英文摘要 |
In this report we compared the total contents and the distribution of isoflavones in six soybeans, including 1 imported genetically modified (GM) soybean and 5 Taiwanese nongenetic modified soybeans, Koushing 10, Tainan 1, Tainan 4, Tainan 5 black, and commercial black. After the soybeans were soaked for 0, 4, 8, 12 and 16 hr in the solutions with different pH values (pH 3, 7 and 9), the contents of the isoflavones in the different 6 soybeans were measured. Nine isoflavones, including daidzin, genistin, and glycitin with a glucoside; acetyl-daidzin, acetyl-genistin, and acetyl-glycitin with acetylglucoside; and daidzein, genistein, and glycitein aglycones, were measured by HPLC. The total content of the isoflavones in Soybean Kaohsiung 10 was the highest at approximately 346 mg/100g. Soybean Tainan 5 black is the one with the lowest content of isoflavones. The isoflavones were present predominantly in forms with glucoside. After soaked in the water for different lengths of time, there was no significant loss of total isoflavones. In GM soybean, Koushing 10, and Tainan 5 black, the contents of aglycons, diadzein and genistein aglycones increased significantly after the soybeans were soaked in the water for 4 hr, compared with the ones in unsoaked soybeans (P < 0.05). In GM soybean, Koushing 10, and Tainan 5 black, the total contents of isoflavones in the soybeans soaked after 8 hr in pH 9 solutions were obviously lower than the ones in pH 3 and pH 7. The level of daidein and genistein from Kaohsiung 10 soaking in pH 3 was higher than pH 7 and pH 9. The contents of deidzein and genistein in Koushing 10 soaked in pH 3 solution was the highest, while the contents of deidzein and genistein in Tainan 5 black soybean soaked in pH 9 solution was the lowest.
本研究主要比較高雄10號大豆、台南1號大豆、台南4號大豆、台南5號黑豆及市售黑豆等5種台灣非基因改造大豆及進口基因改造大豆之異黃酮總含量及其異構物分佈之差異,並進一步了解大豆分別經浸泡0、4,8、12及16小時水溶液,及於pH 3、7及9溶液中浸泡8小時後,其異黃酮的變化情形。異黃酮的測定乃利用高效液相層析法分析含葡萄糖苷之daidzin、glycitin、genistin、acetyldaidzin、acetylglycitin、acetylgenistin及不含葡萄糖苷之daidzein、glycitein及genistein等共9種異黃酮分布情形。分析條件以RP-18逆相管柱為固定相,移動相(A)為氰甲烷及(B)為0.1%三氟醋酸混合溶液。由測定結果顯示台灣非基因改造大豆中以高雄10號黃豆之異黃酮總含量最高約346 mg/100g,台南5號黑豆異黃酮總含量最低。所分析的大豆均以含葡萄糖苷較不含葡萄糖苷之異黃酮含量高。高雄10號、台南黑豆5號及基因改造大豆於浸泡4小時後不含葡萄糖苷之daidzein及gemstem異黃酮含量有顯著增加(P < 0.05)。另外,高雄10號大豆、台南5號黑豆及基因改造大豆浸泡於pH 9溶液下之異黃酮總含量明顯低於pH 3及pH 7的趨勢,以高雄10號大豆浸泡於pH 3溶液daidein及genistein含量最高,台南5號黑豆其daidein及genistein於pH 9溶液下含量最低。 |