ĐẠI CƯƠNG VỀ THỰC PHẨM LÊN MEN_General about fermentation

Fermentation and its application
in Food industry


Microorgan
isms are
small
organisms
characterize
d by a
broad
spectrum of
metabolism
Some of
these
activities
include the
synthesis,
metabolis
m and
decomposi
tion

Used for
productio
n of food,
beverages
,
environm
ental
protection

And other products such as wine fermentation is
brewed from grapes or other fruits, vinegar, soy

Egyptians had a habit of brewing wine

In China, the wine was produced from the Long Son culture



General about fermentation
Fermentation is the metabolic process in which a carbohydrates is converted into alcohol or an acid by organisms.

organisms

Starch or sugar

Alcohol or an acid


This process takes place when there are beneficial bacteria present that break down the starch and sugars in the
food

There are two fermentation processes

Aerobic fermentation

Anaerobic fermentation

The role of fermentation in the food technology industry

Enrichment of the human nutrition

Reservative of substantial amounts of food

Enrich biological food substrate

Detoxification in food fermentation and reduce cooking time, fuel requirements


Beneficial product created from fermentation


However, some enzyme activities during fermentation make the food to smell unpleasant or unattractive flavors,
the

products

are

toxic

or

disease

producing,

Product damaged by fermentation

the

foods

are

described

as

spoiled.


Based on the resulting products, it can be divided into fermentation types such as:

•
•
•
•
•

Alcohol fermentation
Lactic fermentation
Propionic fermentation
Mixed acid fermentation
Butyric fermentation…..

Fermentation in food depends on many factors in which the microbial factor is the most important factor
determining the fermentation process.

Yeasts (nấm men)

Bacteria (VK)

Microfilamentous fungi

Actinomicetes (XK)

Cyanobecteria (VKL)




in the lab, want to make a fermentation process on an industrial scale must propagate, ensure that the
number of cells with the physiological age is at the peak of activity for transplanting into the fermentation
medium

Product recruitment is started by separating the cells from the nutrient medium

The acquisition of high-performance products is critical to the economics of a method

Therefore, the separation and isolation problem must involve all steps. Removal and use of waste and byproducts should also be taken into account to avoid environmental pollution


Application of the fermentation
in Food industry

Pickled vegetables


The fermentation of vegetables

Is due primarily to the activity of naturally occuring lactic acid bacteria

•

Is performed in the anaerobic condition

Yeasts and other micoorganisms may also be participated

•

Depending on the salt concentration and other environmental factors


•
•

•
•

Final

Lactic acid concentration => 1.2 %
Rotten bacteria are killed, lactic acid bacteria are also inhibited

Second

Lactic acid bacteria grow strongly, acidifying the environment
Inhibiting rotten bacteria

The first


Leuconostic

Lactobacillus plantarum:

Lactobacillus

mesenteroides = a

tolerate fairly high

pentoaceticus: raise

malformed bacteria =>

concentrations of acid

concentration of acid up

weak acid, CO2 and
reduce amount of O2

Yogurt is a nutritious food for the body, especially children.


It is a fermented milk product with intestinal beneficial bacteria such as Lactobaccillus bulgaricus,
streptococcus thermophilus.


• It turns lactic acid into milk.
• Increases the nutritional value of milk
• Enhances the absorption of proteins and minerals,
especially calcium, iron and zinc.


•

Lactobacillus bulgaricus and Streptococcus thermophilus are two major bacteria
in yogurt fermentation.

•
•

Fermented lactose to produce lactic acid
Reducing pH and coagulating casein and precipitating Ca.


There are also microorganisms

Lactobacillus acidophilus

Lactobacillus subps casein

bacteria bifido

streptococcus lactic