Chemical Composition of Earthworm (Dendrobaena veneta Rosa) Biomass Is Suitable as an Alternative Protein Source

Abstract

The selected chemical composition (dry matter, ash, total protein, and crude fat) of the integumentary muscles of Dendrobaena veneta were determined, plus the dry matter (DM) percentage content of 17 amino acids and the profile (%) of fatty acids. Results were compared with a more fully studied earthworm, Eisenia fetida. In addition, the composition of exogenous amino acids was compared to the WHO standard for pork, beef, and chicken eggs. Both earthworm species were grown on the same kitchen waste, and protein composition was analyzed using the same methods. Studies indicated that the muscle of D. veneta was characterized by a high level of protein (76.82% DM). A similar content of exogenous amino acids was observed in the protein of both earthworms, but for phenylalanine and isoleucine, slightly higher levels were recorded for E. fetida. More histidine, lysine, threonine, isoleucine, and arginine were found in earthworms compared with chicken egg white. Fatty acids play an essential role in balancing human or animal feed and their content determines the dietary and nutritional value of the food. Both earthworm species contained the appropriate content of saturated and unsaturated acids. In D. veneta, a higher content of arachidonic acid was found, and in E. fetida, lauric, tridecanoic, and palmitic acids were present. Future issues of food security may force us to seriously consider earthworm protein for indirect or even direct human consumption.