Slicing increases antioxidant capacity of fresh-cut lotus root (Nelumbo nucifera G.) slices by accumulating total phenols

Abstract

Summary: Slicing is an abiotic stress during fresh-cut lotus root slices (FLS) preparation. To evaluate the potential ability of slicing to induce antioxidant capacity (AC) in FLS, fresh lotus roots were sliced into 0.4 cm thick slices and stored at 7 °C for 7 days using intact root segments as control. Results showed slicing induced 68.3% higher phenylalanine ammonia-lyase (PAL) activity and parallel 130.5% more total phenol (TP) accumulation after 7 days storage compared to control. AC values in FLS assayed by FRAP and ABTS•+ were 41.5% and 93.8% more than those in control samples at the end of storage, respectively. Such increases in AC values were mainly attributed to TP accumulation as a positive correlation existed between AC and TP. However, slicing significantly accelerated FLS browning by increasing the polyphenol oxidase (PPO) activity during storage. Nevertheless, FLS was still marketable with the maximum browning index of 1.9 after 7 days storage.