TOPIC 4: TRADITIONAL AND FOOD FERMENTATION II Flashcards
NATA DE COCO
o Nata de coco is a chewy, translucent, jelly-like food product produced by the bacterial fermentation of coconut water
o A high fiber, zero fat Philippino dessert
o Highly regarded for its high dietary fiber and its zero fat
and cholesterol content.
o It is produced through a series of steps ranging from milk extraction, mixing, fermentation, separating, cleaning,
cutting to packaging.
WHY NATA DE COCO
- Easily to be obtained(about 900 million liter coconut water per year)
- Unaffected by season
- Cheap
- Good for Health (Nata de coco is highly regarded for its high dietary fiber and its zero fat and cholesterol content. No preservatives or other chemicals are added to Nata de coco.)
- All parts of coconuts are useful, such as art, charcoal, cooking oil, and Nata de Coco
BACTERIA USED IN NATA DE COCO
Great attention has been given to strains from Acetobacter, especially Acetobacter xylinum.
Acetobacter strains are well known for oxidizing alcohols to acids and ketones, especially for the production of vinegars using ethanol, wine, or ciders as carbon sources.
The process of bacteria’s strain formation (Nata De Coco)
1) Cellulose pellicle formed at the upper surface of the coconut water during fermentation
2) The fermentation lasts for 12-14 days
3) The best strains will produce the thickest layer of the cellulose
4) The production is layer by layer
5) Need static condition. Never make any shaking
Types of watery fruits that contain high in sugar;
1) Coconut water
2) Pineapple
3) Soybeans
4) Sugar cane
Process of Nata De Coco
- Preparing starter media
- Filtering and Boiling Media
- Inoculate (mixing with Starter)
- Fermentation
- Preparing starter media (NDC)
o As starter, we use pure culture Acetobacter xylinum.
o This bacteria can be produced from pineapple dregs, which has been incubated for 2-3 weeks.
- Filtering and Boiling Media (NDC)
a. To eliminate contamination in coconut water can be done by filtering using fabric filter.
b. Add sugar 100 gr/L, after that boil the media and cold it.
- Inoculate (mixing with Starter) (NDC)
After cold, make the media to 3-4 pH condition and Inoculate by adding starter 170 ml (Acetobacter xylinum).
- Fermentation (NDC)
a. Take the mixture to pot (e.g. panci) and covered by newspaper
b. Store in a clean-safe place for a week.
c. After curing is complete with the layer formation of Nata at the surface, removed the nata layer.
d. Discard the membrane that attaches at the bottom of nata, cut into pieces, and wash the nata.
e. Put into the pot and soaked for 3 days, everyday the water have to be replaced after boiling for omit the smells of acid
f. Furthermore, Nata de Coco can be preserved with syrup by mixing 3kg Nata de Coco with 2kg of sugar plus 4.5 liters of water and then boiled.
HISTORY OF ACETIC ACID PRODUCTION.
Acetic acid production is as old as wine making (10,000 years).
In 3rd centaury Greek philosopher described how vinegar acted on metals to produce pigments useful in art.
Ancient Romans boiled sour wine in lead pots to produce highly sweet syrup called sypa.
In 8th centaury Persian chemist Jabir Ibn Hayyan concentrated Acetic acid from vinegar through
distillation processes.
In 1847, German chemist Hermann Kolbe synthesized acetic acid from inorganic materials for first time.
By 1910, most of the acetic acid was obtained from the from distillation of wood.
At this time, Germany is producing 10,000 tons of acetic acid
INDUSTRIAL ACETIC ACID
Acetic acid is systematically known as ethanoic acid.
It is a colorless liquid organic compound.
It has a pungent smell (vinegar like).
It is principle constituent of vinegar.
The first vinegar was spoiled wine.
Glacial acetic acid is the pure form of acetic acid (99.98%).
PROPERTIES OF ACETIC ACID
It is a colorless liquid with pungent smell.
Melting point 16-17 ◦C.
Boiling point 118.0 ◦ C.
Glacial acetic acid is highly corrosive to metals.
Soluble in alcohol.
Miscible with water, glycerol, ether, acetone and benzene.
Insoluble in carbon disulfide.
The three important genera’s are;
(1) Genus acetobacterium: The commonly used species are.
o Acetobacterium aceti
o Acetobacterium xylinum
(2) Genus clostridium: the commonly used species is
o Clostridium thermoaceticum- anaerobic thermophile.
(3) Acetic acid bacteria
o Acetobacter
o Glocanobacter are commonly used
PROPERTIES OF ACETIC ACID BACTERIA
o Tolerate high concentration of acetic acid.
o Should require small amount of nutrients.
o Not over-oxidized the acetic acid formed.
o Be high yielding in producing acetic acid.
SUBSTRATES USED
o Ethanol
o Wine and whey
o Molasses
o Fermented grains , malt and rice
PRODUCTION OF ACETIC ACID
i. Conversion of starch to sugar by using amylases enzymes.
ii. Anaerobic conversion of sugars to ethanol by yeast fermentation.
iii. Conversion of ethanol to hydrated acetaldehyde.
iv. Finally by dehydrogenation acetic acid is produced by using aldehyde dehydrogenase enzyme.
METHODS FOR INDUSTRIAL PRODUCTION
o Orleans
o Surface fermentation (trickling generation method)
o Submerged fermentation methods.
APPLICATION’S OF ACETIC ACID (COMMON USE)
Used as solvent in different industrial processes.
Used as an active ingredient in fragrance and perfumes.
Used in production of synthetic fibers and textiles.
Used to make ink and indigo dyes.
Used in manufacturing of rubber and plastics.
APPLICATION OF ACETIC ACID (MEDICINAL INDUSTRY)
Acetic acid in the form of vinegar is used for preservation of food.
Soothe sunburnt skin and to cure from jellyfish stings.
Effective tool for cervical cancer screening.
