Impact of Hypobaric Technology Combined with Fumigation on Freshness Preservation of Post-harvest Litchi

Litchi is rich in nutrients, which is quite beneficial for improving the physical quality of people, but litchi browns in a few days at room temperature, and the shelf life is very short. To study the influence of hypobaric storage on the storage quality of litchi after harvest, a hypobaric storage device combined with fumigation technology was used to fumigate litchi, and the change in pressure and temperature distribution in the hypobaric chamber was simulated. Secondly, during the hypobaric fumigation, litchi was divided into four groups with uniform quality, and humidified at 0%, 2%, 3%, and 5%, respectively. The temperature of the surface and center of the litchi was measured using a thermocouple. The research results show that in the simulation verification, the changes in pressure and temperature in the vacuum chamber during the experiment are basically consistent with the simulated values, and under different humidification specific gravity, when the humidification specific gravity is 3%, the center temperature and surface temperature drop the fastest, in which the surface temperature drops to 277.15 K, and the center temperature drops to 283.15 K, and the hypobaric fumigation and pre-cooling reaching the same temperature. The time required is also minimal.