Functional properties of roe protein and purification of anti-radical peptide from its hydrolysates

• Main Authors: Hong-Chung Chen, 陳鴻鈞
• Other Authors: Jing–Iong Yang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/79907358293215741750

碩士 === 國立高雄海洋科技大學 === 水產食品科學研究所 === 101 === In this study, the functional properties and bioactive activity of defatted roe protein (RP) and roe protein hydrolysated (RH) were investigated. The functional properties of RP were studies including water absorption capacity, fat absorption capacity, emulsification ability, foaming ability, solubility, buffering capacity and moisture sprption isotherm. The protein and peptide contents of RH were determined. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and high performance liquid chromatography (HPLC) analysis were used to estimate molecular weight distribution of the RH. Moreover, antioxidant activies of RH were evaluated, such as radical scavenging activies and protective effect of DNA oxidative damage. The storage experiment indicated that the moisture of RP is 5% when the relative humidity of storage condition is 80%. The result of buffering capacity experiments showed that RP at pH 2 and pH 12 exhibit better buffering effect. In addition, RP has the lowest solubility in pH4. The SDS-PAGE showed that the main molecular weight of RP ranged from 97, 30 to 17 kDa. The main molecular weight of RH is smaller and HPLC chromatogram showed that its major molecular weight ranges from 6511 to 204 Da. RH-A5 (5 hr hydrolysis) displayed highest activity in both of hydroxyl radical scavenging and protective effect of DNA oxidative damage. RH-A5 was further purified by using anion exchange and gel filtration chromatography (G-25) and a fraction, zone Ⅱ, exhibited the strongest anti-free radical activity. The zoneⅡwas then analyzed by high-performance liquid chromatography of (C18 preparative column) and a purified peptide with excellent anti-radical activity was obtained. Its amino acid sequence and molecular weight were studied.