L4 Fermentation: Soya sauce and Bread Flashcards
What is the general process of making soya sauce?
Add wheat, soybeans and aspergillus together and ferment for 2 to 5 days to form koji. Add brine or slat water which is 17-19% NaCl and ferment for 6-8 months with halotolerant lactobacilli and yeasts to form moromi and then pressed to form soy sauce.
Explain the Koji Making Process.
Carefully selected soybeans and wheat are crushed and blended together under controlled conditions. Water is added to the mixture which is boiled until grains are thoroughly cooked and softened. The mash is to cool down to about 27 degrees celsius before the mold aspergillus is added. The mixture is allowed to mature for 3 days in perforated vats through which air is circulated. The resulting culture of soy, wheat and mold is known as koji.
Explain how Moromi is made
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 the soy and wheat paste turns into a semi-liquid and reddish-brown mature mash. The fermentation process creates over 200 flavoured compounds.
Explain how soy sauce is made from moromi.
After approximately 6 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 pasteurised to prolong shelf life and forms additional aromatic and flavour compounds. Finally, the liquid is bottled as soy sauce.
Explain the process of preparing soybeans before koji making and the effect of soybeans in soy sauce.
Soybeans
Soak in water 12-15 hrs until double in weight
Steam to soften and sterilise
Oil must be removed
Soybeans: The unique characteristics of soy sauce originate primarily from the proteins contained in soybeans. Soybeans are first soaked in water over an extended period, and then steamed at high temperatures.
What is Aspergillus Oryzae or A. sojae?
Fungus – developed naturally (mouldy rice)
or commercially available
What is the purpose of Roasted wheat flour in koji making?
Contributes to flavour and colour. Carbohydrates contained in wheat are the components that give soy sauce its fine aroma; the wheat also adds sweetness to the soy sauce. Wheat is roasted at high temperatures and then crushed by rollers to facilitate fermentation.
What is the difference between Chinese and Japanese soy sauce?
Chinese-style soy sauces traditionally are made with 100 percent soy, while Japanese-style soy sauces are made with a mix of soy and wheat (usually 50/50). This gives the Japanese sauces a sweeter, more nuanced flavor than their Chinese counterparts, which are usually saltier and more aggressive.
How does Aspergillus affect soy sauce?
Mycelium start to grow, sporulation
Produces proteases and amylases (extracellular enzymes) that hydrolyze the proteins and polysaccharides forming simple sugars and amino acids
Produces glutaminase – releases glutamic acid – ‘umami’ taste
Colour changes
Other bacteria are found which may contribute to taste
How does Aspergillu’s breakdown of proteins and polysaccharides affect soy sauce?
These sugars and amino acids are further used by halophilic lactic acid bacteria and yeasts to produce final soy sauce product.
Halophilic lactic acid bacteria Tetragenococcus halophilia Yeasts Zygosaccharomyces rouxii Candida versatilis
What is Bran, Endosperm and Germ?
Bran is the outside skin of the wheat kernel.
The endosperm is the food store of the wheat kernel.
The germ is the part of the kernel that grows into a new plant.
How is wheat made into flour and what is the difference between white and brown bread?
Wheat is dry milled (crushed with grinding stones). And brown bread has all the parts of the grain while white has the germ and bran separated.
What is flour?
Flour is mainly starch with 9-14% protein mainly gluten.
What is the difference between hard flour and soft flour and their uses?
Hard Flour
high in gluten, with 12% to 14% gluten content
Elastic when cooked
Suitable for bread
Soft flour
Relatively low in gluten, with 8-10% gluten content
Soft and crumbly when cooked
Suitable for cake and biscuits and other baked goods
What are wheat proteins, their structure and what are they used for?
Gluten proteins are made from gliadins which are alcohol soluble and glutenins which are soluble in diluted acid. Gliadin usually folds to form a complex spherical shape while glutenin forms a more elongated rope-like shape. Gluten is found in the endosperm and a small portion of people are allergic to gluten. Gluten is used in vegetarian mock meat and gives bread its elasticity.
