Structural characterization, biofunctionality, and environmental factors impacting rheological properties of exopolysaccharide produced by probiotic Lactococcus lactis C15.

Exopolysaccharides (EPSs) possess distinctive rheological and physicochemical properties and innovative functionality. This study aimed to investigate the physicochemical, bioactive, and rheological properties of an EPS secreted by Lactococcus lactis subsp. lactis C15. EPS-C15 was found to have an average molecular weight of 8.8 × 105 Da and was identified as a hetero-EPS composed of arabinose, xylose, mannose, and glucose with a molar ratio of 2.0:2.7:1.0:21.3, respectively. The particle size and zeta potential represented 311.2 nm and - 12.44 mV, respectively. FITR exhibited that EPS-C15 possessed a typical polysaccharide structure. NMR displayed that EPS-C15 structure is → 3)α-d-Glcvi (1 → 3)α-d-Xylv (1 → 6)α-d-Glciv(1 → 4)α-d-Glc(1 → 3)ß-d-Man(1 → 2)α-d-Glci(1 → . EPS-C15 scavenged DPPH and ABTS free radicals with 50.3% and 46.4% capacities, respectively. Results show that the antiproliferative activities of EPS-C15 revealed inhibitions of 49.7% and 88.1% against MCF-7 and Caco-2 cells, respectively. EPS-C15 has antibacterial properties that inhibited Staphylococcus aureus (29.45%), Salmonella typhimurium (29.83%), Listeria monocytogenes (30.33%), and E. coli O157:H7 (33.57%). The viscosity of EPS-C15 decreased as the shear rate increased. The rheological properties of the EPS-C15 were affected by changes in pH levels and the addition of salts. EPS-C15 is a promising biomaterial that has potential applications in various industries, such as food, pharmaceuticals, and healthcare.

Characterization, bioactivities, and rheological properties of exopolysaccharide produced by novel probiotic Lactobacillus plantarum C70 isolated from camel milk.

Various industries highly regard the functionalities and bioactivities of bacterial polysaccharides. We aimed to characterize the exopolysaccharide (EPS) produced by novel probiotic Lactobacillus plantarum C70 (accession number KX881779) isolated from camel milk and to investigate its bioactivities and rheological properties. EPS-C70 had a weight-average molecular weight (Mw) of 3.8 × 105 Da. Arabinose (13.3%), mannose (7.1%), glucose (74.6%), and galactose (5.0%) were the major monosaccharides constituents. EPS-C70 had two endothermic peaks at 76.95 °C and 158.76 °C corresponding to glass transition (Tg) and melting point (Tm), respectively. Zeta potential and particle size of EPS-C70 were -330.71 mV and 525.5 nm, respectively. DPPH and ABTS of EPS-C70 were 75.91% and 49.42% at 10 mg/mL concentration, respectively. The cytotoxic activities against colon cancer and breast cancer lines were 88.1% and 73.1% at concentration 10 mg/mL, respectively. EPS-C70 exhibited shear-thinning behaviour. Salts and pH values had a significant impact on the rheological properties of EPS-C70.

Pectins from cashew apple fruit (Anacardium occidentale): Extraction and chemical characterization.

The cashew tree (Anacardium occidentale) is a tropical evergreen tree largely cultivated in Brazil, which produces the cashew apple, a peduncle rich in carbohydrates and considered an industrial waste of the nut production. Until now, there were no data available about the chemical structure of cell wall polysaccharides found in cashew apple. In this work, its pectic polysaccharides have been characterized through monosaccharide composition, HPSEC, methylation and 13C and 1H/13C HSQC-DEPT-NMR analyses. Highly methyl esterified homogalacturonan with a DE of 76% mixed with arabinogalactan were found. This latter was purified and presented a highly branched type II arabinogalactan (AG II) and small amounts of a type I rhamnogalacturonan in which the AG II could be anchored. These findings about the chemical structure of cashew apple pectins could contribute to develop future nutritional, biotechnological and pharmacological uses for this industrial waste from the cashew nut production.