Influence of the diet on the composition of the earthworm Eudrilus eugeniae

The earthworm Eudrilus eugeniae is a well-known source of protein in animal feeding but there is lack of information on its fatty acid profile. This study aimed to determine its nutrient components and fatty acid profile. Earthworms were bred in substrate containing organic matter; peanut powder was added in the experimental group diet. The nutrient components (protein, ash, and minerals) of the adult worms were determined according to the Kjeldahl method and by atomic absorption spectrophotometer. The fatty acid profile was determined by gas chromatography / mass spectrometry. The dry-matter protein content significantly increased in worms fed peanut powder (p < 0.05) as did the minerals measured. The main fatty acid families had similar proportions in the groups. In the saturated fatty acids, C12:0 and C18:0 were present in higher proportions in both groups, whereas in monounsaturated fatty acids, C18:1ω9 prevailed. Significant differences (p < 0.05) in polyunsaturated fatty acids were observed between the two groups. An increase in the proportion of ω6 and ω3 was observed in the experimental group compared to the control. This study showed that peanut powder significantly influenced nutrient components of E. eugeniae. The fatty acid profile of this species was similar to that of most animals. Earthworms’ diet can be altered to improve the nutritional value of E. eugeniae.