Enhancing Tenebrio molitor Larvae Growth and Nutrition: The Potential of Wheat Bran and Coffee Grounds Blends

Abstract

Coffee grounds, a solid residue left after coffee extraction, are often discarded in landfills or incinerated, posing environmental concerns. To promote sustainability, this study explores the potential use of coffee grounds as a feed source for Tenebrio molitor (TM) larvae. The growth performance, survival rates, and nutritional properties of TM larvae were evaluated using three feed groups: wheat bran, coffee grounds, and a blend of the two. TM larvae (2 g of 3rd instar per group) were randomly assigned to one of three treatments in a completely randomized design: (1) 100 g wheat bran, (2) 100 g of a wheat bran and coffee grounds blend, or (3) 100 g coffee grounds. Results revealed that the blend of wheat bran and coffee grounds yielded the highest growth and survival rates, followed by wheat bran, with coffee grounds alone showing the least favorable outcomes. Nutritional analysis indicated that larvae fed on the blended diet exhibited enhanced crude protein content and reduced crude fat compared to larvae fed on wheat bran or coffee grounds alone. These findings suggest that the blend of wheat bran and coffee grounds serves as a promising feed additive for TM larvae, improving growth, survival, and nutritional quality while supporting the sustainable use of coffee byproducts.