碩士 / 靜宜大學 / 食品營養研究所 / 95 / The protein content in green algae is about 60%. Improving the extractability of green algae proteins, and understanding their composition and antioxidant activity will be beneficial to their applications in food industry. The objectives of this research were to establish the optimum conditions for extracting proteins from commercial spray-dried green algae powder, and investigate the antioxidant characteristics of these proteins and their hydrolysates. Bradford reagent was used to measure the protein extractability. The antioxidant activity of green algae proteins was determined by measuring the scavenging ability of ABTS free radicals and the concentration of TBARS in liposome-oxidizing system. The combination of dH2O and ultrasonic treatment resulted in better protein extractability than 0.05 M Tris-HCl buffer (pH 8.0) and with or without ultrasonic treatment. The scanning electron microscopy graphs showed that ultrasonic treated green algae exhibited shrinkage on the surface of cells which could facilitate the release of protein. SDS-PAGE revealed that the 33 and 17 kDa proteins were the main components in green algae proteins, and more and clear bands for proteins extracted with ultrasonic treatment in comparison with those without ultrasonic treatment. Green algae proteins and their hydrolysates, after hydrolysis with papain, trypsin, α-chymotrypsin, peptidase and protease A, all showed antioxidant activity. However, the degree of hydrolysis would influence the extent of antioxidant activity.
| Identifer | oai:union.ndltd.org:TW/095PU005255021 |
| Date | January 1900 |
| Creators | Wei-Ting Chang, 張薇婷 |
| Contributors | Cheng-Hsin Wang, 王正新 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 174 |
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