苦味肽抗氧化活性延长食品保鲜

目的探究苦味肽延长食品保鲜的抗氧化活性。方法研究乳胶珠吞噬细胞的吞噬能力的变化,以此来分析苦味肽的免疫功能。通过2, 2, 1-二苯基-1-吡啶酰肼(DPPH)自由基清除、还原力以及金属螯合活性测定来评定苦味肽的抗氧化能力。在保鲜测试中、分析苦味肽对总羰基和巯基的影响来探究苦味肽对冷藏期间的样品组织是否具有抗氧化作用。最后再通过对样品使用扫描电镜(scanning electron microscopy, SEM)来进一步分析苦味肽对肌肉蛋白质在整个氧化过程中结构稳定性的影响。结果苦味肽会增加吞噬细胞吞噬乳胶珠,表明苦味肽增加非特异性免疫功能;苦味肽具有显著的DPPH自由基清除活性,降低了铁离子的氧化能力和金属螯合能力;扫描电镜结果显示,在苦味肽处理的样品上组织结构的变形较小并且蛋白质的降解较少,而对照组(仅水处理)的样品明显可以观察到其肌肉蛋白失去了原有的有序结构。结论冷藏前用苦味肽处理去皮虾样品能有效减少羰基衍生物和自由巯基的形成,冷藏期间有助于样品的肌原纤维蛋白结构的稳定,表明苦味肽也有益于海洋食物的保鲜。

Antioxidative activity of bitter peptide prolonging food preservation

Objective To explore the antioxidative activity of bitter peptide in prolonging food preservation. Methods The changes of phagocytic ability of phagocytic cells of latex beads were studied to analyze the immune function of bitter peptides. The antioxidative capacity of bitter peptides was evaluated by measuring 2, 2, 1-diphenyl-1-pyridylhydrazine (DPPH) radical scavenging, reducing power, and metal chelation activity. In the freshness test, the effects of bitter peptides on the total carbonyl and thiol groups were analyzed to investigate whether bitter peptides have an antioxidant effect on the sample tissue during cold storage. Finally, the effect of bitter peptides on the structural stability of muscle proteins during the entire oxidation process was further analyzed by using scanning electron microscopy (SEM) on the samples. Results The bitter peptide increased the phagocytic cells phagocytosis of latex beads, indicating that the bitter peptide increased non-specific immune function; the bitter peptide had significant DPPH free radical scavenging activity, which reduced the ability of iron ion oxidation and metal chelation; scanning electron microscope results showed that the bitter peptide-treated samples, the tissue structure was less deformed and the protein was less degraded, while in the control group (water-only) samples, it was obvious that the muscle protein lost its original ordered structure. Conclusion Treating peeled shrimp samples with bitter peptides before refrigeration can effectively reduce the formation of carbonyl derivatives and free sulfhydryl groups, and help stabilize the myofibrillar protein structure of the samples during refrigeration, indicating that bitter peptides are also beneficial for the preservation of marine foods.