Every year, over 30% of food production is wasted. However, promoting a sustainable food supply not only fosters economic stability in agriculture and the food industry, but also safeguards precious natural resources and ensures universal food access and safety. Therefore, the aim of the study was to determine how specific growth conditions (utilizing by-products: sprouted potatoes (1), wheat bran (2), brewers’ spent grain (3), and a control sample with agar-agar gels (4)) affect the larvae of yellow mealworms (Tenebrio molitor). This includes their nutritional and energy value, consumer sensory profiling, and technological parameters of processing. The results have indicated that larvae reared on the substrate with wheat bran had the highest energy value, at 708.26 kcal. In larvae, the difference in protein content was not significant when changing the rearing conditions, and ranged between 48.54 and 59.18%. The larvae contained a significant content of fibers, with the highest amount detected in samples with brewers’ spent grain. The data indicate that glucose and arabinose were distinctive to larvae. Our study has also revealed a statistical difference in ash content between larvae and the substrate, with higher levels of nitrogen, copper, and zinc detected in the larvae compared to the substrate. We have found that the salt was naturally occurring in the substrates, with the brewers’ spent grain sample having the highest amount, at 1.83%. However, the control sample yielded the highest ratings, achieving a score of 7.30 for general smell acceptability. These findings emphasize the potential of utilizing various industrial and farm by-products as substrates for mealworms, transforming them into a sustainable and nutrient-rich food source. This contribution adds to the broader discourse on nutritional value and resource efficiency.

Mealworms provide a viable option for transforming agricultural and food processing by-products that can be converted into a valuable source of high-quality protein and fat suitable for both animals and humans. Hence, our investigation was aimed at employing sprouted and green potatoes, wheat bran, and by-products from brewers’ production as a comprehensive substrate for rearing mealworms. The nutritional value (fat and protein content) and composition of amino acids (AAs) and fatty acids (FAs) were tested in lyophilized and milled larvae. The results showed that the highest amount of protein was detected in sample 3L (59.18 ± 007%), grown on brewers’ spent grain, whereas sample 2S (with wheat bran) comes out with the highest fat content (34.22 ± 0.491%). It was found that the amount of FAs in the larvae depended on the substrate used: the statistically highest amount of monounsaturated FAs was detected in the sample with sprouted potatoes (1L), the highest content of omega-3 FAs was found in the control sample (4CL), with agar–agar gels, and the sample with brewers spent grains (3L) showed a statistically higher amount of oleic acid. Meanwhile, the highest content of total polyunsaturated FAs (36.23%) was detected in the sample with wheat bran (2L). During the study, 16 distinct AAs have been analyzed, and sample 3L has demonstrated the highest content in 11 instances. It is noteworthy that the sample containing brewers’ spent grain exhibited the highest peroxide levels, indicating oxidation. Meanwhile, the determined number of volatile fatty acids did not exceed the regulatory limits for meat. In summary, it can be asserted that adjusting the substrate is essential for extracting specific amino acids and FAs. However, this could potentially affect the content of peroxides. This adaptation enables the desired chemical composition in larvae, making it suitable for specific purposes such as animal or human nutrition and health enhancement.

The meat industry generates large amounts of by-products, and their mass represents approximately one-third of the live weight of animals. Most by-products are disposed of and not used for processing, although they meet hygiene requirements and are suitable for human consumption or for the processing of food supplements. The aim of this study was to investigate the effect of lyophilization on the nutritional value and retention of functional ingredients in ovine and porcine by-products: liver, kidneys, hearts, and lungs. For this purpose, meat by-products of the third category were selected in X and Y slaughterhouses and divided into two parts: one part was freeze-dried at −80 °C for 72 h, and the other part was left raw. Fatty acid composition was determined by gas chromatography–mass spectrometry (GC-MS), and amino acid analysis was performed by AccQ Tag technology (Waters Corp., Milford, MA, USA) and HPLC. Our study shows that the lyophilization process did not significantly affect protein and fat content. The largest decrease in the amount of proteins was determined in samples of ovine kidneys, at 0.8%, while the difference in protein in ovine liver samples before and after lyophilization was 0.38%. The composition of essential amino acids did not change after lyophilization, except a decrease in Leu and Thr in porcine samples and Leu, Thr, and Met in ovine samples (p < 0.05). The lyophilization process did not significantly affect the polyunsaturated fatty acid content, including the amounts of omega 3 and omega 6 fatty acids. The optimal ratio of omega 6 and 3 fatty acids was determined in samples of lyophilized ovine livers (2.65), and the largest ratio was found in samples of lyophilized porcine hearts (16.67). The study results show that, after lyophilization, meat by-products of the third category (according to Regulation (EC) No. 1069/2009, Categorization, Article 10), especially ovine liver, can be used as a source of amino acids and polyunsaturated fatty acids for functional food processing. The process of lyophilization is also appropriate for preserving meat by-products without losing the nutritional value and beneficial components.

The research context involves analyzing the potential benefits derived from integrating insect protein into everyday food items. Utilizing methods consistent with established food science protocols, wheat bread was prepared with variations of 0%, 5%, 10%, and 15% Tenebrio molitor larvae powder, derived from larvae cultivated on brewery spent grain. A substrate selected for its superior nutritional content and a substrate with agar–agar gels were used. The tests included basic bread tests; sugar, acrylamide, amino, and fatty acid (FA) tests; and sensory acceptability. The results have shown that the acrylamide levels in bread with larvae remained below harmful thresholds, suggesting that using T. molitor can be a safe alternative protein source. The incorporation of powdered T. molitor larvae (p-TMLs) into bread was observed to increase certain sugar levels, such as glucose, particularly at higher larval concentrations. The addition of T. molitor significantly raised the protein and fat levels in bread. The inclusion of larvae enriched the bread with essential amino acids, enhancing the nutritional value of the bread significantly. The FA profile of the bread was altered by the inclusion of p-TMLs, increasing the levels of monounsaturated FAs. Despite the nutritional benefits, higher concentrations of larvae decreased the sensory acceptability of the bread. This suggests that there is a balance to be found between enhancing the nutritional content and maintaining consumer appeal. These findings highlight the potential for using p-TMLs as a sustainable, nutritious ingredient in bread making, although the sensory qualities at higher concentrations might limit consumer acceptance.

Our previous research has indicated that bioactive protein hydrolysates derived from porcine by-products possess the potential to be utilized in the production of functional additives and food supplements. The objective of this investigation was to assess the antioxidant and antimicrobial characteristics and amino acid changes in hydrolysates of lyophilized meat of bovine livers and hearts. The relevant enzymes, papain and pepsin, were used to hydrolyze the meat by-products over periods of 3, 6, and 24 h. The antimicrobial properties of all enzymatically digested samples were assessed against Listeria monocytogenes, Bacillus cereus, Salmonella enterica subsp. enterica Serovar Typhimurium. Bacillus cereus, and Escherichia coli, S. aureus subsp. aureus. The assessment of antiradical activity involved the quantification of DPPH• and ABTS•+ absorbance in bovine by-product hydrolysates. The hydrolysates were subjected to amino acid analysis using AccQ Tag technology, which was performed by Waters Corporation in Milford, MA, USA. The bacteria L. monocytogenes had the highest antibacterial activity (inhibition zone) (20.00 ± 0.20 mm) and less against E. coli (10.00 ± 0.10 mm) of bovine heart hydrolysates and were prepared for 24 h with papain. The highest values of ABTS•+ (98.1 ± 0.30%) and of DPPH• scavenging activity (92.56 ± 0.56%) of cationic radicals were evaluated in the bovine liver hydrolysates after the effect of papain for 24 h. Longer hydrolysis time influenced the decrease in free hydrophobic amino acids (Ala, Val, Ile, Leu, Tyr, Phe, Pro, Met). The results confirmed the potential use of bovine liver and heart hydrolysates as functional or biologically active materials.

With the world’s population continuing to grow, ensuring sustainable protein sources for everyone is becoming increasingly challenging. Despite meat being considered unsustainable, people find it challenging to abstain from consuming it. However, one solution to this dilemma could be the incorporation of mealworms into conventional meat products, i.e., sausages. The incorporation of mealworms into sausage formulations appears to shift the fatty acid profile towards higher levels of monounsaturated fats and polyunsaturated fatty acids (PUFAs), particularly omega-3s, potentially enhancing the nutritional value and offering health benefits. Therefore, our study aimed to improve the nutritional value and safety parameters of traditional sausages by enriching them with the flour of mealworm larvae. For this purpose, the larvae were reared on a sustainable substrate with brewery by-products, brewer’s yeast, and carrots. They were used frozen and freeze-dried in sausage recipes, replacing pork in different proportions. The analysis of the product’s chemical safety parameters (biogenic amines, nitrates and nitrites, volatile fatty acids (FA), and peroxide) and nutritional value (including collagen, cholesterol, amino acids, FA, and hydroxyproline) was carried out in an accredited laboratory. The results of our study have demonstrated that the incorporation of mealworms into sausages, particularly through freeze-drying, increased fat content and enhanced the profile of FA, including omega-3s while reducing protein and cholesterol levels, and altering collagen content, suggesting improved nutritional value and potential health benefits without compromising the safety of the product. Therefore, we are highlighting that the addition of mealworms influences the quality of amino acids positively and maintains biogenic amine levels within safe limits, alongside a negligible impact on nitrates and nitrites and a reduction in peroxide values. These findings indicate an overall improvement in sausage quality and safety without compromising safety.