Purification, characterization and antioxidant properties of a novel polysaccharide extracted from Sorghum bicolor (L.) seeds in sausage

A novel polysaccharide named Sorghum Water-Soluble Polysaccharide (SWSP) was purified from Sorghum bicolor (L.) seeds. It was structurally characterized by high performance liquid chromatography (HPLC), thin layer chromatography (TLC), Fourier transform-infrared spectroscopy analysis (FT-IR), X-ray diffraction (XRD) and mass spectroscopy (MS). HPLC and TLC showed that SWSP is a glucose polymer. The FT-IR spectrum proved the polysaccharide characteristic band of SWSP. XRD and microscopy analyses revealed that SWSP is a semi-crystalline polymer. Functional properties of SWSP were determined based on Water Holding Capacity (WHC), Oil Holding Capacity (OHC) and emulsification properties. SWSP showed good WHC and OHC, recorded at 3.01 ± 0.03 and 1.02 ± 0.03 g/g, respectively and exhibited excellent emulsion properties even after 168 h (61.5 ± 0.02%). The effect of SWSP on oxidative stability of sausage during storage up to 12 days at 4 °C was investigated. Results showed a high rate (P < 0.05) of oxymyoglobin and low lipid oxidation. The antioxidant activities of SWSP were also studied in vitro. Results demonstrated that the polysaccharides exhibited interesting 1,1-diphenyl-2-picrylhydrazyl (DPPH), ABTS radical scavenging, and ß-carotene bleaching inhibition activities. Overall, this natural polysaccharide was proved to enhance the oxidation stability of sausages, since it can efficiently substitute synthetic antioxidants in meat industry.