UV-C radiation on fresh fig quality

ABSTRACT: Sanitization using chemical agents to reduce the microbiological load on the surface of agricultural products have the drawback of leaving residues. Conversely, physical treatments, such as ultraviolet radiation C (UV-C), are residue-free, non-toxic and environmentally friendly. Ripe figs are perishable, exhibiting an epidermis with low resistance to mechanical treatment, high water content and the ostiole, which is an open door that expedites undesirable microorganism penetration. In this study, the effect of different energy levels of UV-C radiation on the appearance and physico-chemical properties of the figs when stored at 10 °C and 20 °C was evaluated focusing on the technological parameters of the application of radiation. The energy levels of radiation applied were 0.00, 0.71, 1.32, 2.64 and 4.01 kJ m−2 and they showed neither acceleration nor delay effects on fig ripening. Figs exposed to the radiation energy at 0.71, 1.32, 2.64 and 4.01 kJ m−2 showed a lower incidence of rot at the same temperature, but the figs exposed to the highest radiation, 4.01 kJ m−2, showed more wilting and stains, which significantly impaired their appearance. UV-C radiation reduces the development of rotting, providing evidence of its potential in the postharvest processing of ripe figs. However, radiation levels should be limited to avoid undesirable epidermis stains.摘要：采用化学试剂消杀以降低农产品表面微生物负荷，存在残留弊端。与之相对，物理处理方式如紫外线C（ultraviolet radiation C，UV-C）则无残留、无毒且环保。成熟无花果易腐坏，其表皮对机械处理耐受性低、含水量高，且带有果孔——这一开放性通道会加速有害微生物侵入。本研究评估了不同能量水平的UV-C辐射对10℃与20℃贮藏条件下成熟无花果的外观及理化性质的影响，重点聚焦辐射施用的工艺参数。本次试验设置的辐射能量水平分别为0.00、0.71、1.32、2.64与4.01 kJ·m⁻²，结果显示各处理均未对无花果的成熟进程产生加速或延缓作用。经0.71、1.32、2.64及4.01 kJ·m⁻²辐射处理的无花果，在相同贮藏温度下的腐烂发生率更低，但接受最高辐射剂量（4.01 kJ·m⁻²）的无花果出现了更严重的萎蔫与表皮污渍，显著损害了其外观品质。UV-C辐射可抑制腐烂发生，证明其在成熟无花果采后处理中具备应用潜力，但需限制辐射剂量以避免产生不良表皮污渍。