Fermentation is one of the oldest food processing techniques used worldwide. It allows for the preservation of foods through the creation of acids or alcohols via microbial processes. Many traditional fermented foods have been consumed for thousands of years and play an important role in culture. Examples discussed include bread, cheese, wine, yogurt, pickles, soy sauce, and fermented vegetables and fruits from various regions. Fermentation increases shelf life and nutrient content while reducing cooking times and fuel needs. It has health benefits such as providing probiotics, vitamins, and peptides that can lower blood pressure.
2. INTRODUCTION
Agricultural crops are processed for many different
reasons.
Ranges from removal of anti-nutritional components
and increasing storage life of the final product to add
value.
Fermentation is one of the most ancient and
important food processing technology in the world.
Bread, cheese and wine have been prepared and
consumed for 1000 of years, strongly linked to culture
and tradition.
Its likely the microbial and enzymatic process
responsible for the transformation.
There is tremendous scope and potential for the use
of micro-organisms in growing demand for food.
3. FERMENTATION
Refers to conversion of sugar to alcohol using yeast
under anaerobic conditions
It is the chemical conversion of carbohydrates into
alcohol or acid.
Implies the action of microorganisms to produce
alcoholic beverages such as wine, beer and cider.
Create lactic acid in sour foods such as yogurt and
pickled cucumbers.
4. USES
Primary benefit – conversion of carbohydrate and sugars
Enrichment of diet through development of a diversity of flavors,
aromas and textures in food substrate.
Preservation of substantial amount of food through lactic acid,
alcohol, acetic acid and alkaline fermentations
Biological enrichment of food substrates with proteins, essential
amino acids, fatty acids and vitamins.
Detoxification during fermentation processing.
Decrease cooking times and fuel requirements.
5. OTHER BENEFITS
Exclusive to foods, it produce important nutrients or
eliminate anti nutrients.
In pickling the acid produced by the dominant
bacteria inhibit the growth of all other
microorganisms.
6. FERMENTATION – AN ANCIENT TRADITION
First fermented foods consumed were fermented
fruits by the hunters.
Fermented drinks were being produced over 7000
years in Babylon, 5000 years ago in Egypt, 4000
years ago in Mexico and 3500 years ago in
Sweden.
Bread making originated 3500 years ago in Egypt.
Fermented milk products used over 5000 years ago
in Babylon.
King Nebuchadnezer of Babylon produced
fermented meat products.
7. CONTINUE….
China birth place for fermented vegetables and use of
Aspergillus and Rhizopus moulds to make food.
Fermentation
Slow decomposition process of organic substances induced by micro
– organisms, or by complex nitrogenous substances (enzymes) of
plant or animal origin.
Changes caused fermentation can be both advantageous and
disadvantageous.
Initiated by action of microorganisms occurs naturally , by process of
decay especially in fruits and vegetables.
It is an efficient low energy preservation process, which increases the
shelf life and decreases the need for refrigeration.
8. FERMENTED FOODS BY REGION
Science of fermentation is known as Zymology.
French Chemist Louis Pasteur – first zymologist in
1854.
He defined fermentation as “respiration without air”
German Eduard Buchner, winner of 1907 Nobel
prize in chemistry, determined fermentation was
actually caused by a yeast secretion – Zymase.
9. Region Fermented FoodsS
World wide Alcohol, wine, vinegar, olives,
yogurt, bread and cheese
East and South East Asia Miso, Natto, Soy sauce, Tofu,
Tempeh
Central Asia Kumis (Mare milk), Kefir,
Shubat(Camel milk)
India Appam, Dosa, Dahi (yogurt), Idli,
mixed Pickle and Gun druk
Africa Garri, Hot pepper sauce and ogili
America Chicha, elderberry wine, pickling
and sauerkraut
Europe Sauerkraut, elderberry wine,
Cultured milk products such as
Kefir.
Oceania Poi, Kaanga pirau(rottern corn)
10. TRADITIONAL FERMENTED FOODS
Fermented products supply protein, minerals and other
nutrients which add variety and nutritional fortification.
Soy sauce consumed throughout the world,
fundamental ingredient in diets from Indonesia to Japan.
Gun druk – fermented and dried vegetable product,
served as side dish, an appetiser, important source of
minerals used by Nepali communities.
Casssava – major diet component for 800 million
people in Africa.
Dosa and Idli – A safe and nutritious indian food, highly
acceptable, both protective and therapeutic. Bacteria
causes changes in the batter is ‘Probiotic Bacteria’
11. Traditional Dahi – probiotic food from fermetned
dairy products like yogurt and Buttermilk.
Indian Breads – Chapathi, Poli, Phulka, Roti,
Paratha, Naan and Appam are the primary food in
indian daily breakfast.
12. APPAM
Fermented bread prepared with finely powdered
rice flour.
Variety of Appam are prepared in Kerala and South
India.
Kallappam – made from flat iron griddles.
Vattayappam – steamed bread
Palappam – made in small shallow bottomed pans, kept
covered while the bread cooks
13. NAAN
Round flat bread made of white flour
Resembles pitabread, usually leavened with yeast.
Yeast can be substitute with baking powder.
Milk or yogurt may also be used to give greater
volume and thickness to the naan.
14. SAUERKRAUT
An acid fermentation of vegetables
Name translates as ‘acid cabbage’.
This process can be applied to any type of vegetables.
Lactic acid fermentations are carried under three basic
condition types – dry salted, brained and non – salted.
Salting provides suitable environment for lactic acid
bacteria to grow which impart the
acid flavour to the vegetables.
15. DRY SALTED FERMENTED VEGETABLE
Vegetables (washed & drained)
Placed in container (1st layer 2.5cm depth)
Salt is sprinkled and 2nd layer of vegetable added
Add more salt and repeat process till 3 quarters full
Cloth placed above vegetables
Fermentation completes when no bubbles formed
(takes 1 – 4 weeks)
Pack Pickle
(Optimum temperature for fermentation is around 21ᴼ
c.
For lactobacillus species 22ᴼc favour the temperature.)
16. BRINE SALTED FERMENTED VEGETABLES
Used for vegetables containing less moisture.
Brine solution prepared by dissolving salt in water.
At 20 salometer fermentation takes well in a brine.
Leuconostoc mesenteroides – predominates pickle
fermentation.
17. NON SALTED, LACTIC ACID FERMENTED
VEGETABLES
Some vegetables fermented by lactic acid bacteria, without
salt/ brine. Eg Gundruk, Sinki
Sinki
Fresh radish roots are harvested washed and wilted by
sundrying for 1 – 2 days
Shredded, rewashed and packed tightly in earthen ware /
glass jar
Sealed to ferment for 12 days ( 30ᴼc)
Fermentation is intiated by L.fermentum and L.brevis and
L.Plantarum.
For consumption, sinki is rinsed in water for 2 minutes, squeeze to
remove excess water and fried with salt, tomato, onion and green
chilli. The mixture is boiled in rice water and served as hot soup
along with meat.
18. GUNDRUK
Pediococcus and Lactobacillus species –
predominant micro –organisms.
L.cellobiosus and L.Plantarum initated
fermentation.
Initially shredded leaves are tightly packed in an
earthen ware pot +warm water 30ᴼ c.
Mild acid taste after 5- 7 days indicates fermentation.
It is then removed and sun dried.
19. KANJI
Carrots specially deep purple in color are fermented
to make traditional drink in Northern India and
Pakistan.
Very popular drink having cooling and soothing
properties with high nutritional value.
Lactic acid bacteria produce lactic acid which
prevents the growth of food poisoning organisms.
After fermentation, drink is strained through fine
muslin cloth.
20. YOGURT
Pasteurise milk is cultured using starter –
Streptococcus thermophilus and Lactobacillus
bulgarius.
Incubation period – 35ᴼc.
Under acid conditions casein coagulates and yogurt is
produced.
21. BUTTER
Produced from seperated fats of milk.
The cream is pasteurised and started culture is
added at 15 – 21ᴼc causes the development of acidity
and flavour.
Cream is churned until a phase inversion occurs and
converted fat – in – water to water – in – fat emulsion.
After washing butter can be salted.
22. CONCLUSION
Fermenting the foods produces certain nutrients
like B Complex (folic acid and vitamin B12) and
vitamin K.
Fermentation of milk produce certain
peptides(chains of amino acids) inhibit an enzyme
which tends to increase blood pressure.
Fermented dairy products have some protective
effect against cancer of the large colon.
Regular consumption of thayir sadam lower the
incidence of colon tumours.