碩士 / 國立臺灣海洋大學 / 食品科學系 / 107 / Fish oil is used as a dietary supplement for human health, but it has often been adulterated on the market for years. Fish oil is easily degraded by the environmental factors, leading to mislabel or insecurity. Mackerel is widely distributed and its oil has been made into dietary supplements. Matrix-assisted laser desorption-time-of-flight mass spectrometry (MALDI-TOF MS) has the advantage of easy sample preparation and rapid mass spectrometry analysis. This study explores the optimum extraction conditions for mackerel oil using Bligh and Dyer, soxhlet extraction and microwave-assisted extraction. It was found that the use of microwave-assisted extraction of mackerel oil at a microwave power of 300 W for 30 sec (14.3%) has a higher extraction rate than solvent extraction (10.3%) and soxhlet extraction (3%). To explore conditions for the analysis of triacylglycerides (TAG) of mackerel oil by MALDI-TOF MS, using different matrix, laser intensity, sample to matrix ratio and deposited times. The optimum conditions are 2,5-dihydroxybenzoic acid as matrix and laser energy 90%, the sample to matrix ratio (1/1, v/v) and deposited three times, according to peak abundance and profile clarity in the spectrum. MALDI-TOF MS analysis on TAG is matched with the online database LIPID MAPS Online Tools to identify TAG in mackerel oil. The main TAG molecules and the assigned fatty acid compositions in mackerel oil are identified as 25 TAGs: m/z 799.7 (C46:1, MPP1), 801.7 (C46:0, MPP), 813.6 (C48:8), 815.6 (C48:7, LM1D6/M1M1E5), 817.6 (C48:6, LP1E5/LLn3Ln3), 819.6 (C48:5, MME5), 825.7 (C48:2, MPL2/PP1P1), 827.7 (C48:1, PPP1/MPO1), 829.7 (C48:0, PPP), 839.6 (C50:9), 841.6 (C50:8, M1M1D6/LLn3E5), 843.6 (C50:7, LP1D6/M1P1E5), 845.7 (C50:6, MMD6/MP1E5), 849.7 (C50:4, ML2L2), 851.7 (C50:3, PPLn3/PP1L2), 853.7 (C50:2, PPL2/PP1O1), 867.6 (C52:9, LLn3D6/M1Ln3E5), 869.7 (C52:8, M1P1D6/MLn3E5), 875.7 (C52:5, PPE5/PL2Ln3), 877.7 (C52:4, PL2L2), 879.7 (C52:3, PO1L2), 889.6 (C54:12), 891.6 (C54:11, LE5D6/M1E5E5), 913.6 (C54:0), 915.6 (C56:13).When comparing with the TAG of menhaden and cod liver oils, m/z 813.6, 815.6, 839.6, 843.6, 889.6, 891.6 are unique for mackerel oil, and m/z 799.7, 825.7, 827.7, 829.7, 845.7, 849.7, 853.7, 869.7, 875.7, 877.7, 879.7 are co-present in menhaden and cod liver oils. The TAG shared in vegetable oils of soybean oil and sunflower oil are apparently different from that of the mackerel oil . The TAG molecule of mackerel oil have potential power of discrimination for species identification and determination of adulterated products with lower priced vegetable oils in fish oil or fish oil feed. At the same time, the phosphatidylcholine (PC) of mackerel oil was analyzed by MALDI-TOF MS, which were m/z 803.6, 805.6, 831.7, 833.7, and the molecular composition was PC (18:2/20:5), PC (16:0/22:6), PC (18:1/22:6), PC (20:1/22:6).
| Identifer | oai:union.ndltd.org:TW/107NTOU5253073 |
| Date | January 2019 |
| Creators | Wang, Yu-Fen, 王郁芬 |
| Contributors | Chen,Tai-Yuan, 陳泰源 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 63 |
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