Vitamin D fortification of selected edible insect species through UVB-treatment

Edible insects are attracting increased interest worldwide, because they are arguably more sustainable than more established animal foods. Apart from being rich in protein and minerals, they can also form vitamin D₃ after treatment with UVB light (290-315 nm). However, only limited research, which has almost exclusively been conducted on living insects, reared under UVB lamps, has been done in this regard. As research on mushrooms has shown, that vitamin D formation is much more effective and less time consuming, when a previously sliced or ground product is treated with UVB light, it would likely be more practical to treat powdered insects with UVB light, rather than rearing them under UVB lamps. Therefore, the aim of this work was to confirm the presence of vitamin D₃ in powdered UVB-treated yellow mealworms (Tenebrio molitor), migratory locusts (Locusta migratoria) and two-spotted crickets (Gryllus bimaculatus) as well as to subsequently quantify potential vitamin D content. Samples were analyzed via HPLC, and presence of vitamin D₃ was verified via standard addition and spectrum analysis. UVB-treated migratory locusts and two-spotted crickets did not contain quantifiable amounts of vitamin D₃. However, UVB-treated mealworms showed substantial amounts of vitamin D₃ (8.95-18.24 µg/g dry matter). Thus, the UVB-treatment of powdered mealworm is an effective approach via which to enhance their vitamin D₃ content and even modest serving sizes can supply the recommended daily intake of vitamin D.