Xylan from oat spelts: Extraction and possible use

Abstract

Oat spelts contain high amounts of xylan whereas the lignin content is com-paratively low. This raw material is an interesting candidate for the isolation of xylan. Oat spelts are available in large quantities in oat mills with com-paratively low price. The xylan content showed a large variation from 22 % to 39 %.During the recent years an emerging interest can be registered for the use of renewable resources as a feedstock for chemicals. New processes have been proposed for the separation and isolation of the individual components of agricultural plant residues: cellulose, lignin and xylan. A wide and cheap access to xylan will open new applications as a polymeric material. A new generation of coatings, hydrogels, paper additives is waiting to be discovered. We are convinced that hemicelluloses and especially xylan will play an im-portant role in future world with decreasing dependency from petrochemical resources to a sustainable economy. Oat spelts from different sources were analysed regarding their chemical composition. In the first stage, separation has been made according to provenance, only, as the wholesalers of grain were collecting green oats from different farmers without differentiating bo-tanical species. Between spelts from oats purchased from Finland, Australia and two German sources major differences have been identified as shown in the table. The hydrolysis residue is an indication for the lignin content of the spelts.Furthermore, the result of adding up the xylose and arabinose (arabi-noxylan) content delievers an indication for the possible quantity and quality of xylan. The part of Peter Koelln in the project was the preparation of oat spelts for the isolation of xylan in order to improve quality and yield of xylan and to reduce the quantity of chemicals for the extraction. Using oat spelts coming from the hulling without other impurities, a yield of 70 % to 75 % of intake oat spelts will be achieved.