RESUMEN
Non-dairy creamers have been widely used for coffee whitening and texture improvement. To avoid the intake of trans fatty acids from partially hydrogenated oil, coconut oil-based diacylglycerol (CO-DAG) was applied in non-dairy creamer as core material. In this study, effects of DAG content (30, 50, 70, 90%) on the characteristics of CO-DAG were evaluated, including rheological and thermodynamic properties. The CO-DAG with a content of 50% exhibited a wide plastic range and contained mixture of ß and ß' polymorphic forms. Using CO-DAG (50%) as core material, the physicochemical properties of non-dairy creamer were characterized and compared with commercial products. The results indicated that CO-DAG-based non-dairy creamers showed similar encapsulation efficiency (92.74%) and thermal stability to commercial products. Furthermore, CO-DAG-based non-dairy creamer showed higher whiteness index (54.20) than commercial non-dairy creamers (50.22) when applied to black coffee. Overall, it is anticipated that CO-DAG-based non-dairy creamers have great potentials in coffee whitening.
RESUMEN
A water-in-ionic liquid microemulsion ([Bmim]PF6/Tween20/H2O) was applied as reusable reaction medium to esterify phytosterols with fatty acid by Candida rugosa lipase (CRL) successfully. Two kinds of commercial CRLs, AY30 and AYS which cannot effectively catalyze esterification in conventional reaction system were found effective in the microemulsion system. Effects of reaction parameters on esterification were investigated; results showed that the conversion rate of 87.9 and 95.1 % was obtained in 24 and 48 h of reaction, respectively, under the optimized condition: the molar ratio of water to Tween 20 (w 0 value) at 5.4, Tween 20 at a concentration of 305 mM, 50 °C,pH 7.4, 10 % of enzyme loading (w/w, with respect to total reactants), and phytosterols/lauric acid molar ratio of 1:2. Moreover, by using n-hexane as the extraction agent, the lipase-encapsulated microemulsion could be reused at least seven times (>168 h) without significant changes in the conversion rate, while achieving a purpose of simple separation and purification.
