Beyond the ban: Bacterial microbiota analysis of Hermetia illucens larvae meat-fed in the context of EU regulation.
Gabriele Spatola, Emma Copelotti, Simone Mancini, Asia Zanzot, Roberta Nuvoloni, Angela Trocino +2 more
Food research international (Ottawa, Ont.)
Abstract
Edible insects are gaining attention as a sustainable source of animal protein for food and feed, and several species have been authorized for such purposes in the European Union (EU). Insect farming must comply with EU food and feed legislation, which prohibits the use of meat and fish as ingredients in rearing substrates. Black soldier fly (Hermetia illucens) larvae (BSFL) represent a sustainable food and feed option, capable of converting former foodstuff products (FFPs) into protein-rich biomass. However, safety concerns remain, and further data is needed to assess the risks associated with meat- and fish-based FFPs used as BSFL substrates. This study aimed to characterize the bacterial microbiota of BSFL reared on substrates containing raw and processed meat-based FFPs, while evaluating the effects of post-rearing treatments (fasting, rinsing, and ethanol -EtOH - washing). Three substrates were tested: a 100% plant-based control (C), and two containing 25% raw meat (R) and 25% processed meat (P). BSFL were sampled at the end of rearing as untreated, after 24 h fasting, rinsing, and 70% EtOH washing. The bacterial microbiota of the rearing substrates and BSFL were analyzed through a metagenetic protocol involving the sequencing of the 16S rRNA V3-V4 region. The dominant taxa were the genera Pseudomonas spp., Providencia spp., Myroides spp., and Sphingobacteriaceae family. Substrate type significantly affected BSFL bacterial microbiota, whereas fasting, rinsing, and EtOH washing had limited impact. Notably, no sequences were assigned to the major foodborne pathogens, (sequences assigned to Staphylococcus spp. have been detected in rearing substrates but not in BSFL). These findings support the potential of BSFL in circular economy strategies, although further microbiological assessments are required before using meat-based FFPs in rearing substrates for insects intended to be used as food or feed.