Protein hydrolysate was prepared from poultry viscera by a procedure involving autolysis for 6 h at pH 2.8 and 55 degrees C followed by heat inactivation, filtration and drying. Recovery of nitrogen in the product was 87%. The process reduced the viable count of bacteria by 5-6 log cfu/g. The product contained 84% protein, 6.5% ash and 8.8% moisture. Peptide analysis by gel filtration chromatography showed size in the range of 0.5-5 kDa. RPHPLC exhibited the presence of hydrophilic peptides in higher concentration than that in trypsin digest of casein. Protein hydrolysate exhibited presence of all essential amino acids in comparison with reference protein except for methionine and threonine. The product possesses excellent solubility (> 93%) over a pH range of 1-12. Efficacy of the product as a bacteriological media or feed supplement is discussed. (c) 2008 Published by Elsevier Ltd.