The current investigation examined the effect of inclusion of Black soldier fly (Hermetia illucens; BSF) dry larvae in hens’ diet on egg quality and hen performance. A total of 260 brown egg-laying hens (RIR × RIW) were divided into four groups (65 hens/group; 5 pens/group) and fed with control and experimental diets (inclusion rates 3%, 6%, 9%). Although the four-week feeding period did not influence production parameters, yolk color responded positively to the test diets, showing a linear increase with the percentage of BSF inclusion rate (p < 0.001). This was reaffirmed by the increased levels of yolk carotenoids (astaxanthin and β-carotene) and α-tocopherol, with notable differences in 6% and 9% BSF-fed groups (p ≤ 0.003). Lipids are an important factor in carotenoid absorption and assimilation, and the combination of fat content and carotenoids in BSF suggests the potential of this system for egg enrichment. Along with the increased antioxidant levels, a novel finding is the positive correlation between BSF inclusion rates and hens’ egg yolk levels of C:15 and C:17 fatty acids, key players in the core mechanisms of cell health and longevity. Altogether, the results provide evidence of the potential of BSF for enrichment of eggs with carotenoids and vitamins with strong antioxidant activity, which would have a positive effect on human health.

With increasing interest in Hermetia illucens as a model organism for bioconversion, establishing standardized approaches for evaluating and comparing research outcomes is essential. Diets for black soldier fly (BSF) are often based on raw ingredients, which can vary significantly in quality, seasonality and availability, making research difficult to replicate and slowing industry development. To address this variability, we introduce the Sofia diet, an artificial, standardized diet that can be reproduced globally with consistent nutritional composition. Unlike other diets that are used in BSF research, the proposed Sofia diet is engineered to optimize BSF larva performance by following the performance on basic traits (survival and larva weight). Developed using surface mixture experiments, the diet is optimized for application during the larval stage. Hydrolyzed yeast, sucrose, and xanthan gum were identified as core ingredients in a three-step optimization process, followed by refinement of the preparation methodology. The adoption of standardized diets like the Sofia diet offers a valuable tool for enhancing research across diverse scientific disciplines, while supporting industrial efforts to develop efficient BSF rearing systems and high-value products. We also envision that standard diets like Sofia diet could be used to further study insect nutrition in this species. Further optimizations of the diet recipe are also discussed.