Tilapia (Oreochromis niloticus) hydrolysates were prepared by the commercial enzymes Protease A, Protease N,and papain at 50oC for 0, 3, 6, and 9 hrs. The peptide contents of the hydrolysates increased with the hydrolysis time;however, the soluble protein increased at the first 3 hrs hydrolysis and thereafter decreased. Different antioxidant measurements including the inhibition of linoleic acid autoxidation, scavenging effect on DPPH (α,α-diphenyl-β-piczylhydrazyl) ftee radical, and reducing power showed that tilapia hydrolysates possessed noticeable antioxidant activities. There existed a good conelation between the amount ofpeptides and antioxidant activity. Among the hydrolysates, papain hydrolysates for 9 hrs, had the highest inhibition of linoleic acid autoxidation and were further separated into four groups. The peptide with molecular weight of approximately I,400 Da possessed a stronger inhibition of linoleic acid autoxidation than that of 900, 500 and 200 Da. These results indicate that enzymatic hydrolysates oftilapia protein possess potential antioxidative activity. 吳郭魚肉使用商業用酵素之Protease A Protease N及papain，於50。C下進行O 3、6 、 9小時之水解。水解物之胜肽含量隨水解時間增長而增加;然而可溶性蛋白質的含量在水解3小時期問增加迅速，爾後減緩。吳郭魚酵素水解物經抑制亞麻油酸自氧化、清除DPPH自由基和還原能力等三種方法檢測，得知其具有顯著的抗氧化能力，統計分析顯示，水解物之胜肽含量與抗氧化能力的強弱有關。各酵素水解物皆具有良好的抗氧化活性，其中又以9小時的papain酵素水解物之抗氧化活性為最強，進一步分離得到4個胜肽區分物，分子量約在1400 Da胜肽之抑制亞麻油酸自氧化能力較900、500和200 Da為強。由實驗結果得知，吳郭魚酵素水解物具有較強之抗氧化能力。
