The Extraction of Green Tea Components by the Rapid Increasing-decreasing Pressure Method and Antioxidative Activity and Stability of the Extracts

Abstract

　To establish an efficient extraction method for functional components from food materials, we developed a piece of equipment for increasing-decreasing pressure extractions, which utilizes the pressure difference caused by a flow of water. We extracted the functional components of green tea using this equipment. As a result, catechins, caffeine, amino acids, chlorophyll, and α-tocopherol were efficiently extracted from green tea at a room temperature (20～25℃) in a short time (15 min). In addition, significant antioxidant activity attributed to the green tea extracts was confirmed, which the ethanol concentration was more than 60 % (v/v). Although the concentration of chlorophyll decreased after storage for three months, the concentrations of the catechins, caffeine, and amino acids did not change significantly upon storage. Therefore, even though there was an issue regarding the retention of color owing to the decrease in chlorophyll, this method is suitable for the extraction and storage of functional components from food materials.