Physical and functional characterization of succinoglycan exopolysaccharide produced by Rhizobium radiobacter CAS from curd sample

Identification and rheological behaviour of succinoglycan exopolysaccharide (EPS) from Rhizobium radiobacter CAS isolated from curd was published in earlier reports. In current investigation physicochemical and functional properties of CAS EPS has been studied. SEC-MALLS revealed molecular weight (Mw), number molecular weight (Mn) and polydispersity index (PDI) of CAS EPS as 4.05 x 10(6) g. mol(-1), 3.82 x 10(6) g. mol(-1) and, 1.06 respectively. Thermogravimetric analysis showed the high thermal stability of CAS polymer where approximately 77% of CAS hydrocolloid maintain physical integrity and stability with temperature degradation (T-d) at 290 C. Scanning electron microscopy and particle size analysis confirmed the porous and hygroscopic nature and 2.049 pm size of CAS EPS respectively. Equally important functional properties such as water activity (0.55), water solubility (95%), water contact angle (54.83 degrees), water binding capacity (101 g/g), water holding capacity (68.19 g/g), oil binding ability (soybean and groundnut oils were found 4.35 g/g and 3.68 g/g) and swelling index (17.5 mL/g) were examined for CAS EPS. Prevention of syneresis has been studied at 1% CAS EPS concentration which significantly prohibited the degree of syneresis of starch. These physico-functional properties make CAS EPS a prominent candidate for food processing and product development sector. (C) 2019 Elsevier B.V. All rights reserved.