Biochemical origin of browning during the processing of fresh Yam (Dioscorea spp.) into dried product.

摘要: This study was undertaken to follow the kinetics of polyphenoloxidase (PPO), peroxidase (POD), and phenolic compounds during yam blanching at different temperatures after drying identify by high-performance liquid chromatography (HPLC) main present in products. PPO activity 50% higher nonprocessed freeze-dried Florido (Dioscorea alata) than Deba rotundata). It decreased progressively blanching. Forty-five percent remained 50 min 60 or 65 °C, whereas POD dropped sharply less 20% initial 10 blanching, whatever temperature. No anthocyanidins could be detected HPLC 520 nm yam. Flavanols with a maximum absorption wavelength (λmax) 280 cinnamic acid 320 λmax were detected. Catechin identified as major flavanol concentrations ranging from 0.26 ...