2017年7月12日，中国农业科学院农产品加工研究所重点实验室在期刊Scientific Reports（2023IF=4.6，Q2）上发表了题为“The influence of postharvest UV-C treatment on anthocyanin biosynthesis in fresh-cut red cabbage”的研究论文。论文第一作者是wu jie（实在没找到这个人叫啥），通讯作者是关文杰研究员。
紫甘蓝是一种全球食用的新鲜可食用蔬菜，含有包括花青素在内的高水平抗氧化化合物。采用不同剂量的紫外线C(UV-C)对鲜切紫甘蓝进行处理。在UV-C处理的鲜切紫甘蓝中观察到15个花青素衍生物，其中4个是对照样品中不存在的花青素。UV-C提高鲜切紫甘蓝总花青苷含量的最佳剂量为3.0kJ/m2。不同的UV-C辐射剂量导致每种花色苷化合物的各种反应，并且这些变化似乎是剂量依赖的。UV-C辐射改变了花青素代谢相关基因的表达。例如，生物合成酶的基因，包括糖基转移酶和酰基转移酶，以及R2R3 MYB转录因子(产生花青素1和MYB114)，在UV-C处理后表达显著增加。这些结果与这些基因产物在花青素代谢中的作用是一致的。
据作者所知，这是第一份证明UV-C处理可以提高新鲜切开的紫甘蓝在贮藏中的抗氧化活性的报告。此外，作者详细的植物化学和基因表达分析确定了花青素和代谢基因在这一过程中的特定作用。
Figure 1. HPLC chromatograms of anthocyanins in fresh-cut red cabbage detected at 520 nm. (a) The HPLC profiles of anthocyanins from UV-C treated (3.0 kJ/m2) fresh-cut red cabbage after 8 days of storage. (b) The HPLC profiles of anthocyanins in untreated fresh-cut red cabbage. Peak assignments are listed in Table 1.
Figure 2. The accumulation of each anthocyanin compound assessed during the storage period following
different UV-C treatment doses. The content (mg/g dry weight) of each anthocyanin (P1–P15, representing peaks 1–15, respectively) during the period of storage (from 1 to 12 days) following different UV-C doses (0, 1.0, 3.0, 5.0 kJ/m2). Compound identification assignments are presented in Table 1. The graph shows the average values of three independent experiments with error bars indicative of the standard deviation (SD). *P < 0.05; **P < 0.01.
Figure 3. Expression analysis of anthocyanin biosynthetic genes and regulatory genes in UV-C treated fresh-cut red cabbage. The relative expression levels of anthocyanin biosynthetic genes (a) and regulatory genes (b) in fresh-cut red cabbage treated with UV-C were analyzed at the indicated storage days. The enzyme names encoded by the biosynthetic genes analyzed in this study are as follows: CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3′H, flavanone 3′-hydroxylase; DFR, dihydroflavonol 4-reductase; ANS, anthocyanidin synthase; GT, glucosyltransferase; AT, acyltransferase. The expression of MYB family transcription factors (PAP1, PAP2, MYB113, and MYB114) and the transparent testa genes (TTG1 and TT8) are also displayed. Expression values have been normalized with the tublin gene. The graph shows average values of three replicates, with error bars representing the standard error of the mean (n = 3) and different letters indicate significance at P < 0.05
Figure 4. The biosynthetic pathway of the anthocyanins. Scheme displaying the biosynthetic pathway of Cy-3-O-(sinapoyl)(sinapoyl)-diglucoside-5-O-glucosidein red cabbage. The biosynthetic pathway of anthocyanidins leads to the biosynthesis of cyanidin, which is further modified with several glycosyl and acyl moieties added in a species specific manner by glycosyltransferases and acyltransferases (indicated by dotted lines).
