Cutin from agro-waste as a raw material for the production of bioplastics

Abstract

Cutin is the main component of plant cuticles constituting the framework that supports the rest of the cuticle components. This biopolymer is composed of esterified bi- and trifunctional fatty acids. Despite its ubiquity in terrestrial plants, it has been underutilized as raw material due to its insolubility and lack of melting point. However, in recent years, a few technologies have been developed to obtain cutin monomers from several agro-wastes at an industrial scale. This review is focused on the description of cutin properties, biodegradability, chemical composition, processability, abundance, and the state of art of the fabrication of cutin-based materials in order to evaluate whether this biopolymer can be considered a source for the production of renewable materials.

Linking ATR-FTIR and Raman features to phenolic extractability and other attributes in grape skin

“…However, significant differences (p < 0.05) were found for three internal surface peaks (3324, 1732 and 1018 cm -1 ) among samples with low extractability levels and samples with medium or high extractability levels. As explained earlier, these peaks are assigned to bonds present in polysaccharides and the peak at 1732 cm -1 is also closely linked to the degree of esterification of pectins [26,27,[42][43][44][45]47]. Therefore, the results reaffirm that the amount of polysaccharides and the degree of esterification of pectins have significant influence on the phenolic extractability levels of grape skin tissue.…”

“…Bands at 720, 1464, 2850 and 2916 cm -1 are due to CH 2 rocking, scissoring and symmetrical and asymmetrical stretching, respectively. These bands were ascribed to the aliphatic material present in the plant cuticle: cutin, waxes and cutan [44]. They are all positive peaks in the PC1 plot, which is consistent with the fact that the cuticle is only on the external surface of the skin.…”

“…The abroad band at 3324 cm -1 is assigned to the stretching vibration of hydroxyl groups that interact by hydrogen bonding. The intensity of this band depends on the polysaccharide fraction and, secondly, the non-esterified hydroxyl groups of cutin [44]. This band is negative in the PC1 plot, thus the polysaccharide fraction must be lower in the external grape skin surface than in the internal.…”

“…The peak at 1167 cm -1 , which only appears in external grape skin spectra, is ascribed to asymmetrical C-O-C ester stretching vibrations, and is associated with the cutin matrix [44].…”

“…The loadings of PC1 and PC2 are shown in Fig. 1C and different features corresponding to biologic tissues, such as waxes, pectins, monosaccharides, polysaccharides and lipids can be identified (see Table 2) [26,[42][43][44].…”