Black soldier fly larvae (black soldier fly larvae, BSFL) reveal extraordinary efficiency in converting organic waste into proteins and oils. Circular economy, food security and sustainable development.
Two very recent scientific reviews highlight the potential of this insect species and the versatility of use of larvae e ash in the production of feed and fertilizers. Waiting for the authorization of the larvae such as novel foods (1,2)
1) Introduction. Larvae of black soldier fly
1.1) Biodigester par excellence
The black soldier fly (Hermetia illucens) is an insect native to Central America, different from the housefly. And it is one of the very few alien (i.e. non-native) insect species that can be bred in the EU. The interest in it has been strong in the last decade, since its larva is a biodigester par excellence.
The BSFL (black soldier fly larvae) is in fact capable of converting organic waste - including by-products of vegetable and animal origin (including manure) - into raw materials for feed, fertilizers, biodiesel, cosmetics. And in perspective, in compliance with specific regulations to guarantee food safety, the larvae can also be authorized as novel foods (3,4)
1.2) Bioconversion, values and yields
The bioconversion natural organic waste via black soldier fly larvae (BSFL) has a double meaning:
- economic. Waste that includes food waste, converted in a short time with a minimum consumption of resources (soil, water, energy), can be reused in the production chains,
- environmental. Insects can remove pollutants and contaminants (eg mycotoxins, pathogenic bacteria), thus contributing to the reclamation of ecosystems.
The yields conversion rates of black soldier fly larvae are phenomenal, as it can virtually recycle up to 85% of ingested biomass. With an average yield of 800 g (up to 1.024 g) of larval biomass starting from 4 kg of waste, in relation to the nutritional properties (proteins and carbohydrates) of the waste (substrate). To which is added the ash.
2) Black soldier fly larvae, BSFL. Agricultural and industrial applications
The feed are today the most interesting application for black soldier fly larvae (BSFL). The dried larvae can be used as they are, in integral form, or in oil or powder. Their richness in proteins and essential amino acids (with the exception of methionine) far exceeds conventional mangos. In quantities that vary according to the substrate (waste) administered to the larvae.
The oil of black soldier fly larvae has a lipid profile and a peculiar composition that allow different uses:
- skin care cosmetics,
- food supplements and drugs, thanks to the precious chitosan with chelating function,
- biopolymers and material for bioplastics,
- biodiesel. according to UNI EN 14214. With significant advantages compared to unsustainable palm oil, as it requires much less soil and water, as well as short times.
3) phrase by BSFL
3.1) Biofertilizer with biostimulating properties
Il ash it is a compost obtained from insect manure, the exhausted substrate and the chitin residues produced by the various moults. It can be used as a biofertilizer in agriculture, to enrich the soil with organic matter biostimulating actions (defense against diseases, stimulation of the rhizosphere and production of phytohormones).
The reduction of waste in ash depends on their composition. The best results were observed in the blend of rejects, rather than in single streams. Conversion efficiency varies between 15 and 50%, depending on the substrate. Some tests have also been carried out for its use in aquaculture feeds (eg tilapia, sturgeon), with excellent results on improving the state of health and quality parameters.
3.2) Production requirements
The reg. EU n. 142/2011 has provided provisions on the production and use in agriculture of ash, which must be subjected to heat treatment at 70 ° C for 60 minutes.
Treatments stabilization (eg. thermophilic composting, vermicomposting) are useful for improving the safety and efficiency of the ash, balancing the microbiota and reducing any phytotoxicity profiles that could inhibit its bio-fertilizer function.
The best results on different crops have been found with the use of ash (rich in phosphorus, potassium, micronutrients) not in purity but in combination with other fertilizers that provide nitrogen.
4) Hermetia illucens, nutritional properties
4.1) Nutritional values
Nutritional values of the larvae of Hermetia illucens vary in relation to three factors:
- substrate. If the waste used to feed the larvae is deficient in proteins, it is possible to integrate it with protein by-products (e.g. from fishing, aquaculture and fish industry),
- temperature. It is recommended to establish farms near other production plants in order to exploit the heat (through heat exchangers) and favor the ideal growth of black soldier fly larvae at 25-30 ° C,
- transformation process. The spray drying (pulverization) is a short process that allows for higher concentrations of protein and fiber, with lower levels of saturated fat. In the oven, a higher concentration of lipids, especially saturated fats, and mineral salts is reached. Vitamin profiles are very similar, with richness in vitamins B1, B2 and C. (6)
4.2) Nucleotides, peptides and proteins
The nucleotides - namely the molecular units that make up the nucleic acids DNA and RNA, used as stimulants in aquaculture - are present in black soldier fly larvae at levels equivalent to those of fishmeal.
The enzymatic degradation of the proteins of the larvae of the black soldier fly has allowed to obtain 78 peptides and 57 proteins with high antioxidant capacity, with important potential in the food, cosmetic and pharmaceutical / medical sectors. (7)
This process among other things, it made it possible to identify the (few) allergenic peptides and to selectively remove them. Thus increasing the safety of the black soldier fly for food use. (7)
5) Genotyping
Hermetia illucens it is a species native to the Americas (central zone), currently cosmopolitan following its diffusion in different tropical, subtropical and temperate bands. The commercial and research interest has then encouraged its diffusion and exchanges on a planetary level. However, this phenomenon entails a risk for its genetic integrity, as happens for many other species subject to wide distribution.
A COI mtDNA Barcode was created for the express purpose of characterizing the different populations and breeds of black soldier flies, also to confirm that the species is actually Hermetia illucens and keep accidental hybridizations under control. It is therefore recommended that researchers and economic operators register i bar codes genetics of the black soldier fly larvae used (at a very low cost). DNA and biological samples should ideally also be stored for screening methods future, with identification of markers nuclear. (8)
5) Black soldier fly larvae. European, Euro-Mediterranean and Italian research
5.1) Horizon 2020, Horizon Europe
Horizon 2020 e Horizon europe, the European research programs that have followed one another in recent years and are still ongoing, have devoted primary attention to the study of insects as sources of sustainable proteins, as seen. In a perspective of food security and nutritional safety. (9)
The project EcoeFISHent - In Horizon 2020, under the scientific coordination of the University of Genoa - aims to exploit waste from fishing, aquaculture and the fishing industry also through the breeding of black soldier fly larvae. In view of their use as bio-fuel, ingredient in cosmetics and bioplastics, bio-fertilizer.
5.2) FIRST, EIP-Agri and research in Italy
Several universities in Italy they have followed and / or are following projects on black soldier fly larvae. In particular, the following are worthy of note:
- University of Messina. The project Hermeticia wanted to promote and encourage the capacity of the black soldier fly larvae to reduce waste and increase the availability of alternative protein sources, in addition to the various 'collateral' products that can be obtained, (10)
- University of Pisa. FEDKITO is a project co-financed by PRIMA, Partnership for Research and Innovation in the Mediterranean Area. With the aim of creating the packaging sustainable, using chitosan (from chitin extracted from BSFL) to extend the shelf life of various food products (e.g. fruit, vegetables, cheeses), (11)
- University of Basilicata. In a project of the EIP-AGRI program (Agricultural European Innovation Partnership) we wanted to promote the use of black soldier fly larvae to dispose of the nitrogen that derives from the waste in meat livestock and reinsert its output in the production cycle. (12)
6) Provisional conclusions
ROE Gutman - researcher who since 2019 coordinates a project aimed at producing proteins from black soldier fly larvae for food and feed use in aquaculture, at MIGAL (Galilee Research Institute, Israel) - shared with us a reflection on the role of this insect as game changer in the agri-food chain.
The ability of black soldier fly larvae to convert organic waste into proteins, nutrients and micronutrients is a miracle of nature. Its breeding - at relatively low costs and minimal environmental footprint - can fulfill a primary need for food security and contribute to farmers' income.
Dario Dongo and Andrea Adelmo Della Penna
Footnotes
(1) Siddiqui et al. (2022). Black soldier fly larvae (BSFL) and their affinity for organic waste processing. Waste Management 140: 1-13, https://doi.org/10.1016/j.wasman.2021.12.044
(2) Guidini Lopes et al. (2022) Frass derived from black soldier fly larvae treatment of biodegradable waste. A critical review and future perspectives. Waste Management 142: 65-76, https://doi.org/10.1016/j.wasman.2022.02.007
(3) The EFSA opinion on the application for authorization is expected for 27.9.22 novel foods di Hermetia illucens presented on 28.1.19 by Enorm Bifactory A / S (DK). V. Dario Dongo. Insects at the table, Novel Food authorizations in the EU. The state of the art. GIFTS (Great Italian Food Trade). 13.2.22/XNUMX/XNUMX, https://www.greatitalianfoodtrade.it/innovazione/insetti-a-tavola-autorizzazioni-novel-food-in-ue-lo-stato-dell-arte
(4) Leah W. Bessa, Elsje Pieterse, Louwrens C. Hoffman et al. (2021). Food Safety of Consuming Black Soldier Fly (Hermetia illucens) Larvae: Microbial, Heavy Metal and Cross-Reactive Allergen Risks. Foods. 2021 Aug; 10 (8): 1934. doi: 10.3390 / foods10081934
(5) Regulation (EU) no. 142/2011, laying down provisions for the application of reg. EC 1069/2009 laying down health rules relating to animal by-products and derived products not intended for human consumption. Text updated to 28.3.22 on Europa-Lex, https://bit.ly/3rbQtcA
(6) Zulkifli et al. (2022) Nutritional value of black soldier fly (Hermetia illucens) larvae processed by different methods. PLoS ONE 17 (2): e0263924, https://doi.org/10.1371/journal.pone.0263924
(7) Lu et al. (2022) Probing the antioxidant activity of functional proteins and bioactive peptides in Hermetia illucens larvae fed with food waste. Scientific Reports 12: 2799, https://doi.org/10.1038/s41598-022-06668-9
(8) Ståhls et al. (2020) The puzzling mitochondrial phylogeography of the black soldier fly (Hermetia illucens), the commercially most important insect protein species. BMC Evolutionary Biology 20pm, https://doi.org/10.1186/s12862-020-01627-2
(9) Dario Dongo, Andrea Adelmo Della Penna. Proteins for the future, novel food. Challenges and opportunities in the EU. DO (Food and Agriculture Requirements). 15.12.21/XNUMX/XNUMX, https://www.foodagriculturerequirements.com/archivio-notizie/proteine-per-il-futuro-novel-food-sfide-e-opportunità-in-ue
(10) See https://www.progettohermetia.it/
(11) See https://fedkito.agr.unipi.it/
(12) EIP-AGRI. Enhancement of livestock waste through innovative technology based on the use of the bioconverting insect Hermetia illucens. https://ec.europa.eu/eip/agriculture/en/find-connect/projects/valorizzazione-dei-reflui-zootecnici-mediante
Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
