Funding Information: M.A., L.J., J.K., T.M. and A.P. acknowledge support from FinnCERES flagship (151830423) and Business Finland (211835). L.V. acknowledges funding from the Vilho, Yrjö, and Kalle Väisälä Foundation via personal grants. Publisher Copyright: © 2023, The Author(s).Abstract: Foam-formed cellulose biocomposites are a promising technology for developing lightweight and sustainable packaging materials. In this work, we produce and characterize biocomposite foams based on methylcellulose (MC), cellulose fibers (CF), and lignin (LN). The results indicate that adding organosolv lignin to a foam prepared using MC and CF moderately increases Young’s modulus, protects the foam from the growth of Escherichia coli bacteria, and improves...