Can black soldier fly larvae (Hermetia illucens) be reared on waste streams for food and feed? – A safety perspective

The use of insects as feed and food can be part of the solution towards a circular economy, in case the safety of insect products is assured. Black soldier fly larvae (BSFL, Hermetia illucens) can be reared on different waste streams. However, before BSFL can be legally reared on these streams, the safety of BSFL as feed and food should be assessed thoroughly. This study aimed to investigate several food safety aspects of BSFL grown on waste streams. Therefore, BSFL were reared for 7 days on substrate mixtures of waste streams with similar protein and moisture content. These waste streams included fast food waste (FF), mushroom stem (MS), pig manure solids (PS), poultry meal (PM) and slaughter waste (SW). The substrates, BSFL and the frass were analysed for the presence of metals and veterinary drugs. The substrates and BSFL were also analysed for presence of DNA of ruminant, pig and chicken. Some of the metals accumulated in BSFL, although the concentrations in BSFL (as these would be manufactured as feed) were below maximum limits for feed. Only traces of some of the analysed veterinary drugs were found in the BFSL and no accumulation thereof was observed. DNA of ruminant and pig was traced back in BSFL samples, however, chicken was not. A good understanding of the presence of food safety hazards and possible variance thereof in potential substrates, such as waste streams, and their possible residues in insects is necessary for implementation of this circular way of insect feeding in the food chain.