Effect of Extraction Method on Amino Acid Determination for Alkali-hydrolyzed Feather Meal

Amino acid content of the alkali solution of feather meals was determined using an automatic amino acid analyzer. Extraction by ethanol, water or HCl was applied prior to amino acid analysis for optimization of the methodology. When 80% ethanol was used at pH 3.3 in a 90℃ water bath for the extraction, all 18 amino acids could be detected. The total amino acid content obtained by the ethanol method was 4.5 times and 5.4 times higher than the water and HCl method, respectively. The content of the individual amino acids obtained by the method increased in proportion with the protein concentration. The analytical results could be used to indicate the degree of feather hydrolysis.