Lesson 8: Acetic Acid Fermentation Flashcards
were first recognized as causing wine spoilage in the 19th century.
Acetic acid bacteria
Their ability to oxidize (?) to (?) both induces wine spoilage and is vital to commercial vinegar production.
ethanol to acetic acid
They are product of scalar fermentations carried out by several groups of microorganisms acting at different moments in time.
Vinegar
The metabolic activity of (3) is also crucial for guaranteeing the manufacture of vinegar.
yeasts, molds and lactic acid bacteria
The initial phase represented by alcoholic fermentation carried out by (?), sometimes lactic acid
yeasts
This converts alcohol into vinegar or acetic acid through oxidation, catalyzed by specific fungi or bacteria.
Acetous fermentation
Acetous fermentation requires what?
oxygen
Acetous fermentation involves two reactions with (?) as an intermediate product.
acetaldehyde
This bacteria are required for Acetous fermentation
Mycoderma aceti or Acetobacter aceti
T or F: Acetous fermentation can be aerobic and anaerobic
TRUE
Aerobic involves yeast (S. cerevisiae) converting (?) to (?)
glucose to ethanol
Fermentation typically starts with yeast breaking down (?) into (?) and (?).
breaking down glucose into ethyl alcohol and carbon dioxide.
Crucial in vinegar and fermented food production, influencing flavor and acidity.
Acetous Fermentation
[STRUCTURE] Alcohol - Water - Acetaldehyde
C2H6O + O H2O + C2H4O
[STRUCTURE] Acetaldehyde - Acetic acid
C2H4O + O C2H4O2
Step 1 of vinegar production
Fermentation of Sugar to Ethyl Alcohol
The step 1 of vinegar production is anaerobic and carried out by yeasts, specifically (?)
Saccharomyces cerevisiae var ellipsoideus.
(STEP 1) Sugar concentration should be around (?)%, and pH and temperature maintained at approximately (?) and (?)°C, respectively.
20%; 5 and 32°C
(STEP 1) The optimal alcohol concentration in a successful fermentation
10-13%
Higher concentrations lead to (?) to acetic acid
incomplete oxidation
Lower concentrations result in the loss of vinegar due to (?) and (?).
oxidation of esters and acetic acid
[STRUCTURE] Glucose > Carbon Dioxide + Ethyl Alcohol
C6H12O6 > 2CO2 + 2C2H5OH
Step 2 of Vinegar Production
Oxidation of Alcohol to Acetic Acid
(STEP 2) Is is aerobic, anaerobic, or both?
aerobic
The oxidation of alcohol to acetic acid is carried out by acetic acid bacteria, primarily (?)
Acetobacter aceti
These (2) are the main genera involved in aerobic acetic acid fermentations.
Acetobacter and Gluconobacter
pH and temperature should be maintained around (?) and (?)°C, respectively, for efficient fermentation.
4.5 and 30°C
Approximately (?)% yield of acetic acid from glucose, with three parts of (?) yielding two parts of (?).
60%; glucose; acetic acid
These (2) are commonly used for ethanol and acetic acid analysis.
Gas chromatography and high-performance liquid chromatography
For acetic acid fermentation, optimal conditions include 10% (?), (?)°C temperature, and (?) pH to achieve the best results.
ethanol concentration; 30°C; 4.5 pH
[STRUCTURE] Alcohol + Oxygen > Acetic Acid + Water
C2H5OH + O2 > CH3COOH + H2O
This is an alcoholic liquid that has been allowed to sour. It is primarily used to flavor and preserve foods and as an ingredient in salad dressings and marinades.
Vinegar
The word vinegar is from the French term “vin” that means?
wine
The word vinegar is from the French term “aigre” that means?
sour
This vinegar is made from the Trebbiano and Lambrusco grapes of Italy’s Emilia-Romagna region.
Balsamic vinegar
Home or let alone method-vats of cider are allowed to sit open at room temperature for several months until the alcoholic liquid is converted to acetic acid.or Orleans method or als
Slow method or natural method
Fruit juice is periodically added to small batches of vinegar and stored in wooden barrels. As the fresh juice sours, it is skimmed off the top.
Continuous Method
Generator process or the fogging procedure – alcoholic liquid is in motion; spirits(alcohol)
Quick Method
Based on the goal of infusing much oxygen into the alcoholic product. The oxygen is pumped at the bottom of the steel tanks called acetators. A heater in the tank keeps the temperature between 80-100F (26-38C).This is often used in the production of wine vinegars.
Submerged Method
composition depends on the material used
finishing
Vinegar quality is determined by its strength or acidity, typically ranging from (?)% acetic acid.
5-20%
Includes soluble solids, pH, total acidity, and antioxidant activity (phenolic compounds). Density, melting, and boiling points may also be considered.
Proximate Condition
Aroma, flavor, and texture are essential sensory attributes of vinegar, which can vary depending on the raw materials used and production methods.
Sensory Characteristics
Quality standards for vinegar vary by country of origin, ensuring consistency and adherence to specific criteria.
Standards and Specifications
Iron or copper contamination can cause bluish or black coloration. Oxidase enzymes may lead to darkening of vinegar.
Equipment-Related Defects
Acetic acid bacteria may produce cellulose, while vinegar eels (nematode worms) such as (?), mites, vinegar flies (?), and wine flowers (?) can affect vinegar quality and appearance.
Angeullula aceti; Drosophila; Mycoderma vini
