Extraction, characterization and biological properties of polysaccharide derived from green seaweed "Chaetomorpha linum" and its potential application in Tunisian beef sausages.

A novel polysaccharide extracted from green algae Chaetomorpha linum (PS) was characterized, using infrared spectroscopy, HPLC-FID, gel filtration high-pressure chromatography, thin layer chromatography and spectrum visible UV. Natural antioxidant potential of PS was evaluated based on DPPH free radical, ferrous iron-chelating, β carotene bleaching inhibition activities and DNA nicking assay. Functional properties were estimated based on Water Holding Capacity (WHC), Oil Holding Capacity (OHC), emulsifying activity and foaming ability. Overall, data showed attractive chemical, functional and biological properties with an antioxidant capacity of PS in beef sausages during storage for 12 days. Indeed, as compared to standard formulation (with addition of vitamin C), samples formulated with PS presented lower values in terms of lipid oxidation (TBARS, MetMb), while preserving color properties compared with untreated samples. Furthermore, lower changes in pH, moisture, and the highest values of heme iron were obtained. Successful inhibition of microbial proliferation was proved. Endowed with high antioxidant and antimicrobial activities, PS could thus be used as a natural conservative in functional foods.