Nabarlatz, D: From agriculture to industry:

Lignocellulosic biomass is a renewable source of raw material for the production of a wide variety of compounds. The thesis deals with the production of xylo-oligosaccharides from agricultural residues (typical from the Mediterranean region of Spain) with potential applications in the food and pharmaceutical fields. The xylo-oligosaccharides were produced by autohydrolysis reaction varying the temperature and reaction time. All the xylo- oligosaccharides obtained showed structural features of a partially O-acetylated 4-O-methylglucuronoxylan with different degrees of substitution depending on the raw material used. Several purification methods were tested for the removal of impurities and/or separation in different molecular weight fractions, like precipitation, ultrafiltration using polymeric membranes and adsorption of impurities onto activated carbons. The antioxidant activity and the immunomodulatory activity of xylo-oligosaccharides were also tested. It was found that all of them have a strong antioxidant activity compared with that of natural products, making them potential candidates for their use as food additives.