Kefir has shot to fame over recent years for its potential health benefits. Using sound technology, Russian scientists believe they have found a way to increase some of these benefits.
Kefir, which is a fermented milk-based drink, is made using kefir grains.
Originating in the Caucasus Mountains centuries ago, kefir has recently seen an impressive uptick in popularity.
Aside from its potential benefits as a probiotic, kefir contains a compound called kefiran that has interested medical researchers.
Kefiran is an insoluble polysaccharide constructed of galactose and glucose; it is produced by certain microbes, such as Lactobacillus brevis, that are present in kefir.
Previous studies have shown that kefiran might have antimicrobial, anti-inflammatory, and wound healing properties. There is also some evidence that kefiran might reduce blood pressure and lower cholesterol levels.
Increasing kefir's powers
Normally, kefiran is present in relatively low concentrations in kefir, so designing a way to boost this product could enhance the drink's healthful benefits.
Recently, researchers from South Ural State University in Chelyabinsk, Russia, set out to boost the levels of kefiran using ultrasound. They have published their findings in the journal Ultrasonics Sonochemistry.
Prof. Irina Potoroko explains, "The main objective of our research was to step up the kefiran content in fermented milk drinks. To this end, we treated milk with ultrasound."
The researchers worked alongside scientists from the Russian State Agrarian University and the National Institute of Technology Warangal in India.
Normally, manufacturers produce kefir by adding a fermentation starter to milk; kefiran gradually accumulates during the fermentation process.
In an effort to up kefiran production, the scientists subjected milk to ultrasound before starting the process. They refer to this as sonication.
Ultrasound and kefir
Ultrasound is high-frequency sound — much higher than the human ear can hear. Treating the milk with this type of sound increased the production of kefiran during fermentation. Currently, though, the researchers are not sure why this boost in production occurs.
"The effects of sonication are interesting; it is not quite clear if ultrasound boosts the development of healthy microorganisms or if it suppresses them and they start producing kefiran as a defense response."
Study co-author Irina Kalinina
In future studies, the team will try to unpick the molecular reasons for the boosted kefiran content. If they can understand why more is produced, they may be able to enhance its production even further.
In the recent study, the researchers also tried to find the optimal ultrasound frequency and duration to achieve the highest kefiran content; just 3 minutes was enough time to significantly increase kefiran levels in the final product.
They hope that this type of research could eventually lead to safe, environmentally friendly ways to boost the benefits of a range of dairy products.