Isolation, purification and identification of etiolation substrate from fresh-cut Chinese water-chestnut (Eleocharis tuberosa)

Fresh cut Chinese water-chestnut is a popular ready-to-eat fresh-cut fruit in China. However, it is prone to etiolation and the chemicals responsible for this process are not known yet. To address this problem, we extracted phytochemicals from etiolated Chinese water-chestnut and separated them using MPLC and column chromatography. Four compounds were obtained and their structures were determined by interpretation of UV, TLC, HPLC and NMR spectral data and by comparison with reported data. We identified these compounds as eriodictyol, naringenin, sucrose and ethyl d-glucoside. Among those, eriodictyol and naringenin were both isolated for the first time in fresh-cut Chinese water-chestnut and are responsible for the yellowing of this fruit cutting.