UV-C treatment preserves postharvest quality and aroma of litchi fruit

Litchi (Litchi chinensis Sonn.) is highly perishable after harvest, rapidly developing pericarp browning, decay and aroma loss that reduce its commercial value. A new study demonstrates that UV-C irradiation can effectively delay these deterioration processes and improve fruit quality during storage at room temperature.

Researchers treated the fruit with 4.1 kJ m⁻² UV-C before storage at 25 °C, evaluating quality attributes, antioxidant responses and aroma metabolism throughout the storage period.

Reduced browning and disease incidence

Compared with untreated fruit, UV-C-treated litchis showed significantly lower pericarp browning and reduced disease and decay incidence.

The treatment also decreased electrolyte leakage, malondialdehyde (MDA) accumulation and superoxide anion production, indicating improved membrane integrity and reduced oxidative damage.

Enhanced antioxidant protection

UV-C irradiation increased antioxidant capacity by promoting hydroxyl radical scavenging activity and enhancing the accumulation of proanthocyanidins, particularly procyanidins A2/B2 and epicatechin.

These compounds contribute to protecting fruit tissues against oxidative stress during storage.

Regulation of browning-related genes

The study found that UV-C inhibited the activities of laccase (LAC) and peroxidase (POD), enzymes associated with enzymatic browning.

Gene expression analyses also showed downregulation of browning-related genes while temporarily activating defence-related genes during the early storage period, strengthening the fruit's natural resistance.

Better preservation of characteristic aroma

One of the most important findings was the improved retention of the fruit's characteristic aroma.

UV-C treatment increased the concentration of monoterpenes and aldehydes, while transcriptomic analysis confirmed the activation of genes involved in volatile compound biosynthesis, helping preserve aroma throughout storage.

A promising postharvest technology

The authors conclude that UV-C irradiation represents an effective postharvest technology for extending the shelf life of litchi stored at room temperature.

By combining enhanced antioxidant protection, stronger defence responses, reduced browning and better aroma preservation, the treatment offers an attractive alternative for maintaining commercial fruit quality without refrigeration.

Source

Fu, L., Yang, J., Li, Y., Li, S., Pang, X., Zhang, Z., & Fang, F. (2026). UV-C treatment modulates storage performance and aroma metabolism of postharvest litchi fruit. Postharvest Biology and Technology. https://doi.org/10.1016/j.postharvbio.2026.113749