Phytochemicals, antioxidant, anti-acetyl-cholinesterase, and antimicrobial activities of decoction and infusion of Pelargonium graveolens.

In Tunisia, Pelargonium graveolens is widely consumed as a food aromatizing hydrosol. Recent studies have shown the potential of plant solvent-free extracts as food and pharmaceutical natural additives. Accordingly, in this study, we investigate the phenolic content, the volatile fractions of green P. graveolens extracts such as infusion and decoction, and we evaluate their biological activities. The total phenolic content of the infusion (27.05 mg GAE/gDM) is significantly different from that of decoction (31.2 mg GAE/gDM). The GC-MS analysis identified about twenty volatile components in both extracts. The DPPH inhibition and the ß-carotene bleaching tests of the infusion and the decoction had considerable results. Besides, infusion and decoction exhibited a relatively high anti-acetyl-cholinesterase activity and a considerable antimicrobial activity against S. aureus, among three tested pathogenic bacteria.

Pelargonium graveolens Aqueous Decoction: A New Water-Soluble Polysaccharide and Antioxidant-Rich Extract.

BACKGROUND: The decoction of Pelargonium graveolens yields an antioxidant-rich extract and a water-soluble polysaccharide. This study aims (1) to investigate the effect of process parameters (extraction time and temperature) on the antioxidant activity of the decoction and the extraction yield of CPGP by response methodology and (2) to study the chemical properties of the optimized decoction and rheological properties of the corresponding extracted polysaccharide. RESULTS: The antioxidant-rich decoction contained about 19.76 ± 0.41 mg RE/g DM of flavonoids and 5.31 ± 0.56 mg CE/gDM of condensed tannins. The crude Pelargonium graveolens polysaccharide (CPGP) contained 87.27 % of sugar. Furthermore, the CPGP solutions (0.5%, 1%, and 2%) exhibited shear-thinning or pseudoplastic flow behavior. A central composite design (CDD) was applied to assess the effects of temperature and time on the antioxidant activity of the decoction, on the one hand, and on water-soluble polysaccharide yield, on the other. The decoction optimization of Pelargonium graveolens aimed to use less energy (93°C for 11 minutes) leading to the highest values of decoction phenolic content (33.01 ±0.49 mg GAE/gDM) and DPPH scavenging activity (136.10 ± 0.62 mg TXE/gDM) and the highest values of CPGP yield (6.97%). CONCLUSION: The obtained results suggest that the CPGP rheological characteristics are suitable for applications in many industries, especially food. The values of optimal conditions showed that Pelargonium graveolens decoction operation could have multiple uses, especially for consuming less energy.

Evaluation of the Efficiency of Ethanol Precipitation and Ultrafiltration on the Purification and Characteristics of Exopolysaccharides Produced by Three Lactic Acid Bacteria.

Exopolysaccharides (EPS) produced by three Lactic Acid Bacteria strains, Lactococcus lactis SLT10, Lactobacillus plantarum C7, and Leuconostoc mesenteroides B3, were isolated using two methods: ethanol precipitation (EPS-ETOH) and ultrafiltration (EPS-UF) through a 10 KDa cut-off membrane. EPS recovery by ultrafiltration was higher than ethanol precipitation for Lactococcus lactis SLT10 and Lactobacillus plantarum C7. However, it was similar with both methods for Leuconostoc mesenteroides B3. The monomer composition of the EPS fractions revealed differences in structures and molar ratios between the two studied methods. EPS isolated from Lactococcus lactis SLT10 are composed of glucose and mannose for EPS-ETOH against glucose, mannose, and rhamnose for EPS-UF. EPS extracted from Lactobacillus plantarum C7 and Leuconostoc mesenteroides B3 showed similar composition (glucose and mannose) but different molar ratios. The molecular weights of the different EPS fractions ranged from 11.6±1.83 to 62.4±2.94 kDa. Molecular weights of EPS-ETOH fractions were higher than those of EPS-UF fractions. Fourier transform infrared (FTIR) analysis revealed a similarity in the distribution of the functional groups (O-H, C-H, C=O, -COO, and C-O-C) between the EPS isolated from the three strains.