Effect Of Ultrasound Extraction On The Tea Infusion Quality Of Ready-to-drink Green Tea

It is important to keep the infusion color and sensory quality of tea beverage. Extraction is a primary process of tea beverage production and it will directly influence the quality of tea beverage. A good extraction process will improve quality and reduce production cost. In recent years, there have been many extracting methods according to the needs of green tea beverage production. In order to investigate the effect of different extracting methods on quality of tea infusion in ready-to-drink tea production, experiments were designed with high temperature extraction(90℃), low temperature extraction(50℃) and ultrasound extraction(50℃). The results showed were as follows:1. Effect of different extracting methods on the main components of tea infusion were studied. The results showed that the solids extraction yield by ultrasound extraction was higher than that by low temperature extraction. The high temperature extraction(90 ℃) resulted in the highest solids extraction yield. The ultrasound extraction had a beneficial effect on the extraction of the main components of tea. The contents of tea polyphenols, amino acid and caffeine almost reached that extracted by high temperature extraction(90℃) and obviously exceeded that by low temperature extraction(50℃).2. Main kinds of catechins in tea infusions extracted by different extracting methods were analyzed by HPLC. The results showed that total amount of catechins in high temperature extracting infusion are higher than the other two treatments before 20 min while ultrasound extraction were obviously higher than those of other extracting methods after 30min extraction, especially the content of EGCG. It is probably because that EGCG be isomerized under high temperature.3. The ultrasound and low temperature extraction had high lightness and high temperature extraction had low lightness of tea infusion. The infusion color of tea infusions extracted by low temperature was also good。 A suitable product of tea extraction is presumed to have a godd sensory quality. The results of sensory quality of the tea infusions showed that the ultrasound extraction is benificial to...