Physico-chemical characterization of protein-associated polysaccharides extracted from sugar beet pulp

Abstract

We have solubilized and separated polysaccharides from sugar beet pulp (SBP) into three fractions with steam assisted flash extraction (SAFE). For pectin, recovery ranged from 8 to 14%, degree of methy-esterification 66-73%, crude protein 1.3-1.7%, M(w) 262-318 kDa, η(w) 0.22-0.23 dL/g, Rg(z) 36-39 nm and Rh(z) 41-42 nm. For alkaline soluble polysaccharides, (ASP I) recovery ranged from 4.0 to 6.5%, crude protein 1.2-4.8%, weight average molar mass (M(w)) 66-68 kDa, weight average intrinsic viscosity (η(w)) 0.27-0.30 dL/g, z-average radius of gyration (Rg(z)) 25-29 nm and z-average hydrated radius (Rh(z)) 10-11 nm. ASP II recovery ranged from 2.0 to 8.6%, crude protein 1.2-4.8%, M(w) 299-339 kDa, η(w) 0.22-0.33 dL/g, Rg(z) 33-34 nm and Rh(z) 30-34 nm. Recovery of the residue mainly cellulose, ranged from 20.3 to 22.3%. The cellulose in this fraction was converted to carboxymethyl cellulose (CMC). The CMC fraction contained 0.33-0.43 crude protein and had an M(w) ranging from 127 to 263 kDa, η(w) 3.6-8.0 dL/g, Rg(z) 35-45 nm and Rh(z) 27-40 nm.