In situ enzymatic aided formation of xylan hydrogels and encapsulation of horse radish peroxidase for slow release

Xylans have special gelling and film forming properties for production of hydrogels that can be used as encapsulation matrices for slow release of bioactive agents. Hydrogels with particle sizes ranging from 18 nm to >10 μm and zeta potential of up to −19 mV were formed by selective removal of arabinose side chains from oat spelt xylan by recombinant α-l-arabinofuranosidase (AbfB). The xylan concentration significantly (P < 0.05) influenced both the particle size and zeta potential of the oat spelt xylan hydrogels, and the later was also influenced significantly (P < 0.05) by the hydrolysis time. The horse radish peroxidase was encapsulated in situ, both during and after formation of the xylan hydrogels and was released in an active form for a period of 180 min. Thus, the recombinant AbfB presents a biological tool for modification of xylan into biodegradable encapsulation matrices for slow or targeted release of bioactive agents.