Articles
The big picture of the small picture: examining the mucilage of Opuntia ficus-indica ‘Algerian’ and Opuntia robusta for the effects of postharvest refrigeration – Part 2
Article number
1452_43
Pages
325 – 330
Language
English
Abstract
Extracts from Opuntia ficus-indica (OFI) cladodes were found to have substantially different presentations on examination of the material on scanning electron microscopy (SEM) in an investigation where the extracts of two cultivars, ‘Algerian’ and ‘Turpin’, were compared.
This study compared material extracts from OFI ‘Algerian’ and ‘Turpin’, and O. robusta, quantitatively in order to see the effect of postharvest refrigerated storage time (4 weeks) at 4°C in a walk-in refrigerator on the polysaccharide extracts, and whether the effect was isolated to OFI. It determined that of the 8 distinct morphologies present in OFI mucilage, all but one was observed in O. robusta. One unique morphology was observed in O. robusta. Most morphologies had statistically significant differences (p<0.05) between weeks and cultivars when measured.
Low-density porous amorphous networks, large spherical structures and networked sphericule meshes observed on micrography, differed significantly (p<0.05) over time in at least one measured element of the morphology between weeks for OFI ‘Algerian’ and ‘Turpin’, as well as O. robusta. Weekly changes (p<0.05) in the unique morphology of O. robusta were confirmed.
These results indicate that there were differences between the different weeks of storage, which could indicate a change under refrigerated storage conditions.
Finally, energy-dispersive X-ray spectroscopy (EDS) was used to determine that different morphologies observed were not of uniform in composition, especially in terms of calcium, a known mineral that can affect binding and cross-linking in polymers.
This suggests that there are differences in the material present, and that these differences may relate to the manner in which they interact with, as well as the availability, of certain minerals.
Researchers should therefore be aware of potential differences between cultivars of Opuntia, as well as that the material undergoes changes in postharvest refrigeration.
This study compared material extracts from OFI ‘Algerian’ and ‘Turpin’, and O. robusta, quantitatively in order to see the effect of postharvest refrigerated storage time (4 weeks) at 4°C in a walk-in refrigerator on the polysaccharide extracts, and whether the effect was isolated to OFI. It determined that of the 8 distinct morphologies present in OFI mucilage, all but one was observed in O. robusta. One unique morphology was observed in O. robusta. Most morphologies had statistically significant differences (p<0.05) between weeks and cultivars when measured.
Low-density porous amorphous networks, large spherical structures and networked sphericule meshes observed on micrography, differed significantly (p<0.05) over time in at least one measured element of the morphology between weeks for OFI ‘Algerian’ and ‘Turpin’, as well as O. robusta. Weekly changes (p<0.05) in the unique morphology of O. robusta were confirmed.
These results indicate that there were differences between the different weeks of storage, which could indicate a change under refrigerated storage conditions.
Finally, energy-dispersive X-ray spectroscopy (EDS) was used to determine that different morphologies observed were not of uniform in composition, especially in terms of calcium, a known mineral that can affect binding and cross-linking in polymers.
This suggests that there are differences in the material present, and that these differences may relate to the manner in which they interact with, as well as the availability, of certain minerals.
Researchers should therefore be aware of potential differences between cultivars of Opuntia, as well as that the material undergoes changes in postharvest refrigeration.
Authors
J.A. Viktor, M. de Wit, A. du Toit, G. Osthoff
Keywords
scanning electron microscopy, polymers, morphology, calcium
Groups involved
Online Articles (65)