| 摘要: | 本研究以下列六種不同甲基酯化條件探討對於游離態共軛亞麻油酸 (conjugated hnoletc acid，CLA) 甲基酯化程度之影響：(1) 14％BF3/MeOH，50℃、10分鐘；(2)14 ％BF3/McOH，室溫、30分鐘；(3)4％HCl/MeOH，80℃、1小時；(4)4％HCl/MeOH，60℃、20分鐘； (5)2 N NaOCH3/MeOH，50℃、10分鐘；與(6) 2 N NaOCH3/MeOH，室溫、2分鐘；及下列六種不同甲基酯化條件探討對於乳脂肪之甲基酯化程度之影響：(1)14％BF3/MeOH，室溫、40分鐘；(2)14％BF3/MeOH，50℃、40分鐘；(3)4％HCl/MeOH，60℃、50分鐘；(4)4％HCI/MeOH，80℃、50分鐘；(5) 2 N NaOCH3/MeOH，室溫、20分鐘；與(6) 2 N NaOCH3/MeOH，50℃、40分鐘，並以薄層層析技術測定其甲基酯化程度。結果顯示在三種甲基酯化試劑：BF3/MeOH，HCl/MeOH、與NaOCH3/MeOH中，BF3/MeOH為最佳游離態CLA之甲基酯化試劑，NaOCH3/MeOH無法甲基酯化游離態CLA，因此不適於作為游離態CLA甲基酯化之用；NaOCH3/MeOH為最佳CLA甘油酯化物之甲基酯化試劑，BF3/MeOH與HCl/MeOH因為無法甲基酯化CLA甘油酯化物，因此不適於作為CLA甘油酯化物甲基酯化之用。
Six methylating methods: (1) 14 %BF3/MeOH, 50℃, 10 min, (2) 14 %BF3/MeOH, room temperature, 30 min, (3) 4 %HCl/MeOH, 80 ℃, lhr, (4) 4 %HCl/MeOH, 60 ℃, 20 min, (5)2 N NaOCH3/MeOH, 50 ℃, 10 min, and (6) 2 N NaOCH3/MeOH, room temperature, 2 min were used to methylate free conjugated !inoleic acid (CLA) in order to determine the effect of those methods on the extent of free CLA methylation. Another six methylating methods: (1) 14 %BF3/MeOH, room temperature, 40 min, (2) 14 %BF3/MeOH, 50 ℃, 40 min, (13) 4 % HCl/MeOH, 60℃, 50 min, (4) 4 %HCl/MeOH, 80 ℃, 50 rain, (5) 2 N NaOCH3/MeOH, room temperature. 20 rain, and (6) 2 N NaOCH3/MeOH. 50 ℃, 40 min were also used to methylate milk CLA glyceride for the same determination as previously described, and the extent of methylation was analyzed using thin layer chromatography. While BF3/MeOH was found to be the best in methylating free CLA among the three reagents tested due to its hight, r level of methylation, NaOCH3/MeOH was not suggested for use in methylating free CLA. NaOCH3/MeOH was the best in methylating milk CLA glyceride due to its higher level of mcthylation, whereas BF3/MeOtt and HCl/MeOH were not suggested for use in methylating milk CLA glyceride. |
