乳化剂类型、浓度及水相pH对水包核桃油乳状液物理稳定性的影响

易建华; 程菁菁; 董文宾

doi:10.13386/j.issn1002-0306.2015.13.048

乳化剂类型、浓度及水相pH对水包核桃油乳状液物理稳定性的影响

Effect of p H, emulsifier type and concentration on physical stability of oil-in-water emulsions

摘要

摘要: 为了了解在水包核桃油乳状液中乳化剂类型、浓度及水相p H对其物理稳定性的影响,考察四种乳化剂即乳清分离蛋白(WPI)、十二烷基磺酸钠(SDS)、十二烷基三甲基溴化铵(DTAB)以及失水山梨醇聚氧乙烯酯(Tween20)在p H3.0和p H7.0条件下形成稳定的水包核桃油乳状液所需要的最低浓度。结果表明,p H对阳离子表面活性剂DTAB、非离子表面活性剂Tween20乳化效果影响较大,在p H3.0和7.0条件下形成稳定乳状液所需DTAB最低浓度分别为0.8%、2.0%,而Tween20最低浓度分别为0.6%、0.3%;p H(等电点除外)对两性大分子表面活性剂WPI和阴离子表面活性剂SDS的乳化效果影响较小。研究结果表明不同类型乳化剂在不同p H条件下对水包核桃油乳状液的物理稳定性影响差异较大。

Abstract: To explore the influence of emulsifiers and p H on physical stability of walnut oil- in- water emulsion, the emulsions stabilized by whey protein isolates, sodium dodecyl sulfate ( SDS) , dodecyltrimethylammonium bromide ( DTAB) , and Tween20, respectively, were investigated.And the required minimum concentrations of emulsifiers to form a stable walnut oil- in- water emulsionwerealso determined. Results showed that the influence of p H on the emulsifying effect of cationic surfactant and nonionic surfactant wasremarkable.Under the condition of p H3.0 and7.0, the required minimum concentrations of DTAB were 0.8% and 2.0%, respectively. Meanwhile, the required minimum concentrations of Tween20 were 0.6% and 0.3% at p H3.0 and 7.0, respectively. But forampholytic surfactant WPI and anionic surfactant SDS, the influence of p H ( except for isoelectric point) was non- significant.The above phenomenon indicated that the physical stability of walnut oil- in- water emulsions was greatly influenced by different p H and emulsifiers.