Mechanical properties and water absorption of shiitake mushroom-based films with natural rubber latex

Abstract

Mechanical properties and water absorption were determined of films produced from powdered Lentinula edodes (shiitake) mushrooms with and without the addition of natural rubber latex using 80:20, 60:40, and 40:60 (w/w) mushroom-latex ratios. Pure mushroom material showed a maximum tensile strength of 7.3 ± 0.5 MPa, an elongation at break of 8.2 ± 0.4 %, and a tear strength of 0.65 ± 0.32 N mm -1, while the 40:60 mushroom-latex blend showed values of 2.7 ± 0.1 MPa, 189.3 ± 4.4 % and 4.46 ± 0.98 N mm -1, respectively. Pure latex showed the lowest water uptake after 24 h (6.8 ±4.0 %), which increased with higher mushroom powder content with a maximum of 127.1 ± 9.7 % in the case of the 80:20 mushroom powder-latex blend. Notably, the pure mushroom films demonstrated poor integrity during water absorption tests by gradually falling apart. Together, latex can be used to enhance the integrity, ductility and tear strength of shiitake mushroom-based films, while it reduces the water sorption and maximum tensile strength.