Department of Horticulture and Natural Resources, Kansas State University, 22201 W. Innovation Dr., Olathe, KS 66061, USA.
Department of Horticulture and Natural Resources, Kansas State University, 22201 W. Innovation Dr., Olathe, KS 66061, USA; Eastern Kansas Research and Extension Centers, 35230 W. 135th St., Olathe, KS 66061, USA.
J Food Prot. 2023 Mar;86(3):100056. doi: 10.1016/j.jfp.2023.100056. Epub 2023 Feb 2.
Ultraviolet-C (UV-C) irradiation is a well-recognized technology for improving blueberry postharvest quality, and previous literature indicates that it has the potential for dual-use as an antimicrobial intervention for this industry. However, the practicality and feasibility of deploying this technology in fresh blueberry fruit are significantly hindered by the shadowing effect occurring at the blossom-end scar of the fruit. The purpose of this study was to determine if treating the blueberry fruit within a chamber fitted with UV-Light Emitting Diodes (LEDs) emitting a peak UV-C at 275 nm could minimize this shadowing and result in improved treatment efficacy. Ten blueberry fruits were dip-inoculated with E. coli at a concentration of 10 CFU/mL and irradiated within the system at doses of 0, 1.617, 3.234, 9.702, and 16.17 mJ/cm (0, 30, 60, 180, and 300 s). Statistical analysis was performed to characterize the extent of microbial survival as well as the UV-C inactivation kinetics. A maximum of 0.91-0.95 log reduction was observed, which attenuated after 60 s of treatment. The microbial inactivation and survival were thus modeled using the Geeraerd-tail model in Microsoft Excel with the GInaFIt add-in (RMSE = 0.2862). Temperatures fluctuated between 23 ± 0.5°C and 39.5°C ± 0.5°C during treatment but did not statistically impact the treatment efficacy (P = 0.0823). The data indicate that the design of a UV-LED system may improve the antimicrobial efficacy of UV-C technology for the surface decontamination of irregularly shaped fruits, and that further optimization could facilitate its use in the industry.
紫外线-C（UV-C）辐照是一种公认的提高蓝莓采后品质的技术，先前的文献表明，它有可能作为该行业的一种抗菌干预措施被双重利用。然而，将这项技术应用于新鲜蓝莓果实的实际可行性和实用性受到果实花萼端疤痕处产生的阴影效应的显著阻碍。本研究的目的是确定在配备峰值 UV-C 为 275nm 的紫外线发光二极管（LED）的腔室内对蓝莓果实进行处理是否可以最小化这种阴影效应，并提高处理效果。10 个蓝莓果实用浓度为 10 CFU/mL 的大肠杆菌浸泡接种，然后在系统内以 0、1.617、3.234、9.702 和 16.17 mJ/cm（0、30、60、180 和 300 s）的剂量进行辐照。进行了统计分析以表征微生物存活程度和 UV-C 失活动力学。观察到最大 0.91-0.95 的对数减少，在 60 秒的处理后衰减。使用 Microsoft Excel 中的 Geeraerd-tail 模型以及 GInaFIt 插件（RMSE=0.2862）对微生物失活和存活进行了建模。在处理过程中，温度在 23±0.5°C 和 39.5°C±0.5°C 之间波动，但对处理效果没有统计学影响（P=0.0823）。数据表明，UV-LED 系统的设计可以提高 UV-C 技术对不规则形状水果表面消毒的抗菌效果，进一步优化可能会促进其在行业中的应用。
