Plasticizer-free flexible oxygen barrier films and laminates based on negatively charged and acetylated non-cellulosic polysaccharides isolated from biomass

A process for isolating glucuronoarabinoxylan from biomass comprising:

• obtaining a biomass;
• optionally mechanically processing the biomass;
• steam treating the biomass at a temperature and under conditions and for a time sufficient to facilitate extraction of non-cellulosic polysaccharides;
• optionally filtering and washing the steam treated biomass with ethanol;
• performing an alkaline ethanol extraction by:
• preparing a mixture by mixing the steam treated biomass with about 70% ethanol in a liquid:solid ratio ranging from about 20:1 to 1:1 and adding alkali to a final concentration of about 1-5% by weight of the mixture;
• optionally heating the mixture at a temperature and under conditions and for a time sufficient to extract non-cellulosic polysaccharides;
• optionally treating the mixture with about 5% by weight alkali at a temperature and under conditions and for a time sufficient to extract non-cellulosic polysaccharides;
• obtaining a filtrate comprising the non-cellulosic polysaccharides and treating the filtrate with one or more enzymes of a type and amount sufficient to cleave lignin polysaccharide bonds to obtain glucuronoarabinoxylan;
• preparing a precipitate of the glucuronoarabinoxylan by ethanol addition, drying the precipitate, and obtaining glucuronoarabinoxylan having at least 10% molar concentration of arabinose, at least 15% molar concentration of 4-O-methyl glucuronic acid, and a weight average molecular weight of at least 10,000 g/mol.