Studies On The Microencapsulated Of Jasmin Essential Oil And Its Application In Scented Tea

Microencapsulation of flavouring substance is an important branch of microencapsulation embedding technology. As is known to all, flavour and perfume are two important sensory qualities of food products. With the trend of emphasizing color, flavour and taste in food consumption, microencapsulation of flavouring substance has enjoyed a significantly high value of application.Microencapsulation of essential oil of Jasminum Sambac through appropriate method can not only effectively prevent it from oxidation during storage period, but also change liquid perfume into solid perfume, when added into tea, may raise the utilization rate of Jasmine flavour composition and advance the standardization of the quality of tea products.This research uses beta-cyclodextrin and essential oil of Jasminum Sambac in the embedding experiment, changes the essential oil from liquid into solid, investigates the release law of flavour composition and discusses the possibility of applying the inclusion of essential oil of Jasminum Sambac to tea products.Firstly, the preparatory process of the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin was studied. Using orthogonal experiment, the adding proportion of stirring time, stirring temperature and the essential oil of Jasminum Sambac/beta-cyclodextrin were studied; after a comprehensive evaluation and analysis of the inclusion production rate of essential oil of Jasminum Sambac and beta-cyclodextrin, oil percentage of the inclusion and the utilization rate of essential oil of Jasminum Sambac, the most suitable parameters for inclusion were worked out: the proportion of essential oil of Jasminum Sambac to beta-cyclodextrin is 1:8 (mL: g); time of stirring is 1.5 hours; temperature of stirring is 30℃. Under this condition, the production rate of the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin reaches 84.87%, oil percentage of the inclusion 10.83%, and the utilization rate of essential oil of Jasminum Sambac 97.78%.To demonstrate the formation of the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin, the structure characters of the produced inclusion were given through X-ray diffractometry and infrared spectroscopy (IR), differential scanning colorimetry (DSC) and scanning electron microscopy (SEM).The result of IR clearly indicates: there does exist conspicuous crystal structural differences among beta-cyclodextrin solid, the physical compound of beta-cyclodextrin and essential oil of Jasminum Sambac, and the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin, which are mainly manifested in the differences of peak numbers, peak shapes and peak places. These findings prove that new solid phases had formed in the produced solid inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin.DSC result shows beta-cyclodextrin solid is a kind of pure crystal with only one pure peak; while inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin has visible double peaks in different places, which bears it out that there are two kinds of compositions contained wherein. Both IR and DSC show that they support each other well.SEM shows the produced inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin is roundish granule in shape, which suggests the structural completeness of the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin.Based on head space (HS) solid-phase microextraction (SPME) and gas chromatography/mass Spectrometry (GC/MS), this paper analyzes the compositions and their contents in the raw essential oil of Jasminum Sambac. The results showed that Linalool, Benzamide, N, N-dipropyl, acetic acid, phenyl methyl ester, alpha-Famesene and Acetic acid, 2-propenyl ester are the major compositions, which account for 52.98% of the whole. Due to the fact that Linalool constitutes a relatively high percentage of content in the essential oil of Jasminum Sambac, this research takes it as the characteristic substance in the study of the release process of the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin, and the change of its content as one of the evaluation indexes of products' quality.Based on a comparison and analysis of the volatility of essential oil of Jasminum Sambac, the total and surface content of essential oil in the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin, and an analysis of the change of the total and surface content of essential oil in the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin during storage, this research showed that loss of the surface oil of the inclusion accounts for the main loss of essential oil of Jasminum Sambac during storage. What is more, during storage, the content of Linalool also decreases and its decreasing speed is higher than that of the essential oil of Jasminum Sambac, which demonstrates the strong volatility of Linalool.Based on an HS analysis and comparison of the change of total content of flavour and Linalool in essential oil of Jasminum Sambac spray green tea dust and the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin during storage, this study comes to the conclusion that beta-cyclodextrin inclusion is very useful in the storage of the flavour of essential oil of Jasminum Sambac.This research makes the first step in the application of essential oil of Jasminum Sambac and beta-cyclodextrin in the flavouring of green tea dust, reaching the conclusion that when the adding content of the inclusion of essential oil of Jasminum Sambac and beta-cyclodextrin is 0.5%, the resulted tea tastes best.After a comparison of the embedded tea products using essential oil of Jasminum Sambac and beta-cyclodextrin, tea dust flavoured on the surface by essential oil of Jasminum Sambac and market-sold jasmine tea, it can be concluded that the flavouring substance contained in the tea flavoured by essential oil of Jasminum Sambac is not as flavour-lasting as the tea embedded by the flavour of essential oil of Jasminum Sambac and beta-cyclodextrin.Composition analysis shows for the tea embedded by the flavour of essential oil of Jasminum Sambac and beta-cyclodextrin, the flavouring cost per unit green tea material is 4592.2 RMB/ton (about 4.6 RMB/kg).