benedict

Food Fermentation Microbiology

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INTRODUCTION
• Industrial microbiology uses microorganisms, typically grown on a large scale, to produce valuable commercial products or to carry out important chemical transformations.

• This process is commonly referred to as
Fermentation

DEFINITION OF FERMENTATION
“The process of deriving energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound” • The term fermentation is derived from the latin verb "fevere" which means "to boil".

FERMENTATION

PROS
• Extended shelf life of food (ex. Cheese)
• Eases Digestion (ex.
Wild rice)

• New [better] flavours
(ex. Chocolate)

CONS
• Can be unpredictable
(i.e. bad bacteria win the battle)
• New [worse] flavours
(ex. Mouldy bread tastes terrible)

WHAT ARE FERMENTED FOODS?

Foods or food ingredients that rely on microbial growth as part of their processing or production

METABOLIC ACTIVITIES OCCUR DURING
FERMENTATION


Extend shelf life by producing acids



Change flavor and texture by producing certain compounds such as alcohol



Improve the nutritive value of the product by:
 Microorganisms can synthesize vitamins  Breakdown indigestible materials to release nutrients, i.e., bound nutrients FERMENTED FOODS
 Foods fermented by yeast 




MaltBeer
Fruit (grapes)  Wine
Rice  Saki
Bread dough  Bread

 Foods fermented by bacteria 



 Foods fermented by mold 



Soybeans  Soy sauce
Cheese  Swiss cheese 

Cucumbers  Dill pickles Cabbage 
Sauerkraut
Cream  Sour cream
Milk  Yogurt

FOOD FERMENTATIONS
In food fermentations, we exploit microorganisms’ metabolism for food production and preservation.
Where do the microorganisms come from to initiate the food fermentation?

Two ways to initiate a food fermentation….
...traditional &