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The need to increase sustainability in agriculture, to ensure food security for the future generations, is leading to the emergence of industrial rearing facilities for insects. One promising species being industrially reared as an alternative protein source for animal feed and as a raw material for the chemical industry is the black soldier fly ( Hermetia illucens ). However, scientific knowledge toward the optimization of the productivity for this insect is scarce. One knowledge gap concerns the impact of the microbial community associated with H. illucens on the performance and health of this insect. In this review, the first steps in the characterization of the microbiota in H. illucens and the analysis of substrate-dependent dynamics in its composition are summarized and discussed. Furthermore, this review zooms in on the interactions between microorganisms and the insect during H. illucens development. Finally, attention is paid to how the microbiome research can lead to alternative valorization strategies for H. illucens , such as (i) the manipulation of the microbiota to optimize insect biomass production and (ii) the exploitation of the H. illucens -microbiota interplay for the discovery of new enzymes and novel antimicrobial strategies based on H. illucens immunity using either the whole organism or its molecules. The next decade promises to be extremely interesting for this research field and will see an emergence of the microbiological optimization of H. illucens as a sustainable insect for industrial rearing and the exploitation of its microbiome for novel biotechnological applications.

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Freeze drying represents the current practice to stabilize mealworms, even though it is an energy demanding technique. Therefore, it was examined in the present study whether microwave drying could be a proper alternative. To this end, the impact of both drying techniques on the proximate composition, vitamin B content, fatty acid profile, oxidation status and colour parameters of mealworms was investigated. Furthermore, the influence of the application of vacuum during microwave drying was studied. The different drying technologies resulted in small differences in the proximate composition, while the vitamin B content was only reduced by microwave drying. The fat fraction of freeze dried mealworms showed a higher oxidation status than the fat of microwave dried mealworms. Application of a vacuum during the microwave drying process did not appear to offer advantages. This research shows that for mealworms microwave drying can be a proper alternative to freeze drying.

Effect of blanching followed by refrigerated storage or industrial microwave drying on the microbial load of yellow mealworm larvae (Tenebrio molitor), Food Control (2016),

Enset (Ensete ventricosum) provides staple food for 15 million people in Ethiopia after fermentation into kocho. The fermentation process has hardly been investigated and is prone to optimization. The aim of this study was to investigate the physicochemical and microbial dynamics of fermentation practices in the Gamo highlands. These practices show local variation, but two steps were omnipresent: scraping of the pseudostem and fermenting it in a pit or a bamboo basket. Enset plants were fragmented and fermented for two months in order to investigate the physicochemical (temperature, moisture content, pH and titratable acidity) and microbial dynamics (total viable aerobic counts, counts of Enterobacteriaceae, lactic acid bacteria, yeasts and moulds and Clostridium spores counts, and Illumina Miseq sequencing). Samples were taken on days 1, 7, 15, 17, 31 and 60. The pH decreased, whereas the titratable acidity increased during fermentation. Of all counts those of lactic acid bacteria and Clostridium spores increased during fermentation. Leuconostoc mesenteroides initiated the fermentation. Later on, Prevotella paludivivens, Lactobacillus sp. and Bifidobacterium minimum dominated. These three species are potential candidates for the development of a starter culture.

In the present study, inclusion of mealworm (Tenebrio molitor L.) powder into bread doughs at 5 and 10% substitution level of soft wheat (Triticum aestivum L.) flour was tested to produce protein fortified breads. The addition of mealworm powder (MP) did not negatively affect the technological features of either doughs or breads. All the tested doughs showed the same leavening ability, whereas breads containing 5% MP showed the highest specific volume and the lowest firmness. An enrichment in protein content was observed in experimental breads where the highest values for this parameter were recorded in breads containing 10% MP. Breads fortified with 10% MP also exhibited a significant increase in the content of free amino acids, and especially in the following essential amino acids: tyrosine, methionine, isoleucine, and leucine. By contrast, no differences in nutritional quality of lipids were seen between fortified and control breads. Results of sensory analyses revealed that protein fortification of bread with MP significantly affected bread texture and overall liking, as well as crust colour, depending on the substitution level. Overall, proof of concept was provided for the inclusion of MP into bread doughs started with different leavening agents (sourdough and/or baker’s yeast), at 5 or 10% substitution level of soft wheat flour. Based on the Technology Readiness Level (TRL) scale, the proposed bread making technology can be situated at level 4 (validation in laboratory environment), thus suggesting that the production of breads with MP might easily be scaled up at industrial level. However, potential spoilage and safety issues that need to be further considered were highlighted.

As the Belgian market and legislation on insect-based foods have evolved the past years, this study aimed at generating an updated and representative insight into the consumer acceptance of these foods. Data were collected via a telephone survey. The distribution of the 388 respondents across regions, gender and age matched that of the Belgian population. Of those surveyed, 79% were aware of the fact that foods with insects can be bought; 11.2% had already eaten foods with processed insects; 31.8% had no experience but were willing to try, and 57% had no experience or interest in tasting such products. Potential consumers accepted invisible processed mealworms in energy shakes (60.7%), energy bars (59.6%), burgers (59.3%), soup (56.8%), sandwich spreads (56.2%), unfried snacks (56.2%) and fried snacks (52.7%). Consumers indicated that the presence of insects should be clearly declared on the package and that they wanted to be able to buy these products primarily in the supermarket.