Spectroscopic and Structural Analyses of Opuntia Robusta Mucilage and Its Potential as an Edible Coating

Abstract

Mucilage extracted from the parenchymatous and chlorenchymatous tissues of Opuntia robusta were obtained using water or ethanol as the extraction solvent. The changes in the different tissues by using different extraction solvents were evaluated via scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) and Raman spectroscopy; in addition, the effect of mucilage coating on the various quality characteristics of tomato (Lycopersicum sculentum) was evaluated. The SEM results showed that the mucilage extracted from the parenchyma had a higher aggregation level that the mucilage extracted from the chlorenchyma. The presence of three characteristic bands of pectic substances in the FT-IR spectra between 1050 and 1120 cm −1 indicated that the mucilage extracted from the parenchymatous tissue had a higher content of pectic compounds than the mucilage extracted from the chlorenchymatous tissue. It was also observed in the Raman spectra that the level of pectic substances in the mucilage extracted from the parenchymatous was higher than that in the mucilage extracted from the chlorenchymatous tissue. The mucilage extracted from the parenchymatous tissue was more effective as an edible coating than the mucilage extracted from the chlorenchymatous tissue. Tomatoes covered with mucilage showed significantly enhanced firmness and reduced weight loss. The uncoated tomatoes showed higher lycopene content than the coated tomatoes on the 21st day. This study showed that the Opuntia robusta tissue and extraction solvent influence mucilage characteristics and that Opuntia robusta mucilage is a promising edible coating.

Characterization of mucilage from clones of Opuntia and Nopalea prickly pear cactus harvested in different seasons in Brazilian semiarid

“…The characteristics of the main functional groups associated with the mucilage found in the three studied clones were similar to those reported in the literature (Gheribi et al, 2018;Rodríguez-González et al, 2014), verified in fig 6 A. The major bands were found at 3331 cm -1 , attributed to the OH stretch of alcohol, carboxylic acid, and hydrogen intermolecular bonding; and at 2926 cm -1 , attributed to vibrations of CH bonds, which include symmetric and asymmetric stretching of C-H, CH2, and CH3 bonds of molecules (Bayar et al, 2016;Bernardino-Nicanor et al, 2018;Rodríguez-González et al, 2014).…”

Cactus Mucilage for Food Packaging Applications

“…Such a barrier effect may be particularly ensured by the great water binding capacity of mucilage, as explained by the authors. Moreover, coated fruits exhibited higher firmness than uncoated ones on the 18th day of storage at 4 • C. In fact, cactus mucilage crosslinked with chitosan act as an effective physical and mechanical barrier reducing juice leakage and delaying respiratory metabolism reactions [54] In another study, Bernardino-Nicanor et al [58] used brushing as a coating application method of mucilage (Opuntia Robusta) on tomatoes. The coating method and the cactus species used in this study were shown effective in maintaining firmness and reducing the weight loss of tomatoes.…”

Study on the Effectiveness of Two Biopolymer Coagulants on Turbidity and Chemical Oxygen Demand Removal in Urban Wastewater

“…Other authors reported the characterization of the Opuntia robusta mucilage by FTIR. They observed a peak in the range 2850–2970 cm −1 associated with the stretching of the C–H bonds of the pyranose groups or C–H groups of the methyl ester of the galacturonic acid [ 28 ]. This stretching range of C–H bonds is observed in Figure 1 a.…”