Chemical–physical characterization of isolated plant cuticles subjected to low-dose γ-irradiation

Abstract

Isolated tomato fruit cuticles were subjected to low dose (80 Gy) -irradiation, as a potential methodology to prevent harvested fruit and vegetables spoilage. Both irradiated and non-irradiated samples have been morphologically and chemically characterized by Scanning Electron (SEM), Atomic Force (AFM), Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and X-ray Photoelectron (XPS) spectroscopies. Additionally, electrochemical measurements comprising membrane potential and diffusive permeability were carried out to detect modifications in transport properties of the cuticle as the fruit primary protective membrane. It has been found that low dose -irradiation causes some textural changes on the surface but no significant chemical modification. Texture modification is found to be due to a partial removal of outermost (epicuticular) waxes which is accompanied by mild changes of electrochemical parameters such as the membrane fixed charge, cation transport number and salt permeability. The modification of such parameters indicates a slight reduction of the barrier properties of the cuticle upon low dose -irradiation.

Infrared and Raman spectroscopic features of plant cuticles: a review

“… ATR-FTIR spectra of cutin (adapted from España et al, 2014, with permission of John Wiley and Sons), waxes (adapted from Heredia-Guerrero et al, 2012, with permission of Elsevier), and polysaccharides (adapted from López-Casado et al, 2007) of isolated tomato fruit cuticle .…”

“…This ratio has been used for qualitative comparisons by several authors (even in isolated plant cuticles) and calculated in different forms (Benítez et al, 2004b; Chefetz, 2007; Girard et al, 2012; Heredia-Guerrero et al, 2012; España et al, 2014). We recommend the ratio of intensities ν (C=O)/ν a (CH 2 ) and the denomination of “esterification index.” Thus, values of the “esterification index” are directly related to the cross-linking of cutin.…”

“…In this sense, the effects caused by low dose γ-irradiation in tomato fruit cuticles were identified by ATR-FTIR (Heredia-Guerrero et al, 2012). Samples after the irradiation showed an intense reduction of the asymmetric and symmetric stretching vibrations of the methylene groups, 2917 and 2848 cm −1 respectively, while the C=O stretching region (1800-1650 cm −1 ), associated with the cutin, remained unaltered, indicating a partial removal of epicuticular waxes of these samples.…”

Thermal and Water Effects on Virgin Bitumen, Recycled and Mastic Mixtures

“…Additionally, the distance between the peaks at 730 and 720 cm −1 and between 1460 and 1455 cm −1 increased. Splitting, shifting to lower wavenumbers and increasing of peak intensity are related to the increase of the crystallization degree (Borchman et al 2011;Brubach et al 2007;Heredia-Guerrero et al 2012;Srivastava et al 1993;Ungar and Masic 1985). The increase in intensity of the peak at *720 cm −1 is related to the increase of the amount of alkyl chains, not necessarily assembled in an organized way (e.g.…”

Connecting the Molecular Structure of Cutin to Ultrastructure and Physical Properties of the Cuticle in Petals of Arabidopsis

“…However, studies of several cutin mutants have revealed characteristic changes in the morphology of the petal nanoridges (Panikashvili et al, 2010(Panikashvili et al, , 2011Bessire et al, 2011;Shi et al, 2011), and mutants with a reduction of .95% of the amount of 10,16-dihydroxy hexadecanoic acid (cyp77A6, gpat6, and dcr) do not have petal nanoridges (Li-Beisson et al, 2009;Panikashvili et al, 2009). In addition, initial studies aimed at correlating the structure and function of cuticles, including an assessment of the physicochemical properties, have exploited micrometerthick cuticles, such as those of tomato fruits (Heredia, 2003;López-Casado et al, 2007;Heredia-Guerrero et al, 2012;España et al, 2014).…”