The escalating global population is anticipated to intensify the demand for high-quality proteins, necessitating the exploration of alternative protein sources. Edible insects are a promising solution, owing to their nutritional richness and sustainability. However, their digestibility and protein quality, particularly after culinary treatment, remains underexplored. In the present study, we investigated the effects of various culinary treatments on the protein digestibility of two insect species, Tenebrio molitor and Gryllus assimilis. Our findings revealed that culinary treatments such as boiling, roasting, drying, and microwave heating significantly influenced the digestibility of both insect species. Notably, drying emerged as the most effective method, leading to a substantial increase in digestibility. Furthermore, we assessed protein quality using the digestible indispensable amino acid score (DIAAS) and found that the choice of the calculation method significantly influenced the evaluation of protein quality. By including the sum of the anhydrous amino acids, we eliminated the potential overestimation of protein content and obtained a more reliable assessment of protein quality. Our results underscore the importance of culinary treatments and calculation methods in determining the suitability of insects as protein sources for human nutrition.

This paper reviews the nutritional quality and safety of edible farmed insects from the point of view of the Czech-Slovenian bilateral project: Quality, Safety and Authenticity of Insect Protein-based Food and Feed (INPROFF). Insects as a sustainable source of dietary protein for animal feed and even humans, when integrated into the European agrifood system, could offer a solution to Europe’s feed protein deficit and help alleviate environmental pressure from increasing protein demand, such as declining availability of land, water, marine and energy resources, the overuse of pesticides and reduced biodiversity. However, despite a growing interest in the European Union (EU) in farming edible insects, many economic, scientific, technological, and social barriers remain. In response, Slovenia, represented by the Jožef Stefan Institute, the Biotechnical Faculty of the University of Ljubljana, and Jata Emona d.o.o. (the leading supplier of feedstuffs for the Slovenian market), a country with no history of insect rearing but an interest in alternative protein, joined with the Czech University of Life Sciences Prague, representing the Czech Republic—a country with a history of insect rearing and research into edible insects—to establish INPROFF a three-year bilateral project that aims to close the knowledge gap regarding the quality and safety of insect-based products and boost the farmed insect food and feed value chain. Specifically, it comprises three thematic pillars: (P1) nutritional enhancement, (P2) safety and quality and (P3) authenticity, traceability, and consumer acceptance. The paper also discusses the gaps in the metrological challenges of analysing insects, which will be critical for ensuring safety, quality, and sustainability. The paper finds that although much work has been done, many exciting avenues remain for new research.

With the global population projected to reach nine billion by 2050, the search for alternative protein sources has become critical. This study evaluated the digestibility of cricket protein powder compared with that of whey protein powder. Cricket protein powder had a slightly lower protein content but higher fat content than whey protein powder. Although both contained all essential amino acids, their quantities varied. The most abundant essential amino acid was leucine in both samples. The essential amino acid index (EAAI) for cricket protein powder reached 79% when utilising crude protein for calculation. When using the amino acid sum calculation method, it increased by nearly 13%. The EAAI for whey protein was then 94% when calculated based on crude protein, with a slight increase observed when using the amino acid sum calculation method. Cricket protein exhibited a gradual increase in digestibility during intestinal digestion, reaching nearly 80%, whereas whey protein digestibility surpassed 97%. Despite the lower digestibility of cricket protein compared with whey protein, it remains sufficiently high for consideration as a valuable protein source. This study highlights the potential of cricket proteins and underscores the importance of assessing their protein content and digestibility in evaluating their nutritional value.

The aim of this study was to analyze the functional properties of newly obtained films based on sodium alginate and lecithin with the addition of antioxidant-rich coffee extracts and to verify their potential as safe edible food packaging materials. In our study, we developed alginate–lecithin films enriched with green or roasted coffee bean extracts. The roasting process of coffee beans had a significant impact on the total phenolic content (TPC) in the studied extracts. The highest value of TPC (2697.2 mg GAE/dm³), as well as antioxidant activity (AA) (17.6 mM T/dm³), was observed for the extract of light-roasted coffee beans. Films with the addition of medium-roasted coffee extracts and baseline films had the highest tensile strength (21.21 ± 0.73 N). The addition of coffee extract improved the barrier properties of the films against UV light with a decrease in the transmittance values (200–400 nm), regardless of the type of extract added. Studies on Caco-2, HepG2 and BJ cells showed that digestated films were non-cytotoxic materials (100–0.1 μg/cm³) and had no negative effect on cell viability; an increase was noted for all cell lines, the highest after 48 h in a dose of 1 μg/cm³ for a film with medium-roasted coffee (194.43 ± 38.30) for Caco-2. The tested films at 20% digestate concentrations demonstrated the ability to reduce nitric oxide (NO) production in the RAW264.7 cell line by 25 to 60% compared to the control. Each of the tested films with coffee extracts had growth inhibitory properties towards selected species of bacteria.

Fish are a valuable source of high-quality protein and essential nutrients, making them an integral component of a healthy diet. However, protein digestibility, influenced by preparation methods, is a critical factor in assessing nutritional quality. This study aimed to evaluate the impact of various thermal processing methods on the protein digestibility of two commonly consumed small pelagic fish species: sardines (Sardina pilchardus) and sprats (Sprattus sprattus). Protein digestibility was assessed using two complementary approaches: total protein digestibility and the Digestible Indispensable Amino Acid Score (DIAAS). Fish samples were subjected to different cooking methods, including boiling, steaming, baking, and frying. All thermal treatments enhanced protein digestibility compared to raw fish. Fried samples exhibited the highest total protein digestibility, with sardines reaching 92.4 ± 4.3% and sprats reaching 89.5 ± 4.4%. DIAAS values corroborated these findings, indicating superior protein quality in fried fish. While frying yielded the highest digestibility scores, steaming and boiling provided a favourable balance between improved protein quality and lower potential health risks, with baking achieving comparable results.