Total Nitorgen Content from Earthworm (Eisenia Foetida) Using The Kjeldahl Method

Abstract

In the fish aquaculture management, fish feed is identified as a major problem. The high cost and scarcity of fishmeal in formulated feeds have led to the use of other protein sources such as earthworms and animal by-product. Earthworm is an alternative source of protein to replace the fish meal in the fish feed formulation. In this study, total nitrogen content in the earthworm powder is determined using the Kjeldahl method by employing the statistical software, Full Factorial Design (FFD) which could provide the significant information about the studied parameters. The parameters are, the digestion time (min) and the volume of sulfuric acid (H2SO4) (ml). From the analysis of variance (ANOVA), the volume of H2SO4 and the interaction between digestion time and the volume of H2SO4 are found to be important parameters in the nitrogen determination process via the Kjeldahl method. The highest nitrogen content obtained was 12.23%, when using 15 ml H2SO4 and 60 mins of digestion time. The value of R2 is 0.9986, which shows that the selected parameters (the digestion time and the volume of H2SO4) and its corresponding levels are highly correlated to the percentage nitrogen content in earthworm powder using the Kjeldahl method.