Black soldier fly (BSF) larvae may play a role in a circular economy by upcycling low-value organic streams into high value biomass. In this paper, the capacity of BSF larvae to process 12 organic side-streams (mono-streams) and two standard substrates (chicken start mash and Gainesville diet) was investigated. Survival, larval mass, feed conversion ratio, and waste reduction were evaluated in relation to the proximate composition of the side-streams used. Survival rates larger than 80% were observed for 10 of the organic mono-streams and the two standard substrates. Maximum mean larval weight ranged from 38.3 mg up to 176.4 mg regardless of high survival and was highly correlated with substrate crude protein content. Feed conversion ratio (range 1.58–8.90) and waste reduction (range 17.0–58.9%) were similar to values reported in other studies in the literature. On low protein substrates (e.g., apple pulp), survival rates remained high, however, possibly due to protein deficiency, limited larval growth was observed. It is concluded that several low value organic side-streams can successfully be processed by BSF larvae, thereby opening the possibility of lowering the costs of BSF farming. Potentially mixing nutritionally distinct mono-streams into a mixed substrate might improve BSF performance. However, more research is needed for optimizing diets to guarantee production of BSF larvae of constant yield and quality.

Insect farming, a potential approach to deal with the increasing global protein demand, is a new activity in the Western world with many unanswered questions regarding product quality and safety. Insects may fulfill an important role in a circular economy by upcycling biowaste into valuable biomass. About half of the total mass of mealworm feeding substrates exists out of wet feed. This can be sourced from biowaste, increasing the sustainability of insect farming. This paper reports on the nutritional profile of yellow mealworm, Tenebrio molitor, reared with supplementation of organic sidestreams. These included unsold vegetables, potato cuttings, fermented chicory roots and horticultural foliage. The evaluation was performed by analyzing proximate compositions, fatty acid profiles, mineral and heavy metal contents. Mealworms fed with potato cuttings doubled their fat content and increased saturated and mono-unsaturated fatty acids. Providing fermented chicory roots increased the mineral content and accumulated heavy metals. Additionally, the uptake of minerals by mealworms was selective as only calcium, iron and manganese concentrations increased. Adding vegetable mix or horticultural foliage to the diet did not significantly change the nutritional profile. In conclusion, sidestreams were successfully recycled into protein-rich biomass and their nutrient content and bio-availability influenced the composition of mealworms.

There is a growing interest in the ability of black soldier fly (Hermetia illucens) larvae (BSFL) to convert low-value organic residues into high-value products. This leads to more publications with conversion data for various organic resources. However, these results are rarely comparable between laboratories due to differences in study protocols. This hinders comparisons among studies, the use of results in practice, and overall advancement in BSFL conversion research. Therefore, a standardised research protocol was developed for nursing, rearing and harvesting of BSFL for feed assessment. The utility of this protocol, was assessed via an international ring test with 9 partners. One batch of Gainesville diet (wheat bran (50%), alfa-alfa (30%) and maize (20%)) was produced and distributed among the partners to avoid dietary variations. Five-day-old BSFL larvae were used for the growth trial with six replicates per partner. Average larval weight was assessed after 3 days, 7 days, and harvest (>10% prepupae). Total yield and frass were recorded, and samples were chemically analysed to allow the quantification of the conversion efficiency. The results were used to calculate the within and between partner variability of the protocol. The results indicate that for the biological parameters (average weight, yield and density) the within partner variability was 24% and the between partner variability was 60%. For the assessed chemical parameters (N, fat, ash, P, K, pH), both the within and between variability was lower (respectively 9 and 28%). The results of this study give a first indication of the variability that can be expected within and between BSFL feeding experiments for different parameters and can therefore serve as guideline when developing a new experimental designs, assess standard operating procedures and other applications. The protocol can be used as first basis for future feed experiments, improving the comparability of results.

Due to its potential as a sustainable protein source, the industrial relevance of Tenebrio molitor, known as yellow mealworm, is set to increase substantially. Given the novelty of its application in the food industry, knowledge is lacking regarding the nutritional quality of commercially farmed mealworms. This study investigated the nutritional composition of larvae from four different rearing facilities in Belgium and specifically investigated whether their nutritional profiles adhered to defined European nutrition claims (Regulation (EC) No. 1924/2006). In particular, the European nutrition claims “high in protein”, “high unsaturated fat”, “high in fibre” and “rich in P, Mg, K, Zn and Mn” were applicable for all mealworm samples on a dry matter basis. On a fresh matter basis, yellow mealworms were found to be “high in protein”, “high unsaturated fat” and “low in sugar”.

Microalgae can form renewable feedstock for many sectors. However, most microalgae commercially cultivated are difficult to grow in colder climates. To overcome this problem one could cultivate cold tolerant algae. One such alga is the red marine alga Porphyridium purpureum. It is currently often cultivated in bag systems in limited volumes. In this study we cultivated P. purpureum at pilot-scale in horizontal tubular reactors in a greenhouse. P. purpureum was grown in batch mode in a total volume of either 350, 500, 1000 or 1500 L. A total of 28 batches, spread over two years, were cultivated reaching a maximum dry weight of 1.94 g L⁻¹. The growth was continuously monitored to calculate the productivities and growth rates. The P and N concentrations were measured frequently during four batches to calculate the P and N usage per gram biomass. To calculate CO₂ fixation efficiencies the total CO₂ consumption was monitored during 6 of the 28 batches. A maximum productivity and growth rate of respectively 0.195 g L⁻¹ day⁻¹ and 0.233 day⁻¹ were achieved while the P and N usage varied from 3.2–6.19 and 14.5–36.6 mg g⁻¹ biomass for P and N, respectively. Growth was supported between 10 °C and 30 °C, while temperatures above 34—35 °C proved to be detrimental. The CO₂ efficiencies differed among the 6 tested periods with the highest utilization efficiency being 13.5% and the lowest a mere 1.5%. Further large-scale, continuous, tests would be needed to fully optimize the cultivation of P. purpureum in larger volumes.

: Black soldier fly (Hermetia illucens) larvae are a new source of high-quality bio-based materials that can be implemented for technical applications. Black soldier fly larvae can be bred in high numbers in small areas and organic waste streams, making large scale industrial breeding possible. Fats from the black soldier fly are very rich in lauric acid, and the fatty acid profile resembles that of palm kernel and coconut oil. Therefore, black soldier fly fats could be envisaged to have similar applications to these plant-derived oils. : The aims of this work were (1) to use black soldier fly fat, palm kernel and coconut oil to synthesize a glycine-acyl surfactant by means of a Schotten-Baumann reaction; (2) to determine the yield and purity of the reaction products; and (3) to determine solubility, foaming capacity, surface tension and critical micelle concentration of the surfactants in comparison to a commercially-available glycinecoconut oil surfactant, Amilite GCS-11®. : The aims of this work were (1) to use black soldier fly fat, palm kernel and coconut oil to synthesize a glycine-acyl surfactant by means of a Schotten-Baumann reaction; (2) to determine the yield and purity of the reaction products; and (3) to determine solubility, foaming capacity, surface tension and critical micelle concentration of the surfactants in comparison to a commercially-available glycinecoconut oil surfactant, Amilite GCS-11®. : It is concluded that black soldier fly fats are a suitable alternative to coconut or palm kernel oil for the preparation of glycine-acyl surfactants.