Productions and Characterization of Biocomposite Produced from Solid-State Fermentation of Apple Pomace with Fungi

Abstract

Apple pomace is a by-product from apple juice and cider factories. It has low pH and high nutrient content, which may be detrimental for landfilling. It is a great candidate for conversion into biocomposites through solid-state fermentation (SSF). Apple pomace biocomposite boards were produced by cultivating Rhizomucor sp. and Trametes versicolor in solid-state condition on the apple pomace media to increase the concentration of long-chain polymers in the biocomposite, improving its mechanical properties. Lignocellulosic materials such as wheat straw, wheat bran, and sawdust were incorporated into the media blend in a 1:9 ratio (dw) as fillers to improve mechanical characteristics of the biocomposite. Fungi strain used in SSF and the media blends used showed significant effect on the mechanical properties of the biocomposites. The results indicate that Rhizomucor sp. and Trametes versicolor cultivation could reduce the samples’ percent elongation at break and Young’s Modulus respectively. Addition of wheat straw or sawdust retained the biocomposite’s overall mechanical characteristics. While wheat bran lowered the tensile strength of the biocomposite but produced a plastic-like material with a higher degree of flexibility. No significant interactions between fungal strain and media blend was observed. The apple pomace media with wheat bran and Trametes versicolor cultivation yielded the lowest Young’s Modulus value (3.69 GPa) and the highest elongation (0.93%) amongst the samples tested. The resulting data can serve as preliminary findings for improvements of the material for future industrial applications.