Abstract: Researches were carried out to determine effects of different chemical reagents on hydrolyzation of chicken feathers under acid or alkali conditions in order to select a suitable catalyst to enhance transformation of organic nitrogen into amino acids.Effects of ratio of solid to liquid,dosage of catalyst and duration on hydrolysis were also studied through an orthogonal experiment under the conditions of a constant temperature of 115-120 ℃,3 mol·L^-1 sulfuric acid or 6 mol·L^-1 potassium hydroxide,and a normal atmospheric pressure.The results show that when sulfuric acid was used as hydrolytic reagent,metal salts were the best catalyzer,increasing the production of amino acid by 18.0% as compared with the treatment of no addition of catalyzers,and when potassium hydroxide was used as hydrolytic reagent,however,sodium sulfide was the best,increasing production by 39.8% as compared with treatment of no addition of catalyzers.The solid/liquid ratio of 1∶3 and the catalyzer dosage of 120 g·kg^-1 were the optimal technological parameters for hydrolysis with either sulfuric acid or potassium hydroxide as hydrolytic reagent,but the optimal duration of hydrolysis was 10 h for the former and 12 h for the latter.

Key words: chicken feather, hydrolyzation, chemical degradation, amino acid