Optimization Of Processing Parameters For Water Extract And Essential Oil From Lavender By Spray Drying

In China, Lavender was mainly planted in Yili Xinjiang. Planting area was more than 5400 hectares, Accounts for the lavender planting area was more than 90%. Lavender essential oil accounts for only about 1.5% of the quality of dried flowers, after been extracted oils, the residue containing a large number of flavonoids, polyphenols and other biologically active substances, which was not used effectively. In this paper, the spray drying was used to prepare lavender extract powder and lavender essential oil microcapsule, which provided experimental basis for the development of new lavender products. The main results were as follows:(1) The spray drying conditions of lavender powder preparation were optimized, using the response surface methodology. The results showed that the optimized conditions were the fan frequency of 55 Hz, peristaltic pump speed of 295 mL/h, inlet air temperature of 218℃. Under the conditions, the yield of lavender extract powder was 67.34%, the moisture content was 4.16g/100 g, the solubility was 86.78%, the colour was good, the preserving rate of reducing power was 81.92%, the preserving rate of hydroxyl radical scavenging power was 59.23%.(2) The preparing conditions of the feed solution were optimized, using maltodextrin as the dry agent. The results showed that the best conditions were total solids content of 28%, dry agent adding ratio of 1/3, oscillation time of 1.5 h. Under the conditions, the yield of lavender extract powder was 64.43%, the moisture content was 3.94 g/100 g, solubility was 89.78%, the sensory evaluation was 90, the moisture content was 4.02 ±0.05(g/100 g), the solubility was 86.28 ± 0.002(%), the bulk density was 0.25 ±0.005 g/mL. The preserving rate of reducing power was 82.36%, the preserving rate of hydroxyl radical scavenging power was 64.23%. The ability of scavenging DPPH free radical was decreased significantly(P<0.05), the amount of total flavonoids was decreased, but not significantly(P>0.05), and the total polyphenol content was decreased significantly(P<0.05).(3) Lavender essential oil microcapsule was prepared by spray drying method, and the results showed that the optimum spray drying conditions were the ratio of core to wall of 1:4, emulsifying time of 2 h, peristaltic pump speed of 198 mL/h. Under the conditions, the utilization rate of volatile oil was 62.76%.