Insects are becoming increasingly relevant as protein sources in food and feed. The Black Soldier Fly (BSF) is one of the most utilized, thanks to its ability to live on many leftovers. Vegetable processing industries produce huge amounts of by-products, and it is important to efficiently rear BSF on different substrates to assure an economical advantage in bioconversion and to overcome the seasonality of some leftovers. This work evaluated how different substrates affect the protein and amino acid content of BSF. BSF prepupae reared on different substrates showed total protein content varying between 35% and 49% on dry matter. Significant lower protein contents were detected in BSF grown on fruit by-products, while higher contents were observed when autumnal leftovers were employed. BSF protein content was mainly correlated to fibre and protein content in the diet. Among amino acids, lysine, valine and leucine were most affected by the diet. Essential amino acids satisfied the Food and Agricultural Organization (FAO) requirements for human nutrition, except for lysine in few cases. BSF could be a flexible tool to bio-convert a wide range of vegetable by-products of different seasonality in a high-quality protein-rich biomass, even if significant differences in the protein fraction were observed according to the rearing substrate.

The building sector is responsible for a third of the global energy consumption and a quarter of greenhouse gas emissions. Phase change materials (PCMs) have shown high potential for latent thermal energy storage (LTES) through their integration in building materials, with the aim of enhancing the efficient use of energy. Although research on PCMs began decades ago, this technology is still far from being widespread. This work analyses the main contributions to the employment of PCMs in the building sector, to better understand the motivations behind the restricted employment of PCM-based LTES technologies. The main research and review studies are critically discussed, focusing on: strategies used to regulate indoor thermal conditions, the variation of mechanical properties in PCMs-based mortars and cements, and applications with ground-coupled heat pumps. The employment of materials obtained from wastes and natural sources was also taken in account as a possible key to developing composite materials with good performance and sustainability at the same time. As a result, the integration of PCMs in LTES is still in its early stages, but reveals high potential for employment in the building sector, thanks to the continuous design improvement and optimization driven by high-performance materials and a new way of coupling with tailored envelopes.

The cradle to grave Life Cycle Assessment (LCA) was applied to the preparation of biomaterials derived from proteins, extracted from Black Soldier Flies (BSFs) prepupae, after the larvae were reared on poultry manure-based organic waste. In order to obtain higher added value biomolecules, extraction represents the fundamental step. Therefore, the environmental sustainability assessments of different extraction/fractionation procedures were compared. In this way, it will be possible to consider also their environmental performances in addition to purity, yield and integrity of the extract. A chemical method characterized by one-step proteins extraction was compared to an enzymatic-assisted protocol, employing Bacillus licheniformis protease. Surprisingly, the enzymatic approach resulted for the 31.87% more environmentally impacting with respect to the chemical method, despite its lack of organic solvents and reduction of alkaline and acid solutions employed. Particularly, the long-time necessary to the enzymatic hydrolysis significantly contributed to the environmental impact of this protocol. Therefore, improvements like biomass pre-treatment procedures, or the use of different proteolytic enzymes (e.g. operating at lower temperatures and in shorter times) result needed. Moreover, in order to reduce the environmental load of the protein fraction, attention should also be given to increase extraction yields of lipids and chitin biomolecules obtainable from BSFs prepupae, due to the biorefinery approach under which this study was considered.