Monitoring Stimulated Darkening from UV-C Light on Different Bean Genotypes by NMR Spectroscopy

Abstract

The use of UV-C cool white light on bean (Phaseolus vulgaris 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 (1H; 1H-1H COSY and 1H-13C 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.

Biostimulant activity of Galaxaura rugosa seaweed extracts against water deficit stress in tomato seedlings involves activation of ABA signaling

“…The HSQC correlations of signals at δ C 103.0; 98.5; 96.4; 95.9 and 92.1 ppm, with protons at δ H 4.44 (d, 7.6); 4.90 (brs); 4.60 (d, 7.4); 4.66 (d, 7.6) and 5.25 (d, 3.8) ppm respectively, indicate the presence of other saccharides in minor amounts. Other metabolites detected were: isethionic acid ( Barrow et al., 1993 ), acetic acid ( Sciubba et al., 2020 ), formic and lactic acid ( Ponder and Richards, 1993 ) and the amino acids alanine ( Sciubba et al., 2020 ), valine ( Ryu et al., 2016 ), threonine ( Salvador et al., 2022 ) and N,N-dimethyltaurine ( Blunden et al., 1986 ).…”

“…The presence of each metabolite was confirmed by comparing its spectroscopic data with those previously described in the literature. NMR spectra analysis of the extract of B. hamifera in D 2 O indicated that this extract contains a complex mixture of metabolites, among which floridoside (Ye et al, 2013) (Barrow et al, 1993), acetic acid (Sciubba et al, 2020), formic and lactic acid (Ponder and Richards, 1993) and the amino acids alanine (Sciubba et al, 2020), valine (Ryu (Salvador et al, 2022) and N,Ndimethyltaurine (Blunden et al, 1986). The 1D and 2D NMR spectra analysis of G. rugosa extract in D 2 O showed that this extract also contained a complex mixture of metabolites, including N,N,N-trimethyl taurine (King et al, 1982), N,N-dimethyltaurine, N-monomethyltaurine (McCusker and Klinman, 2009) and taurine (Ye et al, 2013), as well as isethionic acid and floridoside.…”

Fusarium wilt–common bean pathosystem: Pathogen variability and genetic control

“…At a metabolic level, besides being an energy substrate, sugars work as signals of the disease activating PTI and ETI (Chen et al., 2019, 2020; Xue et al., 2015, 2021). In a study with NMR, it was possible to detect that the ‘BRS Estilo’ and ‘BRS Pérola’ carioca tegument genotypes, which have phenotypic characteristics of dark grain and greater resistance to Fop, presented higher concentrations of α‐glucose and β‐glucose (Salvador et al., 2022). Chen et al.…”

Magnetic Resonance and Vibrational Spectroscopy and Imaging in Food Analysis

“…The infrared spectroscopy and imaging papers are as follows: Aykas et al [8] develop a rapid, accurate method to detect acrylamide content in par-frozen French fries using a portable Infrared spectrometer. Ren et al [9] use Fourier transform infrared spectroscopy to study the stability and interactions of anthocyanins and whey proteins. Finally, Jiang et al [10] develop a hyperspectral method, from 400 to 1000 nm, to rapidly and accurately discriminate the maturity stages of Camellia oleifera fruits.…”