Effects of hydrogen peroxide treatment on thiol contents in fresh-cut asparagus (Asparagus officinalis) spears

In this work, the impact of hydrogen peroxide (H₂O₂) was investigated on the thiol content of asparagus. Fresh-cut asparagus was treated with H₂O₂ at varied oxidant concentrations and contact times. A significant decrease (α=0.05) was observed in N-acetylcysteine levels treated with 2.5% H₂O₂ for 10 min and with 5% H₂O₂ for 3, 5 and 10 min. Captopril and cysteine levels significantly decreased (α=0.05) in all and most treatment conditions, respectively. Glutathione levels only significantly decreased with 2.5% and 5% H₂O₂ for 10 min treatment. In order to determine whether asparagus undergoes oxidative stress, a well-known oxidative stress indicator—the glutathione/oxidized glutathione ratio—was calculated. This study showed that the common use of H₂O₂ as a disinfectant/sterilizer by the food industry could markedly diminish the important biothiols and develop oxidative stress in asparagus, and potentially in other vegetables as well.