Cardiac arterial bulbs of Skipjack tuna (Katsuwonus pelamis) are rich in elastin, and its hydrolysates are high quality raw materials for daily cosmetics. In order to effectively utilizing Skipjack tuna processing byproducts-cardiac arterial bulbs and to prepare peptides with high antioxidant activity, pepsin was selected from six proteases for hydrolyzing proteins, and the best hydrolysis conditions of pepsin were optimized. Using ultrafiltration and chromatographic methods, eleven antioxidant peptides were purified from protein hydrolysate of tuna cardiac arterial bulbs. Four tripeptides (QGD, PKK, GPQ and GLN) were identified as well as seven pentapeptides (GEQSN, GEEGD, YEGGD, GEGER, GEGQR, GPGLM and GDRGD). Three out of them, namely the tripeptide PKK and the pentapeptides YEGGD and GPGLM exhibited the highest radical scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and superoxide anion assays. They also showed to protect plasmid DNA and HepG2 cells against H₂O₂-induced oxidative stress. Furthermore, they exhibited high stability under temperature ranged from 20-100 °C, pH values ranged from 3-11, and they simulated gastrointestinal digestion for 240 min. These results suggest that the prepared eleven antioxidant peptides from cardiac arterial bulbs, especially the three peptides PKK, YEGGD, and GPGLM, could serve as promising candidates in health-promoting products due to their high antioxidant activity and their stability.

中文翻译：

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来自鲣鱼心脏动脉球茎的生物活性肽：制备、鉴定、抗氧化活性和对热、pH 和模拟胃肠消化治疗的稳定性

鲣鱼 ( Katsuwonus pelamis ) 的心脏动脉球)富含弹性蛋白，其水解产物是日用化妆品的优质原料。为有效利用鲣鱼加工副产物-心脏动脉球，制备具有高抗氧化活性的多肽，从6种蛋白酶中选择胃蛋白酶进行蛋白质水解，优化了胃蛋白酶的最佳水解条件。使用超滤和色谱法，从金枪鱼心脏动脉球蛋白水解物中纯化出十一种抗氧化肽。鉴定了四种三肽（QGD、PKK、GPQ 和 GLN）以及七种五肽（GEQSN、GEEGD、YEGGD、GEGER、GEGQR、GPGLM 和 GDRGD）。其中三种，即三肽 PKK 和五肽 YEGGD 和 GPGLM 对 2,2-diphenyl-1-picrylhydrazyl (DPPH)、羟基、2、2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) 和超氧阴离子测定。他们还显示保护质粒 DNA 和 HepG2 细胞免受 H₂ O ₂诱导的氧化应激。此外，它们在 20-100 °C 的温度范围内、pH 值范围从 3-11 范围内表现出高稳定性，并且它们模拟胃肠消化 240 分钟。这些结果表明，从心脏动脉球中制备的 11 种抗氧化肽，尤其是 PKK、YEGGD 和 GPGLM 三种肽，由于其高抗氧化活性和稳定性，可以作为健康促进产品的有希望的候选者。