traditional fermentative method of Soy Sauce production

1. FERMENTATIVE PRODUCTION OF
SOY SAUCE
PRESENTED BY: KOMAL (21396007)
FST, I YR

2. WHAT IS SOYA SAUCE?
• Soya sauce is a liquid condiment produced by fermenting soyabeans
with Aspergillus oryzae or Aspergillus sojae molds along with roasted
grains, water and salts.
• It has light brown to black colour with a salty and intense umami taste.
• Originated from China in 2000 BC, but popularized worldwide by Japan
(Kikkoman)
• A traditional ingredient in in East and Southeast Asian cuisines.
• It enhances the flavor and adds to color of meats, sea foods and
vegetables.

3. THE STARTER
• SOYBEAN
The proteins that are the main ingredient of soybeans are broken
down by the protein-breaking enzyme protease from the koji mold,
to produce the amino acids that are the umami constituents of soy
sauce. Defatted soybeans retain the proteins that are essential for
the soy sauce manufacturing process, but have had the unnecessary
fats removed in advance.
Whole Soybeans
/ Defatted
Soybean meal
soaking in water(
for 10-12hr at
29°C)
autoclave cooking(
10psi for 1h)

4. • WHEAT
Either whole wheat, wheat flour, or wheat bran, may be used.
The starch that is the main constituent of wheat is converted to
glucose by the action of the enzyme amylase from the koji mold,
generating sweetness and depth.
The glucose is further changed into organic acids such as lactic
and acetic acid by lactic acid bacteria. These soften the saltiness
and bring together the taste of soy sauce.
Whole Wheat/
wheat bran
Roasting Crushing

5. • SALT
Salt, or sodium chloride, is added at the beginning of fermentation at
approximately 12-18% of the finished product weight.
The salt is not just added to flavour; it also helps to establish the proper
chemical environment for the LAB and yeast to ferment properly.
Also help to prevent in spoilage.
• Fermenting agents
 The wheat soy mixture is exposed to specific strains of mould called Aspergillus oryzae or Aspergillus soyae, which
breaks down the protein in the mash.
 Lactobacillus and yeasts are also added for further fermentation.
• Preservative
Sodium benzoate or benzoic acid is added to help inhibit microbial growth in finished soy products.

6. THE MANUFACTURING PROCESS:
The various steps involved in Soy sauce production are:
• 1. Soaking and cooking
• 2. koji preparation
• 3. brine fermentation
• 4. refining

7. 1. SOAKING AND COOKING
• Soybeans are soaked (10-12h), drained, and steamed
• Wheat is roasted and cracked
• They are mixed in the ratio of 50: 50 by weight and used for koji (malt) making.
Soybean cooking
machine
Wheat roasting machine

8. 2. KOJI PREPARATION
soybean wheat mixture
(50: 50)
Inoculated with starter culture spores of
Aspergillus oryzae/ Aspergillus soyae (0.1% to
0.2%)
Distributed in wooden boxes( 5cm depth)
Incubated at 30°C for 3-4 days
Koji

9. • After 24 hours the mixture is covered with a thin white growth of mold.
• As mold growth continues, the temperature of the mixture could rise above room
temperature to 40°C or higher. Therefore, the mixture should be turned or stirred
periodically to maintain uniform temperature, moisture and aeration.
• As the incubation time increases the mold continues to grow and their growth
turns yellow and dark green. The moisture gradually decreases.
• After 72hrs of incubation, the molded mixture called Shoyu koji is ready for brine
fermentation.

10. 3. BRINE FERMENTATION
Koji is transferred to a deep
vessel
Equal volume of salt soln ( 17-19%) is
added
Mash or moromi
Lactic acid fermentation( Pediococcus soyae)
Yeast fermentation ( Saccharomyces rouxii,
torulopsis sp.)
Ageing

11. The initial pH of mash is 6.5-7.0 which gradually decreases as the lactic acid
fermentation advances and at a pH of around 5.5 yeast fermentation takes place.
The moromi is stirred occasionally during the early stages to provide enough
aeration for good growth of yeast, to prevent the growth of undesirable
m.os., to maintain uniform temperature and to facilitate the removal of CO2.
Good quality Soy Sauce can be obtained by 6 months fermentation when the
temperature of moromi is controlled as follows:
Starting at 15 °C for one month, followed by 28 °C for 4 months and 15 °C for one month
(during finishing)

12. 4. REFINING
Pasteurization
After approximately six months of moromi fermentation, the raw soy
sauce is separated from the cake of wheat and soy residue by pressing
it through layers of filtration cloth and the liquid is pasteurized at 70°C
to 80°C to stop microbial and enzymatic reactions.
Bottling
The liquid is filterate to remove precipitates and bottled for market.
 In Japan, either benzoic acid or butyl-p-hydroxy benzoate is added as a
preservative.
 A good Soy Sauce has a salt content of about 18% and pH between 4.6
and 4.8.

13. IMPORTANT MICROORGANISMS INVOLVED IN SOY SAUCE
PRODUCTION:
• The various organisms important in making soy sauce may be added in pure culture or may become from
previous lots of koji and the ingredients.
 The chief organism is Aspergillus soyae (oryzae), the most important organism, which grows in the koji to
yield proteinases, amylases, and other enzymes for soy sauce brewing and contribute aromas and flavors;
 lactic acid bacteria, e.g., Lactobacillus delbruekii, which makes the koji acid enough to prevent spoilage and
acidifies the mash;
 Bacillus subtilis and other bacilli, which grows in the koji to improve flavor and make the sauce less turbid;
 Pediococcus halophilus, which increases the flavors, decreasing color intensity and reducing the activity of
the mold proteinases;
 and Hansenula spp., Saccharomyces rouxii, and other yeasts, which produce alcohol and help the flavor.

14. QUALITY CONTROL
• Numerous analytical tests are conducted to ensure the finished sauce meets minimum quality
requirements. In brewed sauces, there are several recommended specifications.
• Total salt should be 13-16% of the final product;
• the pH level should be 4.6-5.2;
• and the total sugar content should be 6%.
• In the United States, the quality of the finished sauce is protected under federal specification which
requires that fermented sauce must be made from fermented mash, salt brine, and preservatives
(either sodium benzoate or benzoic acid). This specification also states that the final product should
be a clear, reddish-brown liquid that is essentially free from sediment.

15. Flow sheet of Soy Sauce production:

16. SOY SAUCE USES
• Soy sauce can be used in a marinade or braising liquid
for meat or added when cooking stews or soups.
• It's a basic way of building depth of flavor, is not
affected by heat during cooking, and can provide a
pleasing brown color to your dish.
• In stir-fries, it is usually mixed with the vegetables
before including the noodles, but more soy sauce can
be added at any time in the cooking process.
• Soy sauce can be offered as a condiment at the table,
too, for additional salt and flavor as needed.

17. PRODUCTION PROCESS OF SOY SAUCE
• https://www.youtube.com/watch?v=AZ7U4VohksM
• https://youtu.be/-6Hm4sxSm4s

18. REFERENCES
 William C. Frazier, Dennis C. Westhoff and N.M. Vanitha ( 2017), Food Microbiology, 5th
edition.
 Putu Virgina Partha Devanthia , Konstantinos Gkatzionisb,c ( 2019), Soy sauce fermentation:
Microorganisms, aroma formation, and process modification, Food Research International,
Volume 120, June 2019, Pages 364-374.
 F. M. YONG’ and B.J.B. WOOD Department of Applied Microbiology, University of Strathclyde,
Glasgow, Scotland, Microbiology and Biochemistry of Soy Sauce Fermentation
• Continuous Production of Soy Sauce in A Bioreactor - Applications of Biotechnology to
Fermented Foods - NCBI Bookshelf (nih.gov)
• https://www.miyajima-soy.co.jp/english-site/en-fermented-foods/about-soy-sauce