In pursuit of sustainable protein sources, the agricultural sector and emerging edible insect industry intersect in the valorization of agricultural by-products. Establishing a mutually beneficial relationship involves utilizing agricultural by-products as feeding substrates for insect farming, potentially enhancing the sustainability of both sectors. In the present study, by-products from beer, rice, oat, maize, sunflower, and lucerne, as well as mill residues and spent mushroom substrate from the regions of Thessaly and Central Macedonia (Greece) were investigated as nutritional sources for the larvae of the yellow mealworm (Tenebrio molitor). Results show that the suitability of the tested by-products for rearing T. molitor larvae varies greatly, with larvae surviving better in some by-products than in others. The highest survival rate and the highest weight of larvae were recorded for larvae reared on rice bran, spent grains, and oat by-products. Similarly, high feed conversion and growth rate were observed when the larvae were fed with rice bran and spent grains. Thus, this research promotes cost-effective and sustainable T. molitor rearing, aligning with circular economy principles.

Diatomaceous earth (DE) formulations are promising alternatives over the use of traditional insecticides. In the present study, a series of laboratory bioassays was carried out to assess the efficacy of three diatomaceous earth formulations, i.e., Silicid, Celatom^® MN-23, and SilicoSec^®, for the control of a wide range of stored-product insect species in soft wheat. The species tested were Tribolium confusum, Tribolium castaneum, Sitophilus oryzae, Sitophilus granarius, Rhyzopertha dominica, Oryzaephilus surinamensis, and Alphitobious diaperinus. Different dose rates, i.e., 0 (control), 100, 300, 500, and 1000 ppm, were used for each of the aforementioned dust formulations. Mortality levels of the exposed individuals were assessed after 3, 7, 14, and 21 days of exposure. Moreover, progeny were counted 65 days later. Based on our results, dust formulations were effective for the control of most of the stored-product beetle species tested. Among the DE formulations tested, Silicid could adequately control the stored-product insect species. Complete suppression of offspring was observed only for secondary species (T. confusum, T. castaneum, O. surinamensis, and A. diaperinus). For primary species (S. oryzae, S. granarius, and R. dominica), the lowest number of progeny was observed in wheat treated with Silicid. For instance, in the case of R. dominica, significantly fewer individuals were produced in Silicid-treated wheat at the highest dose rate. The results of the present study aim to encourage the utilization of DE in stored-product protection as an integrated pest management tool. Additional experimentation is required to apply the tested DE formulations in the field and on different surfaces.

The chestnut is a widely appreciated fruit in Europe, Asia, and North America, playing a significant role in the diets of people in these regions. Due to its high nutritional value and diverse health benefits, chestnuts have been gaining considerable research attention. The aim was a comprehensive literature review on the nutritional benefits of chestnuts and the sustainable valorization of their by-products. Following the methodology, all the relevant literature was collected and reviewed. Based on the reviewed data, the chemical composition of chestnuts holds great importance, especially in the food industry, where understanding their nutritional properties can enhance product development. Furthermore, chestnut processing generates a substantial amount of waste, including shells and leaves, which are rich in bioactive compounds with antioxidant properties. Valorizing these by-products presents opportunities for their application across various industries, leading to increased profits, reduced environmental pollution, and enhanced sustainability. This review aims to provide insights into the nutritional benefits of chestnuts and chestnut by-products and explore potential alternative applications for these materials in the food industry. Such applications will possibly positively affect producers’ income and are in line with the circular economy strategy.

Amidst the escalating global demand for protein-rich livestock feed, there’s an urgent call to explore innovative alternatives. Insects, renowned for their rich protein, lipid, and nutrient profiles, offer a sustainable solution. Integrating agricultural waste into insect diets emerges as a promising strategy to alleviate rearing costs. However, large-scale investigations into by-product valorization remain limited. Thus, our study aims to evaluate Greek agricultural by-products—brewer’s spent grains, rice bran, oat and maize by-products, and animal feed mill leftovers—as potential feedstock for Tenebrio molitor larvae, an insect species that is authorized by the European Union for both livestock feed and human consumption. In this study, the larval growth and body composition were assessed in commercial trays, unveiling optimal performance with rice bran and brewer’s spent grains. Conversely, larvae fed with animal feed mill leftovers and maize by-products displayed suboptimal outcomes. These findings underscore the potential efficacy of integrating locally produced agricultural by-products into T. molitor commercial production. Such an approach not only addresses the growing demand for protein-rich livestock feed but also offers a sustainable solution to agricultural waste management. In conclusion, our research contributes valuable insights towards developing economically viable insect farming.

Functional beverages are increasingly sought as components of a healthy diet, and goat milk offers a nutritious base with unique sensory attributes. This study aimed to develop a novel fermented goat milk beverage enriched with spent coffee grounds (SCG) extract, utilizing SCG’s high natural antioxidant content to improve nutritional and functional properties. SCG was extracted via aqueous solid–liquid extraction and lyophilized; its extract was incorporated into goat milk–fructose blends at 0%, 1%, and 2% (w/v). Analyses included physicochemical characterization (pH, acidity, fat, and protein), total phenolic content, and antioxidant capacity via DPPH assay, alongside consumer sensory evaluation for acceptance and purchase intent. Results demonstrated that higher SCG extract levels significantly increased pH, phenolic concentrations, and radical scavenging activity while reducing titratable acidity. The 2% SCG formulation achieved the highest overall, taste, and aftertaste acceptance and purchase intention. These findings suggest that SCG-enriched goat dairy beverages are feasible functional foods with enhanced antioxidant properties and consumer appeal, promoting valorization of coffee by-products.