Optimization of combined treatment condition of hot air and methyl jasmonate for postharvest loquat fruit preservation

In order to determine the optimum condition of hot air combined with methyl jasmonate (MeJA) for preservation of postharvest loquat fruit, the effects of different combined treatment conditions on fruit quality were investigated by using the response surface methodology (RSM). Fresh harvested loquat fruit were pretreated with different concentrations of MeJA (10-30 μmol/ L) in hot air at different temperatures (35-45°C) for different treatment times (3-7 h), and then stored at 1°C for 35 days. Fruit internal browning, firmness and extractable juice were measured after the storage. Three second-order quadratic equations of fruit internal browning, firmness and extractable juice were established, and the fitting degree were analyzed through RSM. The key factors and their interactions affecting the loquat quality were also discussed through RSM. The results indicated that the optimum condition for combined treatment of hot air and MeJA was that temperature was 38.5 °C, treatment time was 5.8 h, MeJA concentration was 16 μmol/L. The optimized combined treatment was more effective in inhibiting flesh leatheriness and maintaining quality than applying hot air or MeJA alone. The data obtained can provide a foundation for application of the combined treatment in loquat fruit preservation.