Abstract: In order to study the high efficient use of Hippocampus kuda Bleeker protein, the degreased hippocampal powder was digested by alkaline protease and trypsin,and the protein hydrolysate (PH) was separated by ultrafiltration into 5 fractions (PH-Ⅰ, PH-Ⅱ, PH-Ⅲ, PH-Ⅳ, PH-Ⅴ). We analyzed and compared the amino acids composition and their antioxidative capacity of the 5 fractions of PH. The results showed that PH-Ⅴ (<2 500 Da) exhibited the highest antioxidative activity with 1, 1-diphenyl -2-picrylhyd-razyl (DPPH) (34.2%±0.1%), superoxide radicals (29.2%±0.1%) scavenging, as well as reducing power (0.28%±0.005%). Although the content of hydrophobic amino acids was lower than hydrophilic amino acids, the former played a crucial role in the scavenging efficiency to eliminate free radicals. Polar and non-polar amino acids synergistically enhanced the scavenging efficiency by increasing the effective concentration of free radical cleanup. Each unit of polar amino acids for antioxidative capacity was about 1.2 times that of nonpolar amino acids. Furthermore, each unit of aromatic amino acids for antioxidative capacity was around 2 times that of aliphatic amino acids on scavenging free radicals. This study not only prepared a class of antioxidant petides with developmental value, but also analyzed the relationship between the antioxidant capacity of those peptides and amino acid composition, which provided the theoretical basis for the high utilization of hippocampus.

Key words: hippocampus, protein hydrolysate, amino acids composition, antioxidative capacity, molecular weight

摘要： 为了探讨大海马蛋白质的高效利用方法,本试验将脱脂大海马粉经碱性蛋白酶和胰蛋白酶联合消解后,酶解液(PH)经超滤膜分离为5组分(PH-Ⅰ、PH-Ⅱ、PH-Ⅲ、PH-Ⅳ、PH-Ⅴ),结合各组分的氨基酸组成,回归分析了各组分的自由基清除能力与氨基酸组成间的相关关系。结果表明,酶解液经超滤膜分离的5组分中PH-Ⅴ (<2 500 Da)抗氧化能力较强,清除DPPH自由基能力为34.2%±0.1%,对超氧阴离子的清除能力为29.2%±0.1%,Fe³⁺还原力为0.28%±0.1%。海马酶解多肽各组成中疏水性氨基酸含量低于亲水性氨基酸,但疏水性氨基酸对自由基的清除能力起着决定性作用,极性氨基酸和非极性氨基酸可通过协同作用来增强海马多肽清除自由基的能力,且每个单位极性氨基酸的抗氧能力是非极性氨基酸的1.2倍,每个单位芳香族氨基酸的抗氧化能力是脂肪族氨基酸的2倍。本研究不仅制备了一类具有开发价值的抗氧化多肽,并且分析了多肽抗氧化能力与氨基酸组成的相关关系,为大海马的高值化利用提供了理论依据。

关键词: 海马, 酶解产物, 氨基酸组成, 抗氧化能力, 分子量