Considering the projected increase in demand for protein sources, finding alternative sources with lower environmental impacts has become of great importance. Insect mass production has emerged as a potential solution, particularly in Western countries. Previous studies indicate that insect farming together with insect processing stages are responsible for most of the environmental impacts associated with the final product. This study compares the environmental impacts linked to alternative processing technologies for insect protein production to traditional ones using a Life Cycle Assessment (LCA) following the Environmental Footprint methodology. The most relevant impact categories were identified as land use, energy use, freshwater ecotoxicity, water use and climate change. Among the processing treatments, FOP (freezing–oven drying–hot pressing) showed the best environmental performance in terms of all selected impact categories except water use, while the BOS (blanching–oven drying–SFE with CO₂) group had the highest environmental impacts in all categories. The results from this study indicate that the environmental impacts of insect protein production can be reduced by using alternative processing technologies. These findings underscore the importance of carefully selecting processing technologies in order to align with global sustainability ambitions in the food industry. This study contributes to the development of ecologically responsible methods that can be adopted across protein production industries.

(1) Background: VALUEWASTE, a European Commission Horizon 2020 project, is attempting to find new and sustainable sources of protein and fertiliser products using biowaste as a resource. Introducing these products to the market is essential to understand the social acceptance, behavioural changes and socioeconomic impacts related to products and value chains. (2) Methods: The applied framework provides insights from market, socioeconomic, and community acceptance points of view. Initially, we designed the context and targets of the study. The acceptance levels were tested in two study regions: the cities of Murcia (Spain) and Kalundborg (Denmark). Secondly, we established a survey questionnaire (N = 523) combining social acceptance and life-cycle assessment methodology questions. Lastly, we performed a scenario-based workshop discussing behavioural changes related to the introduction of new bio-products to customers. (3) Results: Our study of developing new bio-products (food, feed, fertiliser) from biowaste produced forceful comparative results from the two regions regarding three aspects of social acceptance: market, socioeconomic, and community. (4) Conclusions: The present study, engaging citizens, consumers, producers, and policy makers, provides insights into what is important for the social acceptance of new protein sources for food, feed, and recycled fertilisers from bio-waste in the Murcia and Kalundborg city regions. Our observations, based on analyses applying three dimensions of social acceptance, can be directly applied elsewhere, guiding decision makers on how to fortify social acceptance regarding new circular economy business models and the bioeconomy in Europe.

The VALUEWASTE project can offer a sustainable solution to transform biowaste into added-value bioproducts, such as proteins from microorganisms and insects and biofertilizers. The present study focused on the environmental impacts linked to obtaining these bioproducts, which was performed by the standardized Life Cycle Assessment (LCA) approach, using the Environmental Footprint methodology to evaluate the midpoint impact categories considered. At the same time, the bioproducts coming from biowaste were compared to regular ones: other protein sources and mineral fertilizers. The study results show that these new protein sources are firm candidates to reach the market from an environmental point of view. Furthermore, their environmental impacts could be improved by reducing the energy use (the main contributor) within some impact categories, such as ecotoxicity and global warming. In case of the biofertilizers, their environmental performance was overall worse compared to mineral fertilizers, except for the following impact categories: mineral and metal use and water scarcity. Nevertheless, these biofertilizers come from biowaste, extending the circularity concept, and from local places, reducing the dependency on other actors. Hence, the study showed that the obtained bioproducts are real alternatives to implement in a circular economy. However, continuous improvement of the solution should be performed.

Glucose is one of the most abundant monosaccharides and the easiest carbon source to be consumed by bacteria. In this study, four culture media (LB, M9, M63 and MOPS) were supplemented with glucose at three different concentrations (4, 12.5 and 25 g/L) in the presence of a genetically modified strain of Escherichia coli with the purpose of selecting the most suitable culture medium to obtain ABD (acetoin (A) and 2,3-butanediol (2,3-BD)). The selected medium was M9, the cheapest culture medium, since the ABD yields obtained fermenting 12.5 and 25 g/L of glucose in M9 culture medium at 37°C, atmospheric pressure, initial pH 6.5, 100 rpm and 10% (v/v) of inoculum were similar compared to the ABD yields obtained using M63 and LB culture media. The influence of nitrogen on ABD yield was tested adding sodium nitrate (NaNO₃) or urea ((NH₂)₂CO) to M9 culture medium at three different nitrogen concentrations (2.5, 5.0 and 7.0 g N/L). Adding urea (7.0 g N/L) to M9 supplemented with 25 g/L of glucose improved by 23% the ABD yield at 96 h compared to M9 without urea, reaching a value of 27.2% (g ABD/g glucose). In contrast, the use of NaNO₃ had no significant effect on the ABD yield. GRAPHICAL ABSTRACT