关键词: 带鱼, 自由基, 响应面, 氨基酸, 抗氧化

Abstract:

This study is aim to obtain enzymatic hydrolysates with high antioxidant ability from hairtail protein. Taking
scavenging activity on DPPH free radicals and hydrolysis degree as response values, four kinds of proteases were used to
hydrolyze hairtail protein and the optimal protease for preparing antioxidant hydrolysates was screened. Response surface
methodology (RSM) was used to optimize hydrolysis conditions. The molecular weight and amino acid compositions of
the hydrolysates were determined by Sephadex G-25 size-exclusion chromatography and automatic amino acid analyzer,
respectively. RSM tests showed that the optimal conditions for scavenging activity on DPPH free radicals were material-liquid
ratio of 1:3, enzyme addition amount of 1.65%, hydrolysis time of 3.80 h, and hydrolysis temperature of 48 ℃, and scavenging
activity on DPPH free radicals under the above conditions reached up to 60.13%. The resultant hydrolysate showed high
reducing power and hydroxyl radical scavenging activity. The molecular weight of the optimal hairtail protein hydrolysates
was approximately 1311 D. The hydrolysates with leucine had scavenging capability to free radicals and the content of leucine
accounted for 35.10% of total amino acids. The peptides with low molecular weights were the major components of the
hydrolysates and the content of these amino acids consisted of the peptides was approximately 89.8% of total amino acids.

Key words: hairtail, free radicals, response surface methodology, amino acid, antioxidant activity