Effect of ultrasound on the extractibility of corn bran hemicelluloses

Various two-step extraction procedures with and without a short application of ultrasound in the first step were used to examine the effect of sonication on the extractibility and properties of the non-cellulose components of industrial corn bran (CB). The polysaccharides recovered from the extracts of the first (FI) and second (FII) extraction step were characterised by yield and composition. Using water as extractant in the first step, similar yields of total extracted polysaccharides (F-I + F-II) were obtained by the short sonication treatment when compared to the classical procedures using H2O2-containing alkaline media in the first step. The yields of F-I + F-II, showed a substantial increase (10-40%) after application of ultrasound in 1% and 5% NaOH in comparison to those of the classical procedures. The content of the neutral sugar components constituting the CB xylan varied from 65 to 88 mol% in dependence on the conditions used in the first extraction step. (C) 2002 Elsevier Science B.V. All rights reserved.