碩士 / 國立高雄海洋科技大學 / 海洋生物技術研究所 / 103 / In recent years, hydrolyzed proteins from many animal and plant sources had been found to have strong antioxidant activity. Protein derived from Trionychidae (Pelodiscus sinensis) was hydrolyzed using three kinds of proteases (5%) including Alcalase, Neutrase, and Flavourzyme. Protein hydrolysate produced from Flavourzyme was discovered to have the highest antioxidant activity, which is determined by its DPPH radical scavenging activity (22.5±1.2％), Trolox equivalent antioxidant capacity (55.0±1.01％), and reducing power(A620) (0.17±0.01). To find out the optimum parameters for hydrolysate production, Flavourzyme hydrolysis conditions was further investigated. Under pH 7 environment, 4% Flavourzyme was able to produce hydrolysate with 29.91 ± 2.86% DPPH radical scavenging activity within 1 hour. After reaction with o-Phthaldialdehyde, the one-hour fluorescent intensity of Flavourzyme hydrolysate was equivalent to 121.32 ±2.11nM Leucine content. Hence, Flavourzyme hydrolysate produce from optimized condition was further fractionated by size exclusion chromatography on Sephadex G-25 into three major fractions (P1–P3). Since only P2 retain DPPH scavenging activity, it was then again fractionated by reversed-phase high performance liquid chromatography (RP-HPLC) into five major fractions (P2-1–P2-5), among which P2-2 and P2-4 have better DPPH radical scavenging activities. In addition, both Trionychidae protein hydrolysates and purified Trionychidae protein hydrolysates reduced inflammatory reaction through diminishing NO production in RAW mouse macrophage cell. The molecular masses and amino acids sequences of the purified peptides were determined using ESI-MS and ESI-MS/MS, respectively. The peptide sequences were identified as SGVGF, TAAGF, AGINPA, APAGPQ, LGKGY, VAKGY, and THAAPN. In future, isolated bioactive peptides can be used as potent antioxidants to be used as additives in food or pharmaceutical products.
| Identifer | oai:union.ndltd.org:TW/103NKIM0270003 |
| Date | January 2015 |
| Creators | YANG,TING-SHAN, 楊定山 |
| Contributors | CHANG,REY-CHANG, 張瑞璋 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 115 |
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