MIC 303 INDUSTRIAL AND ENVIRONMENTAL MICROBIOLOGY

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MIC 303INDUSTRIAL AND ENVIRONMENTAL MICROBIOLOGY

• INDUSTRIAL PRODUCTS FROM MICROBIAL PROCESSES
  (WINES)

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Alcoholic Beverages - Wines

• WINES
• Winemaking procedure(s) differs at winemaker,
  winery, region, and country level.
• Many different techniques, recipes, outcomes.
• Made from fruits, typically grapes (contain
  sugar, can be directly used by yeast for
  fermentation) ? malting process is unnecessary).
• If other fruits used, might be supplemented with
  other sugars to ensure enough alcohol produced.
• Wines produced by grapes are acidic due to high
  concentration of malic acid ? Lactic acid
  bacteria sometimes added to convert malic acid to
  weaker lactic acid (malolactic fermentation
  process) ? resulting in less acidic, better
  tasting wines.

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Types of Wines

• Red Wine
• made from the pulp of the black grapes
• the whole grapes including the skin is fermented
  ? gives colour to wine.
• White wine
• The skins of grapes was removed, only content of
  the grapes being fermented ? giving a fruit
  characteristics to the wine produced.

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Types of Wines

• Sparkling Wine/ Fortified wine
• introduced by winemakers in the Champange region
  of France.
• Addition of spirit, creating a second carbon
  dioxide fermentation ? giving the wine bubbles
  formation.
• Wine which spirit added during or after
  fermentation, usually contain 20 alcohol (most
  common spirit used Brandy)? Dry / Sweet Wine.
• Sherry wine (Dry wine)
• Spirit added when the fermentation has ended.
• Contain low alcohol
• made from sundried sweetish, low acid Palermo
  grapes.
• Port Wine (Sweet wine)
• spirit added during fermentation ? residual sugar
  will produced a sweet wine, present simple sugar.
• increase blood circulation in ladies.

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Steps of wines production

• Harvest.
• Crush.
• Must Additions.
• Fermentation(s).
• Pressing.
• Settling/Racking.
• Wine produced will be stored at settling/ wooden
  vats.
• Wine start to cool.
• Precipitation of positive charge pulp protein
  with negative charge tannins.
• Filtering/Cold Stabilization.

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Steps of wines production

• Aging/Blending
• Very expensive wine
• Done in wood cask/ vast CO2 in the cask enter
  cask wall porous cause condensation,
  polymerization, precipitation of tannins of red
  wine and lessening harshness
• also cause acetaldehyde formation.
• Bottling

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Process of Making Red Wine
Figure 28.9
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Alcoholic Beverages - Beer

• Ale, beer and lager
• Ale Beer produced by top fermentation with
  S.cerevisiae.
• Lager Beer made by bottom fermentation with
  S.calsbergenesis.
• Raw material use grain starches fermented by
  yeast.
• Starch from grain must converted into glucose and
  maltose ? yeast can ferment converted into
  ethanol and CO2.
• Malting Germinating barley converts starch to
  maltose and glucose ? allowed to sprout and then
  dried and ground ? producing malt.
• This product, contain starch degrading enzymes
  (amylases) that convert cereal starches into
  carbohydrate.
• Light beers ? selected yeast and to convert more
  starch to produce glucose and maltose ? in fewer
  carbohydrates and more alcohol.

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Types of Yeast

• Products of grain starches fermented by yeast

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Alcoholic Beverages other types

• Sake The Japanese rice wine.
• use Aspergillus to convert the rice starche to
  sugar that can be directly fermented without
  going malting process.
• For distilled spirits, vodka, rum, whiskey use
  carbohydrate from cereal grains, potatoes, and
  molasses then fermented into alcohol.