Food waste to new food in an urban context – production, risk assessment and consumer acceptance

Last changed: 25 October 2023

Sustainably produced and safe plant nutrition is needed to produce food in the city. In this project anaerobic digestate based on a high proportion of food waste, produced in biogas plants, has been examined for this purpose.

The focus in waste treatment is currently changing from residues treatment towards resource recovery. This drives a development towards source-separated waste and wastewater systems. In these new treatment systems food waste are collected and subjected to anaerobic degradation, for biogas production, without being mixed with wastewater or other sewage. There are obvious benefits from an environmental perspective in developing urban/local use of the anaerobically digested food waste. Thus, the present project focus on an innovative use of this resource, to allow urban production of healthy food such as oyster mushrooms and new types of leafy vegetables such as Pak Choi. The project addresses a complex area and implies a societal change towards a nutrient loop in the urban context, a prerequisite for the transition towards a biobased society but with hurdles at different levels of the societal context such as legislation, mainstreams beliefs, habits and limitations in knowledge. The project is therefore set in a broader interdisciplinary context including risk assessment and consumer acceptance. The obtained results for indicators relating to crop yield and quality, fate of pollutants (micropollutants, heavy metals, foodborne pathogens) and consumer acceptance of these production systems will assist in further implementation and development of circular food production systems.

Below you will find information and results from the project.

Moving media – a short film describing the project (in Swedish)


Scientific publications Hultberg M, Asp H, Bergstrand KJB, Golovko O (2023) Production of oyster mushroom (Pleurotus ostreatus) on sawdust supplemented with anaerobic digestate. Waste Management 155: 1-7 Hultberg M, Oskarsson C, Bergstrand KJ, Asp H (2022) Benefits and drawbacks of combined plant and mushroom production in substrate based on biogas digestate and peat. Environmental Technology and Innovation 28: 102740 Golovko O, Ahrens L, Schelin J, Sörengård M, Bergstrand KJ, Asp H, Hultberg M, Wiberg K (2022) Organic micropollutants, heavy metals and pathogens in anaerobic digestate based on food waste. Journal of Environmental Management 313 (114997) Weimers K, Bergstrand KJ, Hultberg M, Asp H (2022) Liquid anaerobic digestate as sole nutrient source in soilless horticulture – or spiked with mineral nutrients for improved plant growth. Front. Plant Sci. 13:770179. doi: 10.3389/fpls.2022.770179 Södergren J, Larsson L, Wadsö L, Bergstrand KJ, Asp H, Hultberg M, Schelin J (2022) Food waste to new food: risk assessment and microbial community analysis of anaerobic digestate as a nutrient source in hydroponic production of vegetables. Journal of Cleaner Production 333: 130239 Golovko O, Kaczmarek M, Asp H, Bergstrand KJ, Ahrens L, Hultberg M (2021) Uptake of perfluoroalkyl substances, pharmaceuticals, and parabens by oyster mushrooms (Pleurotus ostreatus) and exposure risk in human consumption. Chemosphere, Nov 12;132898. doi: 10.1016/j.chemosphere.2021.132898. Asp H, Bergstrand KJ, Hultberg M (2021) Circularity in practice: reusing restaurant waste for in-house vegetable production. ISHS Acta Horticulturae 1317: II International Symposium on Growing Media, Soilless Cultivation, and Compost Utilization in Horticulture. doi 10.17660/ActaHortic.2021.1317.32 Pelayo Lind O, Hultberg M, Bergstrand KJ, Larsson Jönsson H, Caspersen S, Asp H (2021) Biogas digestate in vegetable hydroponic production: pH dynamics and pH management by controlled nitrification. Waste and Biomass Valorization 12: 123-133 DOI: 10.1007/s12649-020-00965-y Bergstrand KJ, Asp H, Hultberg M (2020) Utilizing anaerobic digestates as nutrient solutions in hydroponic production systems. Sustainability 12: 10076; doi:10.3390/su122310076


Student thesis (both in English and Swedish)

Master thesis: Michał Kaczmarek. 2021. Investigating the uptake of organic micropollutants by Pleurotus ostreatus as a model fungus via UPLC-MS/MS. Uppsala University Master thesis: Södergren J (2020) Analyses of microbial community in nutrient solution with biofertilizer and risk assessment of establishment of pathogens. Lund University Master thesis: Weimer K (2020) Nutrient dynamics in pak choi cultivation fertilized with biogas digestate – effects of non-nutrient digestate elements and amendment with mineral nutrients. SLU Bachelor thesis: Hjelm N (2022) Kretsloppsnäring - En möjlighet att nyttja stadens resurser. SLU (in Swedish)  Bachelor thesis: Johnsson E (2019) Svampodling i restprodukter. SLU (in Swedish) 


Fact sheets (in Swedish) Asp H, Bergstrand KJ, Hultberg M (2020) Biogödsel som näringskälla vid hydroponisk odling- nitrifiering och pH. LTV-Fakultetens Faktablad 1. (report in Swedish) Hultberg M, Nordström Nilsson K, Jonsson E, Persson C (2019) Odling av ostronskivling på restprodukter. LTV-Fakultetens Faktablad 11. (report in Swedish)




The project "Food waste to new food in an urban context – production, risk assessment and consumer acceptance" is funded by the Swedish research council FORMAS and has been ongoing during the years 2019-2022. The project is interdisciplinary and researchers from several different disciplines are involved. From SLU, the researchers Lutz Ahrens, Håkan Asp, Karl-Johan Bergstrand, Oksana Golovko, Malin Hultberg (project manager), Sara Spendrup, and Karin Wiberg have been involved. Lund University has been involved in the project through Jenny Schelin. Also Hamse Kjerstadius (NSVA) and a large number of Swedish biogas plants have contributed greatly to the project.


Malin Hultberg, Senior Lecturer and External Collaboration Specialist
Department of Biosystems and Technology, SLU, +46 40-41 53 25, +46 73-023 15 74