Since ancient times, a variety of fermented foods have been consumed by humans. Fermentation is a very old and economical method of food preparation and preservation. Traditional Indian fermented foods such as dahi and idli have been described as early as 700BC. Fermentation helps to enhance flavour (by causing slight souring), improve digestibility and enhance nutritional and pharmacological properties of foods.
During fermentation, lactic acid bacteria are formed which being acidic help to lower the pH of the intestine and prevent growth of or destroy the unfriendly bacteria. The lactic acid bacteria has a probiotic effect by promoting growth of friendly gut microflora which in turn result in improved nutritional status through increased levels of essential amino acids (proteins), vitamins and fatty acids.
Classification of fermented foods
Cereal based- cereal grains such a rice, ragi, wheat and barley and pulses such as black gram (urad), red gram (masoor) and green gram (moong) are popularly used for fermentation. The products prepared are idli, dosa, dhokla, koozhu, nan, adai, kallapam, paratha, ambali, pazhaiya soru , etc. these are native to certain populations and all of them are not known to us.
Usually cereal or pulse or cereal pulse mix batter is left to ferment overnight. SOmetimes curd or sodium bicarbonate is added to facilitate the process of lactic acid formation.
While most of us are familiar with idli and dosas, some other are foods that are indigenous to the geographical and cultural environments. Dhoklas are prepared much like idlis but make use of bengal gram flour (chana) instead of black gram. Koozhu is the Tamil name for porridge made from finger millet or ragi.
Fermented rice or Pazhaiya soru is prepared by adding water to cooked rice and by incubating the mixture overnight, and finally adding buttermilk and salt and directly consumed.
Buttermilk based cereal pulse mixture: These include dishes such as rabdi from Rajasthan and Kulu and Kadi from Himachal Pradesh. Rabdi or rabadi is prepared by cooking barley, jowar, bajra or corn flour in buttermilk. Kulu uses wheat flour as base and kadhi is prepared using bengal gram flour in buttermilk.
Sweets : Jalebi, the mouth watering sweet from South India , is prepared using refined wheat flour , cud and sugar. Wheat is used as the base for several other sweet dishes including gulgule, bhature and manna in Himachal Pradesh.
Milk based fermented foods: Dahi or curd is most popular and commonly used traditional Indian fermented product. Yak milk is processed into a number of dairy products such as fermented milk(Kurut),cheese(Chhurpi),Chhur churpen, Churkham, Chhu, Philuk, Shyow and Maa.
Vegetable based : Vegetables such as cabbage, cucumber, radish and carrots are often preserved using fermentation techniques. Kanji prepared with grated carrots and mustard seeds is quite popular in North India.
Benefits of fermented foods
Most of the fermented foods were developed so as to provide medicinal or physiological benefits. Some of them are listed below
- Fermented foods are easily digestible making it specially suitable for infants and individuals recovering from illnesses. E.g. idli, dosa
- Fermentation increases availability of many nutrients. The fermentation of ragi to prepare Koozhu increase in thiamine, riboflavin and niacin contents thereby making it a nourishing food for the rural and agricultural workers.
- Dahi, which is the most popular natural probiotic in Indian diet, has been used to cure intestinal disease such as diarrhea, for lowering cholesterol, anti- carcinogenic and anti-diabetic effect
- Fermented Rai helps in curing stomach pain and gas trouble, and significantly improves digestion
- Carrot Kanji is considered to have high nutritional value and cooling and soothing properties
- Fermented foods help to increase immunity by strengthening the gastrointestinal barrier consisting of potent bacteria
- Minerals such as iron and zinc are better absorbed from fermented foods. These are bound to phytic acid in legumes and seeds and during fermentation, phytic acid is broken down
As we can see that the indigenous fermented foods have a specific role to play in health and disease. Once again, this calls for regression to traditional systems. Fermentation should be used wisely as a treatment that enhances nutritive value and taste of food along with formation of lactic acid which feeds and nourishes the friendly gut bacteria producing the much valued probiotic effect.
Traditional Indian fermented foods: A rich source of lactic acid bacteria. Available from: https://www.researchgate.net/publication/233771759_Traditional_Indian_fermented_foods_A_rich_source_of_lactic_acid_bacteria [accessed Sep 19, 2016].