Effect of developmental stage on the nutritional value of edible insects. A case study with Blaberus craniifer and Zophobas morio

As the demand for sustainable, cost-effective food production increases, edible insects are an important alternative to traditional livestock as a source of human food. Understanding the differences in the nutritional composition of edible insects is essential for the optimization of rearing process. This study investigated the effects of developmental stage on the quantity and quality of nutrients in superworms (Zophobas mono), and the death's head cockroach (Blaberus craniifer). Superworms at 60, 90, and 120 days of age showed no significant variation in basic nutrient content, and no significant differences were found in protein quality (expressed as the essential amino acid index). In contrast, adult cockroaches contained significantly more digestible protein than either small or large nymphs, but of lower quality. Cockroach nymphs contained significantly higher amounts of fat than the adults, and the lipid quality (described by the atherogenicity and thrombogenicity indices) increased over time. Conversely, the lipid quality of superworm larvae decreased with age. The study provides a better understanding of the chemical composition of insects over their lifespan and may help to optimize rearing technology in order to harvest insects as high-quality nutritional biomass, facilitating their application as a potential food source for humans.