肖伊莎,汪 勇,張廣文
(暨南大學食品科學與工程系,廣東廣州510632)
響應面法優化無溶劑體系磷脂酶A1催化酯化制備低聚甘油酯的研究
肖伊莎,汪 勇,張廣文
(暨南大學食品科學與工程系,廣東廣州510632)
以工業油酸和低聚甘油為原料,經磷脂酶A1(Lecitase Ultra)催化酯化制備低聚脂肪酸甘油酯。利用響應面法優化實驗條件,研究反應時間、反應溫度、加酶量、加水量以及底物摩爾比值(工業油酸和低聚甘油摩爾比值)對其酯化率的影響。得出最佳反應條件為:反應溫度45℃,加酶量1.6wt%(占底物總質量),加水量4wt%(占底物總質量),反應時間12h,底物摩爾比值為1∶1。最佳條件下酯化反應平均酯化率可達到56.6%。采用HPLC-ESI質譜通過檢測相對分子質量驗證了部分低聚甘油酯產物的種類。
聚甘油酯,響應面法,磷脂酶A1,酯化
Abstract:Production of oligomerized polyglycerol fatty acid ester by esterification of industry grade oleic acid with oligomerized polyglycerol catalyzed by phospholipase A1(Lecitase Ultra) was investigated in this study.The reaction parameters including reaction time,reaction temperature,enzyme dosage,molar ratio of substrates(industry grade oleic acid to oligomerized polyglycerol) and water dosage were studied using response surface methodology(RSM).Optimum conditions obtained by RSM were as follows:reaction temperature 45℃,enzyme dosage 1.6wt%(of the substrates mass) molar ratio of oliomerized plyglycerol to fatty acid 1∶1,reaction time 12h and water dosage 4wt%.Under these conditions,esterification efficiency of the reaction mixture was 56.6%.Some oligomerized polyglycerol fatty acid ester molecular species were identified by HPLC-ESI-MS.
Key words:polyglycerol fatty acid ester;response surface methodology;phospholipase A1(Lecitase Ultra);esterification
聚甘油脂肪酸酯(polyglycerol fatty acid ester,PGFE)簡稱聚甘油酯,是由聚甘油與脂肪酸直接酯化或與甲酯、油脂進行酯交換而制得,是一類新型、高效、性能優良多羥基酯類非離子型表面活性劑,其具有乳化、保濕、抗菌等作用[1]。PGFE乳化性能比單甘脂優越,原因在于PGFE有更多的親水性羥基[2],且其親水性、親油性可以通過改變聚甘油聚合度、脂肪酸種類以及酯化度來實現,從親油性到親水性不同性能的一系列聚甘油產品,以適于各種特殊用途[3]。另外PGFE可很好地與其他乳化劑復配,具有良好的協同增效作用,因而至今PGFE的應用也已經逐步擴展到日化、石油、紡織、醫藥等領域[4-8]。我國PGFE的開發和應用起步較晚,與國外精致PGFE制品差距依然較大,且品種單一,目前我國PGFE產品的這種現狀已經不能滿足多層次、多行業、多領域的實際需求。……