Academics at Seoul National University, Jawaharlal Nehru University, the Institute of Engineering and Management, and Government Arts College for Women conducted a study to isolate potential probiotic lactic acid from bhaati jaanr, a traditional rice-based fermented beverage.
They tested nine lactic acid bacteria isolates from bhaati jaanr for potential probiotic properties, and found them to have varying pH and bile salt tolerance, antibiotic susceptibility, and antibacterial activity.
One bacterium in particular, Lactobacillus plantarum strain L7, displayed "satisfactory in vitro probiotic characteristics" — including acid resistance, bile tolerance, and antimicrobial properties — and as such, the researchers conducted a six-day study to determine its performance as a starter culture in rice fermentation.
Subsequently, they observed that L. plantarum L7 lowered pH up to the fourth day of fermentation.
The highest concentrations of succinic acid, lactic acid, and acetic acid were observed on the third, fourth and fifth days of fermentation, respectively, while liquefying and saccharifying activity were at their highest on the second and third days, respectively.
Phytase activity and the cleavage of free minerals (calcium, ferrous, magnesium, manganese and sodium) increased up to the third and fourth days.
In addition, the concentration of several accumulated malto-oligosaccharides — including fructose, and glucose — was at its highest on the fourth and fifth days.
This led the researchers to write that "the probiotic, L. plantarum L7, has a significant role in the fermentation of this beverage and enhances its functional properties".
They added that the results showed L. plantarum L7 to possess "desirable in vitro probiotic properties".
They also assessed its role as a starter culture in preparing bhaati jaanr, and found it increased the levels of functional components (i.e., the minerals and nutrients) in the rice-based fermented beverage.
Furthermore, L. plantarum L7's heightened phytase activity was responsible for enhancing the beverage's mineral bio-availability. Its rapid acidification, as well as organic acid generation, also improved the safety of the end product.
The researchers concluded: "Fermentation with this strain improved the digestibility of the final product by reducing starches and increasing its antioxidant potential.
"Currently, beneficial effects of L. plantarum L7 are under investigation in vitro and in vivo to establish its probiotic characteristic."
Source: Frontiers in Microbiology
"Use of a Potential Probiotic, Lactobacillus plantarum L7, for the Preparation of a Rice-Based Fermented Beverage"
Authors: Sib Sankar Giri, et al.