在國內由於鮮乳產量有限，常有以還原乳部分或全部冒充鮮乳出售情形，造成食品管理上之困擾，近年來部分研究顯示己ε-pyrrole -lysine為化學性褐變( Maillard reaction)頗為穩定之中間產物，據此推測應可當做鮮乳中攙雜還原乳之檢出指標。
本研究先以含glucose或lactose之水溶液在105±2℃之溫度反應1-7小時，結果顯示褐變程度與反應時間成正比，只是glucose/lysine組之反應速率較lactose/lysine組者為快。取6 小時反應液經ethylacetate處理之水溶液進行Dowex- 50 W (H+form)之管柱層析，兩組反應液在1 M pyridine之水溶液區劃均可用TLC ( Silicagel，以n-BeOH/HOAC/H2O (4 : 1 : 1)為移動相)檢測ε-pyrrole -lysine之存在 ( Rf=0.57-0.59 ),對2、4-dinitrophenylhydrazine 及 ninhydrin 均有呈色。 In this paper, a process for the formation and detection of ε-pyrrole-Iysine in the Maillard reaction from glucose/lysine and lactose/lysine model systems was described. Glucose or lactose (3.32 g each) and Iysine (1.68 g) were dissolved in 30 ml water and refluxed in an of bath at 105±2℃ for 1-7 hour(s). The extent of browning reaction was proportional to the heating interval. On the other hand, the browning rate of glucose/lysine mixture is faster than that of lactose/lysine one. The solution obtained after browning was extracted twice with ethyl acetate and the remaining aqueous fraction was put onto Dowex 50W(H+ form) column, and eluted sequentially with water, 1 M pyridine and 0.1 N NaOH Fractions were collected separately and checked by thin-layer chromatography on silica gel after being concentrated A solution of n-butanol/acetic acid/water (4:1:1) was used as the moving phase. The main spot (Rf=0.57-0.59) which gave a positive reaction with both 2,4-dinitropbenylhydrazine and ninhydrin is ε-pyrrole-lysine.
