Functional properties of Cactus Pear Mucilage: gel formation, edible coatings, films and spherification
| dc.contributor.advisor | de Wit, Maryna | en_ZA |
| dc.contributor.advisor | du Toit, Alba | en_ZA |
| dc.contributor.advisor | Hugo, Arno | en_ZA |
| dc.contributor.author | Mushanganyisi, Dembe Dynne | en_ZA |
| dc.date.accessioned | 2024-02-14T12:31:58Z | |
| dc.date.available | 2024-02-14T12:31:58Z | |
| dc.date.issued | 2023 | en_ZA |
| dc.description | Dissertation (M.Sc. (Food Science))--University of the Free State, 2023 | en_ZA |
| dc.description.abstract | Mucilage is a hydrocolloid, a gelatinous slimy substance that contains polysaccharides and proteins. Due to mucilage’s ability to absorb large amounts of water, which result in modified viscosity, it can be used as a food additive in the food industry as a hydrocolloid to modify food texture. It is used as an emulsifier, to form gels and as a natural edible coating. The aim of the study was to investigate the functional properties of mucilage and to potentially develop mucilage into a commercially viable food ingredient (hydrocolloid). Cladodes from four cultivars (and two species) were investigated. These include three cultivars from Opuntia Ficus-indica, namely Nepgen, Algerian and Ficus-Indice as well as one cultivar from the O.robusta spp. namely Robusta. Mucilage was extracted, and the yield was determined in percentage, with Algerian at 53.70%, Nepgen at 50.96%, Robusta at 48.40% and Ficus-indice at 37.75%. The mucilage was dried in two ways, namely, freeze-drying, and hot-air dehydration and colour difference was investigated. The drying impacted the colour of mucilage powder, with freeze-dried remaining green and the hot-air dried turned brown, colour difference was observed between the freeze-dried and hot-air dried mucilage a* value. a* value represents the scale from green (negative value) to red (positive value). It is evident that the freeze-dried samples had a green colour (negative values) while the hot air-dried samples had a reddish colour seen by a positive a* value. For example, freeze-dried Robusta had a value of -7.87 as compared to that of hot-air dried at 1. The viscosity of both native liquid and dried mucilage were investigated. Robusta and Nepgen native liquid’s mucilage is viscous more than that of Algerian and Ficus-indice. The reconstituted mucilage powder is thicker than the native liquid powder. Gelling capacity was tested. For spherification or bead formation, mucilage was used to replace the usual gelling agents in both direct and reversed spherification. During gelling ability tests, mucilage from Robusta showed gel-like ability as compared to the other three cultivars. However, it was concluded that mucilage does not form gels on its own, but rather improves gel formation with other hydrocolloids. When mucilage was used to replace the sodium alginate in spherification, it did not form true spheres, but formed a temporary gel-like membrane when incorporated with xanthan and agar. Ultimately, mucilage may be a replacement for food hydrocolloids. It can be used as an emulsifying agent and an edible coating, although different cultivars will give different results. | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/12427 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | cultivar | en_ZA |
| dc.subject | functional | en_ZA |
| dc.subject | hydrocolloid | en_ZA |
| dc.subject | mucilage | en_ZA |
| dc.subject | Opuntia Ficus-indica | en_ZA |
| dc.subject | Opuntia Robusta | en_ZA |
| dc.subject | spherification | en_ZA |
| dc.title | Functional properties of Cactus Pear Mucilage: gel formation, edible coatings, films and spherification | en_ZA |
| dc.type | Dissertation | en_ZA |