碩士 / 國立臺灣海洋大學 / 食品科學系 / 105 / Phycobiliproteins (PBPs) are the major light-harvesting chromoproteins in some seaweeds. PBPs, used as a fluoredcent, are becaming more and more important in commercial sectors. In recent years, PBPs are the rising star of the pharmaceutical industry, but instability of PBPs remain limit their applications. PBPs would easily decay in response to physical and chemical parameters, such as temperature, pH and light. In this study, the stability of the PBPs crude extracts from red alga Porphyra dentata was studied in various temperatures, pH and lights. Besides, addition of alcohol, benzoic acid, L-ascorbic acid, citric acid and sucrose into the PBP crude extracts was evaluated for the stability of the PBPs. The recovery yield of phycoerythrin (PE) and phycocyanin (PC) in the phycobiliproteins extraction [5% (w/v) biomass loadings] were 1.12 and 0.89 mg/g biomass. The purity index of the PE and PC were 0.5 and 0.30. The PE and PC were stable in absorbance and fluorescence at 4–40°C for 1 h. The pH stability test indicated that the PE and PC were stable at pH 2–9 and pH 4–9, respectively, in absorbance and stable at pH 5–9 in fluorescence. In the experiments of phycobiliproteins treated with white, red or blue lights for 2 days, the PE retained 47.9% in absorbance after the exposure of white light, and retained over 60% in aborbance after the exposure of red and blue lights. The PC was relatively less light-sensitive than the PE, and the PC retained over 75% in absorbance after the exposures of three different lights. The phycobiliproteins exhibited 7.6%, 42.7% and 32.0% in fluorescence after the exposures of white, red and blue lights, respectively. Addition of alchol into phycobiliproteins extracts could enhance their stability. The presence of 12% (v/v) alcohol retained the fluorescence by 81 and 16 folds as compared to the control at 4°C and 25°C. Addition of food additive benzoic acid (5 mM) could also enhance the stability of phycobiliproteins by 90 folds at 4°C for 90 days.
| Identifer | oai:union.ndltd.org:TW/105NTOU5253050 |
| Date | January 2017 |
| Creators | Ho, Po-Wen, 何柏彣 |
| Contributors | Lin, Hong-Ting, 林泓廷 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 91 |
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