표제지
목차
Abstract 7
I. 서론 13
II. 재료 및 방법 27
1. AEC(L-AA, EGCG, caffeine) 혼합용액의 준비 27
2. 정량분석 27
2-1. LC-MS/MS에 의한 AEC의 정량 및 정성분석 27
2-2. HPLC에 의한 정량분석 28
2-3. NMR에 의한 AEC의 정량 및 정성분석 30
3. 물리적 가공처리 31
3-1. 가열처리 31
3-2. 초고압처리 32
3-3. Sonication 처리 32
III. 결과 및 고찰 33
1. HPLC와 LC-MS에 의한 정량분석 33
1-1. AEC용액의 HPLC Chromatogram 33
1-2. 각 성분에 대한 HPLC에서의 UV/Vis spectrum 39
1-3. LC-MS/MS에서의 각 성분에 대한 MS spectrum 41
2. NMR을 이용한 AEC의 정량분석 방법설정 44
2-1. NMR sampling 방법의 최적화 44
2-2. NMR parameter의 최적화 47
2-3. Water-suppression technique의 최적화 50
3. NMR을 이용한 AEC solution의 안정성 연구 52
3-1. AEC 용액의 보존성 연구 52
3-2. AEC solution의 NMR 분석 59
4. 물리적 가공처리 공정에서의 AEC의 안정성 연구 70
4-1. 상온 및 sonication에 의한 안정성 평가 70
4-2. 열처리에 의한 안정성 연구 72
4-3. 압력처리에 의한 안정성 연구 83
IV. 결론 85
V. 참고문헌 86
Table 1. Optimized parameters of ¹H-NMR in quantitative and qualitative... 49
Table 2. Information of Chemical shift, coupling constant and Integral of... 55
Table 3. Quantification of L-AA and its degradation products with Integral value and... 56
Table 4. 1D & 2D NMR data of L-ascorbic acid 61
Table 5. 1D & 2D NMR data of EGCG 62
Table 6. 1D & 2D NMR data of Caffeine. 63
Figure 1. Structure of L-ascorbic acid00 14
Figure 2. Degradation of L-ascorbic acid to a-dicarbonyl compounds via... 18
Figure 3. The structure of Green tea catechins. 20
Figure 4. The Structures of Degradation products of EGCG by oxidant. 21
Figure 5. Solvent proportion and flow rate of HPLC for AEC analysis. 29
Figure 6. L-AA calibration curve for HPLC quantification analysis. 30
Figure 7. HPLC chromatogram of AEC222 Oday between D₂O and H₂O. 35
Figure 8. L-AA stability difference between H₂O and D₂O. 36
Figure 9. EGCG quantification of AEC222 between H₂O and D₂O during... 37
Figure 10. Baseline error by degradation products peaks neighboring to... 38
Figure 11. UV/vis spectrum of L-ascorbic acid. 39
Figure 12. UV/vis spectrum EGCG and Caffeine. 40
Figure 13. MS spectrum of EGCG, Caffeine and L-ascorbic acid (ESI-... 42
Figure 14. MS spectrum of L-ascorbic acid after lday storage (ESI... 43
Figure 15. NMR sampling types with NMR-tube and micro-tube. 45
Figure 16. ¹H data comparison between sampling type No.1 and No.3 46
Figure 17. H₂O proton peak and Water-suppression by Noesy-presat in... 51
Figure 18. L-AA H-5 peak of AEC222 Oday analysis by ¹H NMR. 53
Figure 19. Oxidized L-AA protons of AEC222 7day and 14day analysis... 54
Figure 20. Degradation rate of L-AA and the occurring rate of... 57
Figure 21. Determination of dehydroascorbic acid in AEC solution by the coupling constant of ¹H NMR... 58
Figure 22. ¹H NMR spectrum of AEC 10mM solution (D₂O) with peak... 64
Figure 23. Chemical shift change of ¹H NMR spectrum of AEC... 65
Figure 24. Carbon and COSY NMR spectrum of AEC 10mM solution. 66
Figure 25. HSQC and HMBC spectrums of AEC 10mM solution. 67
Figure 26. COSY spectrum between 0day and 7day of AEC 10mM solution (D₂O). 68
Figure 27. Identification of Dehydroascorbic acid by HMBC spectrum of AEC solution 69
Figure 28. Investigation of the components stability of AEC222 solution... 71
Figure 29. EGCG quantity of AEC thermal treatment experiment. 73
Figure 30. Estimation of L-AA quantity alteration according to EGCG... 74
Figure 31. Quantification of L-ascorbic acid and EGCG in the experiment... 76
Figure 32. Investigation of alteration on L-AA stability according to... 78
Figure 33. Caffeine quantification of the experiment AEC 202-212-222-... 79
Figure 34. Quantification of L-ascorbic acid and EGCG in the... 81
Figure 35. HPLC spectrum of EGCG and its degradation products in... 82
Figure 36. Investigation of L-AA stability under HHP treatment. 83
Figure 37. Investigation of EGCG and Caffeine stability under HHP... 84