Temperature-driven chlorophyll breakdown shaping postharvest color in kiwifruit

Degreening remains a major challenge in yellow-fleshed kiwifruit, often requiring labor-intensive practices such as bagging, which can negatively impact fruit quality.

In this study, two cultivars with contrasting postharvest behaviors, ‘Cuiyu’ and ‘Yanoon 3’, were selected to investigate temperature sensitivity during off-vine ripening. Temperature treatments ranging from 1 °C to 20 °C, along with ethylene inhibition using 1-MCP, were applied to evaluate the effects of temperature on postharvest ripening.

Physiological analyses showed that soluble solids content and fruit softening progressed faster at moderate temperatures (5–10 °C), while acidity decreased, indicating accelerated ripening. However, degreening was largely independent of these parameters, demonstrating that chlorophyll degradation is not directly linked to texture or sugar accumulation.

The ‘Cuiyu’ cultivar maintained stable green flesh and chlorophyll levels across all temperatures. In contrast, ‘Yanoon 3’ exhibited strong temperature sensitivity, with the most pronounced chlorophyll degradation and yellow-green coloration observed at 10 °C.

Carotenoid accumulation was temporary and not the main driver of color change, confirming that chlorophyll breakdown is the dominant mechanism. Transcriptomic analysis revealed shared temperature-responsive patterns between cultivars, as well as distinct responses, particularly the activation of the porphyrin metabolism pathway in ‘Yanoon 3’.

Additionally, transcription factor families such as ERF/AP2, MYB, and NAC showed temperature-dependent expression patterns, supporting their regulatory roles in degreening.

Overall, the findings demonstrate that postharvest degreening in kiwifruit is cultivar-dependent and temperature-regulated, operating independently from traditional ripening indicators. This study provides valuable insights for optimizing storage conditions and improving the visual quality and marketability of yellow-fleshed kiwifruit.

Source

Hafeez, A. H., Zhang, Z., Li, A., Zeng, Z., Chen, Y., Li, T., Ji, X., Wang, Y., Wang, Z., Cheng, Y., Sohail, H., Feng, D., & Zeng, Y. (2026). Temperature-sensitive chlorophyll degradation uncouples degreening from other ripening traits and guides postharvest quality improvement in kiwifruit. Postharvest Biology and Technology.

https://www.sciencedirect.com/science/article/abs/pii/S092552142600219X