Optimization of Flavored Lemon Roasted Tea Making Process and Extraction Conditions for Hygienical Component

Effects of extracting factors,the ratio of raw materials,the ratio of raw material to water,extraction temperature and extraction time,on healthy ingredients(polysaccharides and flavonoids contents)and the extract quality(liquor colour,aroma and taste)of lemongrass tea had been studied on the basis of single factor test and orthogonal test with lemongrass as the main material,added with a little stevia,mint,jasmine and marigold.The results showed that the optimal extracting conditions were 100℃,80 min and the ratio of raw material to water 1∶60in the single factor test.With the extracting conditions,the elution volume of flavonoids increased by 35.26%-148.0%,63.3%-244.8% and 5.5%-54.6% as compared with other treatments respectively,and the elution volume of polysaccharides increased by 0%-34.8%,17.6%-119.8% and 2.7%-19.4%,respectively.However,in the orthogonal test,the optimal extracting conditions were 80℃,80 min and the ratio of raw material to water 1∶60,and the extraction liquid was weak ginger,moderate sweet,transparent and yellowish liquid.it suggested that the best ratio of raw material to water is 1∶60for extracting healthy ingredients,and it was 1∶80for producing soft drinks considering the difference of the ratio of raw material to water between single factor test and orthogonal test.Based on the orthogonal test,the best ratio of raw materials(lemongrass∶stevia:mint∶jasmine and marigold)was 5∶1.5∶1.0∶0.5for health ingredients and 3.5∶0.5∶1.0∶1.5for soft drinks.