Integrated post-harvest ethylene management along the value chain

To develop a proof of concept – Development of a large-scale system for photocatalytic and photolysis oxidation of ethylene during postharvest storage of apple fruit.

To investigate pack-house practices and to take into account the influence of exogenous ethylene originating from other sources besides the fruit itself.

The rationale of this project is to determine the impact of ethylene and to investigate the effectiveness of using photocatalytic oxidation techniques for ethylene removal.

WP1: Optimizing photocatalytic oxidation (PCO) and designing vacuum ultraviolet (VUV) photolysis reactors and assessing their ethylene removal efficacy.

WP2: Routine ethylene measurements in the pack-houses to identify ethylene hotspots

WP1: (A) PCO reactor design showed a potential to reduce accumulated ethylene to 10.8 ppm compared to the control which increased to 61.9 ppm

WP1: (B) The ethylene removal efficiency of the VUV photolysis reactor was 86.9% compared to the removal efficiency of the commercially used technique KMnO₄ (25%).

The vacuum ultraviolet (VUV) treatment significantly reduced the ethylene concentration in the storage chamber to 2.5 µL L−1^{-1}, 138 µL L⁻¹ in the control chamber (without an ethylene scrubber).

WP2: None of the pack-houses studied have any effective ethylene management strategy, the highest ethylene concentration (4680 ppb) was observed in an empty regular atmosphere (RA) room (> 5 °C).

Photocatalytic oxidation and photolysis ethylene removals were effective in removing ethylene during postharvest storage of fruit.

Pack-house ventilation and ethylene management strategies significantly affect ethylene concentrations, high and consistent ethylene levels was observed due to limited ventilation and in areas previously used for apple storage.

Photocatalytic oxidation (PCO) and vacuum ultraviolet (VUV) photolysis reactors oxidation systems can be installed/used in the pack houses to effectively control ethylene levels, however direct exposure should be avoided to prevent determinantal effects on the color of the apple fruit peel and firmness.

To effectively manage ethylene, pack-houses should optimize ventilation, consider ethylene-blocking treatments, and account for emissions from operational machinery that can influence overall ethylene concentrations.