Project Presentation

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Project Presentation

• 200-400 words summary
• Product introduction
• Recipe
• Procedure flow chat
• Microbiological/biological conversion
• Product quality standard microbial and chemical
• Market analysis/product promotion

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Project

• Reference
• Total of 10-15 pages, double spaces, font size
  12.
• Participation
• Presentation
• Each group 20 minutes including questions
• Do whatever you could to make it interesting!

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Fermented Soy Products
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Popular food trends

• East meets the West
• Asian fermented foods and ingredients
• Soy-based products most popular
• Main differences between fermented foods from
  Eastern and Western
• Raw material
• plant materials and seafood instead of animal
  products
• Carbohydrates (starch and other polysaccharides)
  instead of simple sugars
• Process
• Convert into simple sugars first
• Aerobic versus anaerobic
• Organisms
• Molds and yeasts

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Types of Asian Fermented Foods

• Plant-based
• Soy
• Rice
• Other grains and legumes
• Fish-based
• Less defined
• Vary depends on availability of the raw materials

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Koji and Tane Koji

• Koji
• Essential for many Asian fermented foods
• A moldy mass of grain (mixed starter)
• Manufacture
• Many types, koji correspond to specific products
  or raw materials
• Source of enzymes converting non-fermentable
  substances into simple products
• Starch, proteins, lipids, cellulose, pectin, etc.

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Koji and Tane Koji

• Manufacture
• Raw materials preparation
• Soybeans soaked, cooked (steam)
• Denatured soy protein are hydrolyzed by fungal
  proteinase
• May contain roasted wheat kernels
• Some with polished rice
• Microorganisms
• Pure culture containing spores of Aspergillus
  oryzae and/or A. sojae
• Or inoculated with tane koji (rice koji with
  starter spores)
• Mix and incubate
• Oxygen and moisture circulation
• Temperature control
• Proteolytic enzymes produced at lower temp
  (25-30C)
• Amylases at higher temp (30-35C)
• days

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Soy Sauce (Shoyu)

• Soybean (or defatted soybean meal or flakes)
  moistened, cooked
• Mixed with roasted and crushed wheat
• Best with 5050 ratio (wt/wt)
• Inoculate with starter (tane koji, chung chu)
  0.1-0.2
• A. oryzae, A. soyae
• Incubate in shallow wooden box, at 30C, 24 h
  followed by higher temp (up to 40C) for 72 h
• Molded mixture-shoyu koji, dark green, pleasant
  aroma, high activities of proteases and amylases
• Brine fermentation

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Soy Sauce Making
Wheat
Soybeans
Starter Aspergillus oryzae (Mixed strains)
Roasted
Soaked
Crush lightly
Cooked
Mixed
Incubation Room
Mold mixture
Mash (Morimi)
Lactic acid fermentation (Pediococcus soyae)
Yeast fermentation (Saccharomyces rouxii,
Torulopsis sp.)
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Soy Sauce Making
Aged
Pressed
Cake
Liquid
Animal feed
Pasteurized
Source
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Mashing

• Process when koji enzymes hydrolyze proteins,
  polysaccharides, etc.
• Start from add high salt brine (20-25) NaCl to
  solid material (solidbrine 11.2 -11.5)
• High salt conc restrict growth of most microbes
  except halo- or osmotolerant ones
• The mash material-moromi or moromi mash
• Ferment in large tanks for up to 1 year
• Low temp (15C) better product, long time high
  temp (up to 35C) as little as 3-4 months
• Agitation and forced aeration

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Moromi Enzymology

• A. oryzae and A. sojae produce good spectrum of
  enzymes
• Secreted proteinases, peptidases, cellulases,
  amylases
• Degrade soy and wheat proteins, starches, other
  macromolecules to smaller units as nutrients or
  substrates for mash microflora
• Lower the temp, the greater the enzyme activity
  (20-35C range)

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Moromi Enzymology

• Fungal proteinases and peptidases
• Wide pH range
• Alkaline proteinase (activity 10 times of the
  others), pH 6.0-11.0 (optima 10.0)
• Neutral proteases (optima pH 7.0)
• Acid-proteases (optima pH 3.0)
• Peptidases (wide pH range)
• Salt-tolerance
• Release glutamic acid or convert glutamine to
  glutamic acid-essential for flavor
• Nearly complete hydrolysis of soy proteins
• For subsequent LAB and yeast fermentation, color
  and flavor development

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Moromi Enzymology

• Amylolytic enzymes
• a- and ß-amylases convert starch to simple sugars
• Most associated with mash, serve as substrate for
  fermentation
• Reducing sugars (glucose, maltose, xylose,
  galactose, arabinose, etc.) essential for color
  and flavor development
• Reducing sugar free amines (non-enzymatic
  browning)

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Moromi Enzymology

• Other enzymes
• Cellulases, pectinases, hemicellulases, etc.
• Tissue degrading, enhance substrate extraction
• Increase yield and nutrient availability
• Formation of pentoses and other sugars assist
  browning

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Fermentation

• Mash contains Aspergillus strains as well as
  yeasts and other bacteria
• Addition of salt brine to the koji (18 salt),
  fungi salt-sensitive and lyse and die
• Micrococcus and Bacillus starting high (108
  cfu/g), LAB and yeasts much lower (101-104)
• Salt-sensitive ones (Micrococcus, wild yeasts and
  most Bacillus) cannot survive
• Select salt, osmotic pressure, low aw tolerant
  ones
• Lb delbrueckiim, Tetragenococuss halophilus reach
  107 cfu/g or higher after 6-8 weeks
• Yeasts Zygosaccharomyces rouxii, Candida
  versitalis dominate once pH below 5.0
• Generate spectrum of products for complex flavor
  of the finished products
• LA, ethanol, CO2, other alcohols, esters,
  furanones, flavor volatiles

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