Extraction Of Bioactive Compounds From Different Types Of Tea By High Hydrostatic Pressure

In this study, high hydrostatic pressure was applied for the extraction of bioactive compounds from green, yellow, white, oolong, and black tea. Extractions were carried out varying solvent (ethanol and water), pressure level (200 and 500 MPa), and pressure holding time (5 and 10 min). Total phenolic content (TPC) and antioxidant capacity were determined spectrophotometrically, while the content of individual catechins and caffeine were determined by HPLC-DAD methodology. Among investigated teas, the highest TPC was determined in the ethanolic extract of green (3,327.27 mg GAE L-1) and white tea (3,136.36 mg GAE L-1) combining pressure of 200 MPa during 5 min, while the highest epigallocatechin gallate (1,446.38 mg/L), epicatechin gallate (354.17 mg/L) and caffeine (862.58 mg/L) contents were determined in the ethanolic extract of white tea PMT obtained also using lower pressure level but with longer pressure holding time. Practical applications Tea represents a great source of natural bioactive compounds whose consumption has been linked to different health benefits. When extracted, teas bioactive compounds can be integrated into different types of foods in order to make them functional. However, in order to achieve a maximal extraction efficiency of the compounds of interest, it is of great importance to choose an extraction technique that will not result in their degradation. High hydrostatic pressure is a nonthermal extraction technique which application in the extraction of bioactive compounds from different types of tea is not well investigated and the present paper will provide new insights in this area.