Formulation of bio-hydrogels from Hericium erinaceus in Paulownia elongata x fortunei autohydrolysis aqueous extracts

From the paper

Abstract

Elaboration of bio-hydrogels was proposed using autohydrolysis extracts of Hericium erinaceus and Paulownia elongata x fortunei (leaves, bark and petioles). Paulownia extracts have been used as a solvent of H. erinaceus gels to provide an enrichment in phenolic content and confer antioxidant properties. Autohydrolysis under non isothermal heating of H. erinaceus was optimized. Regarding to antioxidant features, 210 °C was established as optimal extraction temperature. At this temperature, the extraction yield (67.4 g/100 g mushroom), the total phenol content (2.2 g GAE/100 g extract) and the antioxidant capacity (5.6 g Trolox eq./100 g extract) were maximum. The extract produced at 210 °C contained 30% oligosaccharides, mostly composed of glucose. Rheological testing indicated that glucan-based hydrogels formulated with selected H. erinaceus extracts in the presence of hydrothermal liquors of Paulownia exhibited stronger viscoelastic properties (around 30-fold) than those prepared with their commercial counterparts. The greatest enhancement of the mechanical properties was identified for hydrogels prepared with hydrothermal H. erinaceus extracts treated at 160 °C enriched with Paulownia petioles liquors (elastic modulus: 7 10³ Pa, viscous modulus: 10³ Pa), followed by barks and leaves ones. The absence of syneresis was identified for hydrogels prepared with tested hydrothermal extracts.