Effect of basil leaves and wheat bran water extracts on enzymatic browning of shredded storage iceberg lettuce

Summary The impact of functional solutions (water infusions of radish sprouts, wheat bran (WBE), basil leaves (BLE) and lentil protein hydrolysate) on enzymatic browning of shredded iceberg lettuce was studied. BLE and WBE, limiting enzymatic browning in the highest degree, were tested during cold storage. The best inhibitors of PPO activity in lettuce stored for 8 days were 10% WBE (a decrease by 97%). POD activity was substantially decreased by ascorbic acid (by 75%) and 1% BLE (by 83%). POD and PPO inhibition was reflected in a decrease in enzymatic browning, that is 91% and 88% reduction was found in 8‐day stored lettuce treated with 1% BLE and 1% WBE, respectively. In the case of POD, mixed inhibition was recorded for BLE and WBE, while these solutions acted as competitive inhibitors of PPO activity. The enzymatic browning of shredded iceberg lettuce during cold storage may be effectively suppressed by natural extracts. The natural extracts obtained from basil leaves and wheat bran were potent inhibitors of polyphenol oxidase and peroxidase from iceberg lettuce. Phenolic compounds are mainly responsible for the inhibition of the activity of the enzymes. The suppression of enzymatic activities ensures significant improvement of consumer quality during storage of shredded iceberg lettuce through the control of the enzymatic browning level.