碩士 / 國立臺灣海洋大學 / 食品科學系 / 100 / Spirulina platensis contains 64.89±0.38% curde protein. Phycocyanin is one kind of photosynthetic pigment that is widely used in food industry, cosmetic, biochemical dye and also be evidenced the antioxidant capacity. In this study, we used ultrasound-assisted extracted Spirulina platensis in water, evaluating the production rate, phycocyanin content and antioxidant capacity. Observation by microscopy, fragmentation of algae was increased by ultrasonication with ultrasonic power increasing or the ultrasound frequency decreasing. The higher ultrasounic power, was resulting the higher yields, protein content (R = 0.81) and phycocyanin purity (R = 0.69), on the other hand the lower ultrasounic frequency was resulting the higher protein content (R = 0.63), but the lower phycocyanin purity (R = 0.43). Colors of extracts were affected by phycocyanin purity. The b value have the negative correlation with phycocyanin purity (R = -0.95). Absorbance of extract at 500-800 nm was increased as ultrasounic power increasing. Absorbance of extract was increased as ultrasonic frequency decreasing. It may be causing by ingredients were more complex due to fragmentation of proteins. The main protein of extract is phycocyanin detecting by SDS-PAGE. However the numbers of protein bands become more due to protein denatured at 60℃ and 20 kHz. The higher ultrasounic power makes the antioxidant of extract lower capacity; At 20 kHz, the ingredients were complex due to ultrasonics degradation, making DPPH free radical scavenging activity (88.19±2.62%) and reducing power (25.13±1.95 ppm of ascorbic acid) increase. The higher ultrasounic power, lower frequency and treated temperature at 60℃ making iron-chelating ability and superoxide radical scavenging activity lower.
| Identifer | oai:union.ndltd.org:TW/100NTOU5253059 |
| Date | January 2012 |
| Creators | 黃秋燕 |
| Contributors | Min-Lang Tsai, 蔡敏郎 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 68 |
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