy sauce, comprising the following steps:

[0048] (1) Koji-making process: Mix defatted soybeans and water evenly, mix them with wheat flour in a mass ratio of 5:2, add soy sauce koji essence accounting for 1.5:1 of the total mass of the mixed raw materials, mix well, culture at 30 °C, turn the koji in due time, and make koji for 48 h;

[0049] (2) Fermentation process: Mix the koji made in step (1) with brine containing NaCl in a volume ratio of 3:5, so that the final concentration of salt content in the system ≤ 12 g·100 mL -1 , add flavor-type yeast extract or Aspergillus oryzae K9 and lactic acid bacteria, or add a fermentation agent, wheat koji, bran koji or other types of fermentation koji, ferment at 30 °C for 40 days, and stir in due time during fermentation.

[0050] As Figure 1 shown, Figure 1 is the process flow chart of the present invention. The volatile flavor components of the flavor-type yeast extract in the examples are analyzed, and the types of volatile compounds are shown in Table 1-1, and the specific components are shown in Table 1-2.

[0051] Table 1-1 Types of volatile compounds in flavor-type yeast extract

[0052] Classification Quantity Peak area percentage (%) Alcohol 2 2.25 Aldehyde 2 10.74 Ester 3 7.23 Phenol 1 10.88 Heterocyclic compounds 18 65.98 Others 2 2.91 Total 28 100.00

[0053] Table 1-2 Volatile flavor components of flavor-type yeast extract

[0054]

[0055]

[0056] As can be seen from the results, a total of 28 volatile compounds were detected in the flavor-type yeast extract, which can be classified into six categories: alcohols, aldehydes, esters, phenols, heterocycles, and others. Among them, the heterocyclic compounds accounted for the highest proportion, reaching 65.98%. Pyrazine compounds and N- and S-containing heterocyclic compounds are typical products of the Maillard reaction. Secondly, the phenols and aldehydes had relatively high proportions, 10.88% and 10.74% respectively. The flavor substances with the highest proportions were 2,5-dimethylpyrazine (23.64%), 2-ethyl-6-methylpyrazine (20.54%), guaiacol (10.88%), benzaldehyde (8.33%), and ethyl caprate (6.46%). They mainly presented roasted, caramelized, smoky, and fruity aromas. The study found that caramel and smoky aromas are the keys to the overall flavor of soy sauce, while fruity and floral aromas are used to assist in enhancing the flavor of soy sauce, making the aroma of soy sauce more full and harmonious. The flavor-type yeast extract has relevant characteristic flavor substances, and if added to soy sauce, it is expected to promote the formation of its comprehensive flavor.

[0057] The appearance of the flavor-type yeast extract is as Figure 2 shown. The sample was sent to a third-party testing agency, and the index determination results are shown in Table 2. The items tested meet the requirements of the GB / T 20886.2-2021 standard (flavor-type yeast extract).

[0058] Table 2-1 Detection Results of Flavor-Type Yeast Extract

[0059]

[0060] The flavor-type yeast extract was added as an ingredient to soy sauce and boiled, and then the volatile flavor components of the product were analyzed and compared with soy sauce without yeast extract. The results are shown in Tables 3-1 and 3-2.

[0061] A total of 41 volatile compounds were detected in the two soy sauces, which could be classified into 8 categories of substances: alcohols, aldehydes, acids, esters, ketones, phenols, heterocycles, and others. Among them, the substances with the highest proportions were heterocycles, phenols, and aldehydes, with total proportions reaching 89.27% and 82.35% respectively. The substances with the highest proportions in the control soy sauce were 2-acetylpyrrole (15.91%), 4-ethyl-2-methoxyphenol (15.34%), benzaldehyde (10.27%), phenylacetaldehyde (9.23%), and guaiacol (7.56%). The substances with the highest proportions in the test soy sauce were 4-ethyl-2-methoxyphenol (17.53%), 2-acetylpyrrole (15.83%), guaiacol (8.05%), 3-phenylfuran (7.82%), and phenylacetaldehyde (6.72%). After adding the flavor-type yeast extract, the proportion of the peak areas of heterocyclic and phenolic substances in the soy sauce increased, and the proportions of the main volatile components 4-ethyl-2-methoxyphenol and guaiacol increased. The main component of the flavor-type yeast extract, 2,5-dimethylpyrazine, was also detected in the test soy sauce, indicating that the addition of the flavor-type yeast extract played a certain role in enhancing the flavor; the proportion of the peak area of aldehyde substances decreased, and the proportion of the peak area of ester substances increased. Esters mainly present floral and fruity aromas, which is beneficial to making the overall flavor of the soy sauce more harmonious and mellow.

[0062] Table 3-1 Types of Volatile Compounds in Soy Sauce

[0063]

[0064] Table 3-2 Volatile Flavor Components of Soy Sauce

[0065]

[0066]

[0067]

[0068] The Aspergillus oryzae strain was cultured on malt extract agar plates containing 10% and 15% salt at 32 °C for 5 days, and the colony morphology was observed and the colony diameter was measured. The results are as Figure 3 shown in Table 4-1.

[0069] Table 4-1 Colony Diameters (mm) of Aspergillus oryzae Strains on Plates with Different NaCl Contents

[0070]

[0071] From Figure 3As can be seen from Table 4-1, after culturing the four strains in 10% salt for 5 days, the colony morphology of Aspergillus oryzae strains was similar, with more hyphae produced, and the spores were numerous and dense. In contrast, the hyphae of the control strain were shorter, and the colony diameter was reduced by nearly 26% compared to other strains. However, the number of spores did not decrease significantly. After culturing in 15% salt for 5 days, the spores and hyphae of all strains decreased. At this time, the colony diameter of the control strain was reduced by nearly 40% compared to other strains.

[0072] As described above, the above are only exemplary specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A flavor yeast extract, characterized in that: The invention comprises the following components by weight: 10-25 parts of pure yeast extract, 200-800 parts of pure water, 12-28 parts of edible salt, 8-16 parts of xylose, 6-10 parts of edible glucose and 11-25 parts of food additives; the food additives comprise sodium hydroxide, glycine, L-cysteine ​​hydrochloride monohydrate, vitamin B1 and DL-methionine, and the mass ratio of the sodium hydroxide, glycine, L-cysteine ​​hydrochloride monohydrate, vitamin B1 and DL-methionine is 1:1.2-1.5:2-3:1-2:1.1-1.

9.

2. The flavored yeast extract according to claim 1, characterized in that: The pure yeast extract comprises a sauce-flavor yeast extract and a meat-flavor yeast extract, and the mass ratio of the sauce-flavor yeast extract to the meat-flavor yeast extract is 1-2:2-5.

3. The flavored yeast extract according to claim 1, characterized in that: The pretreatment process of the pure yeast extract is as follows: pouring the pure yeast extract into a reaction tank, adding water, stirring and mixing evenly, and adjusting the pH value to pH=7.

0.

4. The method for preparing the flavor yeast extract according to any one of claims 1 to 3, characterized in that: The following steps are involved: The pre-treated pure yeast extract, pure water, sodium hydroxide, edible salt, glycine, xylose, edible glucose, L-cysteine ​​hydrochloride monohydrate, vitamin B1, and DL-methionine are weighed according to the formula weight, poured into the reaction tank, fully stirred, heated to 90°C-100°C through steam, kept warm and stirred for 90min-120min, and after opening the air valve to exhaust, the temperature was cooled to 62°C-65°C through a plate exchanger.

5. Use of the flavor yeast extract according to claim 1 in soy sauce production.

6. A method for producing high-salt dilute soy sauce by microbial fermentation, characterized in that: Mix the koji with salt water in a mass ratio of 1-3:3-5 to make the final concentration of salt in the system ≤12g·100mL -1 , add the flavor yeast extract, Aspergillus oryzae K9 and lactic acid bacteria described in claim 1, or add fermentation koji, and then ferment at 25-30° C. for at least 30 days.

7. The method for producing high-salt dilute soy sauce by microbial fermentation according to claim 6, characterized in that: 15%-20% NaCl is added to the enzyme solution of Aspergillus oryzae K9 and lactic acid bacteria, and after dissolution, the enzyme solution is placed in a water bath at 40-50° C. for 30-45 minutes.

8. A process for producing high-salt dilute soy sauce by microbial fermentation, characterized in that: The following steps are involved: (1) Koji making process: Mix defatted soybeans and water evenly, and mix them evenly with wheat flour at a mass ratio of 3-5:1-2, add soy sauce koji essence accounting for 1-1.5:1 of the total mass of the mixed raw materials, mix well, culture at 28℃-30℃, turn the koji in time, and make the koji for 40h-48h; (2) Fermentation process: The koji prepared in step (1) is mixed with saline containing NaCl in a volume ratio of 1-3:2-5, so that the final concentration of salt content in the system is ≤12g·100mL -1 , add the flavor yeast extract of claim 1 or the Aspergillus oryzae K9 and lactic acid bacteria of claim 6, or add a starter, wheat koji, bran koji or other types of fermentation koji, and ferment at 25°C-30°C for 40 days, stirring at appropriate times during the fermentation period.

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