Black soldier fly larvae, Hermetia illucens L., (BSFL) convert organic waste material into insect biomass, which can then be processed into a profitable and sustainable protein and fat ingredient in animal feeds. In areas where sanitation remains a challenge, the potential to valorise fecal waste material, using the BSFL technology would increase stakeholder participation in improving sanitation and encourage entrepreneurial opportunities. However, remaining barriers still exist, such as product safety. Therefore, the main objectives of this study were to evaluate BSFL development on varying ratios and combinations of differing types of human fecal waste and organic waste material, and to assess if the use of a novel non-thermal treatment technology, low energy electron beam (LEEB), could lead to safe BSFL products. The first part of the study was conducted in Durban, South Africa, where a public private partnership exists between the Ethekwini Municipality and The BioCycle, to innovatively manage fecal sludge from urine diversion toilets (UD). However, BSFL develop poorly on UD fecal sludge, due to the low nutritional quality. Therefore, the substrates tested in this study were: UD fecal sludge, ventilated improved pit latrine fecal sludge (VIP), primary sludge (PS), restaurant food waste (FW), and brewers’ spent grain (SG). To evaluate this, BSFL development (mass), survivability, bioconversion and waste reduction efficiency were measured. Four-day old BSFL were reared on 250 g wet mass of the specified substrate at the start of the experiment, based on an assumed feeding rate of 100 mg of substrate larvae-1day-1. Experiments were conducted under controlled environmental conditions with a temperature of 30 ± 2°C and relative humidity of 60 ± 5 % for 11 days. Results demonstrated BSFL grown on the substrate combination of 37.5% PS, 37.5% VIP and 25% FW (% m/m) had a high dry bioconversion rate of 18.69 ± 2.11% compared to 3.33 ± 2.78% on 100% VIP. To effectively inactivate pathogens that may be present in BSFL reared on human fecal waste, BSFL were inoculated with Escherichia coli (E. coli, strain K-12 MG1655) and passed through continous LEEB at a specified dose to achieve a 3 to 5-log10 inactivation. The attractiveness of using this non-thermal treatment technology is the potential in reducing microbial concentrations without product damage, in addition to extending the shelf life.

Corresponding author’s email address: dorothymugane@yahoo.com; dorothymugane@gmail.com The use of edible insects as potential alternative sources of food ingredients has been proposed as a sustainable approach towards commercialization of edible insects’ value chain in different parts of the world. In Kenya, edible crickets and grasshoppers are among the popularly promoted insects for commercialization. This study assessed the fat quality and phytochemical composition of the newly described cricket species (Scapsipendus icipe) and Gryllus bimaculutus. Crude fat analysis and physico-chemical properties of cricket oil were determined according to standard AOAC methods. Fatty acid composition was determined using gas chromatography-mass spectrometry (GC-MS). Phytochemical analysis was done using UV–Vis spectrophotometry. Fat contents in both cricket species were comparable with a range between 31.7% and 33.5%. Gryllus bimaculutus was found to contain a higher amount of fat (P = 0.0005) indicating potential future viability as a source of oil. A total of 43 fatty acids consisting of 18 saturated fatty acids (SFA), 10 monounsaturated fatty acids (MUFA) and 5 polyunsaturated fatty acids (PUFA). The total SFA:UFA (unsaturated fatty acid) ratio recorded was 1.6: 1.4 while the fatty acid ratio (SFA:MUFA:PUFA) of 1:1:0.7 and 1:1:0.5 was noted for Scapsipedus icipe and Gryllus bimaculutus respectively. This suggests that both species could potentially provide for an adequate fat intake. PUFA proportion was higher in Scapsipedus icipe (25%) than in Gryllus bimaculutus (18%). Proportionately, SFA: MUFA ratio remained constant in both species but PUFA contents were most pronounced in Scapsipedus icipe. Linoleic acid was the main PUFA with Scapsipedus icipe recording the higher value (8.29 mg/100g) and Gryllus bimaculutus the lower value (6.54 mg/100g). Oxalates, phytates and polyphenols were detected in the two species. The values for polyphenols obtained for the two species ranged from 48 to 53 mg/100g. This could point to potential contribution in industrial applications as a preservative of cricket powder by inhibiting lipid oxidation. Overall, findings of this study confirm industrial viability of the two cricket species as a sustainable alternative ingredient in industrial applications through product formulations.

The Black Soldier Fly (BFS) initially known for its role as manure recycler it is now consider as a valuable food source for livestock. The larvae of BSF are rich in crude protein, fat and gross energy. They are also a rich source of micronutrients (iron and zinc) and all essential amino (such as lysine, threonine and methionine). Chitin, chitosan, and chito-oligosaccharides from BSF have immunity-enhancing effects, promote beneficial bacterial growth and inhibition of pathogenic microorganisms. Whereas BFS has an incredible potential contribution in feed security, safety concerns have been raised for its consumption due to the substrates in which it develops. Our project aim to characterize microbes associated to BSF reared in different diets with the aim of (i) characterize and isolate its associated beneficial and detrimental microbes; (ii) evaluate the transmission of potential human/livestock microbial pathogens from processed larvae through animal feeding; and thus (iii) identify the best BSF larvae processing practices for inclusion in animal feed; and finally, (iv) set up the bases for insect farming safety techniques. To this aims, we are currently conducting 16S rRNA and ITS2 region sequencing of larval guts raised in brewery, kitchen, poultry and rabbit waste. Additionally, we plan to evaluate the transmission of microbes (bacteria and fungi) across the entire value chain - BSF larvae processing methods and swine feeding -.

Palatability is an important parameter in fish feed, as it is paramount for its acceptance by cultured species. Spoilage of fish feeds is often related with lipid rancidification present in fish meal and mostly in fish oil. Under a Circular Economy framework, procedures must be introduced to prevent waste at each stage of the supply chain, to maintain materials and resources in the economy for as long as possible and, consequently, minimize the production of wastes. The capacity of the black soldier fly (BSF) Hermetia illucens to be reared under different types of substrates, including several types of wastes, as well as its ability to modulate its biochemical profile by adjusting to its feeding substrate is already well established. Successful attempts have already been performed to improve the lipid profile of H. illucens, by using algae or finfish as substrates, allowing the encapsulation of n-3 polyunsaturated fatty acids (PUFA) and consequently making more feasible the inclusion of BSF meal on the formulation of aquafeeds of carnivorous marine organisms. Here we used an expired salmon aquafeed enriched with fish oil, aiming to achieve the incorporation of n-3 PUFA in H. illucens larvae, which will then be processed as BSF meal. Further, by considering different levels of fishfeed in BSF larval culture, we surveyed the levels of n-3 PUFA that can be incorporated into larval tissues (5th, 3rd and 1st instar) for 2, 7, and 10 days. Different percentages (0%, 25%, 50%,75%, 100%) of expired salmon feed were blended with a control substrate (chicken feed) and used to feed the larvae of H. illucens. The number of days needed to achieve significant differences in H. illucens lipid profile in terms of n-3 PUFA, namely in 20:5n-3 eicosapentaenoic acid (EPA) and 22:6n-3 docosahexaenoic (DHA), was solely of 2 days with 50% of fish feed inclusion. The maximum amount of EPA and DHA present in the larval tissues was 4.46% with 100% substitution for 10 days and 6.18% with 75% substitution and over 7 days of trial, respectively. The goal of the present study was therefore achieved, as it was possible to demonstrate that the lipid profile of H. illucens can be enhanced in n-3 PUFA by using an expired salmon aquafeed to feed developing larvae of BSF.