Optimization of hydrolysis conditions of Decapterus maruadsi with neutral protease

The aim of this paper is to develop a process for hydrolysis Decapterus maruadsi with neutral protease.The effects of the main parameters including hydrolysis temperature,pH value and hydrolysis time were investigated with single factor experiment,and dosage of enzyme,protein concentration were investigated with central combination experiment.The optimized conditions were:concentration of neutral protease was 3260U/g protein,protein concentration was 1.47%,hydrolysis temperature was 50℃,hydrolysis pH value was 7.0,and hydrolysis time was 10 hours.Under the conditions,amino acid nitrogen concentration attained 1.09mg/ml,hydrolysis degree attained 46.20%,recovery of the total nitrogen attained 92.40% and total volatile basic nitrogen reached 0.047mg/ml.RSD value of amino acid nitrogen concentration,hydrolysis degree and recovery of the total nitrogen was lower than 3%.In short,under these conditions,degree of hydrolysis and the recovery of total nitrogen were high,and the process was stable.