Black Soldier Fly Larvae Biomass Research Articles

Black Soldier Fly Larvae Grown on Hemp Fiber: Nutritional Composition and Production of Potential Bioactive Peptides

Black soldier fly larvae (BSFL) represent a way of converting organic substrates into valuable biomolecules, and are potentially exploitable as feed and food. In the present work, BSFL grown on retted hemp fiber were chemically analyzed to evaluate their nutritional profile. Chemical analysis revealed BSFL biomass to be an interesting source of proteins (40% on dry matter) rich in essential amino acids. In addition, larval biomass contained 12% fat, mainly composed of saturated fatty acids, and β-sitosterol and campesterol were found to be the most abundant among sterols. A total of 9% of the larval biomass was composed of chitin. The investigation extended to the enzymatic hydrolysis of proteins, leading to the identification of potential bioactive peptides. Peptidomics analysis coupled with in silico tools unveiled promising antioxidant, ACE-inhibitory, and DPP-IV-inhibitory properties within the protein hydrolysates. These findings revealed the potential of BSFL grown on retted hemp fiber as a source of dietary compounds as well as bioactive molecules which can be exploited as functional ingredients in the feed and food sectors.

Effect of moisture content on larval gut microbiome and the conversion of pig manure by black soldier fly

The study investigated the influence of varied moisture levels in pig manure on the gut microbiome of black soldier fly larvae (BSFL) and their waste conversion efficiency. This encompassed alterations in nutrient components of both BSFL and pig manure, diversity and characterization of the BSFL gut microbiota, and the reciprocal effects between the BSFL gut microbiota and their growth performance and nutrient composition. Additionally, the investigation delved into the changes in the bacterial community and the presence of potential pathogenic bacteria in pig manure. An initial mixture of fresh pig manure and wheat bran was prepared with a 60 % moisture content (Group A). Distilled water was subsequently added to adjust the moisture levels, resulting in mixtures with 65 % (Group B), 70 % (Group C), and 75 % (Group D) moisture content. Each group underwent BSFL digestion over ten days. Groups C (3.87 ± 0.05 mg/worm) and D (3.97 ± 0.08 mg/worm) showed significantly higher bioconversion efficiencies and enhanced BSFL growth compared to Groups A (2.66 ± 0.21 mg/worm) and B (3.09 ± 0.09 mg/worm) (P < 0.05). A 75 % moisture level was identified as ideal, positively influencing fecal conversion efficiency (FCE) (9.57 ± 0.14 %), crude fat intake (8.92 ± 0.56 %), protein (46.60 ± 0.54 %), and total phosphorus (1.37 ± 0.08 %) from pig manure, and subsequent nutrient accumulation in BSFLs. A decline in larval crude ash content indicated higher organic matter and an increased pig manure conversion rate with elevated moisture. High-throughput sequencing and diversity analyses confirmed different moisture contents influenced the BSFL gut microbiota. Bacteroidetes (32.7–62.0 %), Proteobacteria (6.8–29.3 %), Firmicutes (5.8–23.4 %), and Actinobacteria (1.9–29.0 %) were predominant phyla. A 75 % moisture content significantly impacted the BSFL biomass conversion and growth performance. Additionally, Larval feces met non-hazardous fertilizer standards, according to NY-525 (2012).

Aprovechamiento integral de la Mosca Soldado Negra: Bioconversión, sostenibilidad y desafíos emergentes

The black soldier fly (BSF) has garnered the attention of the scientific community due to its outstanding efficiency in transforming organic waste into raw materials that can be incorporated into the value chain. A bibliometric and bibliographic review was conducted to elucidate the pivotal role played by the bioconversion of organic matter in shaping sustainable circular economy systems. The analysis revealed that black soldier fly larvae (BSFL) have proven effective in the bioconversion of common waste, such as household and livestock waste, yielding valuable biomass. Despite these advancements, the exploration of new sources of organic matter persists to mitigate its environmental impact. Emerging technologies enable the efficient processing of BSFL biomass, yielding substitutes for environmentally unfriendly materials. Although the literature emphasizes the advantages of BSF in constructing circular economy models, obstacles such as limited legislation and insufficient incentives for producers, concerns about pathogens and contaminants, and low public acceptance of this species are identified. However, the growing trend in scientific interest suggests that BSF could play a central role in building sustainable societies in the future.

Analysis of Chemical and Phytotoxic Properties of Frass Derived from Black Soldier Fly-Based Bioconversion of Biosolids

Black soldier fly (BSF)-based bioconversion can reduce significant volumes of biosolids and other organic waste while generating high-value BSF larvae (BSFL) and frass. While the mass of frass is greater than the BSFL biomass, its end use is less explored, especially when the bioprocessed waste, such as biosolids, contains high concentrations of contaminants. We assessed the potential to use frass from bioconverted biosolids as fertiliser by analysing chemical parameters and conducting phytotoxicity germination tests. We included frass from bioconverted food waste and wheat bran as comparisons. The chemical composition and phytotoxicity of the frass was related to the type of feedstock. Frass originating from biosolids and from wheat bran had the highest phytotoxicity, which was correlated with increased NH4+-N and EC. Initially, these feedstocks had significantly higher total N compared to food waste. Frass derived from food waste showed the lowest phytotoxicity, which was related to low NH4+-N and EC. This study demonstrates that frass from BSF-based bioconversion could be used as fertiliser; however, the original feedstock will dictate how this by-product has to be used. In this study, frass from food waste was most suitable as fertiliser. Frass originating from bioconverted biosolids needs to be applied at similar rates as unconverted biosolids to avoid phytotoxicity.

Enhancement of fruit byproducts through bioconversion by Hermetia illucens (Diptera: Stratiomyidae).

Bioconversion is a biological process by which organic materials are converted into products with higher biological and commercial value. During its larval stage the black soldier fly Hermetia illucens is extremely voracious and can feed on a wide variety of organic materials. To study the impact of different fruit byproducts on the insect's growth, final larval biomass, substrate reduction, bioconversion parameters, and larval nutritional composition, 10 000 black soldier fly larvae (BSFL) were reared on 7.0 kg of one of three substrates (strawberry, tangerine, or orange) or on a standard diet as a control. The results highlight that BSFL can successfully feed and grow on each of these diets, though their development time, growth rate, and final biomass were differently impacted by the substrates, with strawberry being the most suitable. The lipid and protein contents of BSFL were similar among larvae fed on different substrates; however, major differences were detected in ash, micronutrient, fiber, fatty acid, and amino acid contents. Overall, the results indicate that fruit waste management through the BSFL bioconversion process represents a commercially promising resource for regional and national agrifood companies. Our study offers new perspectives for sustainable and environmentally friendly industrial development by which fruit byproducts or waste might be disposed of or unconventionally enhanced to create secondary products of high biological and economic value, including BSFL biomass as animal feed or, in perspective, as alternative protein source for human nutrition.

Food industry waste - An opportunity for black soldier fly larvae protein production in Tanzania

Black soldier fly larvae composting is an emerging treatment option with potential to improve biowaste valorization in cities of low-income countries. This study surveyed the current generation and management status of food industry biowaste and their availability and suitability as potential feedstock for black soldier fly larvae (BSFL) composting treatment in three Tanzania cities, Dar es Salaam, Mwanza, and Dodoma. Biowaste-generating food industry companies (n = 29) in the three cities were found to produce banana peels, mango seeds, sunflower press cake, brewery waste, and coffee husks in large quantities (~100,000–1,000,000 kg y−1). Around 50 % of these companies (16/29), primarily vegetable oil companies (10/11), either sold or gave away their waste as animal feed, while most companies (9/11) with unutilized food industry waste landfilled the generated biowaste. Multi-criteria analysis based on substrate availability criteria identified banana peels, mango seeds, and coffee husks with total score points of ≥10/12 as the most suitable feedstock for BSFL composting. However, multi-criteria analysis based on physical-chemical criteria identified brewery waste and sunflower press cake with total score points of ≥11/15 as the most suitable feedstock. Combined availability and physical-chemical properties of individual biowastes showed that all identified types of food industry biowaste can be suitable feedstock for producing BSFL biomass for protein production, but certain waste streams needed to be mixed with other waste streams prior to BSFL-composting to ensure sufficient availability and provide a balanced nutritional profile compared with the single-source biowastes. This study concluded that large volumes of food industry waste are being generated from food industry companies in Tanzania and there is need to establish new biowaste management interventions for resource recovery. Furthermore, for interested stakeholders in the waste management business, multi-stream BSFL-composting can be a suitable solution for managing and closing nutrient loops of the unutilized food industry biowaste in Tanzania and in other similar settings globally.

Mixed microalgae-food waste cake for feeding of Hermetia illucens larvae in characterizing the produced biodiesel

The industrial use of insects, their products, interactions, or activities has been known as industrial entomology. The current study focused on evaluating the effect of mixing the organic food waste with its half percentage of microalgae on the biodiesel production and characterization. The black soldier fly larvae (BSFL) were reared on the organic waste (OW) (fruits, vegetables, and kitchen) only and OW mixed with microalgae, Chlorella vulgaris. Additionally, the levels of oxidants and antioxidants in the biodiesel, after the antioxidants incorporation (ascorbic acid, α-tocopherol, and catechin), were evaluated. The BSFLBD was produced from lipid extraction of BSFL biomass by chloroform/methanol mixture, followed by acid catalyzed esterification and alkaline catalyzed transesterification. The biodiesel yield from the larvae fed on mixed OW-microalgae for 14 days was enhanced by 1.4 folds than the yield of OW group. The unsaturated oleic acid has the most dominant pattern in the fatty acid profile of BSFBD, even in different cases. Lauric (12:0) and myristic (14:0) acids constitute the majority of the methyl ester component of the biodiesel, with amounts of 25.6 and 7.1 for larvae fed on OW, and 25.9 and 7.7 for those fed on OW-microalgae. Following the antioxidants addition, the oxidant's concentration decreased in the biodiesel especially in the insects fed on mixed OW-microalgae. The microalgae added to the organic food waste enhanced the biodiesel quality and quantity of BSFL biomass. Also, the introduction of antioxidants didn't only improve the efficiency of the biodiesel, but also helped in the management of the stress parameters.

Bioconversion of Desiccated Coconut and Soybean Curd Residues for Enhanced Black Soldier Fly Larvae Biomass as a Circular Bioeconomy Approach

Bioconversion of Desiccated Coconut and Soybean Curd Residues for Enhanced Black Soldier Fly Larvae Biomass as a Circular Bioeconomy Approach

Poultry red mite (Dermanyssus gallinae) poses a risk in the rearing of black soldier fly (Hermetia illucens)

The larvae ofHermetia illucens L. (Insecta: Diptera: Stratiomyidae), also known as black soldier fly (BSF), has the unique ability to recycle nutrients from organic wastes. The BSF larvae biomass is a cheap and sustainable protein source that can be used in the feeding of fish, chickens, pigs, and pets. The BSF is a non-pest species, but its mass rearing conditions can attract pathogens and parasites due to the high temperature and moisture requirements. The published literature on the BSF cover aspects such as larval production, conversion efficiency during the rearing stage, adult longevity and mating. However, no published data are available on any parasitic or disease outbreaks in BSF colonies. The present paper reports the first case of an ectoparasite in a BSF colony. The poultry red mite (Dermanyssus gallinae) is an invasive predator of the larvae and pre-pupae of BSF, quickly deteriorating the production and health of BSF colony.

Abattoir sludge and food waste combination as a feed source for black soldier fly larvae: Optimisation of level of larval incorporation in the substrate

The study was conducted to optimize the level of Black Soldier Fly Larvae (BSFL) incorporation in the abattoir sludge and food waste combination. The substrate for the study included a combination of 70 per cent abattoir sludge as the principal substrate (PS) and 30 per cent hostel food waste as the co-substrate (Co- S) for BSFL rearing. Experiments were carried out to fix the level of larval incorporation into 320 g of the substrate and to assess the nutritional qualities of the harvested prepupae. The BSFL were incorporated in four different levels in 320 g of substrate (T1: 150 mg larvae, T2: 450 mg larvae, T3:600 mg larvae and T4: 750 mg larvae). The efficiency of BSFL to feed on the substrate and get converted into biomass was evaluated for the treatment combinations. Among the different treatments, T1had significantly (p&lt;0.001) higher mean prepupal weight and larval survivability. Hence the addition of 150 mg larvae to the 320 g of substrate was found to be optimum for BSFL biomass production.

Predicting black soldier fly larvae biomass and methionine accumulation using a kinetic model for batch cultivation and improving system performance using semi-batch cultivation

Global demand for poultry and associated feed are projected to double over the next 30 years. Insect meal is a sustainable alternative to traditional feeds when produced on low-value high-volume agricultural byproducts. Black soldier fly (BSF) larvae (Hermetia illucens L.) are high in protein and contain methionine, an essential amino acid that is critical to poultry health. BSF larvae can be grown on many organic residues, however, larvae growth and quality vary based on feedstock and cultivation processes. Experiments were completed to monitor temporal changes in BSF larvae growth and composition using almond hulls as a growth substrate under batch and semi-batch processes and with varying substrate carbon to nitrogen ratio (C/N). A logistic kinetic growth model was developed to predict larval biomass and methionine accumulations during batch production. Estimated ranges of model parameters for larvae maximum specific growth rate and carrying capacity were 0.017–0.021 h−1 and 9.7–10.7 g larvae kg−1 hulls dry weight, respectively. Methionine content in larvae increased from 11.1 to 17.1 g kg−1 dry weight over a 30-day batch incubation period. Larvae-specific growth and yield increased by 168% and 268%, respectively, when cultivated in a semi-batch compared to a batch process. Increasing C/N ratio from 26 to 40 increased density of methionine content in larvae per unit feedstock by 25%. The findings demonstrate a logistic model can predict larvae biomass accumulation, harvest time can achieve specific methionine contents, and a semi-batch process is more favorable for larvae biomass accumulation compared to a batch process.

Examination of immune status of rats fed with diet, containing Black soldier fly larvae biomass, during 93 days of ontogenesis

Examination of immune status of rats fed with diet, containing Black soldier fly larvae biomass, during 93 days of ontogenesis

Growth and Nutritional Performance of Black Soldier Fly (Hermetia illucens) Larvae Reared in Fermented Rice Straw and Duck Manure

Black soldier fly larvae (BSFL) are known to convert organic wastes into useful biomass, of which the composition depends on the substrate. It is of interest whether feed protein can be sustainably obtained from waste materials by feeding them to BSFL. This study aimed to convert rice straw and duck manure into BSFL biomass for conversion of waste into animal feed. The growth parameters of BSFL fed with pure fermented rice straw, pure duck manure, and an equal parts mixture of the two as well as its nutritional composition was determined. The larvae’s efficiency to consume and convert the different substrates was also evaluated. Results showed that BSFL fed with duck manure had significantly higher average individual weight of 0.0619±0.004 g, followed by mixture of duck manure and rice straw (0.0614±0.001 g), while those fed solely with rice straw did not accumulate the same biomass (0.0415±0.002 g). Correlations were also made for mass-length, mass-width, and length-width. Mass-length connection was the most reliable correlation (r = 0.732). The harvested BSFL protein was the highest for those fed with rice straw at 34.62%. Feed conversion ratio ranging from 3.71 to 11.3 was achieved for the substrates used. The availability of the waste substrate in large quantities coupled with efficient biomass conversion makes BSFL a sustainable organic matter converter primarily useful as additive to animal feed.

Bioconversion efficiencies, greenhouse gas and ammonia emissions during black soldier fly rearing – A mass balance approach

Black soldier fly larvae (BSFL) are acknowledged for their potential to upcycle waste biomass into animal feed, human food or biofuels. To ensure sustainable BSFL rearing, insight into nutrient bioconversion efficiencies and nutrient losses via gaseous emissions is key. This study used a mass balance approach to quantify nutrient bioconversion efficiencies (i.e., carbon, energy, nitrogen, phosphorus and potassium) and gaseous emissions (i.e., greenhouse gasses and ammonia) of BSFL reared on a substrate used in industrial production. On this substrate, bioconversion efficiencies ranged from 14% (potassium) to 38% (nitrogen). The proportion of dietary inputs found in the residues ranged from 55% (energy) to 86% (potassium), while the proportion of dietary inputs lost via gaseous emissions ranged from 1% (nitrogen) to 24% (carbon). Direct emissions of methane and nitrous oxide during rearing were 16.8 ± 8.6 g CO2-equivalents per kg of dry BSFL biomass. Even though ammonia emissions were minimal, these could have been avoided if larvae would have been harvested before the CO2 peak was reached. Our results provide the first complete mass balance and comprehensive quantification of BSF larval metabolism and GHG emissions, required to assess and improve the environmental sustainability of BSFL production systems.

A Review on Insights for Green Production of Unconventional Protein and Energy Sources Derived from the Larval Biomass of Black Soldier Fly

The purpose of this review is to reveal the lipid and protein contents in black soldier fly larvae (BSFL) for the sustainable production of protein and energy sources. It has been observed from studies in the literature that the larval lipid and protein contents vary with the rearing conditions as well as the downstream processing employed. The homogenous, heterogenous and microbial-treated substrates via fermentation are used to rear BSFL and are compared in this review for the simultaneous production of larval protein and biodiesel. Moreover, the best moisture content and the aeration rate of larval feeding substrates are also reported in this review to enhance the growth of BSFL. As the downstream process after harvesting starts with larval inactivation, various related methods have also been reviewed in relation to its impact on the quality/quantity of larval protein and lipids. Subsequently, the other downstream processes, namely, extraction and transesterification to biodiesel, are finally epitomized from the literature to provide a comprehensive review for the production of unconventional protein and lipid sources from BSFL feedstock. Incontrovertibly, the review accentuates the great potential use of BSFL biomass as a green source of protein and lipids for energy production in the form of biodiesel. The traditional protein and energy sources, preponderantly fishmeal, are unsustainable naturally, pressingly calling for immediate substitutions to cater for the rising demands. Accordingly, this review stresses the benefits of using BSFL biomass in detailing its production from upstream all the way to downstream processes which are green and economical at the same time.

Valorization of exo-microbial fermented coconut endosperm waste by black soldier fly larvae for simultaneous biodiesel and protein productions

The conventional practice in enhancing the larvae growths is by co-digesting the low-cost organic wastes with palatable feeds for black soldier fly larvae (BSFL). In circumventing the co-digestion practice, this study focused the employment of exo-microbes in a form of bacterial consortium powder to modify coconut endosperm waste (CEW) via fermentation process in enhancing the palatability of BSFL to accumulate more larval lipid and protein. Accordingly, the optimum fermentation condition was attained by inoculating 0.5 wt% of bacterial consortium powder into CEW for 14–21 days. The peaks of BSFL biomass gained and growth rate were initially attained whilst feeding the BSFL with optimum fermented CEW. These were primarily attributed by the lowest energy loss via metabolic cost, i.e., as high as 22% of ingested optimum fermented CEW was effectively bioconverted into BSFL biomass. The harvested BSFL biomass was then found containing about 40 wt% of lipid, yielding 98% of fatty acid methyl esters of biodiesel upon transesterification. Subsequently, the protein content was also analyzed to be 0.32 mg, measured from 20 harvested BSFL with a corrected-chitin of approximately 8%. Moreover, the waste reduction index which represents the BSFL valorization potentiality was recorded at 0.31 g/day 20 BSFL. The benefit of fermenting CEW was lastly unveiled, accentuating the presence of surplus acid-producing bacteria. Thus, it was propounded the carbohydrates in CEW were rapidly hydrolysed during fermentation, releasing substantial organic acids and other nutrients to incite the BSFL assimilation into lipid for biodiesel and protein productions simultaneously.

From Waste to Sustainable Feed Material: The Effect of Hermetia Illucens Oil on the Growth Performance, Nutrient Digestibility, and Gastrointestinal Tract Morphometry of Broiler Chickens

Abstract In the present study, the complete cycle of the preconsumer waste transition by black soldier fly larvae (BSFL) into sustainable raw material (dietary fat) for broiler chickens was examined. In two individual experiments, the effects of selected rearing medium made from various preconsumer wastes on the nutritive value and performance of BSFL were tested (1st trial). In the second experiment, partial (25, 50, or 75%) or total replacement of soybean oil fed to broiler chickens by BSFL fat obtained via supercritical CO2 extraction from larvae from the 1st experiment was conducted. In the performance trial on birds, nutrient digestibility, selected gastrointestinal tract (GIT) segments, internal organ traits, and welfare status were also measured. In the first trial, 1-day-old BSFL were allotted to 5 treatments (8 replicates each). The following substrates were tested, i.e., wheat bran, carrots, cabbage, potatoes, and a mixture of the previously mentioned organic food wastes (equal ratio of each). In the second experiment, a total of 960 day-old female Ross 308 chicks were randomly assigned to 5 dietary treatments (16 replicates and 12 birds per replicate). The following groups were applied: SO – 100% soybean oil, HI25 – a mixture containing 25% BSFL fat and 75% SO, HI50 – addition of BSFL and SO in a 50:50 ratio, HI75 – a mixture containing 75% BSFL fat and 25% SO, and HI100 – 100% BSFL fat. The results of the present study showed high variability in the chemical composition of insects among groups (410 vs. 550 g kg−1 CP; 60 vs. 170 g kg−1 EE), as well as a significant influence of rearing substrate composition on BSFL performance, i.e., the average mass of 100 randomly chosen larvae (P&lt;0.001), waste reduction rate (P&lt;0.001), and conversion rate (P=0.008). Moreover, the partial or total replacement of SO by BSFL fat did not affect (P&gt;0.05) the growth performance, coefficients of apparent ileal digestibility of nutrients, selected organ weights and length, or the welfare status of the broilers. In conclusion, it is possible to obtain an environmentally friendly, sustainable energy source from BSFL biomass and implement it in broiler diets without a negative effect on the birds’ production.

An optimal feeding strategy for black soldier fly larvae biomass production and faecal sludge reduction

The dual roles of efficient degradation and bioconversion of a wide range of organic wastes into valuable animal protein and organic fertiliser, has led to increased interest in black soldier fly (BSF) technology as a highly promising tool for sustainable waste management and alternative protein production. The current study investigated the potential application of BSF technology in the valorisation of faecal sludge (FS), a common organic waste in the urban informal settlements in low and middle-income countries. We evaluated the effect of different feeding rates (100, 150, 200 and 250 mg/larva/day), different feeding regimen and supplementation with other waste feedstock (food remains, FR; brewers waste, BW; and banana peelings, BP) on BSF larvae (BSFL) growth rates/yield and FS reduction efficiency. Results showed significantly (P&lt;0.01) higher prepupal yield (179±3.3 and 190±1.2 g) and shorter larval development time (16.7 and 15 days) when reared on 200 and 250 mg/larva/day FS, respectively. However, different feeding regimes of FS did not significantly affect larval growth rate and prepupal yield (P=0.56). Supplementation of FS with other organic substrates resulted in significantly increased BSFL biomass production and substrate reduction, and shortened larval development time; with the effect was more pronounced when FS was supplemented with FR and at 30% supplementation. Protein:fat ratios for BSFL reared on FS, FS:FR, FS:BW were significantly (P&lt;0.05) higher (2.51, 2.53, and 2.44, respectively) compared to FS:BP mixture (1.99). These results demonstrated that supplementation of FS with locally available organic waste can be used to improve its suitability as feedstock for BSF production and organic waste bioremediation from the environment. In conclusion, a daily feeding strategy of substrate containing FS supplemented with 30% organic waste co-substrate at feeding rate of 200 mg/larva/day can be used as a guideline for BSFL mass production and bioremediation of FS both at small- and large-scale level.

Potential Protein and Biodiesel Sources from Black Soldier Fly Larvae: Insights of Larval Harvesting Instar and Fermented Feeding Medium

Primarily produced via transesterification of lipid sources, fatty acid methyl ester (FAME) of biodiesel derived from insect larvae has gained momentum in a great deal of research done over other types of feedstock. From the self-harvesting nature of black soldier fly larvae (BSFL), research had, however, only concentrated on the harvest of BSFL on sixth instar. Through rearing BSFL on coconut endosperm waste (CEW), 100 BSFL were harvested at the fifth and sixth instar, then modification on CEW with mixed-bacteria powder was carried out. It was found that the fifth instar BSFL had 34% lipid content, which was 8% more than the sixth instar. Both instars had similar corrected protein contents around 35–38%. The sixth instar BSFL contained around 19% of chitin, which was about 11% more than the fifth instar. Biodiesel products from both instars showed no differences in terms of FAME content. With modification on CEW, at 0.5 wt% of mixed-bacteria powder concentration, the maximum waste-to-biomass conversion (WBC) and protein conversion (PC) were achieved at 9% and 60%, respectively. Moreover, even with the shorter fermentation time frame of CEW, it did not affect the development of BSFL in terms of its WBC and PC when fed with 14 and 21 days fermented medium. FAME from all groups set, which predominantly constituted about C12:0 at around 60%, followed by C14:0 at around 15%, C16:0, and C18:1 both at 10% on average. Lastly, the FAME yield from BSFL was improved from 25% (sixth instar) to 33% (fifth instar) and showed its highest at 38.5% with modification on raw CEW with 0.5 wt% mixed-bacteria powder and fermented for 21 days. Thus, harvesting BSFL at earlier instar is more beneficial and practical, as it improves the FAME yield from the BSFL biomass.

Enzyme-assisted extraction of insect fat for biodiesel production

Black soldier fly larvae (BSFL), high-fat-containing insects, are a promising non-edible feedstock for biodiesel production. Extracting fat from BSFL biomass for biodiesel production by using traditional methods requires a high amount of solvent, long extraction time, and thermal conditions. To address these limitations, this study proposed an enzyme-assisted extraction method for extracting fat from BSFL biomass for biodiesel production. Different proteases were used to pretreated BSFL biomass prior to the extraction by n-hexane. Among the tested enzymes, Protamex was the most effective for the pretreatment, resulting in the highest fat yield (2.2-fold increase in the fat yield, compared with the extraction without enzymatic treatment). The extraction of insect fat using Protamex-assisted pretreatment was then optimized using response surface methodology (RSM). A four-factor, three-level Box–Behnken design was employed to optimize the factors for the highest fat yield using 27 experimental runs. The optimized conditions were water-to-biomass weight ratio of 4.33:1, enzyme amount of 3.85%, enzymatic treatment temperature of 38.1 °C, and enzymatic treatment time of 4.27 h for a maximum fat yield of 36.09%. The extracted BSFL fat was then used as feedstock for producing biodiesel. Most properties of the synthesized biodiesel met American Society for Testing and Materials (ASTM) specification D6751 and European standard EN 14214. The enzyme-assisted extraction process was then proposed for use in large-scale operations to evaluate its economic feasibility, revealing promising industrial applications. This study suggests that the enzyme-assisted extraction is an efficient method for extracting insect fat, and the extracted fat has potential for use as oil for biodiesel production.