Characterization of exopolysaccharides from meat borne lactic acid bacteria (LAB)

Abstract

Although certain lactic acid bacteria (LAB) strains producing exopolysaccharides (EPS) are considered unsuitable for fermented meat production which may be misinterpreted as spoilage criteria. Nevertheless, the EPS from meat-borne LAB can be explored for their bio-functional properties that make them valuable in industrial, pharmaceutical and biotechnological applications.Kaddid-borne LAB strains were evaluated for theirEPS production phenotypically based on colony texture ropy or mucoid. The selected EPS-producersWeissella (We.). Cibaria BK2, We. Cibaria BK4 and Pediococcus (Pe.). Acidilactici BK14 were cultured in optimized modified-MRS medium, followed by extraction and quantification of EPS-production yield by phenolsulfuric acid method. W. cibaria BK2 demonstrated the highest EPS production reaching the concentration of 471.66 mg/L. In addition, exhibited the highest DPPH scavenging activity with a removal rate value of 52.02%, while ascorbic acid (1 mg/mL) used as positive control reach ~ 105% of DPPH scavenging activity. Meanwhile, hydroxyl radical scavenging assay, W. cibaria BK2achieved 159.06% inhibition, highlighting its remarkable capacity to neutralize highly reactive oxygen species (ROS). In contrast, the EPS from Pe.Acidilactici BK14 demonstrated the lowest antioxidant performance with DPPH and hydroxyl radical removal rates of 32.2 and 35.63%respectively. The FTIR analysis provided further confirmation of EPS composition by revealing characteristic absorption bands. A broad peak at approximately 3300 cm indicated O-H or N-H stretching vibrations, suggesting the presence of hydroxyl or amine groups. A strong peak near 1700 cm was associated with C=O stretching, typical of carbonyl-containing groups such as ketones or carboxylic acids. Additionally, the region between: 1000-1200 cm showed C-O stretching vibrations, indicative of esters or ethers. These spectral features confirm the presence of high-molecular-weight bioactive compounds, such as polysaccharides, proteins, and organic acids, produced by the tested strains. These finding suggest the potential of EPS from We. CibariaBK2 to be used as naturalsource of antioxidants and textural agent for food, pharmaceuticaland agriculturalapplications