Yacon (Smallanthus sonchifolius) is a South American tuber, known for its numerous health benefits. High levels of inulin and fructooligosaccharides are thought to be responsible for yacon prebiotic effects, which enhance the growth of good bacteria in the intestines. In a mutual effort, researchers from three Brazilian universities have conducted a study to investigate yacon's ability as a carrier of probiotics, specifically Lactobaccilus casei (LC-01), whose presence is said to enhance the benefits of yacon for digestive health.
In this study, L. casei biomass was adhered to dried yacon flakes, and the samples were divided into four groups. The first two groups, labeled A and B, were stored for one hour at 77°F (25°C) and 98.6°F (37°C), respectively. The second pair of groups, labeled C and D, were also stored at the same temperatures, but a trehalose, a 2-glucose sugar, was added to both samples. The samples then underwent a series of inoculations, a 72-hour incubation, followed by a 56-day storage. The sample with the highest number of L. casei colonies was then evaluated in conditions that mimic the human gastrointestinal environment.
There are two important components of these findings: first, the successful adherence of L. casei to dried yacon flakes; and second, the survival of bacteria through the digestive tract.
The sample labeled A, which was kept at 77°F (25°C) without trehalose, contained the highest number of bacterial colonies on the last day of storage, although bacteria count did decrease over time.
Sample A also underwent a gastrointestinal simulation. It was observed that almost 85% of bacterial cells were viable after stomach acid treatment, whereas almost 90% were still viable at the end of the study after exposing them to the intestinal conditions, which shows that bacteria must have developed a protection mechanism from harsh environments roughly half-way through the simulation.
What Does This Mean?
Probiotics have long been associated with improving digestion, strengthening the immune system, and many more. Their most common sources are dairy and fermented products, such as pickles or sauerkraut. This study is promising because it shows the potential of dried yacon as a non-dairy carrier of probiotics to enhance human digestive health.
The methods of incorporation of beneficial bacteria in dried yacon, as well as the processing methods, such as drying or storage, can be improved to protect probiotics from the harsh gastric environment and increase their chance of survival, so they are able to reach the colon and thrive.
- LWT- Food Science and Techonology, Evaluation of dried yacon (Smallanthus sonchifolius) as an efficient probiotic carrier of Lactobacillus casei LC-01, 2017