BACKGROUND:The new approach of using UV-C irradiation followed by a specific dark period to control plant diseases has the potential to become a mainstream treatment in the production of strawberries and other fruits and vegetables. Thus, it is imperative to study the effects of this treatment on fruit quality. METHODS:In this study, short-day ‘Chandler’ strawberry plants grown in growth chamber from bloom to harvest were irradiated twice a week with nighttime UV-C light (253 nm peak value 12.36 J/m2 and the total dose of 50 J/m2 in the range of 240 –260 nm). The effects on the content of key phenolic compounds in mature fruit were studied with targeted analysis and a non-targeted metabolomic approach based on ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS). Analysis of variance-principal component analysis (ANOVA-PCA) was used to associate variance with different experimental factors. RESULTS:Results indicate that the content of anthocyanins, glucosides and glucuronides of quercetin and kaempferol, catechin, pelargonidin rutinoside, and ellagic acid was not affected by UV-C treatment. ANOVA-PCA analysis of the metabolomic dataset showed significant differences on composition and content of strawberry metabolites between UV-C and control groups according to harvest time. CONCLUSIONS:Our findings strongly indicate that UV-C treatment of 50 J/m2 twice per week did not affect nutritional values of strawberry fruit. The metabolomic approach combined with ANOVA-PCA used to evaluate strawberry fruit quality after UV-C irradiation proved to be a very powerful tool in providing an overall insight into fruit quality and accurately determines the influence of each experimental factor.

中文翻译：

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夜间紫外线辐照草莓植株对果实中酚含量的影响：有针对性和非目标代谢组学分析

背景：使用UV-C辐照和随后的特定暗期控制植物病害的新方法有可能成为草莓和其他水果和蔬菜生产中的主流治疗方法。因此，必须研究这种处理对果实品质的影响。方法：在这项研究中，每周两次用夜间UV-C光（253 nm峰值12.36 J / m2，总剂量为50 J / m2在240 –260 nm范围内）。基于超高效液相色谱-高分辨率质谱（UHPLC-HRMS），采用靶向分析和非靶向代谢组学方法，研究了对成​​熟果实中关键酚类化合物含量的影响。方差分析-主要成分分析（ANOVA-PCA）用于将方差与不同的实验因素相关联。结果：结果表明，UV-C处理对槲皮素和山chin酚，儿茶素，天竺葵素芸苔苷和鞣花酸的花色苷，苷和葡糖苷酸的含量没有影响。代谢组学数据的ANOVA-PCA分析显示，根据收获时间，UV-C组和对照组之间草莓代谢产物的组成和含量存在显着差异。结论：我们的发现强烈表明，每周两次50 J / m2的UV-C处理不会影响草莓果实的营养价值。