鱼类加工制品蛋白质氧化程度分析

本实验以市场上常见的几种鱼类加工制品为研究对象，测定其羰基含量、巯基含量、二硫键含量及蛋白质疏水性等指标，并进行相关性分析。结果表明：经过不同方式加工后，鱼制品蛋白中羰基、巯基、二硫键含量及疏水性都有显著差异（P＜0.05）。冰鲜类产品的羰基含量较低（0～1 nmol/mg），盐渍类产品的羰基含量最高（6～10 nmol/mg）；冰鲜类产品的巯基含量较高（70～100 nmol/mg），而二硫键含量最低（0.1～0.2 nmol/mg）；其余样品的巯基含量均为30～70 nmol/mg，二硫键含量为1～5 nmol/mg；羰基含量与蛋白质疏水性存在极显著相关性（r=0.84，P＜0.01），巯基含量与二硫键含量存在显著相关性（r=－0.59，P＜0.05）。由实验结果可看出，香烤、盐制类产品蛋白质氧化程度较高，淡干类产品次之，冻鲜类产品蛋白质氧化程度较低。

Protein Oxidation of Processed Fish Products

Common processed fish products in the market were investigated in this study to determine and correlate the contents
of carbonyl group, thiol group and disulfide bond, as well as protein hydrophobicity. The results showed that different processed
fish products exhibited significant differences in the contents of carbonyl group, thiol group and disulfide bond, as well as protein
hydrophobicity (P < 0.05). The carbonyl content of cold fresh products was low (0–1 nmol/mg), while the carbonyl content of
salted products was the highest (6–10 nmol/mg). The thiol group content of frozen fresh products was higher (70–100 nmol/mg),
and the disulfide bond content was the lowest (0.1–0.2 nmol/mg). In other processed fish products, the thiol group content was
30–70 nmol/mg, and the disulfide bond content was 1–5 nmol/mg. Correlation analysis revealed that there was a significant correlation
between carbonyl content and protein hydrophobicity (r = 0.84, P < 0.01). A significant relationship existed between thiol group
content and disulfide bond content (r = −0.59, P < 0.05). Our experimental results showed that the degree of protein oxidation was
higher in roasted and salted products than dried products; the lowest degree of protein oxidation was found in frozen fresh products.