Pressure Flattening Simulation and Associated Response After Unloading Russet Burbank Potatoes From Storage

Abstract Cutting black is an internal dark gray/black discoloration associated with pressure bruise in potatoes stored in piles, where sustained compression causes flattened areas and enzymatic browning. This defect leads to significant post-harvest losses, particularly affecting the fresh market. This 2-year study evaluated the effects of 1-methylcyclopropene, nitric oxide, and diphenylamine on cutting black development during simulated bulk storage of Russet Burbank potatoes. Tubers were stored at 7.2 °C and 95% relative humidity for 7 months under no pressure or constant downward pressure equivalent to 1.66 m pile height, 1,217.53 and 1,220.32 kg m 2 . Pressure increased the external flattened area (7.7% vs. 0.1%), but no internal discoloration was observed. Electrolyte leakage, polyphenol oxidase, and peroxidase enzymatic activity did not vary significantly with applied pile pressure and treatment, suggesting that pressure bruise-damaged areas might require pile pressures higher than 1,220.32 kg m 2 (1.66 m) for cutting black to develop.