Effect of Melatonin Treatment on Storage Quality of Passion Fruit after Harvest

The effects of melatonin treatment on physiological characteristics and quality of passion fruits during post harharvest storage were valuated. The passion fruits were dipped in 0, 0.05, 0.10, 0.20 mmol/L melatonin (MT) solution for 1 hour, then put in crisper and stored at room temperature (25±1 ℃), the parameters of firmness, color, soluble solid, soluble sugar and other indexes were analyzed. The results showed that more than 77% of the passion fruits in the CK group had rotted on the 12th day of storage, the mass loss rate and decay rate of melatonin treatment group were 8.22%~12.81% and 22.22%~38.89%, which were significantly lower than those of CK group (P<0.05), the melatonin treatment groups kept a good quality and the contents of soluble solids, titratable acid and soluble sugar were significantly higher than CK group (P<0.05). On the 16th day, all the fruits in CK group had rotted, the firmness of passion fruits treated with 0.20 mmol/L melatonin was 9.95 kg/cm², which was significantly higher than that in the other two melatonin groups (P<0.05), and the weight loss rate was only 15.52%, which was significantly lower than that in the other two treatment groups (P<0.05), while other quality parameters had no significant differences between the other two treatment groups. In conclusion, 0.05, 0.10 and 0.20 mmol/L melatonin treatments could prolong the storage time of passion fruits and maintain the quality at a high level, while 0.20 mmol/L melatonin treatment had the best effect.