Volume 17 Part 1 Article 23: From Food to Waste to Food – a High Yield of Mushrooms from Food-Waste Compost

Volume 17 Part 1 Article 23
Year 2008
Title: From Food to Waste to Food – a High Yield of Mushrooms from Food-Waste Compost
Authors: K. Stoknes, K. Høiland, E. Norgaard and J.P. Hammer

Abstract:

Municipal-source separated food waste (MSSFW) is an increasingly abundant, nutritionally rich and complex product low in toxic constituents. Thus, it could be fed to heterotrophic organisms such as pigs or mushrooms. While representing a hygiene problem as feed, composting can help overcome the problem. This combination of community service and crop production represents an economic potential for both mushroom growers and waste handlers. There is little of this kind of work reported elsewhere. In the Nordic countries, MSSFW can be further characterised as acid, moist and having a variable content of non-food objects. When entering composting, its properties will also be affected by pre-treatment. To test its suitability, a currently used MSSFW compost formula and facility provided phase 1 compost. After screening, the MSSFW is pre-treated with Ca(OH)2 and mixed with spruce bark. Process and chemical factors are described. Experiments are presented using this as substrate for Agaricus bisporus and A. brasiliensis. A commercial mushroom compost was included for reference. For A. bisporus, the yield from four breaks was 29.3% on the commercial and 27.9% on the MSSFW compost (no significant difference). For A. brasiliensis, four breaks yielded 9.2% on commercial and 17.8% on the MSSFW compost (significantly higher on MSSFW).

The A. brasiliensis mushrooms contained 8 mg cadmium/kg dry matter when grown on the food waste compost and 8.5 when grown on the commercial compost. Agaricus bisporus contained less than 1 mg/kg DM on both composts. The surprisingly high yields are discussed as well as focus for further work.

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