大黄鱼内脏抗氧化肽的稳定性研究

Stability of Antioxidant Peptides Extracted from Pseudosciaena crocea Viscera

本文旨在研究大黄鱼抗氧化肽在不同条件下的抗氧化稳定性。通过凝胶排阻色谱选择抗氧化活性较强的组分,并采用DPPH自由基清除率以及Fe2+螯合力来评价大黄鱼抗氧化肽的抗氧化活性。在中性p H、常温、低浓度Na Cl以及适量K+,Ca2+,Al3+条件下,大黄鱼抗氧化肽抗氧化活性基本保持稳定,DPPH自由基清除率和Fe2+螯合力分别维持在88.5%和66.7%左右。在高浓度盐、高温、Fe2+,Fe3+,Cu2+等离子的引入和长时间紫外辐照下,大黄鱼抗氧化肽抗氧化活性下降超过30%。另外,酸性p H、70℃下加入葡萄糖、果糖、乳糖分别将大黄鱼抗氧化肽DPPH·的清除活性提高至90%左右,相反,碱性条件有利于大黄鱼抗氧化肽螯合Fe2+活性,说明处理过程对不同抗氧化指标的影响有所差异。此外,胃蛋白酶消化处理对大黄鱼抗氧化肽抗氧化活性影响不显著,而进一步的糜蛋白酶消化却显著降低了多肽的抗氧化稳定性。因此,合理的加工、贮藏工艺有利于维持大黄鱼抗氧化肽的稳定性。

The stability of the antioxidant activity of antioxidant peptides extracted from Pseudosciaena crocea viscera were studied under different conditions. Peptides with strong antioxidant activity were selected by size exclusion chromatography（SEC）, and the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl（DPPH·） radical scavenging rate and Fe2＋ chelating capacity as indexes. Under conditions of neutral p H, room temperature, low Na Cl concentration, and appropriate amounts of K＋,Ca2＋, and Al3＋, the antioxidant activity of the antioxidant peptides from Pseudosciaena crocea viscera was generally stable, and DPPH· radical scavenging rate and Fe2＋ chelating capacity were 88.5% and 66.7%, respectively. With high Na Cl concentration, high temperature, additions of K＋, Ca2＋, and Al3＋, and long-duration ultraviolet irradiation, the antioxidant activity of the antioxidant peptides from Pseudosciaena crocea viscera was reduced by 30%. Furthermore, at acidic p H and additions of glucose, fructose, and lactose at 70 ℃, the DPPH· radical scavenging activity of the antioxidant peptides from Pseudosciaena crocea viscera was increased to approximately 90%; while alkaline conditions were conductive for the Fe2＋chelating capacity, indicating that treatments have different impacts on different antioxidant indicators. In addition, pepsin digestion treatmenthad no significant impact on the antioxidant activity of antioxidant peptides from Pseudosciaena crocea viscera, and further chymotrypsin digestion significantly decreased the antioxidant activity stability of the peptides. Therefore, appropriate processing and storage are critical for maintenance of the stability of the antioxidant peptides extracted from Pseudosciaena crocea viscera.