Mechanical Damage Control in Korla Fragrant Pear Harvesting and Handling: Biomechanical Evaluation, Detection, and Simulation

Mechanical damage remains a major constraint in low-damage harvesting and handling of the Korla fragrant pear, owing to its cultivar-specific bruise-sensitive traits (BSTs), namely its thin peel, crisp flesh, smooth epidermis, and high bruise sensitivity. This review synthesizes evidence from the Korla fragrant pear, other pear cultivars, apple, and related fresh produce to clarify damage mechanisms and engineering strategies for damage control. The reviewed studies show that injury is mainly governed by impact energy, compression load, contact stiffness, friction, fruit velocity, spacing, and transfer trajectory. Quasi-static compression and drop-impact tests provide essential thresholds, including elastic modulus, rupture force, absorbed energy, bruise area, and bruise volume, but Korla-specific data remain insufficient. Nondestructive techniques are complementary: RGB machine vision supports rapid surface screening, hyperspectral imaging improves early bruise detection, X-ray computed tomography quantifies internal bruising, and scanning electron microscopy verifies cellular damage mechanisms. FEM and DEM can predict stress distribution, deformation, collision behavior, and equipment-induced injury when calibrated with cultivar-specific parameters. Overall, apple- or general pear-based technologies require recalibration before application to the Korla fragrant pear. Future work should establish Korla-specific damage thresholds and validate detection, simulation, and conveying systems under real orchard and packing-line conditions.