Use of a Potential Probiotic, Lactobacillus plantarum L7, for the Preparation of a Rice-Based Fermented Beverage

Abstract

This study aimed to isolate potential probiotic lactic acid bacteria from a traditional rice-based fermented beverage “bhaati jaanr” and to evaluate their role during preparation of the beverage. Among various isolates, Lactobacillus plantarum strain L7 exhibited satisfactory in vitro probiotic characteristics such as acid resistance and bile tolerance, cell surface hydrophobicity, auto-aggregation, antibiotic susceptibility, and antimicrobial activities. Therefore, performance of L7 as a starter culture in rice fermentation was determined during a 6-day rice fermentation study. L. plantarum L7 decreased the pH, associated with an increase in total titratable acidity and organic acid production up to the 4th day of fermentation. The highest concentrations of succinic acid (0.37 mg/g), lactic acid (4.95 mg/g), and acetic acid (0.36 mg/g) were recorded on the 3rd, 4th, and 5th days of fermentation, respectively. Saccharifying (148.13 μg/min g−1) and liquefying (89.47 μg/min g−1) activities were the highest on days 3 and 2, respectively, and thereafter, they decreased. Phytase activity and the cleavage of free minerals (sodium, calcium, magnesium, manganese, and ferrous) increased up to days 3–4. The concentration of various accumulated malto-oligosaccharides (glucose, fructose, maltotriose, and maltoterose) was noted to be the maximum on days 4 and 5. Furthermore, gas chromatography-mass spectrometry analysis indicated the presence of various volatile compounds. The fermented material also exhibited 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity. Therefore, the probiotic, L. plantarum L7, has a significant role in the fermentation of this beverage and enhances its functional properties.

Use of a Potential Probiotic, Lactobacillus casei L4, in the Preparation of Fermented Coconut Water Beverage

“…The sensitivity of L. monocytogenes was similar to that reported in a recent study, which showed that fermented MCW inhibited the growth of L. monocytogenes (Kantachote et al, 2017), and those authors showed a much greater zone of inhibition. However, in our earlier study, we have shown the antagonistic activity of the neutralized culture supernatant of L4 (identified as L. casei ) against foodborne pathogens (Giri et al, 2018). In that study, the inhibition zones against pathogens ( S. aureus MTCC737, L. monocytogenes MTCC1143, and B. cereus MTCC6629) ranged between >2 mm and >5 mm (Giri et al, 2018), which are comparable to those observed in this study.…”

“…The L. casei L4 strain was previously isolated from the ethnic fermented rice beverage bhaati jaaner and shown to have probiotic properties in vitro (Giri et al, 2018). The L4 isolate was identified based on its biochemical and morphological properties, and the phenotypic identification was confirmed by 16S rRNA gene sequencing, which revealed 99% similarity to the corresponding gene sequence of several L. casei strains.…”

“…The CW was pre-filtered through a 0.65-μm polyethersulphone filter (Sigma-Aldrich) before being filtered through 0.45-μm filter paper (Millipore, United States). The pH of filtered CW was adjusted to 6.5 to achieve the optimum pH for the growth of L. casei L4 in MRS medium (Giri et al, 2018). Filtered CW (1 L) was inoculated with a 1.0% (v/v) pure culture of L. casei L4 at a final concentration of 10 8 cells/mL.…”

“…Probiotic bacteria are used as nutritional supplements in functional foods, which are easily digestible. Lactic acid bacteria (LAB) are most commonly used for these purposes (Plessas et al, 2017), and of these, members of the Lactobacillus and Bifidobacterium genera are predominantly associated with food fermentation (Plessas et al, 2017; Giri et al, 2018). LAB and other starter cultures transform the biochemical and organoleptic characteristics of substrates, produce various metabolites, and enrich beverages/foods with micronutrients such as minerals, vitamins, amino acids, probiotics, prebiotics, and digestive enzymes (Ray et al, 2016).…”

“…However, only a few archaeal and bacterial species can produce large quantities of vitamin B12, such as Lactobacillus plantarum LZ95 (Li et al, 2017) and Lactobacillus reuteri CRL1098 (Taranto et al, 2003). Previously, we isolated Lactobacillus casei L4 from the Indian ethnic fermented rice beverage “bhaati jaaner” (Giri et al, 2018) and demonstrated that it exhibits satisfactory in vitro probiotic properties, including acid and bile tolerance, antibiotic susceptibility, antagonistic activity against foodborne pathogens, cell surface hydrophobicity, and auto-aggregation. Therefore, in this study, we focused on the production of a functional beverage from CW using L. casei L4, with the aim of improving the health benefits of this beverage.…”