| Rose is deciduous shrub of genus Rosa in the Rosaceae families, and widely grown in our country. Cultivation of roses had been developed, but some rose resources have not been fully utilized. Rose essential oil concentrated aroma components of rose petals, which is an advanced, expensive fragrance, and has moisturizing, antibacterial, antioxidant effect, as well as reduces pressure and improves sleeping. Rose essential oil has been widely used in cosmetics, food, medicine industry for its great development potential. In the present study, in order to utilize local rose resources and improve oil yield, extraction of rose essential oil from Rosa of Changbai Mountain by hydro distillation combined with high intensity pulsed electric fields(PEF) was investigated. The antioxidant activity of rose oil was analyzed and microencapsulation was prepared, with a view to develop a new way of efficient extraction of rose essential oil and providing a theoretical basis for the application of rose resources and its oil.1. Extraction of rose essential oil by hydro distillation was studied. Base on the single factor experiment, orthogonal design was used to optimize the extraction process and optimum parameters were obtained, homogenized rose, with liquid ratio of 1:6(g/m L), concentration of sodium chloride of 10%, distillation time of 4h. Under this condition, the rose essential oil yield was 0.0802%.2. The method of high intensity pulsed electric fields, ultrasonic-microwave, enzyme and surfactant assisted distillation were used to extract rose essential oil. The effects of different extraction conditions on rose oil yield were studied. The contrast test showed that the use of high intensity pulsed electric fields assisted distillation had higher yields, lower temperatures, and less time consuming.3. Response surface was applied to get the quadratic regression equation between rose oil yield(Y) and the electric field intensity(X1), pulse number(X2), distillation time(X3):Y=-0.22800+7.442520×10-3X1+0.038019X2+0.1039X3+3.325×10-4X1X2-4.4×10-4X1X3-2.21177×10-1X2X3-2.425×10-4X12-2.82812×10-3X22-0.02155X32According to the variance analysis, optimum parameters were obtained, with electric field intensity of 18.89(KV/cm), pulse number 8.03(ea) and distillation time of 2.19(h), and the maximum yield of rose oil was 0.1053%. The influence of various factors in the test range on rose oil yield of the size of the order: distillation time, electric field strength and pulse number.4. The antioxidant activities of rose essential oil were evaluated by determining the ability of free radical scavenging on DPPH, hydroxyl and superoxide anion, the inhibiting lipid peroxidation and the total reducing power. The results showed that rose oil had shown antioxidant capacity in various systems in a certain concentration rage. With rose essential oil concentration increased, antioxidant capacity gradually increased. Rose essential oil had a certain degree of antioxidant activity compared with the control of Vc.5. The chemical composition of rose essential oil extracted by hydro distillation and hydro distillation combined with high intensity pulsed electric fields were analyzed by GC-MS. 45 and 52 chemical components were identified,and accounting for 85.73% and 93.34 % of the total essential oil respectively. The major aroma components of two methods were linalool, geraniol, neral acetate, citronella acetate, eugenol, methyl eugenol so on. It can be concluded that using PEF treatment might not change the kinds of rose oil components significantly, but have influence on its contents.6. Microencapsulation of rose essential oil was prepared by using the method of saturated aqueous solution, and the factors that influence the effect of inclusion of rose oil were studied. The results indicated that the maximum inclusion rate was obtained with the ratio of ethanol and oil of 20:1, the ratio of β-cyclodextrin and oil of 6:1, inclusion time of 2.5 h and inclusion temperature of 50 ℃. According to storage stability test, microscopy and scanning and Fourier transform infrared spectroscopy of rose oil microcapsule, the stability of rose oil after inclusion had been improved with regular shape and uniform size. IR spectrum had proved the formation of microencapsulation of rose essential oil. Innovation:PEF assisted hydro distillation had been used to extraction of rose essential oil from Rosa of Changbai Mountain for the first time, which explored a new way for efficient extraction of rose essential with increasing yield and reducing extraction time. |
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