Work

Modulated UV-C radiation as an innovative strategy for postharvest disease control and quality preservation in papaya and orange fruits

Year: 2026

Type: article

Abstract: Postharvest losses remain a major challenge in fruit production systems, affecting both climacteric fruits, such as papaya, and non-climacteric fruits, such as orange. Ultraviolet-C (UV-C) radiation has emerged as a sustainable alternative to chemical fungicides; however, its effectiveness depends on the applied dose and radiation delivery mode. This study investigated the comparative effects of continuous and frequency-modulated UV-C radiation on postharvest disease control and fruit quality on papaya and orange. Two independent experiments were conducted. Experiment 1 evaluated the influence of modulation frequencies (0, 15, 30, and 45 Hz) on disease progression, while Experiment 2 combined the most effective frequencies with different exposure times to define optimal treatment conditions. In papaya, UV-C modulation at 30 Hz/20 s (0.44 kJ m⁻²) provided effective control of anthracnose (67% reduction in incidence), while minimizing photothermal damage, with no visible epidermal injuries. In orange, continuous UV-C radiation (0 Hz) applied for 30 s (1.99 kJ m⁻²), completely suppressed sour rot development (100%) without visible peel injury. Therefore, the selection of the UV-C radiation application mode is species-specific. Notably, modulation of UV-C irradiation has demonstrated enhanced efficiency in postharvest disease control while reducing epidermal burn. Additionally, the treatments stimulated defense responses, as evidenced by increased activities of phenylalanine ammonia-lyase, polyphenoloxidase, peroxidase, and catalase. Physicochemical analyses confirmed the maintenance of firmness, acidity, and color stability, indicating the preservation of postharvest quality in both fruits. Overall, modulated UV-C radiation represents a promising non-chemical postharvest technology, enabling efficient disease control while maintaining fruit quality.

Source: Postharvest Biology and Technology

DOI: 10.1016/j.postharvbio.2026.114388