# Mycelium-Based Composites Using Minimally Processed Industrial Hemp Biomass: Impact of Species and Feedstock Ratio on Mechanical Performance Compared to Polystyrene Packaging

## TL;DR

This paper explores using minimally processed hemp biomass with fungi to create sustainable packaging materials that can match or exceed polystyrene foam in strength.

## Contribution

The study is the first to evaluate minimally processed hemp as a substrate for mycelium-based composites without fiber separation.

## Key findings

- Some mycelium-based composites using hemp matched or exceeded polystyrene foam in compressive strength.
- Minimally processed hemp can be a feasible substrate for sustainable biocomposites.
- Three locally available mushroom strains were successfully used in the experiments.

## Abstract

Mycelium-based composites (MBCs\) are formed from lignocellulosic substrates and biopolymer matrices derived from fungal mycelium. Due to their low fossil energy demand and biodegradability, MBCs represent a versatile and sustainable material suitable for a range of applications, with increasing interest focused on packaging. Hemp fibers are an example of natural fibers with great promise as a substrate to improve the mechanical properties of MBCs. However, the separation of bast and hurd fiber requires processing and commercial-scale facilities that are logistically challenging and may be cost-prohibitive. Here, the potential for minimally processed hemp, with no separation of fibers, is evaluated for the first time to demonstrate feasibility as a substrate for MBCs. Screening included different fiber ratios combined with three different, locally available mushroom strains, which are among the most common in MBC research. The resulting MBCs were tested as an alternative to environmentally harmful expanded polystyrene (EPS, or polystyrene foam), with a focus on compressive strength to reflect load-bearing performance. Some MBCs revealed mechanical performance that met or exceeded EPS, demonstrating the utility of minimally processed hemp fiber in biocomposites for safer packaging.