Skip to main content
Research article - Peer-reviewed, 2022

Sustainable Wheat Protein Biofoams: Dry Upscalable Extrusion at Low Temperature

Bettelli, Mercedes A.; Capezza, Antonio J.; Nilsson, Fritjof; Johansson, Eva; Olsson, Richard T.; Hedenqvist, Mikael S.


Glycerol-plasticized wheat gluten was explored for producing soft high-density biofoams using dry upscalable extrusion (avoiding purposely added water). The largest pore size was obtained when using the food grade ammonium bicarbonate (ABC) as blowing agent, also resulting in the highest saline liquid uptake. Foams were, however, also obtained without adding a blowing agent, possibly due to a rapid moisture uptake by the dried protein powder when fed to the extruder. ABC's low decomposition temperature enabled extrusion of the material at a temperature as low as 70 degrees C, well below the protein aggregation temperature. Sodium bicarbonate (SBC), the most common food-grade blowing agent, did not yield the same high foam qualities. SBC's alkalinity, and the need to use a higher processing temperature (120 degrees C), resulted in high protein cross-linking and aggregation. The results show the potential of an energy-efficient and industrially upscalable low-temperature foam extrusion process for competitive production of sustainable biofoams using inexpensive and readily available protein obtained from industrial biomass (wheat gluten).

Published in

2022, volume: 23, number: 12, pages: 5116-5126

Authors' information

Bettelli, Mercedes A.
Royal Institute of Technology
Capezza, Antonio J.
Royal Institute of Technology
Nilsson, Fritjof
Mid-Sweden University
Swedish University of Agricultural Sciences, Department of Plant Breeding
Olsson, Richard T.
Royal Institute of Technology
Hedenqvist, Mikael S.
Royal Institute of Technology

Sustainable Development Goals

SDG2 Zero hunger

UKÄ Subject classification

Polymer Technologies

Publication Identifiers


URI (permanent link to this page)