Chapter 12: Food Fermentation Flashcards
Germicidal
Microbes becoming adjusted to new environment and overcoming nature’s protective mechanism (lactenin in milk). Little, if any, breakdown of constituents occurs.
What are the 4 stages in natural fermentation of a food? Ex: milk at room temp exposed to microbes.
Germicidal
Acidification
Neutralization
Proteolysis
Acidification
Bacteria converts sugars to acids and lowers pH to 4.5. Food becomes sour.
Neutralization
Molds and yeast consume the acid. Changes pH to around 7.
Proteolysis
Protein splitting bacteria break down proteins. Putrid odors and flavors result.
Today we have controlled ___ ___
Food fermentation. We have cultures of desirable bacteria.
Fermentation
Conversion of CHO’s (sugars) to acids + CO2 gas (bacteria) + yeast convert sugar to alcohol + CO2 gas.
Proteolysis
Protein breakdown
Lipolysis
Breakdown of fats
Catabolic
Break down
Anabolic
Build up
If enough ___ or ___ is present in the food, it will inhibit proteolytic and lipolytic bacteria.
Alcohol or acid
If the pH is less than ___, ___ ___ cannot grow and reproduce its deadly toxin. Such foods are usually not ___.
4.7
Clostridium botulinum
Retorted
What are the 4 major general chemical flavor contributors for fermented foods?
Acid
Alcohols
Aldehydes
Ketones
Acid in foods are what 3 things?
Naturally present
Added to food
In fermentation
Some ___% ___ will preserve a wine.
15
OH
Natural wine is ___-___ alcohol just from fermentation, therefore mildly chemical pasteurized by ___ to prevent contamination by yeast.
9-13%
SO2
Fortified wine
Natural wine to which enough alcohol has been added to bring alcohol content to 20%
Cultures or starters
Large #s of a concentrated source of a selected bacteria or group of bacteria to ferment foods
Different bacteria grow best at different temps, therefore ___
Process of making fermented products, different temps are used.
Different temps are usually ___-___
70-90 F
Halophilic bacteria
Salt loving bacteria
___ must have oxygen to live. They are ___.
Molds
Aerobic
Aerobes
Must have oxygen to live
Anaerobes
Must have absence of oxygen to live
Facilitated aerobe
Grows better in the presence of oxygen
Facilitated anaerobe
Grows better without oxygen
Know the cabbage to sauerkraut diagram in notes
Look in notes
2 types of yeast
Sacchromyces ellipsoideus- helps make wine
Sacchromyces serevisiae- helps make bread
Yeast reproduce to large #s faster under ___ ___.
Aerobic conditions
Yeast converts sugar to alcohol faster under ___ ___
Anaerobic conditions
