Assessment of the Production of Oligomeric Compounds from Sugar Beet Pulp

In order to obtain pectin-derived oligosaccharides (mainly arabinooligosaccharides and oligogalacturonides), samples of sugar beet pulp (SBP) were subjected to hydrothermal processing under nonisothermal conditions. Experiments carried out to reach temperatures in the range 160-175 degrees C (corresponding to values of the severity factor R-0 in the range 287-835 min) led to comparatively high concentrations of both oligogalacturonides and arabinooligosaccharides. When SBP was treated to achieve a maximum temperature of 160 degrees C (R-0 = 287 min) or 163 degrees C (R-0 = 357 min), the overall amount of oligomers present in the reaction liquors recovered by pressing accounted for 31.2 and 29.9 g/100 g of oven-dried SBP, respectively, with a limited amount of nonvolatile impurities (about 0.15 g/g of oven-dried matter) and a mass ratio of arabinooligosaccharides/oligogalacturonides of about 1:1. Spent solids were washed with water, and the washing liquors were assayed for oligomers. Recovery of washing liquors would increase the overall yield process by 10%, to reach near 33 g/100 g of oven-dried SBP. Washed spent solids (with increased cellulose content) were obtained as a process byproduct.