Research On New Jasmine Tea Process For Improving Jasmine Aroma Utilization And Its Process Effect Evaluation

Jasmine tea is the biggest production and consumption in flower-scented tea in China,because of its rich and fresh spirit aroma.However,there are many problems,such as complex processing,long production cycle,high labor intensity and low utilization rate of jasmine flower,in the processing of jasmine tea.Among them,the low utilization rate of jasmine aroma is an important cause 'of the high cost of Jasmine Tea.Key factors that contribute to the low utilization of jasmine aroma are that the flowers cannot completely release the aroma of the flowers,the ability of the tea to adsorb the aroma is insufficient,and the serious desorption phenomenon is caused by the drying.Therefore,this experiment has formed a new process of jasmine tea processing,including the use of steam distillation purification of jasmine extract process,heat-moisture treatment to make the taste mellow,Jasmine flowers scenting to add fresh spiritual process,while eliminating the drying process after scenting process to avoid the desorption of aroma.Analysis of the new process and the traditional process of tea in the sensory quality,the main biochemical composition,aroma utilization and other aspects of the difference,the results show that:(1)In the heat-moisture treatment,temperature,water content of tea and processing time had significant impacts on the flavor sensory quality of green tea.Under the given conditions,the green tea sensory scores was increased first then decreased with time,temperature and water content increasing.The results of orthogonal test showed that the optimum conditions for the heat-moisture treatment of the green tea were:6h,10%and 50 ?.(2)Steam distillation of jasmine extract and fragrance process,in the 0.2MPa vapor pressure conditions for the distillation of jasmine extract 4 minutes,3min before the amount of essential oil distillation accounted for 96.88%of the total distillate,accounting for 37.10%of the total amount of extract,and distraction of essential oils with rich freshness and high purity of the characteristics.Under the condition of single factor test,the vapor pressure,distillation time and the amount of extract and other factors have obvious effect on the sensory quality of tea.The results of orthogonal test show that the optimum conditions of steaming fragrance were pressure 0.3MPa,time 120s,extract 0.8g/kgtea.(3)The experimentation study on increasing aroma and freshness of fresh flowers showed that the rate of flower and the time of scenting had significant effect on the moisture content of tea.In a certain amount of flower,the tea moisture content with scenting time increases;in scenting time fixed conditions,the tea moisture content with amount of flowers increases.The tea moisture content does not exceed the national standard of 8.5%conditions:rate of flowers 18%,scenting time of 12h was the optimal conditions.(4)Compared with the traditional craft tea using the same material,the paper analyzes the new technology's sensory quality and biochemical components.The appearance of the new process Jasmine-scented tea is not obviously different from the traditional way.The content of chlorophyll a was lower,but chlorophyll b and total chlorophyll were both higher.There is no difference in tea liquid color.The tea shape in brewing is neater.The content of water extracts,tea polyphenols,catechins were reduce,free amino acid content increased slightly.The catechin astringent index(CAI)and Phenol ammonia ratio were decreased.The catechin quality index was increased.To the aroma about relatively proportion,the relative content of ester aroma including Benzyl acetic and cis-3-Hexenyl Benzoate and Nitrogenous compounds liking indole was higher than the traditional,and then the relative content of volatile substances such as alcohols,aldehydes and ketones was lower than the tradition.(5)Compared with the traditional jasmine tea processing technology,the new process jasmine tea jasmine aroma utilization rate as high as 70.19%,the traditional process utilization is 21.86%,the new process is 3.21 times the traditional process and savings of jasmine 72.28%.At the same time,the new process also simplifies the process,reducing the physical strength of processing operations and saving at least 3d processing time.