A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat

Abstract

The invention discloses a method for improving the color, aroma and taste of soy sauce based on soybean and wheat, belongs to the technical field of food seasoning, and solves the problems of poor color, insufficient aroma and freshness, long brewing time, and complex process of soy sauce produced by traditional brewing process. Wheat and soybean are used as raw materials to prepare wheat syrup and salt-free soy sauce crude oil respectively, a part of salt-free soy sauce crude oil is subjected to Maillard reaction with wheat syrup after electrodialysis to obtain reactants, a part of salt-free soy sauce crude oil and wheat syrup are mixed for glutamic acid fermentation to obtain soy sauce base oil, and the reactants are compounded with soy sauce base oil, filtered, and obtained. The invention organically combines glutamic acid fermentation and Maillard reaction, and provides a new method for preparing pure natural original brewed soy sauce without food additives. The product has the special aroma and taste of Maillard reaction at the same time, the product is fresh and natural, has a unique taste, and has excellent color, aroma, taste, and body shape, and has high social benefits and commercial value.

Description

Technical Field

[0001] The invention belongs to the technical field of food condiments and relates to soy sauce, and in particular to a method for improving the color, aroma and taste of soy sauce based on soybeans and wheat. Background Art

[0002] In recent years, as people's living standards have improved, their requirements for the quality and flavor of soy sauce have become higher and higher. "GB 2717-2018 National Food Safety Standard Soy Sauce" redefines soy sauce, stipulating that soy sauce is a liquid condiment with special color, aroma and taste made from soybeans and / or defatted soybeans, wheat and / or wheat flour and / or wheat bran as the main raw materials, fermented by microorganisms. According to this definition, vegetable protein hydrolyzate and sauces produced from raw materials other than soybeans and wheat cannot be called soy sauce.

[0003] Soy sauce produced by traditional brewing process with soybean and wheat as raw materials has the disadvantages of long brewing time, poor color and insufficient freshness. At present, domestic soy sauce manufacturers basically add caramel color to meet the needs of body and coloring effect, and add monosodium glutamate to improve the umami taste of soy sauce. The improvement of soy sauce flavor is mainly achieved through post-blending and adding soy sauce flavor. The above-mentioned method of adding food additives has the following defects: 1) It affects the original flavor of soy sauce and affects the taste to a certain extent; 2) It does not conform to the modern human consumption concept of advocating nature.

[0004] With the continuous growth of my country's national economic level, consumers' health demands are constantly increasing, which also promotes the consumption upgrade of the soy sauce industry. The demand for household soy sauce is transitioning from low-end to high-end products, and high-value-added products such as natural original brewed soy sauce and additive-free soy sauce are becoming more and more popular with consumers. The group standard "T / CNFIA 114-2019 Original Brewed Soy Sauce" issued by the China Food Industry Association proposed the concept of original brewed soy sauce, which is defined as a liquid condiment with special color, aroma and taste made from non-GMO soybeans and (or) non-GMO defatted soybeans (edible soybean meal), wheat and (or) wheat flour and (or) wheat bran as the main raw materials, without adding MSG and food additives (except processing aids for the food industry), and fermented by microorganisms. At present, the industry has conducted a lot of research on substitutes and production process improvements for food additives commonly used in soy sauce.

[0005] Research on caramel color of soy sauce: Chinese patent with publication number CN 104403362A records a method for preparing dark soy sauce, publication number CN 111264836A records a production process for dark soy sauce, and publication number CN111000203A records a color change process for light soy sauce. Although these methods can significantly improve the color of soy sauce, they require the addition of other additional substances, resulting in high production costs and low soy sauce process efficiency.

[0006] Research on improving the aroma and flavor of soy sauce in soy sauce technology: Chinese patent publication number CN1041868A records a multi-enzyme hydrolysis and fermentation flavor enhancement method for rapid brewing of soy sauce, publication number CN 105942450A records a method for improving the flavor of soy sauce by multi-strain synergistic fermentation, and publication number CN 109463713A records a multi-strain fermentation process for improving the flavor of soy sauce, and publication number CN101904486A A method for improving the flavor of soy sauce by using flavoring yeast is recorded, and the publication number CN104982892A records a method for using flavoring yeast in a very fresh soy sauce. Basically, various strains such as flavoring lactic acid bacteria and yeast are added to the soy sauce mash by self-cultivation to achieve the purpose of improving the flavor of soy sauce. Although such methods can effectively shorten the fermentation cycle and enrich the content of aroma substances, they require additional cultivation of one or more microorganisms, which not only increases the production cost, but also has the disadvantages of cumbersome operation and poor process stability in industrial production; the Chinese patent with the publication number CN108185392A records a method for preparing flavoring soy sauce, and the Chinese patent with the publication number CN 111406925A records a flavoring base material, preparation method and flavoring method of soy sauce powder, and the publication number CN Chinese patent No. 104982885A records a method for preparing a flavor base using soy sauce residue as the main raw material. Such methods all add other raw materials to soy sauce to enhance the flavor of the soy sauce. This process not only increases the cost of soy sauce production, but the raw materials often do not meet the requirements of soy sauce and original brewed soy sauce.

[0007] Research on the taste of soy sauce: Chinese patent No. CN 110301617A records soy sauce prepared using corn fermented sauce and its production method, and No. CN 104754961A records a method for preparing IMP fermentation broth or glutamic acid fermentation broth as a raw material for preparing natural flavoring agents, and No. CN 101801217A, records a natural flavor-enhancing umami base and a preparation method thereof, the purpose of which is to enhance the umami taste of soy sauce without including food additives such as monosodium glutamate and flavor nucleotides in the ingredient list. By using grains as raw materials, producing umami components such as glutamate and flavor nucleotides through microbial fermentation, the umami base or flavor base food raw materials are prepared without separation and purification, and added to soy sauce in the form of brewing sauce; these methods partially solve the clean label problem of umami-enhancing food additives not being included in the ingredient list, and the umami base components obtained are of natural origin, but because their production raw materials and production processes are separated from the soy sauce process system, the natural umami components obtained thereby are derived from raw materials other than soy sauce, and are exogenously added, and do not completely belong to the original brewed soy sauce.

[0008] In summary, in order to solve the above-mentioned defects in color, aroma and taste in the traditional soy sauce brewing process, the present invention has developed a method for improving the color, aroma and taste of soy sauce based on soybeans and wheat. Summary of the invention

[0009] The invention aims to solve the shortcomings of soy sauce produced by traditional brewing technology, such as poor color, insufficient aroma and freshness, long brewing time, complicated process, etc., and develops a method for improving the color, aroma and taste of soy sauce based on soybean and wheat.

[0010] The present invention is achieved through the following technical solutions:

[0011] A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat comprises the following steps: using wheat and soybeans as raw materials, respectively preparing wheat syrup and salt-free soy sauce crude oil; subjecting a portion of the salt-free soy sauce crude oil to electrodialysis and then subjecting it to Maillard reaction with the wheat syrup to obtain a reactant; mixing a portion of the salt-free soy sauce crude oil with the wheat syrup to glutamic acid fermentation to obtain a soy sauce base oil; and compounding the reactant with the soy sauce base oil and filtering to obtain the soy sauce base oil.

[0012] Furthermore, after the salt-free soy sauce crude oil is subjected to ion exchange membrane electrodialysis, the ammonium salt amino acid concentrate in the concentration chamber is collected and mixed with wheat syrup in a volume ratio of 3-6:4-7 to carry out Maillard reaction.

[0013] The preparation method of the wheat syrup comprises the following steps:

[0014] (1) Soaking wheat in water and beating the wheat into a wheat slurry with a mass concentration of 10 to 25%;

[0015] (2) Add α-amylase for liquefaction. The amount of enzyme added is 5-10 units per gram of wheat. The liquefaction temperature is 80-95°C and the liquefaction time is 15-40 minutes.

[0016] (3) Adjust the pH to 4.0-5.0, add 100-300 units of saccharifying enzyme per gram of wheat, saccharify at 50-65°C, and saccharify for 15-35 hours;

[0017] (4) Centrifuge the saccharified liquid and collect the supernatant, which is wheat syrup.

[0018] The method for preparing the salt-free soy sauce crude oil comprises the following steps:

[0019] (1) Soak soybeans in water, steam and cool;

[0020] (2) Use closed disc koji making, with a koji making temperature of 28-32°C, a relative humidity of 70%-90%, and a koji making time of 35-45 hours;

[0021] (3) Add water to the koji and ferment at high temperature at 40-50°C for 4-10 days to obtain the mash;

[0022] (4) After the mash is mature, it is filtered through a filter press and the clear liquid is the salt-free soy sauce crude oil.

[0023] The koji making is inoculated with Aspergillus oryzae Shanghai Niang 3.042, and the inoculation amount is 0.02% to 0.06%.

[0024] The electrodialysis method of the salt-free soy sauce crude oil comprises the following steps:

[0025] (1) Add unsalted soy sauce crude oil into the desalting chamber of ion exchange membrane electrodialysis, add an equal volume of water into the concentrating chamber, and add 1% to 3% mass fraction of sodium sulfate solution into the electrode chamber;

[0026] (2) Desalination voltage 7V~15V, operating current 2.5~3.5A, soy sauce circulation flow rate 3~8cm / s, cyclic desalination, desalination time 5min~20min;

[0027] (3) Collect the ammonium salt amino acid concentrate in the concentration chamber and carry out the Maillard reaction.

[0028] The glutamate fermentation is carried out by mixing wheat syrup, salt-free soy sauce crude oil and low sodium salt in a mass ratio of 50-70:30-70:0.1-2.

[0029] The glutamate fermentation is inoculated with a temperature-sensitive Corynebacterium glutamicum seed culture solution, with an inoculation amount of 5-15%, a temperature of 30-38°C, and food-grade ammonia water or NaOH is used to control the fermentation pH to 7.0-7.5 in stages.

[0030] The reactant is compounded with the soy sauce base oil, wherein the added mass of the reactant is 3% to 10% of the soy sauce base oil.

[0031] The present invention uses wheat and soybean as raw materials, wherein soybean is preferably non-genetically modified soybean, and prepares wheat syrup and salt-free soy sauce crude oil respectively according to traditional processes to produce soy sauce base oil, and the salt-free soy sauce crude oil is subjected to electrodialysis desalination and Maillard reaction with wheat syrup, and then compounded, so as to obtain natural original brewed soy sauce without adding any food additives. Electrodialysis technology is used in the traditional soy sauce industry to remove edible salt to reduce the content of NaCl in soy sauce, but since this technology causes a large loss of amino acids, lactic acid and acetic acid, it will have an adverse effect on the flavor of soy sauce, resulting in reduced soy sauce quality; the present invention is beneficial to the feature of electrodialysis technology, and salt-free soy sauce is prepared by electrodialysis technology to obtain one of the substrates for Maillard reaction, ammonium salt and amino acid solution, that is, the substrates of the Maillard reaction of the present invention are all derived from the raw materials wheat and soybeans specified in the national standard of soy sauce; after the salt-free soy sauce crude oil and wheat syrup are mixed, glutamic acid fermentation is carried out by using the fermentation acid production characteristics of temperature-sensitive Corynebacterium glutamicum.

[0032] Compared with the prior art, the present invention has the following characteristics:

[0033] (1) The Maillard reaction is carried out using wheat syrup and ammonium salt amino acid solution produced by electrodialysis, without the need to add additional caramel color, thereby greatly improving the color of soy sauce and achieving an ideal coloring effect;

[0034] (2) The present invention prepares soy sauce from wheat and soybeans. No monosodium glutamate or flavor nucleotides are added during the production process. The aroma components of soy sauce and flavor substances with a burnt aroma are produced through the Maillard reaction, thereby improving the quality of soy sauce in terms of aroma.

[0035] (3) The present invention utilizes the fermentation and acid production characteristics of temperature-sensitive Corynebacterium glutamicum to carry out glutamate fermentation, thereby greatly improving the umami taste of soy sauce.

[0036] In summary, the present invention organically combines glutamate fermentation and Maillard reaction, provides a new method for preparing pure natural original brewed soy sauce without food additives, the production process is mild and safe, and no three wastes are discharged; the product also has the special aroma and taste of the Maillard reaction, the product is fresh and natural, the taste is unique, the color, aroma, taste and shape are all excellent, and it has high social benefits and commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Process flow chart of the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0039] Example 1

[0040] A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat, the process flow is as follows Figure 1 As shown, the steps are:

[0041] A. Preparation of wheat syrup:

[0042] ⑴ Mix 100 kg wheat with water and soak for 2 hours;

[0043] ⑵ Use a pulping machine to grind wheat slurry with a concentration of 20%;

[0044] ⑶ Add high temperature α-amylase for liquefaction, the enzyme addition amount is 7 units per gram of wheat, the liquefaction temperature is 90℃, the liquefaction time is 30min, and the liquefaction is terminated when the hydrolyzate iodine reaction turns yellow-brown;

[0045] (4) Adjust the solution pH to 4.5, add 200 units of saccharifying enzyme per gram of wheat, saccharify at 55°C, and saccharify for 25 hours;

[0046] ⑸ Centrifuge the saccharified liquid at a speed of 4000r / min for 15min, and the supernatant is the wheat syrup;

[0047] (6) The concentration of glucose after saccharification was 12 g / 100 mL, the glucose yield (glucose / wheat) was 60%, the glucose / reducing sugar was 98%, and the glucose recovery rate was 76.7%.

[0048] B. Preparation of salt-free soy sauce crude oil:

[0049] ⑴ Select 500 kg of full, large, golden non-GMO soybeans, soak them in water for 6 hours;

[0050] ⑵ Heating and cooking at 110℃ for 20min;

[0051] ⑶ After cooling, add Aspergillus oryzae Shanghai Brew 3.042 and mix, the inoculation amount is 0.04% (i.e. add 0.4g of koji per kilogram of soybean);

[0052] (4) Making koji using a closed disc, with a temperature of 30°C, a relative humidity of 80%, and a time of 40 hours;

[0053] ⑸ Add twice the volume of water to the koji and start high temperature fermentation at 45°C for 5 days, stirring every 12 hours;

[0054] (6) After the mash is mature, it is filtered by a conventional filter press, and the clear liquid is the salt-free soy sauce crude oil;

[0055] ⑺ The unsalted soy sauce crude oil was tested and found to have soluble salt-free solids of 18 g / 100mL, total nitrogen (calculated as nitrogen) of 1.8 g / 100mL, amino acid nitrogen (calculated as nitrogen) of 1.05 g / 100mL, and ammonium salt (calculated as nitrogen) of 0.3 g / 100mL.

[0056] C. Electrodialysis:

[0057] (1) Using the commonly used electrodialysis desalination device, the electrodialyzer is selected to be equipped with a domestic ion exchange membrane, the desalting chamber (i.e., the desalting chamber) is added with unsalted soy sauce crude oil, the concentration chamber (i.e., the concentration chamber) is added with an equal volume of deionized water, and the electrode chamber is added with a 2% mass fraction of sodium sulfate solution as the cathode liquid and the anode liquid;

[0058] (2) The electrodialysis device was turned on, and electrodialysis desalination treatment was performed at a constant voltage of 12 V, an operating current of 3.0 A, a soy sauce circulation flow rate of 5 cm / s, and normal temperature and pressure. The desalination time was 15 min, and the cathode liquid, the anode liquid, the desalted liquid, and the concentrated liquid were continuously circulated by a pump. During the circulation process, the ammonium salt and some ionized amino acid components in the soy sauce as the desalted liquid were transferred to the concentration chamber, so that the ammonium salt and some amino acids were separated from the soy sauce, and the ammonium salt and some amino acids were successfully enriched and collected to obtain an ammonium salt amino acid liquid;

[0059] The treated ammonium salt amino acid concentrate was tested to have an amino acid nitrogen content (in terms of nitrogen) of 0.5 g / 100 mL and an ammonium salt content (in terms of nitrogen) of 0.3 g / 100 mL.

[0060] D. Maillard reaction

[0061] ⑴ Mix wheat syrup and ammonium salt amino acid solution in a volume ratio of 6:4, mix well, and the pH of the mixed solution is about 6.2;

[0062] ⑵ The mixed solution was concentrated to 1 / 4 of the original volume by evaporation under reduced pressure, so that the dry matter (i.e. solid content) of the final concentrated solution was 45%;

[0063] ⑶ Carry out Maillard reaction (thermal reaction) under closed conditions, select a thermal reactor, control the thermal reaction conditions, the processing temperature is 135°C, and the processing time is 45 minutes;

[0064] (4) After the heat treatment is completed, the hot reaction liquid is cooled to room temperature to obtain flavor substances with special roasted and burnt aromas, with a color rate of 41,000 EBC and a red index of 5.1.

[0065] E. Glutamate fermentation

[0066] ⑴ The slant culture medium is LB medium: tryptone 10 g / L, yeast extract 5 g / L, sodium chloride (NaCl) 10 g / L, agar powder 17 g / L, the pH of the culture medium is adjusted to 7.0 with NaOH, the strain is the temperature-sensitive Corynebacterium glutamicum with high L-glutamic acid production, the slant culture temperature is 32°C, and the culture time is 18h;

[0067] ⑵ The composition of the shake flask seed culture medium (by weight): 20 parts of wheat syrup, 7 parts of unsalted soy sauce crude oil, 0.5 parts of low sodium salt, 72.5 parts of water, the low sodium salt is a mixed edible salt containing only 65% ​​sodium chloride, 25% potassium chloride and 10% magnesium sulfate, and the following low sodium salts are the same. Select 1 ring of Corynebacterium glutamicum strain preserved on a slant, add it to a volume of 150mL seed culture medium, and culture it at 32°C, 110r / min reciprocating shaker for 15h to obtain a primary seed solution. The absorbance value of the seed solution is OD 620 is 0.5 (diluted 26 times), and the bacteria are short, thick, and mostly arranged in a figure eight shape under microscope;

[0068] ⑶ Preparation of fermentation medium (by weight): 60 parts of wheat syrup, 50 parts of unsalted soy sauce crude oil, 0.5 parts of low sodium salt, heat sterilize, inoculate the fermenter with the first-grade seed liquid at an inoculation rate of 10%;

[0069] Fermentation culture conditions are: ventilation and stirring, liquid deep fermentation, temperature control at 32°C in the first stage and 38°C in the second stage, fermentation pH controlled at 7.2 in stages using food-grade ammonia or NaOH, ventilation volume of 0.2-1.5 vvm (v / v·min), stirring speed of 50-300 r / min, fermentation time of 40 h, fermentation liquid is soy sauce-based oil, and the glutamate content is 39 g / L after testing.

[0070] F. Mixing

[0071] The obtained Maillard reaction product is mixed with soy sauce base oil, wherein the amount of the Maillard reaction product added is 5% of the weight percentage of the soy sauce base oil. The composite liquid is then subjected to ultrafiltration to remove bacteria and large particles, and is heated and sterilized to obtain a finished soy sauce product.

[0072] The finished soy sauce product obtained in Example 1 was analyzed, and the results are shown in Table 1.

[0073] Table 1 Product quality standards and product specifications

[0074]

[0075] As can be seen from Table 1, the soy sauce product prepared by the present invention is rich in small peptides and amino acids (mainly glutamic acid), and has the special aroma and taste of the Maillard reaction. The product is fresh and natural, has a unique taste, and is excellent in color, aroma, taste, and body. The amino acid nitrogen and total nitrogen meet and exceed the national standards and the quality standards of original brewed soy sauce. Compared with commercially available soy sauce, the ingredients are more natural, no food additives need to be added, the product is healthier, and has high social benefits and commercial value.

[0076] Example 2

[0077] A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat:

[0078] A. Preparation of wheat syrup:

[0079] ⑴ Mix 150 kg wheat with water and soak for 4 hours;

[0080] ⑵ Use a pulping machine to grind the wheat pulp into a 25% concentration of wheat pulp;

[0081] ⑶ Add high temperature α-amylase for liquefaction, the enzyme addition amount is 10 units per gram of wheat, the liquefaction temperature is 95°C, the liquefaction time is 15 minutes, and the liquefaction is terminated when the iodine reaction of the hydrolyzate turns yellow-brown;

[0082] (4) Adjust the solution pH to 5.0, add 300 units of saccharifying enzyme per gram of wheat, saccharify at 65°C, and saccharify for 35 hours;

[0083] ⑸ Centrifuge the saccharified liquid at a speed of 6000r / min for 10min, and the supernatant is the wheat syrup;

[0084] (6) The concentration of glucose after saccharification was 15g / 100mL, the glucose yield (glucose / wheat) was 60%, the glucose / reducing sugar was 98%, and the glucose recovery rate was 76.8%.

[0085] B. Preparation of salt-free soy sauce crude oil:

[0086] ⑴ Select 600 kg of full, large, golden non-GMO soybeans, soak them in water for 8 hours;

[0087] ⑵ Heating and cooking at 120℃ for 15min;

[0088] ⑶ After cooling, add Aspergillus oryzae Shanghai Brew 3.042 and mix, the inoculation amount is 0.06% (i.e. add 0.6g of seed koji per kilogram of soybean);

[0089] (4) Making koji using a closed disc, with a temperature of 32°C, a relative humidity of 90%, and a time of 35h;

[0090] ⑸ Add twice the volume of water to the koji and start high temperature fermentation at 50℃ for 4 days, stirring every 12 hours;

[0091] (6) After the mash is mature, it is filtered by a filter press, and the clear liquid is the salt-free soy sauce crude oil;

[0092] ⑺ The unsalted soy sauce crude oil was tested and found to have soluble salt-free solids of 18.2 g / 100mL, total nitrogen (calculated as nitrogen) of 1.85 g / 100mL, amino acid nitrogen (calculated as nitrogen) of 1.09 g / 100mL, and ammonium salt (calculated as nitrogen) of 0.25 g / 100mL.

[0093] C. Electrodialysis:

[0094] (1) Using the commonly used electrodialysis desalination device, the electrodialyzer is selected to be installed with a domestic ion exchange membrane. Add salt-free soy sauce crude oil to the desalting chamber (i.e., the desalting chamber), add an equal volume of deionized water to the concentration chamber (i.e., the concentration chamber), and add 3% mass fraction sodium sulfate solution, i.e., the cathode liquid and the anode liquid, to the electrode chamber;

[0095] (2) The electrodialysis device was turned on, and electrodialysis desalination treatment was performed at a constant voltage of 15 V, an operating current of 2.5 A, a soy sauce circulation flow rate of 8 cm / s, and normal temperature and pressure. The desalination time was 5 min, and the cathode liquid, the anode liquid, the desalted liquid, and the concentrated liquid were continuously circulated by a pump. During the circulation process, the ammonium salt and some ionized amino acid components in the soy sauce as the desalted liquid were transferred to the concentration chamber, so that the ammonium salt and some amino acids were separated from the soy sauce, and the ammonium salt and some amino acids were successfully enriched and collected to obtain an ammonium salt amino acid liquid;

[0096] The treated ammonium salt amino acid concentrate was tested to have an amino acid nitrogen content (in terms of nitrogen) of 0.6 g / 100 mL and an ammonium salt content (in terms of nitrogen) of 0.25 g / 100 mL.

[0097] D. Maillard reaction

[0098] ⑴ Mix wheat syrup and ammonium salt amino acid solution in a volume ratio of 3:7, mix well, and the pH of the mixed solution is about 6.3;

[0099] ⑵ The mixed solution was concentrated to 1 / 5 of the original volume by evaporation under reduced pressure, so that the dry matter (i.e. solid content) of the final concentrated solution was 48%;

[0100] ⑶ Carry out Maillard reaction (thermal reaction) under closed conditions, use a thermal reactor, control the thermal reaction conditions, the processing temperature is 125°C, and the processing time is 60 minutes;

[0101] (4) After the heat processing is completed, the hot reaction liquid is cooled to room temperature to obtain flavor substances with special roasted and burnt aromas, with a color rate of 38,000 EBC and a red index of 4.7.

[0102] E. Glutamate fermentation

[0103] ⑴ The slant culture medium is LB medium: tryptone 10 g / L, yeast extract 5 g / L, sodium chloride (NaCl) 10 g / L, agar powder 17 g / L, the pH of the culture medium is adjusted to 7.2 with NaOH, the strain is the temperature-sensitive glutamicum Corynebacterium glutamicum with high L-glutamic acid production, the slant culture temperature is 30°C, and the culture time is 24h;

[0104] ⑵ The composition of the shake flask seed culture medium (by weight): 15 parts of wheat syrup, 5 parts of salt-free soy sauce crude oil, 0.5 parts of low sodium salt, 79.5 parts of water, the low sodium salt is a mixed edible salt containing only 65% ​​sodium chloride, 25% potassium chloride and 10% magnesium sulfate, and the following low sodium salts are the same. Select 1 ring of Corynebacterium glutamicum strain preserved on a slant, add it to a volume of 120mL seed culture medium, and culture it at 32°C, 110r / min reciprocating shaker for 16h to obtain a primary seed solution. The absorbance value of the seed solution is OD 620 is 0.55 (diluted 26 times), and the bacteria are short, stout, and mostly arranged in a figure eight shape under microscope;

[0105] ⑶ Preparation of fermentation medium (by weight): 50 parts of wheat syrup, 70 parts of unsalted soy sauce crude oil, 0.1 parts of low sodium salt, heat sterilize, inoculate the fermenter with the first-grade seed liquid at an inoculation rate of 5%;

[0106] Fermentation culture conditions are: ventilation and stirring, liquid deep fermentation, temperature control at 30°C in the first stage and 37°C in the second stage, fermentation pH controlled at 7.0 in stages using food-grade ammonia or NaOH, ventilation volume of 0.2-1.5 vvm (v / v·min), stirring speed of 50-300 r / min, fermentation time of 48 h, fermentation liquid is soy sauce-based oil, and the glutamate content is 37 g / L after testing.

[0107] F. Mixing

[0108] The obtained Maillard reaction product is mixed with soy sauce base oil, wherein the amount of the Maillard reaction product added is 3% of the weight percentage of the soy sauce base oil. The composite liquid is then subjected to ultrafiltration to remove bacteria and large particles, and is heated and sterilized to obtain a finished soy sauce product.

[0109] The finished soy sauce product obtained in Example 2 was analyzed, and the results are shown in Table 2.

[0110] Table 2 Product quality standards and product specifications

[0111]

[0112] As can be seen from Table 2, the soy sauce product prepared by the present invention is rich in small peptides and amino acids (mainly glutamic acid), and has the special aroma and taste of the Maillard reaction. The product is fresh and natural, has a unique taste, and is excellent in color, aroma, taste, and body. Both amino acid nitrogen and total nitrogen meet and exceed national standards and the quality standards of original brewed soy sauce. Compared with commercially available soy sauce, the ingredients are more natural, no food additives need to be added, the product is healthier, and has high social benefits and commercial value.

[0113] Example 3

[0114] A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat:

[0115] A. Preparation of wheat syrup:

[0116] ⑴ 80 kg of wheat mixed with water and soaked for 1.5 hours;

[0117] ⑵ Use a pulping machine to grind the wheat pulp into a 10% concentration of wheat pulp;

[0118] ⑶ Add high temperature α-amylase, the enzyme addition amount is 5 units per gram of wheat, the liquefaction temperature is 80℃, the liquefaction time is 40min, and the liquefaction is terminated when the iodine reaction of the hydrolyzate turns yellow-brown;

[0119] (4) Adjust the solution pH to 4.0, add 100 units of saccharifying enzyme per gram of wheat, saccharify at 50°C, and saccharify for 15 hours;

[0120] ⑸ Centrifuge the saccharified liquid at a speed of 3000r / min for 25min, and the supernatant is the wheat syrup;

[0121] (6) After saccharification, the concentration of glucose was 5.9 g / 100 mL, the glucose yield (glucose / wheat) was 59%, the glucose / reducing sugar was 95%, and the glucose recovery rate was 74.9%.

[0122] B. Preparation of salt-free soy sauce crude oil:

[0123] ⑴ Select 500 kg of full, large, golden non-GMO soybeans, soak them in water for 4 hours;

[0124] ⑵ Heating and steaming at 100℃ for 30min;

[0125] ⑶ After cooling, add Aspergillus oryzae Shanghai Brew 3.042 and mix, the inoculation amount is 0.02% (i.e. add 0.2g of koji per kilogram of soybean);

[0126] (4) Making koji using a closed disc, with a temperature of 28°C, a relative humidity of 70%, and a time of 45 hours;

[0127] ⑸ Add twice the volume of water to the koji and start high temperature fermentation at 40°C for 10 days, stirring every 12 hours;

[0128] (6) After the mash is mature, it is filtered by a conventional filter press, and the clear liquid is the salt-free soy sauce crude oil;

[0129] ⑺ The unsalted soy sauce crude oil was tested and found to have soluble salt-free solids of 17.8 g / 100mL, total nitrogen (calculated as nitrogen) of 1.6 g / 100mL, amino acid nitrogen (calculated as nitrogen) of 0.8 g / 100mL, and ammonium salt (calculated as nitrogen) of 0.3 g / 100mL.

[0130] C. Electrodialysis:

[0131] (1) Using the commonly used electrodialysis desalination device, the electrodialyzer is selected to be installed with a domestic ion exchange membrane, the desalting chamber (i.e., the desalting chamber) is added with unsalted soy sauce crude oil, the concentration chamber (i.e., the concentration chamber) is added with an equal volume of deionized water, and the electrode chamber is added with a 1% mass fraction sodium sulfate solution as the cathode liquid and the anode liquid;

[0132] (2) The electrodialysis device was turned on, and electrodialysis desalination treatment was performed at a constant voltage of 7 V, an operating current of 3.5 A, a soy sauce circulation flow rate of 3 cm / s, and normal temperature and pressure. The desalination time was 20 min, and the cathode liquid, the anode liquid, the desalted liquid, and the concentrated liquid were continuously circulated by the pump. During the circulation process, the ammonium salt and some ionized amino acid components in the soy sauce as the desalted liquid were transferred to the concentration chamber, so that the ammonium salt and some amino acids were separated from the soy sauce, and the ammonium salt and some amino acids were successfully enriched and collected to obtain an ammonium salt amino acid liquid;

[0133] The treated ammonium salt amino acid concentrate was tested and found to have amino acid nitrogen (in terms of nitrogen) of 0.55 g / 100 mL and ammonium salt (in terms of nitrogen) of 0.32 g / 100 mL.

[0134] D. Maillard reaction

[0135] ⑴ Mix wheat syrup and ammonium salt amino acid solution in a volume ratio of 5:5, mix well, and the pH of the mixed solution is about 6.5;

[0136] ⑵ The mixed solution was concentrated to 1 / 6 of the original volume by evaporation under reduced pressure, so that the dry matter (i.e. solid content) of the final concentrated solution was 40%;

[0137] ⑶ Carry out Maillard reaction (thermal reaction) under closed conditions, select a thermal reactor, control the thermal reaction conditions, the processing temperature is 110°C, and the processing time is 120min;

[0138] (4) After the heat treatment is completed, the hot reaction liquid is cooled to room temperature to obtain a flavor substance with a special roasted aroma and a caramelized aroma, a color rate of 35,000 EBC, and a red index of 4.4.

[0139] E. Glutamate fermentation

[0140] ⑴ The slant culture medium is LB medium: tryptone 10 g / L, yeast extract 5 g / L, sodium chloride (NaCl) 10 g / L, agar powder 17 g / L, the pH of the culture medium is adjusted to 7.5 with NaOH, the strain is the temperature-sensitive glutamicum Corynebacterium glutamicum with high L-glutamic acid production, the slant culture temperature is 33°C, and the culture time is 16h;

[0141] ⑵ The composition of the shake flask seed culture medium (by weight): 40 parts of wheat syrup, 10 parts of salt-free soy sauce crude oil, 0.5 parts of low sodium salt, 49.5 parts of water, the low sodium salt is a mixed edible salt containing only 65% ​​sodium chloride, 25% potassium chloride and 10% magnesium sulfate, and the following low sodium salts are the same. Select 1 ring of Corynebacterium glutamicum strain preserved on a slant, add it to a volume of 100 mL of seed culture medium, and culture it at 33°C, 110r / min reciprocating shaker for 14h to obtain a primary seed solution. The absorbance value of the seed solution is OD 620 is 0.65 (diluted 26 times), and the bacteria are short, stout, and mostly arranged in a figure eight shape under microscope observation;

[0142] ⑶ Preparation of fermentation medium (by weight): 70 parts of wheat syrup, 30 parts of unsalted soy sauce crude oil, 2 parts of low sodium salt, heat sterilize, inoculate the fermenter with the first-grade seed liquid at an inoculation rate of 15%;

[0143] Fermentation culture conditions are: ventilation and stirring, liquid deep fermentation, temperature control at 31°C in the first stage and 38°C in the second stage, fermentation pH controlled at 7.5 in stages using food-grade ammonia or NaOH, ventilation volume of 0.2-1.5 vvm (v / v·min), stirring speed of 50-300 r / min, fermentation time of 50 h, fermentation liquid is soy sauce-based oil, and the glutamate content is 2.2 g / L after testing.

[0144] F. Mixing

[0145] The obtained Maillard reaction product is mixed with soy sauce base oil, wherein the amount of the Maillard reaction product added is 10% of the weight percentage of the soy sauce base oil. The composite liquid is then subjected to ultrafiltration to remove bacteria and large particles, and is heated and sterilized to obtain a finished soy sauce product.

[0146] The finished soy sauce product obtained in Example 3 was analyzed. The results are shown in Table 3.

[0147] Table 3 Product quality standards and product specifications

[0148]

[0149] It can be seen from Table 3 that the soy sauce product prepared by the present invention is rich in small peptides and amino acids (mainly glutamic acid), and has the special aroma and taste of the Maillard reaction. The product is fresh and natural, has a unique taste, and is excellent in color, aroma, taste, and body. Both amino acid nitrogen and total nitrogen meet and exceed national standards and the quality standards of original brewed soy sauce. Compared with commercially available soy sauce, the ingredients are more natural, no food additives need to be added, the product is healthier, and has high social benefits and commercial value.

[0150] The specific implementation methods described above further explain the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only preferred embodiments of the present invention and do not limit the scope of protection of the present invention. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content proposed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the scope of protection of the present invention.

Claims

1. A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat, characterized in that: The method uses wheat and soybean as raw materials, prepares wheat syrup and salt-free soy sauce crude oil respectively, collects ammonium salt amino acid concentrate in a concentration chamber after a part of the salt-free soy sauce crude oil is subjected to ion exchange membrane electrodialysis, mixes it with wheat syrup in a volume ratio of 3-6:4-7 to carry out Maillard reaction to obtain reactants, mixes a part of the salt-free soy sauce crude oil with wheat syrup to carry out glutamic acid fermentation to obtain soy sauce base oil, and composites the reactants with the soy sauce base oil, filters, and obtains the product; The preparation method of wheat syrup comprises the following steps: (1) soaking wheat in water and beating wheat to obtain wheat slurry with a mass concentration of 10-25%; (2) adding α-amylase for liquefaction, wherein the amount of enzyme added is 5-10 units per gram of wheat, the liquefaction temperature is 80-95°C, and the liquefaction time is 15-40 minutes; (3) adjusting the pH 4.0-5.0, the amount of saccharifying enzyme added is 100-300 units per gram of wheat, the saccharification temperature is 50-65°C, and the saccharification time is 15h-35h; (4) the saccharification liquid is centrifuged, and the supernatant is collected, which is the wheat syrup; the preparation method of the salt-free soy sauce crude oil comprises the following steps: (1) soybeans are soaked in water and then steamed and cooled; (2) a closed disc is used to make koji, the koji making temperature is 28-32°C, the relative humidity is 70%-90%, and the koji making time is 35-45h; (3) water is added to the koji, and high-temperature fermentation is performed at a temperature of 40-50°C for 4-10 days to obtain a sauce mash; (4) after the sauce mash is mature, it is filtered by a conventional filter press, and the clear liquid is the salt-free soy sauce crude oil; The glutamate fermentation is carried out by mixing wheat syrup, salt-free soy sauce crude oil and low sodium salt in a mass ratio of 50-70:30-70:0.1-2. The glutamate fermentation is inoculated with a seed culture solution of a temperature-sensitive glutamicum bacteria with high L-glutamate production, with an inoculation amount of 5-15%, a temperature of 30-38°C, and a fermentation pH of 7.0-7.5 is controlled in stages using food-grade ammonia water or NaOH.

2. A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat, characterized in that: The method uses wheat and soybean as raw materials, prepares wheat syrup and salt-free soy sauce crude oil respectively, collects ammonium salt amino acid concentrate in a concentration chamber after a part of the salt-free soy sauce crude oil is subjected to ion exchange membrane electrodialysis, mixes it with wheat syrup in a volume ratio of 3-6:4-7 to carry out Maillard reaction to obtain reactants, mixes a part of the salt-free soy sauce crude oil with wheat syrup to carry out glutamic acid fermentation to obtain soy sauce base oil, and composites the reactants with the soy sauce base oil, filters, and obtains the product; The preparation method of wheat syrup comprises the following steps: (1) soaking wheat in water and beating wheat to obtain wheat slurry with a mass concentration of 10-25%; (2) adding α-amylase for liquefaction, wherein the amount of enzyme added is 5-10 units per gram of wheat, the liquefaction temperature is 80-95°C, and the liquefaction time is 15-40 minutes; (3) adjusting the pH 4.0-5.0, the amount of saccharifying enzyme added is 100-300 units per gram of wheat, the saccharification temperature is 50-65°C, and the saccharification time is 15h-35h; (4) the saccharification liquid is centrifuged, and the supernatant is collected, which is the wheat syrup; the preparation method of the salt-free soy sauce crude oil comprises the following steps: (1) soybeans are soaked in water and then steamed and cooled; (2) a closed disc is used to make koji, the koji making temperature is 28-32°C, the relative humidity is 70%-90%, and the koji making time is 35-45h; (3) water is added to the koji, and high-temperature fermentation is performed at a temperature of 40-50°C for 4-10 days to obtain a sauce mash; (4) after the sauce mash is mature, it is filtered by a conventional filter press, and the clear liquid is the salt-free soy sauce crude oil; The glutamate fermentation is carried out by mixing wheat syrup, salt-free soy sauce crude oil and low sodium salt in a mass ratio of 50-70:30-70:0.1-2. The glutamate fermentation is inoculated with a seed culture solution of a temperature-sensitive glutamicum bacteria with high L-glutamate production, with an inoculation amount of 5-15%, a temperature of 30-38°C, and a fermentation pH of 7.0-7.5 is controlled in stages using food-grade ammonia water or NaOH.

3. A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat according to claim 1, characterized in that: The koji making is inoculated with Aspergillus oryzae Shanghai Niang 3.042, and the inoculation amount is 0.02% to 0.06%.

4. A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat according to claim 1 or 2, characterized in that: The electrodialysis method of the salt-free soy sauce crude oil comprises the following steps: (1) Add unsalted soy sauce crude oil into the desalting chamber of ion exchange membrane electrodialysis, add an equal volume of water into the concentrating chamber, and add 1% to 3% mass fraction of sodium sulfate solution into the electrode chamber; (2) Desalination voltage 7V~15V, operating current 2.5~3.5A, soy sauce circulation flow rate 3~8cm / s, cyclic desalination, desalination time 5min~20min; (3) Collect the ammonium salt amino acid concentrate in the concentration chamber and carry out the Maillard reaction.

5. A method for improving the color, aroma and taste of soy sauce based on soybeans and wheat according to claim 1 or 2, characterized in that: The reactant is compounded with the soy sauce base oil, wherein the added mass of the reactant is 3% to 10% of the soy sauce base oil.

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