氨肽酶对罗非鱼下脚料水解液脱苦的研究

Research on the Removal of Bitter of Protein Hydrolysates of Tilapia By-product by Aminopeptidase

为了更好地利用罗非鱼下脚料制备呈味肽,研究了罗非鱼下脚料水解液脱苦的酶解工艺。利用巨大芽孢杆菌L-19发酵制备得到活性为1.06×104U/mg的氨肽酶粉剂,以罗非鱼下脚料经中性蛋白酶所得的呈味肽为氨肽酶酶解底物,经酶解试验确定,最适的p H、温度、酶用量和时间分别为:p H8.5、60℃、6.0×104U/g和10 h。在最适的条件下,呈味肽溶液的游离氨基酸增量为5 607.71 mg/L,疏水氨基酸的增加量占63.63%,苦味基本消失,表明氨肽酶具有良好的水解能力和脱苦能力。

In order to take full advantage of tilapia by-product to manufacture flavor peptide, the process conditions of removal of bitter protein hydrolysates of tilapia by-product were studied. Enzyme activity of 1.06 ＆#215; 104 U/mg aminopeptidase powder was prepared by fermentation using bacillus megaterium L-19 strain. Using flavor peptide as substrates obtained from tilapia by-product hydrolyzed by neutral protease , a series of enzymatic hydrolysis tests using aminopeptidase were carried on and the optimum conditions were determined as follows：, pH was 8.5, the temperature was 60℃, enzyme dosage is 6.0 ＆#215;104 U/g and enzymatic hydrolysis time is 10 h. Under above optimum conditions, in the peptide solution, the increment of free amino acids was 5 607.71 mg/L and the increase of hydrophobic amino acids accounted for 63.63%. The bitter nearly disappeared completely , thus the result showed aminopeptidase possessed excellent hydrolysis and debitterizing ability.