Departamento de Química, Universidade Federal de São Carlos, Rodovia Washington Luís, São Carlos 13565-905, Brazil.
Centro de Recursos Genéticos Vegetais, Instituto Agronômico de Campinas, Av. Barão de Itapura 1481, Campinas 13075-630, Brazil.
Molecules. 2022 Mar 23;27(7):2060. doi: 10.3390/molecules27072060.
The use of UV-C cool white light on bean ( L.) seeds significantly increases the biochemical seed coat post-harvest darkening process, whilst preserving seed germination. The aim of this work consists in monitoring the effect caused by the incidence of UV-C light on different bean genotypes using NMR spectroscopy. The genotype samples named IAC Alvorada; TAA Dama; BRS Estilo and BRS Pérola from the Agronomic Institute (IAC; Campinas; SP; Brazil) were evaluated. The following two methodologies were used: a prolonged darkening, in which the grain is placed in a room at a controlled temperature (298 K) and humidity for 90 days, simulating the supermarket shelf; an accelerated darkening, where the grains are exposed to UV-C light (254 nm) for 96 h. The experiments were performed using the following innovative time-domain (TD) NMR approaches: the RK-ROSE pulse sequence; one- and two-dimensional high resolution (HR) NMR experiments (H; H-H COSY and H-C HSQC); chemometrics tools, such as PLS-DA and heat plots. The results suggest that the observed darkening occurs on the tegument after prolonged (90 days) and accelerated (96 h) conditions. In addition, the results indicate that phenylalanine is the relevant metabolite within this context, being able to participate in the chemical reactions accounted for by the darkening processes. Additionally, it is possible to confirm that a UV-C lamp accelerates oxidative enzymatic reactions and that the NMR methods used were a trustworthy approach to monitor and understand the darkening in bean seeds at metabolite level.
UV-C 冷白光照射对豆类（L.）种子的使用显著增加了生化种子外皮的收获后变暗过程，同时保持了种子的发芽率。本工作的目的是使用 NMR 光谱监测 UV-C 光对不同豆类基因型的影响。评估了来自巴西坎皮纳斯农业研究所（IAC）的基因型样本 IAC Alvorada、TAA Dama、BRS Estilo 和 BRS Pérola。使用了以下两种方法：延长黑暗期，将谷物放置在温度（298 K）和湿度受控的房间中 90 天，模拟超市货架；加速黑暗期，将谷物暴露于 UV-C 光（254nm）96 小时。实验使用了以下创新的时域（TD）NMR 方法：RK-ROSE 脉冲序列；一维和二维高分辨率（HR）NMR 实验（H；H-H COSY 和 H-C HSQC）；化学计量学工具，如 PLS-DA 和热图。结果表明，在延长（90 天）和加速（96 小时）条件下，观察到的外皮变暗发生在种皮上。此外，结果表明苯丙氨酸是该背景下的相关代谢物，能够参与解释变暗过程的化学反应。此外，可以证实 UV-C 灯加速了氧化酶促反应，并且所使用的 NMR 方法是一种可靠的方法，可以在代谢物水平上监测和理解豆类种子的变暗。
