PCOG LAB - Experiment 9 (Wine Fermentation of Sugars)

Fermentation

A biochemical process where sugars are converted into:

• Ethanol

• Carbon dioxide

Sugars

Fermentation is a biochemical process where _____ are converted into:

• Ethanol

• Carbon dioxide

Ethanol and Carbon dioxide

In fermentation, sugars are converted into?

Yeast

Fermentation occurs through the action of _____ enzymes

Anaerobic

Fermentation is an Aerobic or Anaerobic process?

Johannes Baptista van Helmont

They coined the term gas

Anton van Leeuwenhoek

They observed yeast cells

Joseph Black

They identified CO2

Antoine Lavoisier

They contributed quantitative fermentation studies

Joseph Gay-Lussac

They contributed that glucose → ethanol + CO2

Jons Jacob Berzelius

They proposed catalytic role of yeast

Louis Pasteur

They said that fermentation is a biological process

Eduard Buchner

They said that enzymes catalyze fermentation

Arthur Harden

They studied the role of phosphates in glycolysis

Yeast growth is inhibited at high ethanol levels

Why does the alcohol content rarely exceeds 14% (v/v)?

Philippines Fruits Used for Wine

• Pineapple

• Kasuy

• Duhat

• Bignay

• Guyabano

• Caimito

Dry Wine

Complete fermentation of wine will result to?

Sweet Wine

Excess sugar on wine will result to?

Sweet Wine

Short fermentation period will result to?

High Alcohol Content

Long fermentation period will result to?

Fortification

• Addition of brandy or ethanol to wine

  • Added when there is not enough alcohol

Clarification

Removal of tannins using:

• Egg white

• Gelatin

• Albumin

Pasteurization

What prevents conversion of wine to acetic acid?

Invertase

Enzyme involved in fermentation that converts sucrose → glucose + fructose

Zymase

Enzyme involved in fermentation that converts glucose → ethanol + CO2

• pH

• Temperature

• Nutrient Availability

• Additional Factors: Ethanol and SO2

Enzyme activity depends on?

4.5-5.0

pH required

Emden-Meyerhof-Parnas (EMP) Pathway

Pathway involved in fermentation

The “Lees” Effect

After fermentation, dead yeast cells can be left in the wine to add creamy, bready flavors and complexity

• Nagsettle na yeast sa wine (sa baba)

Converts Sugar to Alcohol

What is the role of yeast in fermentation?