Rajapaksha Surakshi, Shimizu Naoto
Laboratory of Agricultural Biosystem Engineering, Graduate School of Agriculture, Hokkaido University, Hokkaido 060-8589, Japan.
Research Faculty of Agriculture/Field Science Center for Northern Biosphere, Hokkaido University, Hokkaido 060-8589, Japan.
Food Chem X. 2021 Dec 29;13:100200. doi: 10.1016/j.fochx.2021.100200. eCollection 2022 Mar 30.
Spent black tea (SBT) is a residue from tea beverage production and considered as a potential source of active polyphenols. This study aimed to develop a pilot-scale process on semi-continuous subcritical solvent extraction (SSE) of polyphenols from SBT by exploiting the lab-scale knowledge. Treatment of SBT with ethanol-water (50% w/w) as solvent at 125 °C and 0.3 MPa achieved a significantly higher yield of polyphenols (80.82 g gallic acid equivalents/kg black tea) with antioxidant activity (64.20 g gallic acid equivalents/kg black tea), compared to hot water extraction (HWE). SSE increased the soluble matter content in extracts than HWE. Based on the results of LC-MS, theaflavin-3,3'-digallate was the most abundant polyphenol from a total of 12 compounds to be extracted by SBT with 50% ethanol. The results suggested that SSE can be used as a scale-up extraction method to recover polyphenols from SBT.
废红茶（SBT）是茶饮料生产过程中的残渣，被认为是活性多酚的潜在来源。本研究旨在利用实验室规模的知识，开发一种中试规模的半连续亚临界溶剂萃取（SSE）工艺，从SBT中提取多酚。以乙醇-水（50% w/w）为溶剂，在125°C和0.3MPa条件下处理SBT，与热水萃取（HWE）相比，多酚产量（80.82g没食子酸当量/kg红茶）和抗氧化活性（64.20g没食子酸当量/kg红茶）显著更高。SSE比HWE增加了提取物中的可溶性物质含量。基于液相色谱-质谱（LC-MS）结果，茶黄素-3,3'-二没食子酸酯是SBT用50%乙醇萃取的12种化合物中含量最丰富的多酚。结果表明，SSE可作为一种放大提取方法，从SBT中回收多酚。
