果糖月桂酸单酯的分离纯化及其表面性质研究

Study on Lsolation and Surface Activities of Fructose Monolaurate

利用毕赤酵母展示的南极假丝酵母脂肪酶B(Candida antarctica lipase B,CALB)催化合成了果糖月桂酸单酯,研究了两步法萃取分离纯化的影响因素,优化条件下果糖月桂酸单酯萃取率接近90%,产品纯度超过95%。研究考察了果糖月桂酸单酯的理化性质,其亲水亲油平衡值(HLB值)为5.775,临界胶束浓度(CMC值)为0.25 mmol/L,临界表面张力γ为24.22 mN/m,表明其在较低浓度下能较好地改变溶液的表面性质。比较了制备的果糖月桂酸单酯与商购的蔗糖月桂酸单酯的起泡性与乳化性,结果表明:在低浓度下,果糖月桂酸单酯起泡能力和泡沫稳定性优于蔗糖月桂酸单酯,乳化能力和乳化稳定性与蔗糖月桂酸单酯相近。

Fructose monolaurate was synthesized by Candida antarctica Lipase B （CALB） displayed on the cell surface of Pichia pastoris. The parameters affecting the two-step extraction of fructose monolaurate was studied. The fructose monolaurate could be obtained with a yeild of approximately 90% and with a purity of surpass 95% under optimal condition. The surface activities of fructose monolaurate were shown as following： HLB 5. 775, CMC 0.25 mmol/L and critical surface tension γ24.22 mN/m, indicating that it owns the good ability to change the surface activities of aqueous solution. Frutose monolaurate displayed better foaming power and foaming stability at low concentrations as well as similar emulsion power and emulsion stability comparing with that of the commercial surcrose esters.