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Soya Sauce fermentation
Submitted by
Prayas P. Chavhan
M.Sc. I
Contents
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What is fermentation
What are fermentation product
What is soya sauce
Raw Materials of soya sauce
Fermenting agents
Preservatives and other additives
The Manufacturing Process
Non-brewed method
(chemical hydrolysis)
Quality Control
Byproducts/Waste
The Future
Application
Reference
What is
fermentation
 fermentation is the conversion of a carbohydrate
such as sugar into an acid or an alcohol.
 More specifically, fermentation can refer to the
use of yeast to change sugar into alcohol or the
use of bacteria to create lactic acid in certain
foods.
 Fermentation occurs naturally in many different
foods given the right conditions, and humans
have intentionally made use of it for many
thousands of years.
 The anaerobic conversion of sugar to carbon dioxide and alcohol by yeast.
 Any of a group of chemical reactions induced by living or nonliving
ferments that split complex organic compounds into relatively simple
substances.
What are fermentation
product
 The product which we get from the fermentation
process are called fermentation product.
 Mainly these product are classified on the basis of
raw materials used for the fermentation these are
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Bean-based
Grain-based
Vegetable-based
Fruit-based
Honey-based
Dairy-based
Fish-based
Meat-based
What is soya sauce
Soy sauce is a condiment produced by fermenting
soybeans with Aspergillus oryzae or Aspergillus sojae
molds,along with water and salt.
After the fermentation, which yields moromi, the
moromi is pressed, and two substances are obtained: a
liquid, which is the soy sauce, and a cake of (wheat and)
soy residue, the latter being usually reused as animal feed.
Most commonly, a grainis used together with the
soybeans in the fermentation process.
Raw Materials of soya sauce
 Soybeans (Glycine max) are also called soya beans, soja beans, Chinese
peas, soy peas, and Manchurian beans. They have been referred to as the
"King of Legumes" because of their valuable nutritive properties. Of all
beans, soybeans are lowest in starch and have the most complete and best
protein mix. They are also high in minerals, particularly calcium and
magnesium, and in Vitamin B.
Wheat
 In many traditional brewed recipes, wheat is blended in equal parts with the
soybeans. Pulverized wheat is made part of the mash along with crushed
soy beans. The nonbrewed variety does not generally use wheat.
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 for flavor; it also helps establish the proper chemical environment
for the lactic acid bacteria and yeast to ferment properly. The high salt
concentration is also necessary to help protect the finished product from
spoilage
Fermenting agents
 The wheat-soy mixture is exposed to specific strains of mold called
Aspergillus oryzae or Aspergillus soyae, which break down the proteins in
the mash. Further fermentation occurs through addition of specific
 bacteria (lactobaccillus) and yeasts which enzymatically react with the
protein residues to produce a number of amino acids and peptides,
including glutamic and aspartic acid, lysine, alanine, glycine, and
tryptophane. These protein derivatives all contribute flavor to the end
product.
Preservatives and other
additives
 Sodium benzoate or benzoic acid is added to help inhibit microbial growth
in finished soy sauce. The non-brewed process requires addition of extra
color and flavor agents.
The Manufacturing Process
 Traditional brewed method
Brewing, the traditional method of making soy sauce, consists of three
steps: koji -making, brine fermentation, and refinement
 Koji-making
Carefully selected soybeans and wheat are crushed and blended together
under controlled conditions. Water is added to the mixture, which is boiled
until the grains are thoroughly cooked and softened. The mash, as it is
known, is allowed to cool to about 80°F (27°C) before a proprietary seed
mold (Aspergillus) is added. The mixture is allowed to mature for three
days in large perforated vats through which air is circulated. This resulting
culture of soy, wheat, and mold is known as koji.
 Brine fermentation
The koji is transferred to fermentation tanks, where it is mixed with water and
salt to produce a mash called moromi. Lactic acid bacteria and yeasts are then
added to promote further fermentation. The moromi must ferment for several
months, during which time the soy and wheat paste turns into a semi-liquid,
reddish-brown "mature mash." This fermentation process creates over 200
different flavor compounds.
 Refinement
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. The liquid that emerges is then pasteurized. The
pasteurization process serves two purposes. It helps prolong the shelf life of the
finished product, and it forms additional aromatic and flavor compounds.
Finally, the liquid is bottled as soy sauce.
Non-brewed method
(chemical hydrolysis)
 Instead of fermenting, many modern manufactures artificially break
down the soy proteins by a chemical process known as hydrolysis
because it is much faster. (Hydrolysis takes a few days as compared
to several months for brewing.)
 In this method, soybeans are boiled in hydrochloric acid for 15-20
hours to remove the amino acids. When the maximum amount has
been removed, the mixture is cooled to stop the hydrolytic reaction.
 The amino acid liquid is neutralized with sodium carbonate, pressed
through a filter, mixed with active carbon, and purified through
filtration. This solution is known as hydrolyzed vegetable protein.
 Caramel color, corn syrup, and salt are added to this protein mixture
to obtain the appropriate color and flavor. The mixture is then
refined and packaged.
 Sauces produced by the chemical method are harsher and do not have
as desirable a taste profile as those produced in the traditional brewed
manner. The difference in taste occurs because the acid hydrolysis
used in the non-brewed method tends to be more complete than its
fermentation counterpart. This means that almost all the proteins in
the non-brewed soy sauce are converted into amino acids, while in the
brewed product more of the amino acids stay together as peptides,
providing a different flavor. The brewed product also has alcohols,
esters, and other compounds which contribute a different aroma and
feel in the mouth.
 In addition to the brewed method and the non-brewed method, there
is also a semi-brewed method, in which hydrolyzed soy proteins are
partially fermented with a wheat mixture. This method is said to
produce higher quality sauces than can be produced from straight
hydrolysis.
Quality Control
 Numerous analytical tests are conducted to ensure the finished sauce meets
minimum quality requirements. For example, 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%. For the non-brewed type, there is 42% minimum of
hydrolyzed protein; corn syrup should be less than 10%; and carmel color
1-3%.
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 which is essentially free from sediment. The non-fermented
sauce is defined as a formulated product consisting of hydrolyzed vegetable
protein, corn syrup, salt, caramel color, water, and a preservative. It should
be a dark brown, clear liquid.
Byproducts/Waste
 The fermentation process produces many "byproducts" that are actually useful
flavor compounds. For example, the various sugars are derived from the
vegetable starches by action of the moromi enzymes. These help subdue the
saltiness of the finished product. Also, alcohols are formed by yeast acting on
sugars. Ethanol is the most common of these alcohols, and it imparts both
flavor and odor. Acids are generated from the alcohols and sugars, which round
out the flavor and provide tartness. Finally, aromatic esters (chemicals that
contribute flavor and aroma) are formed when ethanol combines with organic
acids.
 Chemical hydrolyzation also leads to byproducts, but these are generally
considered undesirable. The byproducts are a result of secondary reactions that
create objectionable flavoring components such as furfural, dimethyl sulfide,
hydrogen sulfide, levulinic acid, and formic acid. Some of these chemicals
contribute off odors and flavors to the finished product.
The Future
 The future of soy sauce is constantly evolving as advances are made in
food technology. Improved processing techniques have already allowed
development of specialized types of soy sauces, such as low-sodium and
preservative-free varieties. In addition, dehydrated soy flavors have been
prepared by spray drying liquid sauces. These powdered materials are used
in coating mixes, soup bases, seasoning rubs, and other dry flavorant
applications. In the future, it is conceivable that advances in biotechnology
will lead to improved understanding of enzymatic reactions and lead to
better fermentation methods. Technology may someday allow true brewed
flavor to be reproduced through synthetic chemical processes
Application
 Enrichment of the diet through development of a diversity of flavors,
aromas, and textures in food substrates
 Preservation of substantial amounts of food through lactic acid,
alcohol, acetic acid and alkaline fermentations
 Biological enrichment of food substrates with protein, essential
amino acids, essential fatty acids, and vitamins
 Elimination of antinutrients
 A decrease in cooking times and fuel requirements
 Some fermentation products (e.g., fusel alcohol) are deleterious.
Reference
Rokas, A. (2009). "The effect of domestication on the fungal proteome".
Trends in genetics : TIG 25 (2): 60–63.
Kitamoto, Katsuhiko (2002). "Molecular Biology of the Koji Molds".
Advances in Applied Microbiology 51: 129
Goffeau, André (December 2005). "Multiple moulds". Nature 438 (7071):
1092–1093.
Machida, Masayuki et al.; Asai, K; Sano, M; Tanaka, T; Kumagai, T; Terai,
G; Kusumoto, K; Arima, T et al. (December 2005). "Genome sequencing
and analysis of Aspergillus oryzae". Nature 438 (7071): 1157–1161
Galagan, James E. et al.; Calvo, SE; Cuomo, C; Ma, LJ; Wortman, JR;
Batzoglou, S; Lee, SI; Baştürkmen, M et al. (December 2005).
"Sequencing of Aspergillus nidulans and comparative analysis with A.
fumigatus and A. oryzae". Nature 438 (7071): 1105–1115.