Effect of exogenous melatonin treatment on Aspergillus decay, aflatoxin B1 accumulation and nutritional quality of fresh 'Akbari' pistachio fruit

摘要

This study aimed to investigate the mechanisms activated by melatonin treatment forattenuating Aspergillus decay, suppressing aflatoxin B1 (AB1) accumulation, and preservingnutritional quality in fresh pistachio fruits during storage at 25°C for 18 days.At 6-dayintervals, samples from each of three replications were selected, and subjectedto biochemical analysis. Our results showed that fresh pistachio fruits treatedwith 1,000 μM melatonin and inoculated with Aspergillus flavus, exhibited lowerAspergillus decay accompanied by lower endogenous AB1 accumulation. Melatonintreated fruit also showed lower H_2O_2 and malondialdehyde accumulation during storage.Furthermore, higher linolenic acid accumulation accompanied by higher phenolsand flavonoids accumulation as well as superior DPPH scavenging capacity in freshpistachio fruits treated with 1,000 μM melatonin, could be ascribed to lower lipoxygenaseand higher phenylalanine ammonia-lyaseenzymes activity, respectively, duringstorage. Besides, melatonin applying at 1,000 μM suppressed spore germinationand germ tube elongation in A. flavus.