Abstract: The process conditions for procyanidins extraction from faba bean episperm by microwave pretreatment followed by ethanol extraction were investigated. The effects of microwave pretreatment conditions (microwave power, microwave treatment time, water-to-faba bean episperm powder ratio) and extraction conditions (70% ethanol-to-faba bean episperm powder ratio, temperature and time) on the extraction yield of procyanidins were explored. The results showed that the optimum conditions for microwave pretreatment and ethanol extraction were obtained as follows: faba bean episperm powder was soaked in water at a liquid-to-solid ratio of 2:1 (mL/g) before microwave pretreatment at 140 W for 50 s and subsequent extraction for 72 min with 70% ethanol at a liquid-to-solid ratio of 21:1 (mL/g), 55 ℃. Under these conditions, the extraction recovery of procyanidins was 94.53%.

Key words: faba bean episperm, procyanidins, microwave-pretreatment