abstract
To study structure-function relationships of pectic polysaccharides with their immunostimulatory activity, broccoli by-products were used. Pectic polysaccharides composed by 64 mol% uronic acids, 18 mol% Ara, and 10 mol% Gal, obtained by hot water extraction, activated B lymphocytes in vitro (25???250 ??g/mL). To disclose active structural features, combinations of ethanol and chromatographic fractionation and modification of the polysaccharides were performed. Polysaccharides insoluble in 80 % ethanol (Et80) showed higher immunostimulatory activity than the pristine mixture, which was independent of molecular weight range (12???400 kDa) and removal of terminal or short Ara side chains. Chemical sulfation did not promote B lymphocyte activation. However, the action of pectin methylesterase and endo-polygalacturonase on hot water extracted polysaccharides produced an acidic fraction with a high immunostimulatory activity. The de-esterified homogalacturonan region seem to be an important core to confer pectic polysaccharides immunostimulatory activity. Therefore, agri-food by-products are a source of pectic polysaccharide functional food ingredients.
keywords
WHITE CABBAGE; CELL-WALLS; IMMUNOSTIMULATORY ACTIVITY; SOLUBLE POLYSACCHARIDES; BIOLOGICAL-ACTIVITY; SIDE-CHAINS; ARABINAN; PURIFICATION; EXTRACTION; FEATURES
subject category
Chemistry; Polymer Science
authors
Ferreira, SS; Correia, A; Silva, AMS; Wessel, DF; Cardoso, SM; Vilanova, M; Coimbra, MA
our authors
