A Chemically Safe Way to Produce Insect Biomass for Possible Application in Feed and Food Production

Abstract

Black soldier fly (Hermetia illucens, HI, Diptera, Stratiomydae) has great potential as a food and feed ingredient in the European Union (EU). The production of insects as livestock feed or as food ingredients requires strict monitoring of the content of potentially toxic elements (PTEs) in the growth substrate, to meet the security requirements. This study aims to investigate the presence of PTEs, like cadmium, lead, mercury, arsenic, and nickel, in HI prepupae and in their growth substrates based on coffee roasting by-product and microalgae Schizochytrium sp. and Isochrysis sp. Analyses were carried out via graphite furnace atomic absorption spectrophotometry for Cd, Pb, Ni, and As, and via Direct Mercury Analyzer for Hg. All element concentrations found in growth substrates were below the legal limit of undesirable substances in animal feed (2002/32/EC). Elements concentrations in HI prepupae were in the range (mg kg−1 wet weight) of 0.072 to 0.084 for Cd, 0.018 to 0.026 for Pb, 0.010 to 0.032 for Hg, 0.036 to 0.047 for As, and 0.18 to 0.76 for Ni. Even if HI prepupae accumulated Cd, Pb, and Hg, our results indicated that the risk of exposure to PTEs from HI prepupae consumption is relatively low and in compliance with EU regulations.

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

“…Another contaminant of concern is the heavy metal content. Studies have shown that BSFL bioaccumulate certain heavy metals from their feed, with heavy metals such as cadmium, copper, lead and mercury being of particular concern due the severe health risks associated with their consumption [8,[16][17][18][19][20]. Mercury for example can have bioaccumulation factors ranging from 1.6 [17] to 4.5 [18] in BSFL, and cadmium, which is highly accumulative in BSFL, has bioaccumulation factors of between 2.5 to 9.5 [18].…”

Toxic Elements and Mineral Content of Different Tissues of Endemic Edible Snails (Helix vladika and H. secernenda) of Montenegro

“…The general mean values of selenium in our study were comparable with the content of the latter element in the mealworm (Tenebrio molitor) larvae, which ranged from 0.057 to 0.085 mg kg −1 w.w. [17]. The values of the Se content in the snails of our study (0.04-0.08 mg kg −1 w.w.) were similar with those reported for pork (0.078 mg kg −1 w.w.) and beef (0.064 mg kg −1 w.w.) [18], as well as for the liver (0.06 mg kg −1 w.w.), kidney (0.41 µg/g w.w.), heart and lungs (0.05 mg kg −1 w.w.) of roe deer [19].…”

Occurrence of Antibiotic Resistance Genes in Hermetia illucens Larvae Fed Coffee Silverskin Enriched with Schizochytrium limacinum or Isochrysis galbana Microalgae

“…Cs obtained from a mixture of Robusta and Arabica varieties of roasting coffee (Saccaria caffè S.R.L., Marina di Montemarciano, AN, Italy) was used as a basal rearing substrate (control). The Cs was frozen at −20 °C and then ground to a 2 ± 0.4 mm particle size before the preparation of rearing substrates as detailed by Truzzi et al [ 9 , 24 ]. The experimental substrates were prepared by including increasing percentages (5%, 10%, 20%, and 25%) of freeze-dried S. limacinum (S) or I. galbana (I) microalgae in the basal Cs substrate.…”

“…No antibiotics were used for the commercial and experimental rearing of H. illucens larvae. The details of the rearing conditions are as reported by Truzzi et al [ 9 , 24 ]. At the end of the experiment, larvae, and frass from each of five replicates per substrate type were collected manually under sterile conditions, pooled together to reduce the effect of biological variation, and stored at −20 °C until analysis.…”

“…Given the above premises, the present study was designed to elucidate the possible effect of rearing substrates on the occurrence of selected AR genes in H. illucens larvae as well as on their accumulation or even depletion in frass. In the concept of circular economy, the H. illucens larvae were reared on a basal substrate constituted by coffee roasting byproducts (coffee silverskin, Cs) supplemented with increasing percentages of microalgae ( Schizochytrium limacinum or Isochrysis galbana ) as the source of PUFAs such as docosahexaenoic, stearidonic, and α-linolenic acid [ 9 , 24 ]. On the other hand, Cs, rich in polyphenols and mainly composed of dietary fibers (≈55%), proteins (≈19%), carbohydrates (≈6%), and fat (≈2%), has been reported to have prebiotic and antioxidant activities [ 25 ].…”