We talked about the importance and benefits of fermentation in our last class, but if you missed it or want a recap, here are the highlights!
Also, you can find the links to the dosa recipes here:
What is dosa?
Dosa is a savory crepe that is made from a batter of fermented rice and urad (black gram) dal. (Of note, idlis are steamed rice cakes made from the same batter). The fermentation process is key to the creation of a soft, fluffy batter which produces a delicious, crispy dosa. As we did some research into the details of the fermentation process of dosas, we found some fascinating information that we wanted to share.
What is fermentation?
The process of fermentation transforms food into other products using microorganisms such as yeast and bacteria. These microorganisms ferment the raw ingredients and produce byproducts which are very beneficial to the host.
For dosa fermentation, there are specific lactic acid bacteria that are present in small amounts in the raw ingredients (the rice and dal), and these are multiplied during the soaking process, then again during the resting process after grinding (see recipe for dosa).
Immune-boosting good bacteria
Several studies have isolated a variety of Lactobacillus strains from idli and dosa batter, and most studies isolated Leuconostoc mesenteroides as well. Studies have shown that these bacteria exert antimicrobial and antifungal properties, help to stabilize the environment of the digestive system, can help to better use cholesterol, and are immune boosting. Interestingly, the production of lactic acid from these bacteria inhibits the growth of common food pathogens such as B. cereus, S. aureus, and L. monocytogenes, as well as Salmonella, Shigella, and E.coli. Current research is focusing on further investigations of the beneficial effects of lactic acid bacteria.
Other nutritional benefits of fermentation
Other nutritionally important changes that occur during fermentation include an increase in B and C vitamins, and a decrease in phytate (the hard to digest component of legumes). Some studies have shown a nearly 50% decrease in phytates after fermentation of dosa batter. Additionally, methionine (an essential amino acid – meaning the body cannot produce it naturally and it must come from the diet) is significantly increased after fermentation of dosa batter and also improves the protein content of the final product.
Eating complete proteins
Together, rice and dal create a “complete protein”, meaning the combination contains all 20 of the essential amino acids that our body needs. Legumes contain the amino acid lysine which is lacking in rice, and rice is high in methionine and cysteine, which is lacking in legumes. It is amazing how our ancestors instinctively knew how to combine various foods to optimize the nutritional value!
Ayurveda and digestion
A quick final note about the importance of the digestive system in Ayurveda. According to Ayurveda, Agni, the digestive fire, is both the literal and figurative center of your lifeforce. If your digestive health is strong and balanced, the rest of your body can thrive. If your digestive health is weak, you can accumulate toxins (ama) from improperly digested foods. Added fermented foods regularly to the diet is one way to nourish your gut and has been done for centuries. It is amazing to look at the science behind food, and learn how you can truly achieve optimum health through a well-balanced diet.
Ghosh D, Chattopadhyay P. Preparation of idli batter, its properties and nutritional improvement during fermentation. Journal of food science and technology. 2011;48(5):610-615. doi:10.1007/s13197-010-0148-4.
Agaliya PJ, Jeevaratnam K. Molecular characterization of lactobacilli isolated from fermented idli batter. Brazilian Journal of Microbiology. 2013;44(4):1199-1206.
Tamang JP, Shin D-H, Jung S-J, Chae S-W. Functional Properties of Microorganisms in Fermented Foods. Frontiers in Microbiology. 2016;7:578. doi:10.3389/fmicb.2016.00578.
National Research Council (US) Panel on the Applications of Biotechnology to Traditional Fermented Foods. Applications of Biotechnology to Fermented Foods: Report of an Ad Hoc Panel of the Board on Science and Technology for International Development. Washington (DC): National Academies Press (US); 1992. 5, Lactic Acid Fermentations.Available from: https://www.ncbi.nlm.nih.gov/books/NBK234703/
Rhee SJ, Lee J-E, Lee C-H. Importance of lactic acid bacteria in Asian fermented foods. Microbial Cell Factories. 2011;10(Suppl 1):S5. doi:10.1186/1475-2859-10-S1-S5.