Silkworm (Bombyx mori) larva converts less bioavailable plant-based zinc in mulberry (Morus alba) leaf to more bioavailable animal-based zinc

This is the first report on the in vitro bioavailability of zinc (Zn) in silkworm (Bombyx mori) larva powder (SLP) developed for human consumption. We used the chick bioassay, which has been extensively employed to evaluate the relative Zn bioavailability of animal feeds and foodstuffs, using ZnSO₄ · H₂O as the 100% reference standard. Multiple regression analysis of total tibia Zn against supplemental Zn intake yielded a slope-ratio relative bioavailability value of 175% for Zn in SLP, which was significantly higher (P < 0.05) than that of mulberry (Morus alba) leaf (91%). SLP is an excellent efficacious source of very highly bioavailable Zn.