11 Jun Fermentation: Beyond Probiotics
June 10, 2019
What do dosa, beer, tempeh, and kefir have in common? They are all fermented foods. Some fermented foods like yogurt and sauerkraut are great natural sources of probiotics, but that’s not all that fermented foods are good for! The process of fermentation changes the nutritional profile of the food. Fermentation can reduce FODMAPs (fermentable oligosacharides, disaccharides, and polyols), increase anti-oxidants, increase anti-hypertensive compounds, lower the glycemic index, and improve digestibility. The process of fermentation breaks down proteins making meat and dairy products easier to digest. It also breaks down carbohydrates, thus altering FODMAP levels.
The nutritional benefits of fermentation vary depending on multiple parameters. The first is what food is being fermented. Milks, meats, grains, fruits, and vegetables can all be fermented. The types of sugars naturally found in each food as well as the fat content play into the nutritional changes. The second is which particular strains of bacteria are doing the work. Some fermented foods rely on the bacteria naturally found on or in the food, as is the case with yogurt. Other fermented foods, such as beer, require bacteria or yeast to be added. The third parameter is the culture conditions. This includes variables like temperature, pH, oxygen, and time.
Recent fermentation studies reported interesting and exciting finding! Here are some highlights.
Fat free yogurt is higher in antioxidants than low fat or full fat yogurt.
Fermented fruits and vegetables not only have a much longer shelf-life, but they are also high in probiotics.
Sourdough fermentation produces multiple flavor compounds that allow bread to be made with less salt and still taste good.
Goats milk has high antioxidant levels when fermented with Pediococcus pentosaceus. Lactobacillus rhamnosus PTCC 1637 holds the key for camel milk.
Fermented grains have higher levels of vitamin B-12 than unfermented grains, which is especially important for anyone who eats a mostly plant-based diet.
Antioxidant levels in buckwheat are mostly unchanged by fermentation.
Antioxidants are higher in quinoa fermented with Lb. paracasei than P. pentosaceus.
Fermented dairy products can have anti-hypertensive compounds which work by inhibiting angiotensin converting enzyme.
Fermentation increases folate and other B-vitamins in dairy products.
Thanks to starches being digested during fermentation, sourdough bread has a glycemic index of 54, which classifies it as a low sugar food.
With all of these benefits, it’s no wonder India, Australia, Kenya, and other countries include fermented foods in the national dietary guidelines. More research on fermented foods is needed to know the precise benefits, but the studies thus far have a clear message. Fermented foods, eaten in moderation, are a good addition to the diet. It’s a good thing there are so many to choose from!
If you’re interested in the scientific details, check out the following scholarly article.
Melini F, Melini V, Luziatelli F, Ficca AG, Ruzzi M. Health-Promoting Components in Fermented Foods: An Up-to-Date Systematic Review. Nutrients. 2019 May 27;11(5).