Optimization of protein determination using design of experiment methodology in earthworm (Eisenia foetida) powder

Abstract

Proteins have long been considered very important nutrients; in fact the word ‘protein’ is derived from the Greek and means ‘holding first place’. The chemical compositions of the earthworm Eisenia foetida, its casts and body fluids were investigated and compared with those of a variety of common foods and animal feeds. Nutrient analyses showed that Eisenia foetida meal has high protein content in the range of 54.6 to 76.0% dry matter. The protein content and amino acid composition were close to those of fish meal and eggs, and higher than cow milk powder and soybean meal. With this study, Eisenia foetida has the potential to be used as a food supplement for animals especially in fish meals. The cost of fish meals has been recognized as a major factor affecting the development and expansion of aquaculture enterprise. Therefore, the earthworm Eisenia foetida was a good choice to be replaced as fish meals. Analysis of proteins was done by using Kjeldahl method and Design of Experiment (DOE). Furthermore, the study was achieved successfully which to obtain the significant parameters for each performance of time digestion for the Kjeldahl method and variable of sulfuric acid (98%) volume.