The origin of soy sauce

A liquid condiment brewed from beans, wheat, and bran. Reddish-brown in color, with a unique sauce aroma and delicious taste, it helps stimulate appetite. It is a traditional Chinese condiment.

Development overview Soy sauce evolved and developed from bean paste. The earliest use of the name "soy sauce" in Chinese history was in the Song Dynasty. Lin Hong's "Shanjia Qinggong" recorded that "those with tender leek leaves should be mixed with shredded ginger, soy sauce and dripping vinegar." In addition, ancient soy sauce has other names, such as clear soy sauce, bean paste clear, sauce, sauce, soy sauce, soy sauce, leaching oil, pomelo oil, sun oil, seat oil, volt oil, autumn oil, mother oil, Set oil, double set oil, etc. After 755 AD, soy sauce production technology was introduced to Japan with Master Jianzhen. Later, it was introduced to North Korea, Vietnam, Thailand, Malaysia, the Philippines and other countries.

Production process The raw materials used in soy sauce are plant-based protein and starch. Plant-based protein is generally obtained from soybean cake after soybean oil extraction, or soybean meal after solvent leaching of oil. Peanut cake and broad beans are also used as substitutes. In traditional production, soybeans are mainly used. Starchy raw materials are generally wheat and bran, and some are also shredded. Rice and corn are substituted, and flour is the main ingredient in traditional production. The raw materials are steamed and cooled, and pure cultured Aspergillus oryzae strains are added to make the koji. The koji is moved into a fermentation tank and fermented with salt water. After the fermented sauce is mature, the soy sauce is extracted by leaching. The purpose of making koji is to enable Aspergillus oryzae to fully grow and develop on the koji material, and to produce and accumulate a large amount of required enzymes, such as protease, peptidase, amylase, glutaminase, pectinase, cellulase, and hemicellulose Suzyme etc. The formation of flavor during the fermentation process utilizes the action of these enzymes. For example, protease and peptidase hydrolyze proteins into amino acids, producing umami taste; glutaminase converts extremely tasteless glutamine into umami-flavored glutamic acid; amylase hydrolyzes starch into sugar, producing sweet taste. ; Pectinase, cellulase and hemicellulase can completely rupture the cell wall, allowing protease and amylase to hydrolyze it more thoroughly. At the same time, during the koji making and fermentation processes, yeast and bacteria falling from the air also reproduce and secrete various enzymes. Purely cultured lactobacilli and yeasts can also be added. An appropriate amount of lactic acid is produced by lactic acid bacteria, ethanol is produced by yeast fermentation, and various components such as alcohols, acids, aldehydes, esters, phenols, acetals and furanones produced from raw materials and metabolites of Aspergillus, although most of them are in trace amounts , but it can contribute to the complex aroma of soy sauce. In addition, the tyrosine in the raw protein is oxidized to produce melanin and starch. Classic mold amylase hydrolyzes it into glucose and reacts with amino acids to produce melanoidin, which makes the soy sauce produce a bright and shiny reddish-brown color. A series of extremely complex biochemical changes during the fermentation period produce umami, sweet, sour, winey, estery aromas and the salty taste of salt water, and finally form soy sauce with a unique color, aroma and flavor.

The commonly used low-salt solid-state fermentation process flow is shown in the figure.

Raw material processing is divided into 3 steps. ①Add water and moisturize the cake: the amount of water added shall be based on the moisture content of the koji material reaching 47-50% after steaming. ② Mixing: After moistening the cake, mix it thoroughly with the crushed wheat and bran. ③ Cooking: Use a rotary steamer to steam the material under pressure (0.2MPa) to moderately denature the protein, steam and gelatinize the starch, and kill microorganisms attached to the raw material.

Making music is divided into two steps. ①Cooling inoculation: Rapidly cool the clinker to 45°C, add 0.3-0.4% of the Aspergillus oryzae strain that has been purely expanded and cultured, and mix thoroughly. ② Thick layer ventilation koji making: the inoculated koji material is sent into the koji chamber koji. Intermittent ventilation first, then continuous ventilation. The koji-making temperature is controlled at 30-32°C during the spore germination stage and at a maximum of no more than 35°C during the mycelial growth stage. During this period, turning and shoveling of songs are required. In the early stage of spore emergence, enzyme production is the most vigorous, and the product temperature should be controlled at 30-32°C.

Fermentation: Add 12-13°Be' hot salt water into the fermentation tank and mix it into the fermentation tank. The product temperature is maintained at 42-45°C for about 20 days, and the fermented fermented rice is basically mature.

Leaking oil: Heat the three oils left over from the previous production to 85℃, then put them into mature soy fermented grains for soaking, so that the soy sauce is completely dissolved in it, and then pour the raw soy sauce from the bottom of the fermentation tank. (The head oil is slowly released, and the concentration and salt content are replenished through the salt layer. The oil leaching is to separate the soy sauce and the soy sauce residue. Generally, multiple soaking is used to drain out the head oil, second oil and third oil in sequence, and the soy sauce can be soaked in cycles. Basically all the ingredients are extracted.

Post-processing: The soy sauce is heated to 80-85°C for sterilization and then prepared (blended), clarified and quality inspected to obtain finished products that meet quality standards.

Outlook The soy sauce industry is breaking away from traditional methods and gradually adopting new methods. For example, if the raw materials are continuously steamed, the water-added raw materials are steamed for 3 minutes under a pressure of 0.16-0.18MPa and quickly cooled, which can increase the total nitrogen utilization rate of the raw materials from 75% in the original rotary cooking pot to about 85%; the use of circular cylinders for koji making After the machine is turned on, the koji enzyme activity is high, the quality is good, the labor force is reduced and the working conditions are improved. In addition, mutation breeding to produce excellent new mutant strains and the application of liquid koji are also important development directions.

1 Raw material requirements

1.1 Defatted soybeans should comply with the provisions of GB 1352-86 "Soybeans" and GB 2715-81 "Food Hygiene Standards".

1.2 Wheat should comply with the provisions of GB 1351-78 "Wheat".

1.3 Water Production water should comply with GB 5749-85 "Hygienic Standards for Drinking Water".

1.4 Table salt should comply with the provisions of GB 5461-85 "Edible Salt".

1.5 Food additives should comply with the provisions of GB 2760-86 "Hygienic Standards for the Use of Food Additives".

2 Process flow

┏━━┓ ┏━━━━┓ ┏━━━━━┓ ┏━┓ ┏━━━┓

┃ Zhongqu┃ ┃ Wheat┃ ┃ Defatted soybeans┃ ┃Water┃ ┃ Salt┃

┗┳━┛ ┗━━━━┛ ┗━━┳━━┛ ┗┳┛ ┗━┳ ━┛

┃ ｜ ┃ ┃ ┃

┃ Selected broken pieces ┃ ┃

┃ ｜ ｜ ┃ ┃

┃ Fried wheat mixed with water━━━ ━━━┻━━━━Dissolve

┃ ｜ ｜ ｜

┃ Cooling and cooking brine

┃ ｜ ｜ ┃

┃ Crushing cooling┃

┃ ｜ ┃ ┃

┗━━━━━━━Mixing━━━━━━━━━━┛

┃ ┃

Ventilation to make music┃

┃ ┃

┏━┻━┓ ┃

┃ Complete music┃ ┃

< p> ┗━┳━┛ ┃

┣━━━━━━━━Heating━━━━━━━━━┫

Solid state fermentation┃

< p> ┣━━━━━━━━Heating━━━━━━━━━┛

Insulation dilute fermentation

｜

Room temperature dilute fermentation

┃

┏━━┻━━┓

┃ Ripe soy sauce┃

┗━━┳━━┛

┃

┃ ┏━━━┓

Press filter━━━━┫ Sauce residue┃

┃ ┗━━━┛< /p>

┏━┻━┓

┃raw soy sauce┃

┗━┳━┛

┃ ┏━━┓

Warming━━━━━━Blending━━━━━ Clarification━━━┫Finished product┃

┗━━┛

3 Production methods

3.1 Seed koji manufacturing

3.1.1 Bacteria

3.1.2 Seed koji culture test tube strain → conical strain → koji strain (or quchi , Qubian), expand the training step by step. Test tube strains should be purified and rejuvenated regularly.

3.1.3 Quality requirements

3.1.3.1 Sensory indicators: Spores are clustered, yellow-green, no smell, no pollution.

3.1.3.2 Physical and chemical indicators: Each gram of seed koji (dry basis) contains more than 5×10**9 spores. The spore germination rate is above 90%.

3.2 Raw material processing

3.2.1 Processing of defatted soybeans The crushing degree of defatted soybeans should be uniform in thickness. The particle diameter is required to be 2~3mm, and the amount of powder below 2mm should not exceed 20%.

3.2.1.1 Soaking: Mix the crushed defatted soybeans evenly with hot water at 80-90℃. The amount of water added is 120%-125% of the raw material (defatted soybeans), and soaked for an appropriate time.

3.2.1.2 Steaming process:

a. Steam pressure: 1.5～2.0kg/cm**2;

b. Steam temperature: 125～130℃;

c. Pressure holding time: 5～15min.

3.2.1.3 Clinker quality requirements

a. It is light reddish brown, neither raw nor sticky, loose, has a sweet aroma and elasticity, and has moderate protein denaturation;

< p>b. Digestibility is over 80%;

c. No N-based precipitation.

3.2.2 Treatment of wheat

3.2.2.1 The roasting temperature of wheat is 170℃.

3.2.2.2 The roasted wheat is cooled and then crushed.

3.2.2.3 Crushing particle size: 1~3mm, allowing 35% of the powder to pass through the 32-mesh sieve.

3.2.2.4 Quality standards for roasted and cracked wheat: The moisture content does not exceed 10%. The roasted wheat is light brown in color and has a unique aroma after being crushed.

3.3 Making koji

3.3.1 Inoculation into the pond, mix the steamed defatted soybeans and roasted and cracked wheat evenly, cool to below 40℃, and insert the seed koji. Dosage of seed koji: 2‰~3‰, mix evenly and then transfer to the koji pond to make koji.

3.3.2 Koji-making process conditions

a. Curved layer thickness: 25~30cm;

b. During the koji-making process, the product temperature is controlled at 30 ~32°C, the maximum temperature shall not exceed 35°C;

c. The temperature of the bending chamber is 28~32°C;

d. The relative humidity of the bending chamber is above 90%;

< p>e. The koji making time is 3 days;

f. The koji should be turned over 2 to 3 times during the koji making process.

3.3.3 Quality requirements for the finished koji

a. Sensory requirements: The koji material is loose, soft and elastic, the mycelium is plump, yellow-green, the spores are flying, and it has the unique aroma of the finished koji , no odor.

b. Physical and chemical requirements: Moisture content of the finished koji: 26% to 28%; protease activity of the finished koji should not be less than 1,000 units per gram of koji (dry basis) (Forint method).

3.4 Fermentation

3.4.1 Preparation of salt water Dissolve salt in water and prepare it to the required concentration. After clarification, take the supernatant and use it.

3.4.2 Solid-state fermentation The finished koji and brine are evenly mixed into the fermentation tank for solid-state fermentation. When mixing (mixing), the flow rate of koji and brine must be strictly controlled. Specific gravity of salt water: 12~14°Be'. Specific gravity of salt water: 40~45℃ in summer; 45~50℃ in winter. The ratio of salt water to koji raw materials: 1:1. During solid-state fermentation, keep the product temperature at 40 to 42°C and not exceed 45°C. In order to prevent the fermented grains from oxidizing, the surface of the fermented grains should be sprinkled with salt, and the solid-state fermentation time is 14 days.

3.4.3 Insulated dilute fermentation After 10 to 14 days of solid-state fermentation, add secondary brine. The specific gravity of the secondary brine is 18°Be', and the temperature of the secondary brine is 35~37°C. The amount of the secondary brine added is 1.5 times of the raw materials for making the koji. After adding the secondary brine, the fermented sauce becomes a thin mash, and then the dilute fermentation is carried out. . Insulate and dilute the fermentation, keep the product temperature at 35~37℃, and the fermentation time is 15~20 days. During the dilute fermentation stage of heat preservation, compressed air should be used to stir the mash. At the beginning, stir once a day for 3 to 4 minutes each time. After 4 to 5 days, the mash will rise. After a mash lid is formed on the surface, stir once every 2 to 3 days. , stir until the mash lid disappears, then stop stirring. If the fermentation is strong, the number of stirrings should be increased.

3.4.4 Normal temperature dilute fermentation After the insulation dilute fermentation, the mash is transported to the normal temperature fermentation tank by a pump, and the normal temperature dilute fermentation is carried out at a product temperature of 28 to 30°C for 30 to 100 days. During the dilute fermentation stage at room temperature, the mixture is generally stirred 1 to 2 times a week.

3.4.5 Quality requirements for mature soy sauce mash: Sensory requirements: It has the unique sauce aroma and ester aroma of soy sauce mash. The mash filtrate is reddish brown, clear, transparent, has strong umami flavor, long aftertaste, and no Other odors.

Physical and chemical requirements:

a. The specific gravity of the mash filtrate: 21~22°Be';

b. The salt-free solid content of the mash filtrate is not less than 18g/100mL;

C. The salt of the mash filtrate should not be less than 16g/100mL;

d. The pH should not be less than 4.8.

3.5 Press filtration The mature sauce mash is transported to a press (plate and frame filter press, or hydraulic press, hydraulic press, etc.) for press filtration. All the raw soy sauce separated by pressure filtration flows into the sedimentation tank (pool) and settles for 7 days.

3.6 Heat sterilization: Raw soy sauce should be kept at 5 to 70°C for 30 minutes. For continuous heating, the outlet temperature of the heat exchanger should be controlled at 85°C. The heated soy sauce is then cooled through a heat exchanger. It is generally controlled to cool to 60°C and then transported to a precipitation tank for natural precipitation for 7 days.

3.7 Blending The sterilized soy sauce will be blended according to the soy sauce quality standards.

4 Finished product quality requirements shall be implemented in accordance with the quality standards of ZB X 66012-87 "High Salt Dilute Fermented Soy Sauce".