Food Safety of Consuming Black Soldier Fly (Hermetia illucens) Larvae: Microbial, Heavy Metal and Cross-Reactive Allergen Risks

Abstract

Black soldier fly (Hermetia illucens) larvae (BSFL) are a promising, sustainable source of nutrients, however, there is limited knowledge regarding the food safety of consuming BSFL. This study determined the safety of consuming BSFL for direct human consumption in terms of microbial, heavy metal and allergen content. Microbial counts were determined using ISO (International Organization for Standardization) methods, heavy metals were determined using inductively coupled plasma mass spectrometry and allergens were determined via Orbitrap mass spectrometry and ELISA (enzyme-linked immunosorbent assay) kits. Feed and killing method influenced the presence of Bacillus cereus (p = 0.011), and only the killing method influenced Escherichia coli (p < 0.00) and total viable count (TVC) (p < 0.00). Blanching resulted in a 3-log reduction in E. coli and a 3.4 log reduction in the TVC counts. Salmonella spp. and Listeria spp. were not detected in the BSFL samples. Heavy metals were detected although they were below maximum legal limits. Cross-reactive allergens, tropomyosin and arginine kinase, were detected in the BSFL samples, although the clinical significance requires research. The feed fed to the BSFL and blanching were found to influence the safety of consuming BSFL, highlighting the importance of incorporating sufficient decontamination steps, such as blanching, to ensure food safety.

The Effect of Rearing Scale and Density on the Growth and Nutrient Composition of Hermetia illucens (L.) (Diptera: Stratiomyidae) Larvae

“…This may explain the higher Mo and B concentrations in the smaller scale where the larvae were significantly smaller. Nevertheless, the factors that influence the accumulation of micro and macro elements in the larvae is a topic for future research due to their importance for the production of larvae with a higher nutritional value and enhanced safety [65]. The differences observed in this study point out the need for developing industrial larvae harvesting methods that enable the separation of larvae before fully consuming or drying the substrate.…”

Suppression of Methicillin-Resistant Staphylococcus aureus and Reduction of Other Bacteria by Black Soldier Fly Larvae Reared on Potato Substrate

“…Analysis of some larval extracts by Dong et al ( 28 ) found lauric acid and medium-chain fatty acid derivatives in high concentrations with antimicrobial effects against Gram-positive bacteria ( 28 ). Additionally, factors like pH and the enzymatic reactions of the BSFL gut are believed to reduce bacterial populations ( 29 , 30 ). Characterization of antimicrobial peptides, such as the defensin-like peptides, found in BSFL have proven antibacterial effects on both Gram-positive and Gram-negative bacteria ( 29 , 31 , 32 ).…”

Welfare considerations for farming black soldier flies, Hermetia illucens (Diptera: Stratiomyidae): a model for the insects as food and feed industry

“…Larvae are currently fed vegetable, dairy, and bakery byproducts, spent brewers' or distillers' grains, and animal feeds, with short-term plans to expand into food surplus and animal by-products. Long-term plans for BSF propose feeding them manure, municipal waste, and slaughterhouse, meat, or fish waste, though these may present safety concerns for organisms consuming the final BSF as a product (Bessa et al, 2021;EFSA, 2015;FAO, 2021).…”

“…Finally, selective breeding for particular life-history traits (such as fast development, or high fecundity) may result in genetic bottlenecks, inbreeding depression, and potentially colony collapse due to reductions in stress resistance and longevity (Gilchrist et al, 2012); colonies should be carefully managed to maintain genetic diversity, and thus healthier populations (Hoffman et al, 2021;Rhode et al, 2020).…”