Litchi fruit is prone to browning after harvest.To investigate the effects of exogenous γ-aminobutyric acid(GABA)on litchi pericarp browning and changes in phenolic compounds,litchi fruit was immersed in 5 mmol/L of GABA solution for 15 min and then stored at(20±1)℃for 6 days.Samples were collected at regular intervals to measure the physiological indices related to pericarp browning and phenolic compounds.The results demonstrate that GABA treatment can significantly delay litchi pericarp browning.The browning index of litchi treated with 5 mmol/L of GABA was 2.80 after storage at 20℃for 6 days,which was significantly lower than that of the control group(3.60).Meanwhile,the good fruit rate was 36.67%,and the weight loss rate was only 3.82%.During storage,GABA treatment significantly reduced the accumulation of MDA in the litchi pericarp and inhibited PPO,POD,and LAC activities while activating PAL.In addition,GABA-treated litchi pericarp showed higher total phenol(525.93 mg GA/g),flavonoid(14.06 mg rutin/g),and anthocyanin(0.54 ∆A/g)content after 6 days of storage.The DPPH free radical scavenging ability of the pericarp was also improved.In summary,5 mmol/L GABA treatment can effectively delay litchi pericarp browning by inhibiting enzymatic browning and affecting phenolic metabolic processes,which is an effective method of improving litchi storage quality after harvest.
维普
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