Optimization of Conditions of Hydrolysis Decapterus Maruadsi with Alkaline Protease

The effects of the main parameters including hydrolysis temperature,pH value, hydrolysis time on hydrolysis degree were investigated with single factor experiment and dosage of enzyme,protein concentration were investigated with response surface methodology (RSM). The optimized conditions were: concentration of alkaline protease was 4 320 U/g protein, protein concentration was 1.57 %, hydrolysis temperature was 55 ℃, hydrolysis pH value was 7.5, hydrolysis time was 6 hours;under the conditions, amino acid nitrogen concentration attained 1.30 g/L, hydrolysis degree attained 51.88 %, recovery of the total nitrogen attained 97.07 % and total volatile basic nitrogen reached 0.030 g/L. RSD value of amino acid nitrogen concentration, hydrolysis degree and recovery of the total nitrogen was lower than 2 %.