Abstract:
Abstract: Jasmine scented tea is a kind of flavored tea. It is popular for its elegant aroma and mellow taste. Jasmine flower is a typical "temperament flowers", it blooms at night when it releases fragrant aroma. In traditional jasmine tea processing, the tea and the jasmine flower are mixed together during which the materials are spread for heat dissipation, when the temperature increasing and the tea is re-dried. The process is repeated for several times. However, many problems exist with this type of production, including its complicated process, longer production period, higher labor intensity, higher flower consumption, seasonal and field limitations. To solve these problems, technological processes have been developed that employ a device to absorb the aroma of jasmine flowers, perform a clean extraction of essential oil, and produce jasmine tea with the oil.A jasmine aroma releasing and collecting device was developed using coconut shell activated carbon. The device consisted of an environmental control system, an aroma releasing warehouse and an aroma collection system. The environment control system consisted of a temperature sensor, a humidity sensor, a humidifier, an air inlet and refrigeration components, which could provide suitable environment for jasmine flower releasing fragrant aroma. The aroma releasing warehouse was composed of four shelves, which could provide space for jasmine flower laying and airflow distribution uniform. The aroma collection system was consisted of an adsorption column, a vacuum pump, an air outlet and activated carbon. The device could control the environmental parameters precisely, extending the releasing time from 10 hours to 18 hours. It collected the jasmine flower aroma through negative pressure using activated carbon, which decreased the loss of aroma and simplified the essential oil collection process.The optimum temperature and humidity for aroma releasing and collecting were getted. The test showed that the optimum conditions were temperature 30℃ and relative humidity 85%(T2), 30℃ and 95%(T3), 35℃ and 85% (T5), respectively. The range of water loss rate, openness, aroma score, morphology score and collection rate in the three optimal condition combinations were 4.08%-10.03%, 179.67%-176.89%, 6.90-6.80, 6.90-6.80 and 10.76%-15.48%.The volatile components of tests were assayed by chromatography-mass spectrometry detection (GC-MS). Principal component analysis (PCA) was used to evaluate the results. It showed that the score of aroma quality testing at 35℃ was the highest, in which the level of ester compounds was high. This was beneficial to the quality of jasmine essential oil. The optimum environment parameters for jasmine aroma releasing were 35℃ and relative humidity of 85%, under which the collection rate of the released aroma was 13.96%. Moreover, the profit of jasmine essential oil in this study was more than 28% of solvent extraction. In conclusion, the new aroma releasing and collecting device could be applied widely in the production of jasmine essential oil.