Postharvest L-cysteine application delayed pericarp browning, suppressed lipid peroxidation and maintained antioxidative activities of litchi fruit

摘要

Efficacy of L-cysteine as an anti-browning agent was investigated on 'Gola' litchi fruit. Fruit were treated with its different concentrations (0.0, 0.25, 0.50, 0.75 and 1.0%) and stored at 5 +/- 1 degrees C with 90 +/- 5% relative humidity (RH) for 28 d. Among the used concentrations, 0.25% treatment was most effective. L-cysteine (0.25%) treated-fruit showed significantly reduced weight loss, disease incidence, disease severity, browning index, membrane leakage and malondialdehyde (MDA) contents. Application of L-cysteine (0.25%) to litchi fruit maintained acidic pericarp pH, exhibited higher total anthocyanins, 2,2-Diphenyl-1-picryl-hydrazyl (DPPH) radical-scavenging-activity and total phenolic contents (TPC) along with reduced activities of peroxidase (POD) and polyphenol oxidase (PPO) enzymes. L-cysteine (0.25%) treatment also maintained substantially higher soluble solid contents (SSC), titratable acidity (TA), ascorbic acid contents and activities of catalase (CAT) and superoxide dismutase (SOD) enzymes. In conclusion, pre-storage L-cysteine (0.25%) application to litchi fruit exhibited reduced pericarp browning index and maintained antioxidative system for 28 d. (C) 2016 Elsevier B.V. All rights reserved.