Browning mechanism and inhibition of Amorphophallus Konjac and Amorphophallus albus

The phenol contents, Polyphenol Oxidase(PPO) activity, browning substrates and the browning mechanism during process of desiccation of Amorphophallus Konjac(AK) and Amorphophallus albus(AA) were studied. And the inhibition effects of nuisance-free enzymatic browning inhibitors, such as phytic acid, ascorbic acid, citric acid and cysteine were investigated. Results show that during the storage from November to January of next year, the total phenol content in the corm of AA is higher than that in the AK, the PPO activity of AK is higher than that of AA, the browning intensity of AA is always weaker than that of AK, and the browning intensity has positive correlation with the PPO activity of konjac corm. The substrate which causes browning is dopamine mostly. The enzyme which arouse the browning of AK and AA is polyphenol oxidase. The AA dry slice is white in color and has good quality which can be obtained by the process of dipping it in the solution containing 0.01% cysteine for about 5 min and firing at 60℃. The AK dry slice is white in color and good in quality which can be obtained by the process of dipping it in the solution containing 0.15% cysteine + 1% citric acid + 1% phytic acid + 0.01% ascorbic acid for around 5 min and then firing at 60℃.