First Optimization of Tomato Pomace in Diets for Tenebrio molitor (L.)(Coleoptera: Tenebrionidae)

Abstract

Tomato pomace (TP), an agricultural industrial waste product from the tomato processing industry, was valorized by being used as a rearing substrates for Tenebrio molitor (L.). This study evaluated bran-based diets with increasing tomato pomace (0%, 27%, 41% and 100%). Protein sources, as brewer’s spent grain and yeast, are used in TP27 and TP41 diets, respectively, to ensure equal protein content to control diet (TP0). Results showed larval survival, larval and pupal weight no different between diets; however, growth time significantly increases in TP100 compared at all diets. The feed conversion rate progressively increases from 2.7 to 4.3, respectively from TP0 to TP100. Conversely, Lycopene and β-Carotene increases in the larvae. Fatty acid composition improves by increasing polyunsaturated fatty acids (mainly -Linoleic acid). Although the best nutritional quality was obtained in T100, the TP41 is the optimal diet for balance between larval performance and qualitative improvement of larvae. Therefore, tomato pomace is suitable for the formulation of mealworm diets, even in high dosages when supplemented with sustainable protein sources.