When excess food at any stage of the food system can’t be diverted to people in need, the next best option is to feed it to animals. Even with the best systems in place to develop an efficient food system, there will always be some fraction that is not fit for consumption. This material should be recycled and reused to minimize the environmental burden and allow for recovery of part of the resources initially used in its production, processing and transport, creating a more circular food system.
In a circular system, food waste is recycled by treatment to stabilize it, anaerobic digestion and composting are common food waste treatment technologies used to stabilize waste and produce residual materials that can replenish the soil, thus contributing to a circular food system. While a circular system uses resources more efficiently, the approach is not without risk. The authors of this paper investigated heavy metals, halogenated organic compounds, foodborne pathogens and antibiotic resistance genes (ARGs) in the food system and their fates during digestion and composting.
While not impossible to mitigate, design, planning, and waste characterization play tremendous roles in sustainable systems.