Amelioration of chilling injury and enhancement of quality maintenance in cold-stored guava fruit by melatonin treatment

The influence of melatonin treatment on the quality and chilling injury of guavas during storage at 4 +/- 1 degrees C were evaluated. Compared with control group, fruit of guava cv. Xiguahong exposed to various concentrations (50, 100, 150, and 200 mu mol/L) of melatonin showed a significantly lower fruit respiration rate, weight loss, cell membrane permeability, and chilling injury index, but a higher commercially acceptable fruit rate, higher peel L*, h degrees value, and chlorophyll content. Melatonin treatment also delayed the decreases of fruit firmness, sucrose, total soluble sugar, vitamin C, titratable acidity, and total soluble solids. These data indicate that melatonin treatment could increase chilling tolerance and retain quality of cold-stored guavas. Among various concentrations of melatonin treatment, 100 mu mol/L melatonin-treated guavas showed the preferable quality properties and lowest chilling injury index. Thus, melatonin may be a novel method of postharvest handling to enhance cold resistance and extend storage-life of cold-stored guava fruit.

Automated summary

The influence of melatonin treatment on the quality and chilling injury of guavas during cold storage was evaluated. The study showed that melatonin treatment significantly reduced fruit respiration rate, weight loss, cell membrane permeability, and chilling injury index, while increasing commercially acceptable fruit rate, peel color, and chlorophyll content. Melatonin treatment also delayed the deterioration of fruit firmness, sugars, vitamin C, acidity, and soluble solids.