Preparation And Quality Evaluation Of Pomelo Seed Oil Microemulsion

There is more than50%oil in pomelo seed, and pomelo seed oil is a promising source of nutritional plant oil, which contains a great quality of unsaturated fatty acid and other functional ingredients. However, pomelo seed oil was not reasonable and effective used. In this research, pomelo seed oil microemulsion was prepared by phase inversion emulsification method, in order to supporting reference for development and utilization.1. Preparation of pomelo seed oil microemulsionFormula of pomelo seed oil microemulsion was confirmed by investigating some influencing factors. Surfactant:Tween80:Span80(4:1-5:1), EL40:Span80(5:1-6:1), RH40:Span80(3:1-5:1)., cosurfactant:propanetriol,1,2-propylene glycol, n-butyl alcohol, the oil phase:IPM, TPP, were choosed as formula by prescriptions. Meanwhile, surfactant, Km value, temperature were key influencing factors in preparing pomelo seed oil microemulsion.Pseudoternary phase diagrams were drawn by determining formation point, using percolation-conductance model, and then microemulsion areas were measured and compared by the help of AUTO CAD software. At last, optimum formula of pomelo seed oil microemulsion obtained was as follows:IPM/pemole seed oil/RH40/Span80/n-butyl alcohol/deionized water, RH40:Span80=3:1,Cosurfactant is n-butyl alcohol, oil phase(IPM:Pomelo seed oil)=2:1, Km(Surfactant:cosurfactant=8:1), Surfactant:oil phase=7:3, temperature was25℃。2. Pysicochemical property of pomelo seed oil microemulsionPomelo seed oil microemulsion was bright yellow, chear and transparent O/W microemulsion with good mobility. Contents of linoleic acid and oleic acid were46.39mg/ml and36.77mg/ml by HPLC, respectively. Entrapment efficiency of Pomelo seed oil microemulsion was97.5%. Its drops were ball shaped and average diameter was19.1nm, in uniform distribution. The conductivity, refractive index, viscosity and pH value of Pomelo seed oil microemulsion was329μS/cm,1.338,230 mpa.s,6.8.3. Stability of pomelo seed oil microemulsionCentrifugal stability, high temperature, high-light exposure, accelerated and storage observation experiments was used to investigating the stability of pomelo seed oil microemulsion, and all the results showed good stability of pomelo seed oil microemulsion. Pomelo seed oil microemulsion was still chear and transparent O/W microemulsion with good mobility after centrifugal experiment (4000rpm,30min). Retention rates of linoleic acid and oleic acid in microemulsion were70.81%,91.93%on the10th day, respectively, more than pomelo seed oil (30.13%,54.40%), in high temperature experiment. Retention rates of linoleic acid and oleic acid in microemulsion were71.27%,89.37%on the10th day, respectively, more than pomelo seed oil (38.02%,59.72%) at4500LX experiment. Retention rates of linoleic acid and oleic acid in microemulsion were45.80%,64.65%on the3rd month, respectively, more than pomelo seed oil (32.15%,49.21%), in accelerated experiment. In sample observation experiments, Retention rates of linoleic acid and oleic acid in microemulsion were90.09%,92.27%on the3rd month at4℃, respectively, more than pomelo seed oil (58.93%,79.98%), retention rates of linoleic acid and oleic acid in microemulsion were83.13%,86.44%on the3rd month at ambinent temperature, respectively, more than pomelo seed oil (50.07%,70.03%). Retention rates of linoleic acid and oleic acid in Pomelo seed oil microemulsion decreased less than pomelo seed oil, which indicated better stability of former. Moreover, Pomelo seed oil microemulsion stored at4℃showed better stability than ambient temperature.